Sample records for joint global ocean

  1. Topex/Poseidon satellite - Enabling a joint U.S.-French mission for global ocean study

    NASA Technical Reports Server (NTRS)

    Hall, Ralph L.

    1990-01-01

    A joint U.S./French mission, which represents a merging of the prior NASA Topex and CNES Poseidon progams, is described. The Topex/Poseidon satellite will contribute to two of the World Climate Research Program's phases: the World Ocean Circulation Experiment and the Tropical Ocean Global Atmosphere experiment. The satellite's instruments will measure the ocean currents and their variability on the global basis via satellite altimetry and precision orbit determinations. The paper describes the satellite configuration and characteristics and the mission instruments and system elements. The Topex/Poseidon's design diagrams and block diagrams are included.

  2. The Global Ocean Observing System: One perspective

    NASA Technical Reports Server (NTRS)

    Wilson, J. Ron

    1992-01-01

    This document presents a possible organization for a Global Ocean Observing System (GOOS) within the Intergovernmental Oceanographic Commission and the joint ocean programs with the World Meteorological Organization. The document and the organization presented here is not intended to be definitive, complete or the best possible organization for such an observation program. It is presented at this time to demonstrate three points. The first point to be made is that an international program office for GOOS along the lines of the WOCE and TOGA IPOs is essential. The second point is that national programs will have to continue to collect data at the scale of WOCE plus TOGA and more. The third point is that there are many existing groups and committees within the IOC and joint IOC/WMO ocean programs that can contribute essential experience to and form part of the basis of a Global Ocean Observing System. It is particularly important to learn from what has worked and what has not worked in the past if a successful ocean observing system is to result.

  3. OceanSITES: Sustained Ocean Time Series Observations in the Global Ocean.

    NASA Astrophysics Data System (ADS)

    Weller, R. A.; Gallage, C.; Send, U.; Lampitt, R. S.; Lukas, R.

    2016-02-01

    Time series observations at critical or representative locations are an essential element of a global ocean observing system that is unique and complements other approaches to sustained observing. OceanSITES is an international group of oceanographers associated with such time series sites. OceanSITES exists to promote the continuation and extension of ocean time series sites around the globe. It also exists to plan and oversee the global array of sites in order to address the needs of research, climate change detection, operational applications, and policy makers. OceanSITES is a voluntary group that sits as an Action Group of the JCOMM-OPS Data Buoy Cooperation Panel, where JCOMM-OPS is the operational ocean observing oversight group of the Joint Commission on Oceanography and Marine Meteorology of the International Oceanographic Commission and the World Meteorological Organization. The way forward includes working to complete the global array, moving toward multidisciplinary instrumentation on a subset of the sites, and increasing utilization of the time series data, which are freely available from two Global Data Assembly Centers, one at the National Data Buoy Center and one at Coriolis at IFREMER. One recnet OceanSITES initiative and several results from OceanSITES time series sites are presented. The recent initiative was the assembly of a pool of temperature/conductivity recorders fro provision to OceanSITES sites in order to provide deep ocean temperature and salinity time series. Examples from specific sites include: a 15-year record of surface meteorology and air-sea fluxes from off northern Chile that shows evidence of long-term trends in surface forcing; change in upper ocean salinity and stratification in association with regional change in the hydrological cycle can be seen at the Hawaii time series site; results from monitoring Atlantic meridional transport; and results from a European multidisciplinary time series site.

  4. Global Ocean Phytoplankton

    NASA Technical Reports Server (NTRS)

    Franz, B. A.; Behrenfeld, M. J.; Siegel, D. A.; Werdell, P. J.

    2014-01-01

    Marine phytoplankton are responsible for roughly half the net primary production (NPP) on Earth, fixing atmospheric CO2 into food that fuels global ocean ecosystems and drives the ocean's biogeochemical cycles. Phytoplankton growth is highly sensitive to variations in ocean physical properties, such as upper ocean stratification and light availability within this mixed layer. Satellite ocean color sensors, such as the Sea-viewing Wide Field-of-view Sensor (SeaWiFS; McClain 2009) and Moderate Resolution Imaging Spectroradiometer (MODIS; Esaias 1998), provide observations of sufficient frequency and geographic coverage to globally monitor physically-driven changes in phytoplankton distributions. In practice, ocean color sensors retrieve the spectral distribution of visible solar radiation reflected upward from beneath the ocean surface, which can then be related to changes in the photosynthetic phytoplankton pigment, chlorophyll- a (Chla; measured in mg m-3). Here, global Chla data for 2013 are evaluated within the context of the 16-year continuous record provided through the combined observations of SeaWiFS (1997-2010) and MODIS on Aqua (MODISA; 2002-present). Ocean color measurements from the recently launched Visible and Infrared Imaging Radiometer Suite (VIIRS; 2011-present) are also considered, but results suggest that the temporal calibration of the VIIRS sensor is not yet sufficiently stable for quantitative global change studies. All MODISA (version 2013.1), SeaWiFS (version 2010.0), and VIIRS (version 2013.1) data presented here were produced by NASA using consistent Chla algorithms.

  5. Global Ocean Phytoplankton

    NASA Technical Reports Server (NTRS)

    Franz, B. A.; Behrenfeld, M. J.; Siegel, D. A.; Werdell, P. J.

    2013-01-01

    Phytoplankton are free-floating algae that grow in the euphotic zone of the upper ocean, converting carbon dioxide, sunlight, and available nutrients into organic carbon through photosynthesis. Despite their microscopic size, these photoautotrophs are responsible for roughly half the net primary production on Earth (NPP; gross primary production minus respiration), fixing atmospheric CO2 into food that fuels our global ocean ecosystems. Phytoplankton thus play a critical role in the global carbon cycle, and their growth patterns are highly sensitive to environmental changes such as increased ocean temperatures that stratify the water column and prohibit the transfer of cold, nutrient richwaters to the upper ocean euphotic zone.

  6. Sharing Data in the Global Ocean Observing System (Invited)

    NASA Astrophysics Data System (ADS)

    Lindstrom, E. J.; McCurdy, A.; Young, J.; Fischer, A. S.

    2010-12-01

    We examine the evolution of data sharing in the field of physical oceanography to highlight the challenges now before us. Synoptic global observation of the ocean from space and in situ platforms has significantly matured over the last two decades. In the early 1990’s the community data sharing challenges facing the World Ocean Circulation Experiment (WOCE) largely focused on the behavior of individual scientists. Satellite data sharing depended on the policy of individual agencies. Global data sets were delivered with considerable delay and with enormous personal sacrifice. In the 2000’s the requirements for global data sets and sustained observations from the likes of the U.N. Framework Convention on Climate Change have led to data sharing and cooperation at a grander level. It is more effective and certainly more efficient. The Joint WMO/IOC Technical Commission on Oceanography and Marine Meteorology (JCOMM) provided the means to organize many aspects of data collection and data dissemination globally, for the common good. In response the Committee on Earth Observing Satellites organized Virtual Constellations to enable the assembly and sharing of like kinds of satellite data (e.g., sea surface topography, ocean vector winds, and ocean color). Individuals in physical oceanography have largely adapted to the new rigors of sharing data for the common good, and as a result of this revolution new science has been enabled. Primary obstacles to sharing have shifted from the individual level to the national level. As we enter into the 2010’s the demands for ocean data continue to evolve with an expanded requirement for more real-time reporting and broader disciplinary coverage, to answer key scientific and societal questions. We are also seeing the development of more numerous national contributions to the global observing system. The drivers for the establishment of global ocean observing systems are expanding beyond climate to include biological and

  7. Aircraft remote sensing of phytoplankton spatial patterns during the 1989 Joint Global Ocean Flux Study (JGOFS) North Atlantic bloom experiment

    NASA Technical Reports Server (NTRS)

    Yoder, James A.; Hoge, Frank E.

    1991-01-01

    Mesoscale phytoplankton chlorophyll variability near the Joint Global Ocean Flux study sites along the 20 W meridian at 34 N, 47 N, and 59 N is discussed. The NASA P-3 aircraft and the Airborne Oceanographic Lidar (AOL) system provides remote sensing support for the North Atlantic Bloom Experiment. The principal instrument of the AOL system is the blue-green laser that stimulates fluorescence from photoplankton chlorophyll, the principal photosynthetic pigment. Other instruments on the NASA P-3 aircraft include up- and down-looking spectrometers, PRT-5 for infrared measurements to determine sea surface temperature, and a system to deploy and record AXBTs to measure subsurface temperature structure.

  8. Global Ocean Carbon and Biogeochemistry Coordination

    NASA Astrophysics Data System (ADS)

    Telszewski, Maciej; Tanhua, Toste; Palacz, Artur

    2016-04-01

    The complexity of the marine carbon cycle and its numerous connections to carbon's atmospheric and terrestrial pathways means that a wide range of approaches have to be used in order to establish it's qualitative and quantitative role in the global climate system. Ocean carbon and biogeochemistry research, observations, and modelling are conducted at national, regional, and global levels to quantify the global ocean uptake of atmospheric CO2 and to understand controls of this process, the variability of uptake and vulnerability of carbon fluxes into the ocean. These science activities require support by a sustained, international effort that provides a central communication forum and coordination services to facilitate the compatibility and comparability of results from individual efforts and development of the ocean carbon data products that can be integrated with the terrestrial, atmospheric and human dimensions components of the global carbon cycle. The International Ocean Carbon Coordination Project (IOCCP) was created in 2005 by the IOC of UNESCO and the Scientific Committee on Oceanic Research. IOCCP provides an international, program-independent forum for global coordination of ocean carbon and biogeochemistry observations and integration with global carbon cycle science programs. The IOCCP coordinates an ever-increasing set of observations-related activities in the following domains: underway observations of biogeochemical water properties, ocean interior observations, ship-based time-series observations, large-scale ocean acidification monitoring, inorganic nutrients observations, biogeochemical instruments and autonomous sensors and data and information creation. Our contribution is through the facilitation of the development of globally acceptable strategies, methodologies, practices and standards homogenizing efforts of the research community and scientific advisory groups as well as integrating the ocean biogeochemistry observations with the

  9. The Global Ocean Observing System

    NASA Technical Reports Server (NTRS)

    Kester, Dana

    1992-01-01

    A Global Ocean Observing System (GOOS) should be established now with international coordination (1) to address issues of global change, (2) to implement operational ENSO forecasts, (3) to provide the data required to apply global ocean circulation models, and (4) to extract the greatest value from the one billion dollar investment over the next ten years in ocean remote sensing by the world's space agencies. The objectives of GOOS will focus on climatic and oceanic predictions, on assessing coastal pollution, and in determining the sustainability of living marine resources and ecosystems. GOOS will be a complete system including satellite observations, in situ observations, numerical modeling of ocean processes, and data exchange and management. A series of practical and economic benefits will be derived from the information generated by GOOS. In addition to the marine science community, these benefits will be realized by the energy industries of the world, and by the world's fisheries. The basic oceanic variables that are required to meet the oceanic and predictability objectives of GOOS include wind velocity over the ocean, sea surface temperature and salinity, oceanic profiles of temperature and salinity, surface current, sea level, the extent and thickness of sea ice, the partial pressure of CO2 in surface waters, and the chlorophyll concentration of surface waters. Ocean circulation models and coupled ocean-atmosphere models can be used to evaluate observing system design, to assimilate diverse data sets from in situ and remotely sensed observations, and ultimately to predict future states of the system. The volume of ocean data will increase enormously over the next decade as new satellite systems are launched and as complementary in situ measuring systems are deployed. These data must be transmitted, quality controlled, exchanged, analyzed, and archived with the best state-of-the-art computational methods.

  10. Decadal Changes in Global Ocean Chlorophyll

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Conkright, Margarita E.; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    The global ocean chlorophyll archive produced by the Coastal Zone Color Scanner (CZCS) was revised using compatible algorithms with the Sea-viewing Wide Field-of-view Sensor (SeaWIFS), and both were blended with in situ data. This methodology permitted a quantitative comparison of decadal changes in global ocean chlorophyll from the CZCS (1979-1986) and SeaWiFS (Sep. 1997-Dec. 2000) records. Global seasonal means of ocean chlorophyll decreased over the two observational segments, by 8% in winter to 16% in autumn. Chlorophyll in the high latitudes was responsible for most of the decadal change. Conversely, chlorophyll concentrations in the low latitudes increased. The differences and similarities of the two data records provide evidence of how the Earth's climate may be changing and how ocean biota respond. Furthermore, the results have implications for the ocean carbon cycle.

  11. The relationship between delta C-13 of organic matter and (CO2(aq)) in ocean surface water - Data from the JGOFS site in the northeast Atlantic Ocean and a model. [Joint Global Ocean Flux Study

    NASA Technical Reports Server (NTRS)

    Rau, G. H.; Takahashi, T.; Des Marais, D. J.; Repeta, D. J.; Martin, J. H.

    1992-01-01

    Consistent with the hypothesis that plankton delta C-14 and (CO2(aq)) are inversely related, increases in both sinking and suspended particulate organic matter (POM) delta C-13 detected by the Joint Global Ocean Flux Study (JGOFS) were highly negatively correlated with mixed-layer (CO2(aq)). A model of plant delta C-13 by Farquhar et al. (1982) is adapted to show that under a constant phytoplankton demand for CO2 an inverse nonlinear suspended POM delta C-13 response to ambient (CO2(aq)) is expected. Differences between predicted and observed suspended POM delta C-13 vs. (CO2(aq)) trends and among observed relationships can be reconciled if biological CO2 demand is allowed to vary.

  12. Simulating PACE Global Ocean Radiances

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Rousseaux, Cecile S.

    2017-01-01

    The NASA PACE mission is a hyper-spectral radiometer planned for launch in the next decade. It is intended to provide new information on ocean biogeochemical constituents by parsing the details of high resolution spectral absorption and scattering. It is the first of its kind for global applications and as such, poses challenges for design and operation. To support pre-launch mission development and assess on-orbit capabilities, the NASA Global Modeling and Assimilation Office has developed a dynamic simulation of global water-leaving radiances, using an ocean model containing multiple ocean phytoplankton groups, particulate detritus, particulate inorganic carbon (PIC), and chromophoric dissolved organic carbon (CDOC) along with optical absorption and scattering processes at 1 nm spectral resolution. The purpose here is to assess the skill of the dynamic model and derived global radiances. Global bias, uncertainty, and correlation are derived using available modern satellite radiances at moderate spectral resolution. Total chlorophyll, PIC, and the absorption coefficient of CDOC (aCDOC), are simultaneously assimilated to improve the fidelity of the optical constituent fields. A 5-year simulation showed statistically significant (P < 0.05) comparisons of chlorophyll (r = 0.869), PIC (r = 0.868), and a CDOC (r =0.890) with satellite data. Additionally, diatoms (r = 0.890), cyanobacteria (r = 0.732), and coccolithophores (r = 0.716) were significantly correlated with in situ data. Global assimilated distributions of optical constituents were coupled with a radiative transfer model (Ocean-Atmosphere Spectral Irradiance Model, OASIM) to estimate normalized water-leaving radiances at 1 nm for the spectral range 250-800 nm. These unassimilated radiances were within 0.074 mW/sq cm/micron/sr of MODIS-Aqua radiances at 412, 443, 488, 531, 547, and 667 nm. This difference represented a bias of 10.4% (model low). A mean correlation of 0.706 (P < 0.05) was found with global

  13. Joint spatiotemporal variability of global sea surface temperatures and global Palmer drought severity index values

    USGS Publications Warehouse

    Apipattanavis, S.; McCabe, G.J.; Rajagopalan, B.; Gangopadhyay, S.

    2009-01-01

    Dominant modes of individual and joint variability in global sea surface temperatures (SST) and global Palmer drought severity index (PDSI) values for the twentieth century are identified through a multivariate frequency domain singular value decomposition. This analysis indicates that a secular trend and variability related to the El Niño–Southern Oscillation (ENSO) are the dominant modes of variance shared among the global datasets. For the SST data the secular trend corresponds to a positive trend in Indian Ocean and South Atlantic SSTs, and a negative trend in North Pacific and North Atlantic SSTs. The ENSO reconstruction shows a strong signal in the tropical Pacific, North Pacific, and Indian Ocean regions. For the PDSI data, the secular trend reconstruction shows high amplitudes over central Africa including the Sahel, whereas the regions with strong ENSO amplitudes in PDSI are the southwestern and northwestern United States, South Africa, northeastern Brazil, central Africa, the Indian subcontinent, and Australia. An additional significant frequency, multidecadal variability, is identified for the Northern Hemisphere. This multidecadal frequency appears to be related to the Atlantic multidecadal oscillation (AMO). The multidecadal frequency is statistically significant in the Northern Hemisphere SST data, but is statistically nonsignificant in the PDSI data.

  14. Building a Global Ocean Science Education Network

    NASA Astrophysics Data System (ADS)

    Scowcroft, G. A.; Tuddenham, P. T.; Pizziconi, R.

    2016-02-01

    It is imperative for ocean science education to be closely linked to ocean science research. This is especially important for research that addresses global concerns that cross national boundaries, including climate related issues. The results of research on these critical topics must find its way to the public, educators, and students of all ages around the globe. To facilitate this, opportunities are needed for ocean scientists and educators to convene and identify priorities and strategies for ocean science education. On June 26 and 27, 2015 the first Global Ocean Science Education (GOSE) Workshop was convened in the United States at the University of Rhode Island Graduate School of Oceanography. The workshop, sponsored by the Consortium for Ocean Science Exploration and Engagement (COSEE) and the College of Exploration, had over 75 participants representing 15 nations. The workshop addressed critical global ocean science topics, current ocean science research and education priorities, advanced communication technologies, and leveraging international ocean research technologies. In addition, panels discussed elementary, secondary, undergraduate, graduate, and public education across the ocean basins with emphasis on opportunities for international collaboration. Special presentation topics included advancements in tropical cyclone forecasting, collaborations among Pacific Islands, ocean science for coastal resiliency, and trans-Atlantic collaboration. This presentation will focus on workshop outcomes as well as activities for growing a global ocean science education network. A summary of the workshop report will also be provided. The dates and location for the 2016 GOES Workshop will be announced. See http://www.coexploration.net/gose/index.html

  15. U.S. GODAE: Global Ocean Prediction With the HYbrid Coordinate Ocean Model (HYCOM)

    DTIC Science & Technology

    2009-06-01

    REPORT DATE (DD-MM- YYYY) 12-08-2009 2. REPORT TYPE Journal Article 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE U.S. GODAE: Global ...the lerformance and application of eddy-resolving, real-time global - and basin-scale ocean prediction systems using the HYbrid Coordinate Ocean...prediction system outputs. In addnion to providing real-time, eddy-resolving global - and basin-scale ocean prediction systems for the US Navy and NOAA, this

  16. Comparison of Two Global Ocean Reanalyses, NRL Global Ocean Forecast System (GOFS) and U. Maryland Simple Ocean Data Assimilation (SODA)

    NASA Astrophysics Data System (ADS)

    Richman, J. G.; Shriver, J. F.; Metzger, E. J.; Hogan, P. J.; Smedstad, O. M.

    2017-12-01

    The Oceanography Division of the Naval Research Laboratory recently completed a 23-year (1993-2015) coupled ocean-sea ice reanalysis forced by NCEP CFS reanalysis fluxes. The reanalysis uses the Global Ocean Forecast System (GOFS) framework of the HYbrid Coordinate Ocean Model (HYCOM) and the Los Alamos Community Ice CodE (CICE) and the Navy Coupled Ocean Data Assimilation 3D Var system (NCODA). The ocean model has 41 layers and an equatorial resolution of 0.08° (8.8 km) on a tri-polar grid with the sea ice model on the same grid that reduces to 3.5 km at the North Pole. Sea surface temperature (SST), sea surface height (SSH) and temperature-salinity profile data are assimilated into the ocean every day. The SSH anomalies are converted into synthetic profiles of temperature and salinity prior to assimilation. Incremental analysis updating of geostrophically balanced increments is performed over a 6-hour insertion window. Sea ice concentration is assimilated into the sea ice model every day. Following the lead of the Ocean Reanalysis Intercomparison Project (ORA-IP), the monthly mean upper ocean heat and salt content from the surface to 300 m, 700m and 1500 m, the mixed layer depth, the depth of the 20°C isotherm, the steric sea surface height and the Atlantic Meridional Overturning Circulation for the GOFS reanalysis and the Simple Ocean Data Assimilation (SODA 3.3.1) eddy-permitting reanalysis have been compared on a global uniform 0.5° grid. The differences between the two ocean reanalyses in heat and salt content increase with increasing integration depth. Globally, GOFS trends to be colder than SODA at all depth. Warming trends are observed at all depths over the 23 year period. The correlation of the upper ocean heat content is significant above 700 m. Prior to 2004, differences in the data assimilated lead to larger biases. The GOFS reanalysis assimilates SSH as profile data, while SODA doesn't. Large differences are found in the Western Boundary Currents

  17. Simulating PACE Global Ocean Radiances

    PubMed Central

    Gregg, Watson W.; Rousseaux, Cécile S.

    2017-01-01

    The NASA PACE mission is a hyper-spectral radiometer planned for launch in the next decade. It is intended to provide new information on ocean biogeochemical constituents by parsing the details of high resolution spectral absorption and scattering. It is the first of its kind for global applications and as such, poses challenges for design and operation. To support pre-launch mission development and assess on-orbit capabilities, the NASA Global Modeling and Assimilation Office has developed a dynamic simulation of global water-leaving radiances, using an ocean model containing multiple ocean phytoplankton groups, particulate detritus, particulate inorganic carbon (PIC), and chromophoric dissolved organic carbon (CDOC) along with optical absorption and scattering processes at 1 nm spectral resolution. The purpose here is to assess the skill of the dynamic model and derived global radiances. Global bias, uncertainty, and correlation are derived using available modern satellite radiances at moderate spectral resolution. Total chlorophyll, PIC, and the absorption coefficient of CDOC (aCDOC), are simultaneously assimilated to improve the fidelity of the optical constituent fields. A 5-year simulation showed statistically significant (P <0.05) comparisons of chlorophyll (r = 0.869), PIC (r = 0.868), and aCDOC (r = 0.890) with satellite data. Additionally, diatoms (r = 0.890), cyanobacteria (r = 0.732), and coccolithophores (r = 0.716) were significantly correlated with in situ data. Global assimilated distributions of optical constituents were coupled with a radiative transfer model (Ocean-Atmosphere Spectral Irradiance Model, OASIM) to estimate normalized water-leaving radiances at 1 nm for the spectral range 250–800 nm. These unassimilated radiances were within −0.074 mW cm−2 μm1 sr−1 of MODIS-Aqua radiances at 412, 443, 488, 531, 547, and 667 nm. This difference represented a bias of −10.4% (model low). A mean correlation of 0.706 (P < 0.05) was found with

  18. Improved Global Ocean Color Using Polymer Algorithm

    NASA Astrophysics Data System (ADS)

    Steinmetz, Francois; Ramon, Didier; Deschamps, ierre-Yves; Stum, Jacques

    2010-12-01

    A global ocean color product has been developed based on the use of the POLYMER algorithm to correct atmospheric scattering and sun glint and to process the data to a Level 2 ocean color product. Thanks to the use of this algorithm, the coverage and accuracy of the MERIS ocean color product have been significantly improved when compared to the standard product, therefore increasing its usefulness for global ocean monitor- ing applications like GLOBCOLOUR. We will present the latest developments of the algorithm, its first application to MODIS data and its validation against in-situ data from the MERMAID database. Examples will be shown of global NRT chlorophyll maps produced by CLS with POLYMER for operational applications like fishing or oil and gas industry, as well as its use by Scripps for a NASA study of the Beaufort and Chukchi seas.

  19. Decadal Changes in Global Ocean Annual Primary Production

    NASA Technical Reports Server (NTRS)

    Gregg, Watson; Conkright, Margarita E.; Behrenfeld, Michael J.; Ginoux, Paul; Casey, Nancy W.; Koblinsky, Chester J. (Technical Monitor)

    2002-01-01

    The Sea-viewing Wide Field-of-View Sensor (SeaWiFS) has produced the first multi-year time series of global ocean chlorophyll observations since the demise of the Coastal Zone Color Scanner (CZCS) in 1986. Global observations from 1997-present from SeaWiFS combined with observations from 1979-1986 from the CZCS should in principle provide an opportunity to observe decadal changes in global ocean annual primary production, since chlorophyll is the primary driver for estimates of primary production. However, incompatibilities between algorithms have so far precluded quantitative analysis. We have developed and applied compatible processing methods for the CZCS, using modern advances in atmospheric correction and consistent bio-optical algorithms to advance the CZCS archive to comparable quality with SeaWiFS. We applied blending methodologies, where in situ data observations are incorporated into the CZCS and SeaWiFS data records, to provide improvement of the residuals. These re-analyzed, blended data records provide maximum compatibility and permit, for the first time, a quantitative analysis of the changes in global ocean primary production in the early-to-mid 1980's and the present, using synoptic satellite observations. An intercomparison of the global and regional primary production from these blended satellite observations is important to understand global climate change and the effects on ocean biota. Photosynthesis by chlorophyll-containing phytoplankton is responsible for biotic uptake of carbon in the oceans and potentially ultimately from the atmosphere. Global ocean annual primary decreased from the CZCS record to SeaWiFS, by nearly 6% from the early 1980s to the present. Annual primary production in the high latitudes was responsible for most of the decadal change. Conversely, primary production in the low latitudes generally increased, with the exception of the tropical Pacific. The differences and similarities of the two data records provide evidence

  20. Global trends in ocean phytoplankton: a new assessment using revised ocean colour data.

    PubMed

    Gregg, Watson W; Rousseaux, Cécile S; Franz, Bryan A

    2017-01-01

    A recent revision of the NASA global ocean colour record shows changes in global ocean chlorophyll trends. This new 18-year time series now includes three global satellite sensors, the Sea-viewing Wide Field of view Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS-Aqua), and Visible Infrared Imaging Radiometer Suite (VIIRS). The major changes are radiometric drift correction, a new algorithm for chlorophyll, and a new sensor VIIRS. The new satellite data record shows no significant trend in global annual median chlorophyll from 1998 to 2015, in contrast to a statistically significant negative trend from 1998 to 2012 in the previous version. When revised satellite data are assimilated into a global ocean biogeochemical model, no trend is observed in global annual median chlorophyll. This is consistent with previous findings for the 1998-2012 time period using the previous processing version and only two sensors (SeaWiFS and MODIS). Detecting trends in ocean chlorophyll with satellites is sensitive to data processing options and radiometric drift correction. The assimilation of these data, however, reduces sensitivity to algorithms and radiometry, as well as the addition of a new sensor. This suggests the assimilation model has skill in detecting trends in global ocean colour. Using the assimilation model, spatial distributions of significant trends for the 18-year record (1998-2015) show recent decadal changes. Most notable are the North and Equatorial Indian Oceans basins, which exhibit a striking decline in chlorophyll. It is exemplified by declines in diatoms and chlorophytes, which in the model are large and intermediate size phytoplankton. This decline is partially compensated by significant increases in cyanobacteria, which represent very small phytoplankton. This suggests the beginning of a shift in phytoplankton composition in these tropical and subtropical Indian basins.

  1. A global ocean climatology of preindustrial and modern ocean δ13C

    NASA Astrophysics Data System (ADS)

    Eide, Marie; Olsen, Are; Ninnemann, Ulysses S.; Johannessen, Truls

    2017-03-01

    We present a global ocean climatology of dissolved inorganic carbon δ13C (‰) corrected for the 13C-Suess effect, preindustrial δ13C. This was constructed by first using Olsen and Ninnemann's (2010) back-calculation method on data from 25 World Ocean Circulation Experiment cruises to reconstruct the preindustrial δ13C on sections spanning all major oceans. Next, we developed five multilinear regression equations, one for each major ocean basin, which were applied on the World Ocean Atlas data to construct the climatology. This reveals the natural δ13C distribution in the global ocean. Compared to the modern distribution, the preindustrial δ13C spans a larger range of values. The maxima, of up to 1.8‰, occurs in the subtropical gyres of all basins, in the upper and intermediate waters of the North Atlantic, as well as in mode waters with a Southern Ocean origin. Particularly strong gradients occur at intermediate depths, revealing a strong potential for using δ13C as a tracer for changes in water mass geometry at these levels. Further, we identify a much tighter relationship between δ13C and apparent oxygen utilization (AOU) than between δ13C and phosphate. This arises because, in contrast to phosphate, AOU and δ13C are both partly reset when waters are ventilated in the Southern Ocean and underscore that δ13C is a highly robust proxy for past changes in ocean oxygen content and ocean ventilation. Our global preindustrial δ13C climatology is openly accessible and can be used, for example, for improved model evaluation and interpretation of sediment δ13C records.

  2. Global Ocean Vertical Velocity From a Dynamically Consistent Ocean State Estimate

    NASA Astrophysics Data System (ADS)

    Liang, Xinfeng; Spall, Michael; Wunsch, Carl

    2017-10-01

    Estimates of the global ocean vertical velocities (Eulerian, eddy-induced, and residual) from a dynamically consistent and data-constrained ocean state estimate are presented and analyzed. Conventional patterns of vertical velocity, Ekman pumping, appear in the upper ocean, with topographic dominance at depth. Intense and vertically coherent upwelling and downwelling occur in the Southern Ocean, which are likely due to the interaction of the Antarctic Circumpolar Current and large-scale topographic features and are generally canceled out in the conventional zonally averaged results. These "elevators" at high latitudes connect the upper to the deep and abyssal oceans and working together with isopycnal mixing are likely a mechanism, in addition to the formation of deep and abyssal waters, for fast responses of the deep and abyssal oceans to the changing climate. Also, Eulerian and parameterized eddy-induced components are of opposite signs in numerous regions around the global ocean, particularly in the ocean interior away from surface and bottom. Nevertheless, residual vertical velocity is primarily determined by the Eulerian component, and related to winds and large-scale topographic features. The current estimates of vertical velocities can serve as a useful reference for investigating the vertical exchange of ocean properties and tracers, and its complex spatial structure ultimately permits regional tests of basic oceanographic concepts such as Sverdrup balance and coastal upwelling/downwelling.

  3. Ocean Salinity Variance and the Global Water Cycle.

    NASA Astrophysics Data System (ADS)

    Schmitt, R. W.

    2012-12-01

    Ocean salinity variance is increasing and appears to be an indicator of rapid change in the global water cycle. While the small terrestrial water cycle does not reveal distinct trends, in part due to strong manipulation by civilization, the much larger oceanic water cycle seems to have an excellent proxy for its intensity in the contrasts in sea surface salinity (SSS). Change in the water cycle is arguably the most important challenge facing mankind. But how well do we understand the oceanic response? Does the ocean amplify SSS change to make it a hyper-sensitive indicator of change in the global water cycle? An overview of the research challenges to the oceanographic community for understanding the dominant component of the global water cycle is provided.

  4. Global Mapping of Oceanic and Continental Shelf Crustal Thickness and Ocean-Continent Transition Structure

    NASA Astrophysics Data System (ADS)

    Kusznir, Nick; Alvey, Andy; Roberts, Alan

    2017-04-01

    The 3D mapping of crustal thickness for continental shelves and oceanic crust, and the determination of ocean-continent transition (OCT) structure and continent-ocean boundary (COB) location, represents a substantial challenge. Geophysical inversion of satellite derived free-air gravity anomaly data incorporating a lithosphere thermal anomaly correction (Chappell & Kusznir, 2008) now provides a useful and reliable methodology for mapping crustal thickness in the marine domain. Using this we have produced the first comprehensive maps of global crustal thickness for oceanic and continental shelf regions. Maps of crustal thickness and continental lithosphere thinning factor from gravity inversion may be used to determine the distribution of oceanic lithosphere, micro-continents and oceanic plateaux including for the inaccessible polar regions (e.g. Arctic Ocean, Alvey et al.,2008). The gravity inversion method provides a prediction of continent-ocean boundary location which is independent of ocean magnetic anomaly and isochron interpretation. Using crustal thickness and continental lithosphere thinning factor maps with superimposed shaded-relief free-air gravity anomaly, we can improve the determination of pre-breakup rifted margin conjugacy and sea-floor spreading trajectory during ocean basin formation. By restoring crustal thickness & continental lithosphere thinning to their initial post-breakup configuration we show the geometry and segmentation of the rifted continental margins at their time of breakup, together with the location of highly-stretched failed breakup basins and rifted micro-continents. For detailed analysis to constrain OCT structure, margin type (i.e. magma poor, "normal" or magma rich) and COB location, a suite of quantitative analytical methods may be used which include: (i) Crustal cross-sections showing Moho depth and crustal basement thickness from gravity inversion. (ii) Residual depth anomaly (RDA) analysis which is used to investigate OCT

  5. Dynamical Interpolation of Mesoscale Flows in the TOPEX/Poseidon Diamond Surrounding the U.S. Joint Global Ocean Flux Study Bermuda Atlantic Time-Series Study Site

    NASA Technical Reports Server (NTRS)

    McGillicuddy, Dennis J., Jr.; Kosnyrev, V. K.

    2001-01-01

    An open boundary ocean model is configured in a domain bounded by the four TOPEX/Poseidon (T/P) ground tracks surrounding the US Joint Global Ocean Flux Study Bermuda Atlantic Time-Series Study (BATS) site. This implementation facilitates prescription of model boundary conditions directly from altimetric measurements (both TIP and ERS-2). The expected error characteristics for a domain of this size with periodically updated boundary conditions are established with idealized numerical experiments using simulated data. A hindcast simulation is then constructed using actual altimetric observations during the period October 1992 through September 1998. Quantitative evaluation of the simulation suggests significant skill. The correlation coefficient between predicted sea level anomaly and ERS observations in the model interior is 0.89; that for predicted versus observed dynamic height anomaly based on hydrography at the BATS site is 0.73. Comparison with the idealized experiments suggests that the main source of error in the hindcast is temporal undersampling of the boundary conditions. The hindcast simulation described herein provides a basis for retrospective analysis of BATS observations in the context of the mesoscale eddy field.

  6. Dynamical Interpolation of Mesoscale Flows in the TOPEX/ Poseidon Diamond Surrounding the U.S. Joint Global Ocean Flux Study Bermuda Atlantic Time-Series Study Site

    NASA Technical Reports Server (NTRS)

    McGillicuddy, D. J.; Kosnyrev, V. K.

    2001-01-01

    An open boundary ocean model is configured in a domain bounded by the four TOPEX/Poseidon (TIP) ground tracks surrounding the U.S. Joint Global Ocean Flux Study Bermuda Atlantic Time-series Study (BATS) site. This implementation facilitates prescription of model boundary conditions directly from altimetric measurements (both TIP and ERS-2). The expected error characteristics for a domain of this size with periodically updated boundary conditions are established with idealized numerical experiments using simulated data. A hindcast simulation is then constructed using actual altimetric observations during the period October 1992 through September 1998. Quantitative evaluation of the simulation suggests significant skill. The correlation coefficient between predicted sea level anomaly and ERS observations in the model interior is 0.89; that for predicted versus observed dynamic height anomaly based on hydrography at the BATS site is 0.73. Comparison with the idealized experiments suggests that the main source of error in the hindcast is temporal undersampling of the boundary conditions. The hindcast simulation described herein provides a basis for retrospective analysis of BATS observations in the context of the mesoscale eddy field.

  7. Enhanced deep ocean ventilation and oxygenation with global warming

    NASA Astrophysics Data System (ADS)

    Froelicher, T. L.; Jaccard, S.; Dunne, J. P.; Paynter, D.; Gruber, N.

    2014-12-01

    Twenty-first century coupled climate model simulations, observations from the recent past, and theoretical arguments suggest a consistent trend towards warmer ocean temperatures and fresher polar surface oceans in response to increased radiative forcing resulting in increased upper ocean stratification and reduced ventilation and oxygenation of the deep ocean. Paleo-proxy records of the warming at the end of the last ice age, however, suggests a different outcome, namely a better ventilated and oxygenated deep ocean with global warming. Here we use a four thousand year global warming simulation from a comprehensive Earth System Model (GFDL ESM2M) to show that this conundrum is a consequence of different rates of warming and that the deep ocean is actually better ventilated and oxygenated in a future warmer equilibrated climate consistent with paleo-proxy records. The enhanced deep ocean ventilation in the Southern Ocean occurs in spite of increased positive surface buoyancy fluxes and a constancy of the Southern Hemisphere westerly winds - circumstances that would otherwise be expected to lead to a reduction in deep ocean ventilation. This ventilation recovery occurs through a global scale interaction of the Atlantic Meridional Overturning Circulation undergoing a multi-centennial recovery after an initial century of transient decrease and transports salinity-rich waters inform the subtropical surface ocean to the Southern Ocean interior on multi-century timescales. The subsequent upwelling of salinity-rich waters in the Southern Ocean strips away the freshwater cap that maintains vertical stability and increases open ocean convection and the formation of Antarctic Bottom Waters. As a result, the global ocean oxygen content and the nutrient supply from the deep ocean to the surface are higher in a warmer ocean. The implications for past and future changes in ocean heat and carbon storage will be discussed.

  8. Global oceanic production of nitrous oxide

    PubMed Central

    Freing, Alina; Wallace, Douglas W. R.; Bange, Hermann W.

    2012-01-01

    We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N2O) to estimate the concentration of biologically produced N2O and N2O production rates in the ocean on a global scale. Our approach to estimate the N2O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N2O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N2O are not taken into account in our study. The largest amount of subsurface N2O is produced in the upper 500 m of the water column. The estimated global annual subsurface N2O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr−1. This is in agreement with estimates of the global N2O emissions to the atmosphere and indicates that a N2O source in the mixed layer is unlikely. The potential future development of the oceanic N2O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed. PMID:22451110

  9. Global oceanic production of nitrous oxide.

    PubMed

    Freing, Alina; Wallace, Douglas W R; Bange, Hermann W

    2012-05-05

    We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N(2)O) to estimate the concentration of biologically produced N(2)O and N(2)O production rates in the ocean on a global scale. Our approach to estimate the N(2)O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N(2)O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N(2)O are not taken into account in our study. The largest amount of subsurface N(2)O is produced in the upper 500 m of the water column. The estimated global annual subsurface N(2)O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr(-1). This is in agreement with estimates of the global N(2)O emissions to the atmosphere and indicates that a N(2)O source in the mixed layer is unlikely. The potential future development of the oceanic N(2)O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed.

  10. State of Climate 2011 - Global Ocean Phytoplankton

    NASA Technical Reports Server (NTRS)

    Siegel, D. A.; Antoine, D.; Behrenfeld, M. J.; d'Andon, O. H. Fanton; Fields, E.; Franz, B. A.; Goryl, P.; Maritorena, S.; McClain, C. R.; Wang, M.; hide

    2012-01-01

    Phytoplankton photosynthesis in the sun lit upper layer of the global ocean is the overwhelmingly dominant source of organic matter that fuels marine ecosystems. Phytoplankton contribute roughly half of the global (land and ocean) net primary production (NPP; gross photosynthesis minus plant respiration) and phytoplankton carbon fixation is the primary conduit through which atmospheric CO2 concentrations interact with the ocean s carbon cycle. Phytoplankton productivity depends on the availability of sunlight, macronutrients (e.g., nitrogen, phosphorous), and micronutrients (e.g., iron), and thus is sensitive to climate-driven changes in the delivery of these resources to the euphotic zone

  11. Global Ocean Prediction with the HYbrid Coordinate Ocean Model, HYCOM

    NASA Astrophysics Data System (ADS)

    Chassignet, E.

    A broad partnership of institutions is collaborating in developing and demonstrating the performance and application of eddy-resolving, real-time global and Atlantic ocean prediction systems using the the HYbrid Coordinate Ocean Model (HYCOM). These systems will be transitioned for operational use by both the U.S. Navy at the Naval Oceanographic Office (NAVOCEANO), Stennis Space Center, MS, and the Fleet Numerical Meteorology and Oceanography Centre (FNMOC), Monterey, CA, and by NOAA at the National Centers for Environmental Prediction (NCEP), Washington, D.C. These systems will run efficiently on a variety of massively parallel computers and will include sophisticated data assimilation techniques for assimilation of satellite altimeter sea surface height and sea surface temperature as well as in situ temperature, salinity, and float displacement. The Partnership addresses the Global Ocean Data Assimilation Experiment (GODAE) goals of three-dimensional (3D) depiction of the ocean state at fine resolution in real-time and provision of boundary conditions for coastal and regional models. An overview of the effort will be presented.

  12. Global Real-Time Ocean Forecast System

    Science.gov Websites

    services. Marine Modeling and Analysis Branch Logo Click here to go to the MMAB home page Global Real-Time 17 Oct 2017 at 0Z, the Global RTOFS model has been upgraded to version 1.1.2. Changes include: The ). The global operational Real-Time Ocean Forecast System (Global RTOFS) at the National Centers for

  13. Global Ocean Currents Database

    NASA Astrophysics Data System (ADS)

    Boyer, T.; Sun, L.

    2016-02-01

    The NOAA's National Centers for Environmental Information has released an ocean currents database portal that aims 1) to integrate global ocean currents observations from a variety of instruments with different resolution, accuracy and response to spatial and temporal variability into a uniform network common data form (NetCDF) format and 2) to provide a dedicated online data discovery, access to NCEI-hosted and distributed data sources for ocean currents data. The portal provides a tailored web application that allows users to search for ocean currents data by platform types and spatial/temporal ranges of their interest. The dedicated web application is available at http://www.nodc.noaa.gov/gocd/index.html. The NetCDF format supports widely-used data access protocols and catalog services such as OPeNDAP (Open-source Project for a Network Data Access Protocol) and THREDDS (Thematic Real-time Environmental Distributed Data Services), which the GOCD users can use data files with their favorite analysis and visualization client software without downloading to their local machine. The potential users of the ocean currents database include, but are not limited to, 1) ocean modelers for their model skills assessments, 2) scientists and researchers for studying the impact of ocean circulations on the climate variability, 3) ocean shipping industry for safety navigation and finding optimal routes for ship fuel efficiency, 4) ocean resources managers while planning for the optimal sites for wastes and sewages dumping and for renewable hydro-kinematic energy, and 5) state and federal governments to provide historical (analyzed) ocean circulations as an aid for search and rescue

  14. The positive Indian Ocean Dipole-like response in the tropical Indian Ocean to global warming

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luo, Yiyong; Lu, Jian; Liu, Fukai

    Climate models project a positive Indian Ocean Dipole (pIOD)-like SST response in the tropical Indian Ocean to global warming. By employing the Community Earth System Model (CESM) and applying an overriding technique to its ocean component Parallel Ocean Program version 2 (POP2), this study investigates the similarity and difference of the formation mechanisms for the changes in the tropical Indian Ocean during the pIOD versus global warming. Results show that their formation processes and related seasonality are quite similar; in particular, the Bjerknes feedback is the leading mechanism in producing the anomalous cooling over the eastern tropics in both cases.more » Some differences are also found, including that the cooling effect of the vertical advection over the eastern tropical Indian Ocean is dominated by the anomalous vertical velocity during the pIOD while it is dominated by the anomalous upper-ocean stratification under global warming. Lastly, these findings above are further examined with an analysis of the mixed layer heat budget.« less

  15. The positive Indian Ocean Dipole-like response in the tropical Indian Ocean to global warming

    DOE PAGES

    Luo, Yiyong; Lu, Jian; Liu, Fukai; ...

    2016-02-04

    Climate models project a positive Indian Ocean Dipole (pIOD)-like SST response in the tropical Indian Ocean to global warming. By employing the Community Earth System Model (CESM) and applying an overriding technique to its ocean component Parallel Ocean Program version 2 (POP2), this study investigates the similarity and difference of the formation mechanisms for the changes in the tropical Indian Ocean during the pIOD versus global warming. Results show that their formation processes and related seasonality are quite similar; in particular, the Bjerknes feedback is the leading mechanism in producing the anomalous cooling over the eastern tropics in both cases.more » Some differences are also found, including that the cooling effect of the vertical advection over the eastern tropical Indian Ocean is dominated by the anomalous vertical velocity during the pIOD while it is dominated by the anomalous upper-ocean stratification under global warming. Lastly, these findings above are further examined with an analysis of the mixed layer heat budget.« less

  16. Mean global ocean temperatures during the last glacial transition.

    PubMed

    Bereiter, Bernhard; Shackleton, Sarah; Baggenstos, Daniel; Kawamura, Kenji; Severinghaus, Jeff

    2018-01-03

    Little is known about the ocean temperature's long-term response to climate perturbations owing to limited observations and a lack of robust reconstructions. Although most of the anthropogenic heat added to the climate system has been taken up by the ocean up until now, its role in a century and beyond is uncertain. Here, using noble gases trapped in ice cores, we show that the mean global ocean temperature increased by 2.57 ± 0.24 degrees Celsius over the last glacial transition (20,000 to 10,000 years ago). Our reconstruction provides unprecedented precision and temporal resolution for the integrated global ocean, in contrast to the depth-, region-, organism- and season-specific estimates provided by other methods. We find that the mean global ocean temperature is closely correlated with Antarctic temperature and has no lead or lag with atmospheric CO 2 , thereby confirming the important role of Southern Hemisphere climate in global climate trends. We also reveal an enigmatic 700-year warming during the early Younger Dryas period (about 12,000 years ago) that surpasses estimates of modern ocean heat uptake.

  17. Mean global ocean temperatures during the last glacial transition

    NASA Astrophysics Data System (ADS)

    Bereiter, Bernhard; Shackleton, Sarah; Baggenstos, Daniel; Kawamura, Kenji; Severinghaus, Jeff

    2018-01-01

    Little is known about the ocean temperature’s long-term response to climate perturbations owing to limited observations and a lack of robust reconstructions. Although most of the anthropogenic heat added to the climate system has been taken up by the ocean up until now, its role in a century and beyond is uncertain. Here, using noble gases trapped in ice cores, we show that the mean global ocean temperature increased by 2.57 ± 0.24 degrees Celsius over the last glacial transition (20,000 to 10,000 years ago). Our reconstruction provides unprecedented precision and temporal resolution for the integrated global ocean, in contrast to the depth-, region-, organism- and season-specific estimates provided by other methods. We find that the mean global ocean temperature is closely correlated with Antarctic temperature and has no lead or lag with atmospheric CO2, thereby confirming the important role of Southern Hemisphere climate in global climate trends. We also reveal an enigmatic 700-year warming during the early Younger Dryas period (about 12,000 years ago) that surpasses estimates of modern ocean heat uptake.

  18. Analysis of global oceanic rainfall from microwave data

    NASA Technical Reports Server (NTRS)

    Rao, M.

    1978-01-01

    A Global Rainfall Atlas was prepared from Nimbus 5 ESMR data. The Atlas includes global oceanic rainfall maps based on weekly, monthly and seasonal averages, complete through the end of 1975. Similar maps for 1973 and 1974 were studied. They reveal several previously unknown areas of enhanced rainfall and preliminary data on interannual variability of oceanic rainfall.

  19. Assimilation of SeaWiFS Ocean Chlorophyll Data into a Three-Dimensional Global Ocean Model

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.

    2005-01-01

    Assimilation of satellite ocean color data is a relatively new phenomenon in ocean sciences. However, with routine observations from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), launched in late 1997, and now with new data from the Moderate Resolution Imaging Spectroradometer (MODIS) Aqua, there is increasing interest in ocean color data assimilation. Here SeaWiFS chlorophyll data were assimilated with an established thre-dimentional global ocean model. The assimilation improved estimates of hlorophyll and primary production relative to a free-run (no assimilation) model. This represents the first attempt at ocean color data assimilation using NASA satellites in a global model. The results suggest the potential of assimilation of satellite ocean chlorophyll data for improving models.

  20. The Global Ocean Data Assimilation Experiment (GODAE)

    NASA Astrophysics Data System (ADS)

    Le Traon, P.; Smith, N.

    The Global Ocean Data Assimilation Experiment (GODAE) will conduct its main demonstration phase from 2003 to 2005. From 2003 to 2005, operational and research institutions from Australia, Japan, United States, United Kingdom, France and Norway will be performing global oceanic data assimilation and ocean forecast in order to provide regular and comprehensive descriptions of ocean fields such as temperature, salinity and currents at high temporal and spatial resolution. A central objective of GODAE is to provide an integrated description that combines remote sensing data, in-situ data and models through data assimilation. Climate and seasonal forecasting, navy applications, marine safety, fisheries, the offshore industry and management of shelf/coastal areas are among the expected beneficiaries of GODAE. The integrated description of the ocean that GODAE will provide will also be highly beneficial to the research community. An overview of GODAE will be given; we will detail the GODAE objectives and strategy and the way it is implemented as an international experiment. Results from first pre-operational or prototype systems will finally be shown.

  1. Global oceanic emission of ammonia: Constraints from seawater and atmospheric observations

    NASA Astrophysics Data System (ADS)

    Paulot, F.; Jacob, D. J.; Johnson, M. T.; Bell, T. G.; Baker, A. R.; Keene, W. C.; Lima, I. D.; Doney, S. C.; Stock, C. A.

    2015-08-01

    Current global inventories of ammonia emissions identify the ocean as the largest natural source. This source depends on seawater pH, temperature, and the concentration of total seawater ammonia (NHx(sw)), which reflects a balance between remineralization of organic matter, uptake by plankton, and nitrification. Here we compare [NHx(sw)] from two global ocean biogeochemical models (BEC and COBALT) against extensive ocean observations. Simulated [NHx(sw)] are generally biased high. Improved simulation can be achieved in COBALT by increasing the plankton affinity for NHx within observed ranges. The resulting global ocean emissions is 2.5 TgN a-1, much lower than current literature values (7-23 TgN a-1), including the widely used Global Emissions InitiAtive (GEIA) inventory (8 TgN a-1). Such a weak ocean source implies that continental sources contribute more than half of atmospheric NHx over most of the ocean in the Northern Hemisphere. Ammonia emitted from oceanic sources is insufficient to neutralize sulfate aerosol acidity, consistent with observations. There is evidence over the Equatorial Pacific for a missing source of atmospheric ammonia that could be due to photolysis of marine organic nitrogen at the ocean surface or in the atmosphere. Accommodating this possible missing source yields a global ocean emission of ammonia in the range 2-5 TgN a-1, comparable in magnitude to other natural sources from open fires and soils.

  2. Decline in global oceanic oxygen content during the past five decades.

    PubMed

    Schmidtko, Sunke; Stramma, Lothar; Visbeck, Martin

    2017-02-15

    Ocean models predict a decline in the dissolved oxygen inventory of the global ocean of one to seven per cent by the year 2100, caused by a combination of a warming-induced decline in oxygen solubility and reduced ventilation of the deep ocean. It is thought that such a decline in the oceanic oxygen content could affect ocean nutrient cycles and the marine habitat, with potentially detrimental consequences for fisheries and coastal economies. Regional observational data indicate a continuous decrease in oceanic dissolved oxygen concentrations in most regions of the global ocean, with an increase reported in a few limited areas, varying by study. Prior work attempting to resolve variations in dissolved oxygen concentrations at the global scale reported a global oxygen loss of 550 ± 130 teramoles (10 12  mol) per decade between 100 and 1,000 metres depth based on a comparison of data from the 1970s and 1990s. Here we provide a quantitative assessment of the entire ocean oxygen inventory by analysing dissolved oxygen and supporting data for the complete oceanic water column over the past 50 years. We find that the global oceanic oxygen content of 227.4 ± 1.1 petamoles (10 15  mol) has decreased by more than two per cent (4.8 ± 2.1 petamoles) since 1960, with large variations in oxygen loss in different ocean basins and at different depths. We suggest that changes in the upper water column are mostly due to a warming-induced decrease in solubility and biological consumption. Changes in the deeper ocean may have their origin in basin-scale multi-decadal variability, oceanic overturning slow-down and a potential increase in biological consumption.

  3. NOAA's Role in Sustaining Global Ocean Observations: Future Plans for OAR's Ocean Observing and Monitoring Division

    NASA Astrophysics Data System (ADS)

    Todd, James; Legler, David; Piotrowicz, Stephen; Raymond, Megan; Smith, Emily; Tedesco, Kathy; Thurston, Sidney

    2017-04-01

    The Ocean Observing and Monitoring Division (OOMD, formerly the Climate Observation Division) of the National Oceanic and Atmospheric Administration (NOAA) Climate Program Office provides long-term, high-quality global observations, climate information and products for researchers, forecasters, assessments and other users of environmental information. In this context, OOMD-supported activities serve a foundational role in an enterprise that aims to advance 1) scientific understanding, 2) monitoring and prediction of climate and 3) understanding of potential impacts to enable a climate resilient society. Leveraging approximately 50% of the Global Ocean Observing System, OOMD employs an internationally-coordinated, multi-institution global strategy that brings together data from multiple platforms including surface drifting buoys, Argo profiling floats, flux/transport moorings (RAMA, PIRATA, OceanSITES), GLOSS tide gauges, SOOP-XBT and SOOP-CO2, ocean gliders and repeat hydrographic sections (GO-SHIP). OOMD also engages in outreach, education and capacity development activities to deliver training on the social-economic applications of ocean data. This presentation will highlight recent activities and plans for 2017 and beyond.

  4. Practical global oceanic state estimation

    NASA Astrophysics Data System (ADS)

    Wunsch, Carl; Heimbach, Patrick

    2007-06-01

    The problem of oceanographic state estimation, by means of an ocean general circulation model (GCM) and a multitude of observations, is described and contrasted with the meteorological process of data assimilation. In practice, all such methods reduce, on the computer, to forms of least-squares. The global oceanographic problem is at the present time focussed primarily on smoothing, rather than forecasting, and the data types are unlike meteorological ones. As formulated in the consortium Estimating the Circulation and Climate of the Ocean (ECCO), an automatic differentiation tool is used to calculate the so-called adjoint code of the GCM, and the method of Lagrange multipliers used to render the problem one of unconstrained least-squares minimization. Major problems today lie less with the numerical algorithms (least-squares problems can be solved by many means) than with the issues of data and model error. Results of ongoing calculations covering the period of the World Ocean Circulation Experiment, and including among other data, satellite altimetry from TOPEX/POSEIDON, Jason-1, ERS- 1/2, ENVISAT, and GFO, a global array of profiling floats from the Argo program, and satellite gravity data from the GRACE mission, suggest that the solutions are now useful for scientific purposes. Both methodology and applications are developing in a number of different directions.

  5. An ensemble of eddy-permitting global ocean reanalyses from the MyOcean project

    NASA Astrophysics Data System (ADS)

    Masina, Simona; Storto, Andrea; Ferry, Nicolas; Valdivieso, Maria; Haines, Keith; Balmaseda, Magdalena; Zuo, Hao; Drevillon, Marie; Parent, Laurent

    2017-08-01

    A set of four eddy-permitting global ocean reanalyses produced in the framework of the MyOcean project have been compared over the altimetry period 1993-2011. The main differences among the reanalyses used here come from the data assimilation scheme implemented to control the ocean state by inserting reprocessed observations of sea surface temperature (SST), in situ temperature and salinity profiles, sea level anomaly and sea-ice concentration. A first objective of this work includes assessing the interannual variability and trends for a series of parameters, usually considered in the community as essential ocean variables: SST, sea surface salinity, temperature and salinity averaged over meaningful layers of the water column, sea level, transports across pre-defined sections, and sea ice parameters. The eddy-permitting nature of the global reanalyses allows also to estimate eddy kinetic energy. The results show that in general there is a good consistency between the different reanalyses. An intercomparison against experiments without data assimilation was done during the MyOcean project and we conclude that data assimilation is crucial for correctly simulating some quantities such as regional trends of sea level as well as the eddy kinetic energy. A second objective is to show that the ensemble mean of reanalyses can be evaluated as one single system regarding its reliability in reproducing the climate signals, where both variability and uncertainties are assessed through the ensemble spread and signal-to-noise ratio. The main advantage of having access to several reanalyses differing in the way data assimilation is performed is that it becomes possible to assess part of the total uncertainty. Given the fact that we use very similar ocean models and atmospheric forcing, we can conclude that the spread of the ensemble of reanalyses is mainly representative of our ability to gauge uncertainty in the assimilation methods. This uncertainty changes a lot from one ocean

  6. Global Modeling Study of the Bioavailable Atmospheric Iron Supply to the Global Ocean

    NASA Astrophysics Data System (ADS)

    Myriokefalitakis, S.; Krol, M. C.; van Noije, T.; Le Sager, P.

    2017-12-01

    Atmospheric deposition of trace constituents acts as a nutrient source to the open ocean and affect marine ecosystem. Dust is known as a major source of nutrients to the global ocean, but only a fraction of these nutrients is released in a bioavailable form that can be assimilated by the marine biota. Iron (Fe) is a key micronutrient that significantly modulates gross primary production in the High-Nutrient-Low-Chlorophyll (HNLC) oceans, where macronutrients like nitrate are abundant, but primary production is limited by Fe scarcity. The global atmospheric Fe cycle is here parameterized in the state-of-the-art global Earth System Model EC-Earth. The model takes into account the primary emissions of both insoluble and soluble Fe forms, associated with mineral dust and combustion aerosols. The impact of atmospheric acidity and organic ligands on mineral dissolution processes, is parameterized based on updated experimental and theoretical findings. Model results are also evaluated against available observations. Overall, the link between the labile Fe atmospheric deposition and atmospheric composition changes is here demonstrated and quantified. This work has been financed by the Marie-Curie H2020-MSCA-IF-2015 grant (ID 705652) ODEON (Online DEposition over OceaNs; modeling the effect of air pollution on ocean bio-geochemistry in an Earth System Model).

  7. Patterns and Emerging Trends in Global Ocean Health

    PubMed Central

    Halpern, Benjamin S.; Longo, Catherine; Lowndes, Julia S. Stewart; Best, Benjamin D.; Frazier, Melanie; Katona, Steven K.; Kleisner, Kristin M.; Rosenberg, Andrew A.; Scarborough, Courtney; Selig, Elizabeth R.

    2015-01-01

    International and regional policies aimed at managing ocean ecosystem health need quantitative and comprehensive indices to synthesize information from a variety of sources, consistently measure progress, and communicate with key constituencies and the public. Here we present the second annual global assessment of the Ocean Health Index, reporting current scores and annual changes since 2012, recalculated using updated methods and data based on the best available science, for 221 coastal countries and territories. The Index measures performance of ten societal goals for healthy oceans on a quantitative scale of increasing health from 0 to 100, and combines these scores into a single Index score, for each country and globally. The global Index score improved one point (from 67 to 68), while many country-level Index and goal scores had larger changes. Per-country Index scores ranged from 41–95 and, on average, improved by 0.06 points (range -8 to +12). Globally, average scores increased for individual goals by as much as 6.5 points (coastal economies) and decreased by as much as 1.2 points (natural products). Annual updates of the Index, even when not all input data have been updated, provide valuable information to scientists, policy makers, and resource managers because patterns and trends can emerge from the data that have been updated. Changes of even a few points indicate potential successes (when scores increase) that merit recognition, or concerns (when scores decrease) that may require mitigative action, with changes of more than 10–20 points representing large shifts that deserve greater attention. Goal scores showed remarkably little covariance across regions, indicating low redundancy in the Index, such that each goal delivers information about a different facet of ocean health. Together these scores provide a snapshot of global ocean health and suggest where countries have made progress and where a need for further improvement exists. PMID:25774678

  8. Evaluation of High Resolution IMERG Satellite Precipitation over the Global Oceans using OceanRAIN

    NASA Astrophysics Data System (ADS)

    Kucera, P. A.; Klepp, C.

    2017-12-01

    Precipitation is a key parameter of the essential climate variables in the Earth System that is a key variable in the global water cycle. Observations of precipitation over oceans is relatively sparse. Satellite observations over oceans is the only viable means of measuring the spatially distribution of precipitation. In an effort to improve global precipitation observations, the research community has developed a state of the art precipitation dataset as part of the NASA/JAXA Global Precipitation Measurement (GPM) program. The satellite gridded product that has been developed is called Integrated Multi-satelliE Retrievals for GPM (IMERG), which has a maximum spatial resolution of 0.1º x 0.1º and temporal 30 minute. Even with the advancements in retrievals, there is a need to quantify uncertainty of IMERG precipitation estimates especially over oceans. To address this need, the OceanRAIN dataset has been used to create a comprehensive database to compare IMERG products. The OceanRAIN dataset was created using observations from the ODM-470 optical disdrometer that has been deployed on 12 research vessels worldwide with 6 long-term installations operating in all climatic regions, seasons and ocean basins. More than 6 million data samples have been collected on the OceanRAIN program. These data were matched to IMERG grids for the study period of 15 March 2014-01 April 2017. This evaluation produced over 1500 matched IMERG-OceanRAIN pairs of precipitation observed at the surface. These matched pairs were used to evaluate the performance of IMERG stratified by different latitudinal bands and precipitation regimes. The presentation will provide an overview of the study and summary of evaluation results.

  9. Sensitivity of the ocean overturning circulation to wind and mixing: theoretical scalings and global ocean models

    NASA Astrophysics Data System (ADS)

    Nikurashin, Maxim; Gunn, Andrew

    2017-04-01

    The meridional overturning circulation (MOC) is a planetary-scale oceanic flow which is of direct importance to the climate system: it transports heat meridionally and regulates the exchange of CO2 with the atmosphere. The MOC is forced by wind and heat and freshwater fluxes at the surface and turbulent mixing in the ocean interior. A number of conceptual theories for the sensitivity of the MOC to changes in forcing have recently been developed and tested with idealized numerical models. However, the skill of the simple conceptual theories to describe the MOC simulated with higher complexity global models remains largely unknown. In this study, we present a systematic comparison of theoretical and modelled sensitivity of the MOC and associated deep ocean stratification to vertical mixing and southern hemisphere westerlies. The results show that theories that simplify the ocean into a single-basin, zonally-symmetric box are generally in a good agreement with a realistic, global ocean circulation model. Some disagreement occurs in the abyssal ocean, where complex bottom topography is not taken into account by simple theories. Distinct regimes, where the MOC has a different sensitivity to wind or mixing, as predicted by simple theories, are also clearly shown by the global ocean model. The sensitivity of the Indo-Pacific, Atlantic, and global basins is analysed separately to validate the conceptual understanding of the upper and lower overturning cells in the theory.

  10. An operational global ocean forecast system and its applications

    NASA Astrophysics Data System (ADS)

    Mehra, A.; Tolman, H. L.; Rivin, I.; Rajan, B.; Spindler, T.; Garraffo, Z. D.; Kim, H.

    2012-12-01

    A global Real-Time Ocean Forecast System (RTOFS) was implemented in operations at NCEP/NWS/NOAA on 10/25/2011. This system is based on an eddy resolving 1/12 degree global HYCOM (HYbrid Coordinates Ocean Model) and is part of a larger national backbone capability of ocean modeling at NWS in strong partnership with US Navy. The forecast system is run once a day and produces a 6 day long forecast using the daily initialization fields produced at NAVOCEANO using NCODA (Navy Coupled Ocean Data Assimilation), a 3D multi-variate data assimilation methodology. As configured within RTOFS, HYCOM has a horizontal equatorial resolution of 0.08 degrees or ~9 km. The HYCOM grid is on a Mercator projection from 78.64 S to 47 N and north of this it employs an Arctic dipole patch where the poles are shifted over land to avoid a singularity at the North Pole. This gives a mid-latitude (polar) horizontal resolution of approximately 7 km (3.5 km). The coastline is fixed at 10 m isobath with open Bering Straits. This version employs 32 hybrid vertical coordinate surfaces with potential density referenced to 2000 m. Vertical coordinates can be isopycnals, often best for resolving deep water masses, levels of equal pressure (fixed depths), best for the well mixed unstratified upper ocean and sigma-levels (terrain-following), often the best choice in shallow water. The dynamic ocean model is coupled to a thermodynamic energy loan ice model and uses a non-slab mixed layer formulation. The forecast system is forced with 3-hourly momentum, radiation and precipitation fluxes from the operational Global Forecast System (GFS) fields. Results include global sea surface height and three dimensional fields of temperature, salinity, density and velocity fields used for validation and evaluation against available observations. Several downstream applications of this forecast system will also be discussed which include search and rescue operations at US Coast Guard, navigation safety information

  11. A Multiyear Dataset of SSM/I-Derived Global Ocean Surface Turbulent Fluxes

    NASA Technical Reports Server (NTRS)

    Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Ardizzone, Joe; Nelkin, Eric; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The surface turbulent fluxes of momentum, latent heat, and sensible heat over global oceans are essential to weather, climate and ocean problems. Evaporation is a key component of the hydrological cycle and the surface heat budget, while the wind stress is the major forcing for driving the oceanic circulation. The global air-sea fluxes of momentum, latent and sensible heat, radiation, and freshwater (precipitation-evaporation) are the forcing for driving oceanic circulation and, hence, are essential for understanding the general circulation of global oceans. The global air-sea fluxes are required for driving ocean models and validating coupled ocean-atmosphere global models. We have produced a 7.5-year (July 1987-December 1994) dataset of daily surface turbulent fluxes over the global oceans from the Special Sensor microwave/Imager (SSM/I) data. Daily turbulent fluxes were derived from daily data of SSM/I surface winds and specific humidity, National Centers for Environmental Prediction (NCEP) sea surface temperatures, and European Centre for Medium-Range Weather Forecasts (ECMWF) air-sea temperature differences, using a stability-dependent bulk scheme. The retrieved instantaneous surface air humidity (with a 25-km resolution) validated well with that of the collocated radiosonde observations over the global oceans. Furthermore, the retrieved daily wind stresses and latent heat fluxes were found to agree well with that of the in situ measurements (IMET buoy, RV Moana Wave, and RV Wecoma) in the western Pacific warm pool during the TOGA COARE intensive observing period (November 1992-February 1993). The global distributions of 1988-94 seasonal-mean turbulent fluxes will be presented. In addition, the global distributions of 1990-93 annual-means turbulent fluxes and input variables will be compared with those of UWM/COADS covering the same period. The latter is based on the COADS (comprehensive ocean-atmosphere data set) and is recognized to be one of the best

  12. Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses.

    PubMed

    Roux, Simon; Brum, Jennifer R; Dutilh, Bas E; Sunagawa, Shinichi; Duhaime, Melissa B; Loy, Alexander; Poulos, Bonnie T; Solonenko, Natalie; Lara, Elena; Poulain, Julie; Pesant, Stéphane; Kandels-Lewis, Stefanie; Dimier, Céline; Picheral, Marc; Searson, Sarah; Cruaud, Corinne; Alberti, Adriana; Duarte, Carlos M; Gasol, Josep M; Vaqué, Dolors; Bork, Peer; Acinas, Silvia G; Wincker, Patrick; Sullivan, Matthew B

    2016-09-29

    Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface- and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting 'global ocean virome' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they

  13. Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses

    NASA Astrophysics Data System (ADS)

    2016-09-01

    Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface- and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting ‘global ocean virome’ dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where

  14. Stochastic Forcing for High-Resolution Regional and Global Ocean and Atmosphere-Ocean Coupled Ensemble Forecast System

    NASA Astrophysics Data System (ADS)

    Rowley, C. D.; Hogan, P. J.; Martin, P.; Thoppil, P.; Wei, M.

    2017-12-01

    An extended range ensemble forecast system is being developed in the US Navy Earth System Prediction Capability (ESPC), and a global ocean ensemble generation capability to represent uncertainty in the ocean initial conditions has been developed. At extended forecast times, the uncertainty due to the model error overtakes the initial condition as the primary source of forecast uncertainty. Recently, stochastic parameterization or stochastic forcing techniques have been applied to represent the model error in research and operational atmospheric, ocean, and coupled ensemble forecasts. A simple stochastic forcing technique has been developed for application to US Navy high resolution regional and global ocean models, for use in ocean-only and coupled atmosphere-ocean-ice-wave ensemble forecast systems. Perturbation forcing is added to the tendency equations for state variables, with the forcing defined by random 3- or 4-dimensional fields with horizontal, vertical, and temporal correlations specified to characterize different possible kinds of error. Here, we demonstrate the stochastic forcing in regional and global ensemble forecasts with varying perturbation amplitudes and length and time scales, and assess the change in ensemble skill measured by a range of deterministic and probabilistic metrics.

  15. Coordination and Integration of Global Ocean Observing through JCOMM

    NASA Astrophysics Data System (ADS)

    Legler, D. M.; Meldrum, D. T.; Hill, K. L.; Charpentier, E.

    2016-02-01

    The primary objective of the JCOMM Observations Coordination Group (OCG) is to provide technical coordination to implement fully integrated ocean observing system across the entire marine meteorology and oceanographic community. JCOMM OCG works in partnership with the Global Ocean Observing System, , which focusses on setting observing system requirements and conducting evalutions. JCOMM OCG initially focused on major global observing networks (e.g. Argo profiling floats, moored buoys, ship based observations, sea level stations, reference sites, etc), and is now expanding its horizon in recognition of new observing needs and new technologies/networks (e.g. ocean gliders). Over the next five years the JCOMM OCG is focusing its attention on integration and coordination in four major areas: observing network implementation particularly in response to integrated ocean observing requirements; observing system monitoring and metrics; standards and best practices; and improving integrated data management and access. This presentation will describe the scope and mission of JCOMM OCG; summarize the state of the global ocean observing system; highlight recent successes and resources for the research, prediction, and assessment communities; summarize our plans for the next several years; and suggest engagement opportunities.

  16. Including eddies in global ocean models

    NASA Astrophysics Data System (ADS)

    Semtner, Albert J.; Chervin, Robert M.

    The ocean is a turbulent fluid that is driven by winds and by surface exchanges of heat and moisture. It is as important as the atmosphere in governing climate through heat distribution, but so little is known about the ocean that it remains a “final frontier” on the face of the Earth. Many ocean currents are truly global in extent, such as the Antarctic Circumpolar Current and the “conveyor belt” that connects the North Atlantic and North Pacific oceans by flows around the southern tips of Africa and South America. It has long been a dream of some oceanographers to supplement the very limited observational knowledge by reconstructing the currents of the world ocean from the first principles of physics on a computer. However, until very recently, the prospect of doing this was thwarted by the fact that fluctuating currents known as “mesoscale eddies” could not be explicitly included in the calculation.

  17. Validation of High Resolution IMERG Satellite Precipitation over the Global Oceans using OceanRAIN

    NASA Astrophysics Data System (ADS)

    Kucera, Paul; Klepp, Christian

    2017-04-01

    Precipitation is a key parameter of the essential climate variables in the Earth System that is a key variable in the global water cycle. Observations of precipitation over oceans is relatively sparse. Satellite observations over oceans is the only viable means of measuring the spatially distribution of precipitation. In an effort to improve global precipitation observations, the research community has developed a state of the art precipitation dataset as part of the NASA/JAXA Global Precipitation Measurement (GPM) program. The satellite gridded product that has been developed is called Integrated Multi-satelliE Retrievals for GPM (IMERG), which has a maximum spatial resolution of 0.1° x 0.1° and temporal 30 minute. Even with the advancements in retrievals, there is a need to quantify uncertainty of IMERG especially over oceans. To address this need, the OceanRAIN dataset has been used to create a comprehensive database to compare IMERG products. The OceanRAIN dataset was collected using an ODM-470 optical disdrometer that has been deployed on 12 research vessels worldwide with 6 long-term installations operating in all climatic regions, seasons and ocean basins. More than 5.5 million data samples have been collected on the OceanRAIN program. These data were matched to IMERG grids for the study period of 15 March 2014-31 January 2016. This evaluation produced over a 1000 matched pairs with precipitation observed at the surface. These matched pairs were used to evaluate the performance of IMERG for different latitudinal bands and precipitation regimes. The presentation will provide an overview of the study and summary of evaluation results.

  18. Vertical resolution of baroclinic modes in global ocean models

    NASA Astrophysics Data System (ADS)

    Stewart, K. D.; Hogg, A. McC.; Griffies, S. M.; Heerdegen, A. P.; Ward, M. L.; Spence, P.; England, M. H.

    2017-05-01

    Improvements in the horizontal resolution of global ocean models, motivated by the horizontal resolution requirements for specific flow features, has advanced modelling capabilities into the dynamical regime dominated by mesoscale variability. In contrast, the choice of the vertical grid remains a subjective choice, and it is not clear that efforts to improve vertical resolution adequately support their horizontal counterparts. Indeed, considering that the bulk of the vertical ocean dynamics (including convection) are parameterized, it is not immediately obvious what the vertical grid is supposed to resolve. Here, we propose that the primary purpose of the vertical grid in a hydrostatic ocean model is to resolve the vertical structure of horizontal flows, rather than to resolve vertical motion. With this principle we construct vertical grids based on their abilities to represent baroclinic modal structures commensurate with the theoretical capabilities of a given horizontal grid. This approach is designed to ensure that the vertical grids of global ocean models complement (and, importantly, to not undermine) the resolution capabilities of the horizontal grid. We find that for z-coordinate global ocean models, at least 50 well-positioned vertical levels are required to resolve the first baroclinic mode, with an additional 25 levels per subsequent mode. High-resolution ocean-sea ice simulations are used to illustrate some of the dynamical enhancements gained by improving the vertical resolution of a 1/10° global ocean model. These enhancements include substantial increases in the sea surface height variance (∼30% increase south of 40°S), the barotropic and baroclinic eddy kinetic energies (up to 200% increase on and surrounding the Antarctic continental shelf and slopes), and the overturning streamfunction in potential density space (near-tripling of the Antarctic Bottom Water cell at 65°S).

  19. Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation?

    NASA Astrophysics Data System (ADS)

    Sun, Shantong; Eisenman, Ian; Stewart, Andrew L.

    2018-03-01

    Paleoclimate proxy data suggest that the Atlantic Meridional Overturning Circulation (AMOC) was shallower at the Last Glacial Maximum (LGM) than its preindustrial (PI) depth. Previous studies have suggested that this shoaling necessarily accompanies Antarctic sea ice expansion at the LGM. Here the influence of Southern Ocean surface forcing on the AMOC depth is investigated using ocean-only simulations from a state-of-the-art climate model with surface forcing specified from the output of previous coupled PI and LGM simulations. In contrast to previous expectations, we find that applying LGM surface forcing in the Southern Ocean and PI surface forcing elsewhere causes the AMOC to shoal only about half as much as when LGM surface forcing is applied globally. We show that this occurs because diapycnal mixing renders the Southern Ocean overturning circulation more diabatic than previously assumed, which diminishes the influence of Southern Ocean surface buoyancy forcing on the depth of the AMOC.

  20. Global Earth Response to Loading by Ocean Tide Models

    NASA Technical Reports Server (NTRS)

    Estes, R. H.; Strayer, J. M.

    1979-01-01

    Mathematical and programming techniques to numerically calculate Earth response to global semidiurnal and diurnal ocean tide models were developed. Global vertical crustal deformations were evaluated for M sub 2, S sub 2, N sub 2, K sub 2, K sub 1, O sub 1, and P sub 1 ocean tide loading, while horizontal deformations were evaluated for the M sub 2 tidal load. Tidal gravity calculations were performed for M sub 2 tidal loads, and strain tensor elements were evaluated for M sub 2 loads. The M sub 2 solution used for the ocean tide included the effects of self-gravitation and crustal loading.

  1. Alexander Polonsky Global warming hiatus, ocean variability and regional climate change

    NASA Astrophysics Data System (ADS)

    Polonsky, A.

    2016-02-01

    This presentation generalizes the results concerning ocean variability, large-scale interdecadal ocean-atmosphere interaction in the Atlantic and Pacific Oceans and their impact on global and regional climate change carried out by the author and his colleagues for about 20 years. It is demonstrated once more that Atlantic Multidecadal Oscillation (AMO, which was early referred by the author as "interdecadal mode of North Atlantic Oscillation") is the crucial natural interdecadal climatic signal for the Atlantic-European and Mediterranean regions. It is characterized by amplitude which is the same order as human-induced centennial climate change and exceeds trend-like anthropogenic change at the decadal scale. Fast increasing of the global and Northern Hemisphere air temperature in the last 30 yrs of XX century (especially pronounced in the North Atlantic region and surrounded areas) is due to coincidence of human-induced positive trend and transition from the negative to the positive phase of AMO. AMO accounts for about 50% (60%) of the global (Northern Hemisphere) temperature trend in that period. Recent global warming hiatus is mostly the result of switch off the AMO phase. Typical AMO temporal scale is dictated by meridional overturning variability in the Atlantic Ocean and associated magnitude of meridional heat transport. Pacific Decadal Oscillation (PDO) is the other natural interdecadal signal which significantly impacts the global and regional climate variability. The rate of the ocean warming for different periods assessed separately for the upper mixed layer and deeper layers using data of oceanic re-analysis since 1959 confirms the principal role of the natural interdecadal oceanic modes (AMO and PDO) in observing climate change. At the same time a lack of deep-ocean long-term observing system restricts the accuracy of assessment of the heat redistribution in the World Ocean. I thanks to Pavel Sukhonos for help in the presentation preparing.

  2. Energetics of global ocean tides from Geosat altimetry

    NASA Technical Reports Server (NTRS)

    Cartwright, David E.; Ray, Richard D.

    1991-01-01

    The present paper focuses on resonance and energetics of the daily tides, especially in the southern ocean, the distribution of gravitational power input of daily and half-daily tides, and comparison with other estimates of global dissipation rates. The present global tidal maps, derived from Geosat altimetry, compare favorably with ground truth data at about the same rms level as the models of Schwiderski (1983), and are slightly better in lunar than in solar tides. Diurnal admittances clearly show Kelvin wave structure in the southern ocean and confirm the resonant mode of Platzman (1984) at 28.5 + or - 0.1 hr with an apparent Q of about 4. Driving energy is found to enter dominantly in the North Pacific for the daily tides and is strongly peaked in the tropical oceans for the half-daily tides. Global rates of working on all major tide constituents except S2 agree well with independent results from analyses of gravity through satellite tracking. Comparison at S2 is improved by allowing for the air tide in gravitational results but suggests deficiencies in all solar tide models.

  3. Decoupling of Iron and Phosphate in the Global Ocean

    NASA Technical Reports Server (NTRS)

    Parekh, Payal

    2003-01-01

    Iron is an essential micronutrient for marine phytoplankton, limiting their growth in high nutrient, low chlorophyll regions of the ocean. I use a hierarchy of ocean circulation and biogeochemistry models to understand controls on global iron distribution. I formulate a mechanistic model of iron cycling which includes scavenging onto sinking particles and complexation with an organic ligand. The iron cycle is coupled to a phosphorus cycling model. Iron's aeolian source is prescribed. In the context of a highly idealized multi-box model scheme, the model can be brought into consistency with the relatively sparse ocean observations of iron in the oceans. This biogeochemical scheme is also implemented in a coarse resolution ocean general circulation model. This model also successfully reproduces the broad regional patterns of iron and phosphorus. In particular, the high macronutrient concentrations of the Southern Ocean result from iron limitation in the model. Due to the potential ability of iron to change the efficiency of the carbon pump in the remote Southern Ocean, I study Southern Ocean surface phosphate response to increased aeolian dust flux. My box model and GCM results suggest that a global ten fold increase in dust flux can support a phosphate drawdown of 0.25-0.5 micromolar.

  4. Recent Trends in Global Ocean Chlorophyll

    NASA Technical Reports Server (NTRS)

    Gregg, Watson; Casey, Nancy

    2004-01-01

    Recent analyses of SeaWiFS data have shown that global ocean chlorophyll has increased more than 5% since 1998. The North Pacific ocean basin has increased nearly 19%. To understand the causes of these trends we have applied the newly developed NASA Ocean Biogeochemical Assimilation Model (OBAM), which is driven in mechanistic fashion by surface winds, sea surface temperature, atmospheric iron deposition, sea ice, and surface irradiance. The mode1 utilizes chlorophyll from SeaWiFS in a daily assimilation. The model has in place many of the climatic variables that can be expected to produce the changes observed in SeaWiFS data. Ths enables us to diagnose the model performance, the assimilation performance, and possible causes for the increase in chlorophyll.

  5. Seafloor 2030 - Building a Global Ocean Map through International Collaboration

    NASA Astrophysics Data System (ADS)

    Ferrini, V. L.; Wigley, R. A.; Falconer, R. K. H.; Jakobsson, M.; Allen, G.; Mayer, L. A.; Schmitt, T.; Rovere, M.; Weatherall, P.; Marks, K. M.

    2016-12-01

    With more than 85% of the ocean floor unmapped, a huge proportion of our planet remains unexplored. Creating a comprehensive map of seafloor bathymetry remains a true global challenge that can only be accomplished through collaboration and partnership between governments, industry, academia, research organizations and non-government organizations. The objective of Seafloor 2030 is to comprehensively map the global ocean floor to resolutions that enable exploration and improved understanding of ocean processes, while informing maritime policy and supporting the management of natural marine resources for a sustainable Blue Economy. Seafloor 2030 is the outcome of the Forum for Future of Ocean Floor Mapping held in Monaco in June 2016, which was held under the auspices of GEBCO and the Nippon Foundation of Japan. GEBCO is the only international organization mandated to map the global ocean floor and is guided by the International Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission of UNESCO. The task of completely mapping the ocean floor will require new global coordination to ensure that both existing data are identified and that new mapping efforts are coordinated to help efficiently "map the gaps." Fundamental to achieving Seafloor 2030 will be greater access to data, tools and technology, particularly for developing and coastal nations. This includes bathymetric post-processing and analysis software, database technology, computing infrastructure and gridding techniques as well as the latest developments in seafloor mapping methods and emerging crowd-sourced bathymetry initiatives. The key to achieving this global bathymetric map is capacity building and education - including greater coordination between scientific research and industry and the effective engagement of international organizations such as the United Nations.

  6. Performance and Quality Assessment of the Forthcoming Copernicus Marine Service Global Ocean Monitoring and Forecasting Real-Time System

    NASA Astrophysics Data System (ADS)

    Lellouche, J. M.; Le Galloudec, O.; Greiner, E.; Garric, G.; Regnier, C.; Drillet, Y.

    2016-02-01

    Mercator Ocean currently delivers in real-time daily services (weekly analyses and daily forecast) with a global 1/12° high resolution system. The model component is the NEMO platform driven at the surface by the IFS ECMWF atmospheric analyses and forecasts. Observations are assimilated by means of a reduced-order Kalman filter with a 3D multivariate modal decomposition of the forecast error. It includes an adaptive-error estimate and a localization algorithm. Along track altimeter data, satellite Sea Surface Temperature and in situ temperature and salinity vertical profiles are jointly assimilated to estimate the initial conditions for numerical ocean forecasting. A 3D-Var scheme provides a correction for the slowly-evolving large-scale biases in temperature and salinity.Since May 2015, Mercator Ocean opened the Copernicus Marine Service (CMS) and is in charge of the global ocean analyses and forecast, at eddy resolving resolution. In this context, R&D activities have been conducted at Mercator Ocean these last years in order to improve the real-time 1/12° global system for the next CMS version in 2016. The ocean/sea-ice model and the assimilation scheme benefit among others from the following improvements: large-scale and objective correction of atmospheric quantities with satellite data, new Mean Dynamic Topography taking into account the last version of GOCE geoid, new adaptive tuning of some observational errors, new Quality Control on the assimilated temperature and salinity vertical profiles based on dynamic height criteria, assimilation of satellite sea-ice concentration, new freshwater runoff from ice sheets melting …This presentation doesn't focus on the impact of each update, but rather on the overall behavior of the system integrating all updates. This assessment reports on the products quality improvements, highlighting the level of performance and the reliability of the new system.

  7. Global rates of mantle serpentinization and H2 release at oceanic transform faults

    NASA Astrophysics Data System (ADS)

    Ruepke, Lars; Hasenclever, Joerg

    2017-04-01

    The cycling of seawater through the ocean floor is the dominant mechanism of biogeochemical exchange between the solid earth and the global ocean. Crustal fluid flow appears to be typically associated with major seafloor structures, and oceanic transform faults (OTF) are one of the most striking yet poorly understood features of the global mid-ocean ridge systems. Fracture zones and transform faults have long been hypothesized to be sites of substantial biogeochemical exchange between the solid Earth and the global ocean. This is particularly interesting with regard to the ocean biome. Deep ocean ecosystems constitute 60% of it but their role in global ocean biogeochemical cycles is much overlooked. There is growing evidence that life is supported by chemosynthesis at hydrothermal vents but also in the crust, and therefore this may be a more abundant process than previously thought. In this context, the serpentine forming interaction between seawater and cold lithospheric mantle rocks is particularly interesting as it is also a mechanism of abiotic hydrogen and methane formation. Interestingly, a quantitative global assessment of mantle serpentinization at oceanic transform faults in the context of the biogeochemical exchange between the seafloor and the global ocean is still largely missing. Here we present the results of a set of 3-D thermo-mechanical model calculations that investigate mantle serpentinization at OTFs for the entire range of globally observed slip rates and fault lengths. These visco-plastic models predict the OTF thermal structure and the location of crustal-scale brittle deformation, which is a prerequisite for mantle serpentinization to occur. The results of these simulations are integrated with information on the global distribution of OTF lengths and slip rates yielding global estimates on mantle serpentinization and associated H2 release. We find that OTFs are potentially sites of intense crustal fluid flow and are in terms of H2 release

  8. A joint global carbon inversion system using both CO2 and 13CO2 atmospheric concentration data

    NASA Astrophysics Data System (ADS)

    Chen, Jing M.; Mo, Gang; Deng, Feng

    2017-03-01

    Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites (62 collocated with 13CO2 sites) for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using prior CO2 fluxes estimated with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. This joint inversion system using both13CO2 and CO2 observations is effectively a double deconvolution system with consideration of the spatial variations of isotopic discrimination and disequilibrium. Compared to the CO2-only inversion, this 13CO2 constraint on the inversion considerably reduces the total land carbon sink from 3.40 ± 0.84 to 2.53 ± 0.93 Pg C year-1 but increases the total oceanic carbon sink from 1.48 ± 0.40 to 2.36 ± 0.49 Pg C year-1. This constraint also changes the spatial distribution of the carbon sink. The largest sink increase occurs in the Amazon, while the largest source increases are in southern Africa, and Asia, where CO2 data are sparse. Through a case study, in which the spatial distribution of the annual 13CO2 discrimination rate over land is ignored by treating it as a constant at the global average of -14. 1 ‰, the spatial distribution of the inverted CO2 flux over land was found to be significantly modified (up to 15 % for some regions). The uncertainties in our disequilibrium flux estimation are 8.0 and 12.7 Pg C year-1 ‰ for land and ocean, respectively. These uncertainties induced the unpredictability of 0.47 and 0.54 Pg C year-1 in the inverted CO2 fluxes for land and ocean, respectively. Our joint inversion system is therefore

  9. Ocean plankton. Structure and function of the global ocean microbiome.

    PubMed

    Sunagawa, Shinichi; Coelho, Luis Pedro; Chaffron, Samuel; Kultima, Jens Roat; Labadie, Karine; Salazar, Guillem; Djahanschiri, Bardya; Zeller, Georg; Mende, Daniel R; Alberti, Adriana; Cornejo-Castillo, Francisco M; Costea, Paul I; Cruaud, Corinne; d'Ovidio, Francesco; Engelen, Stefan; Ferrera, Isabel; Gasol, Josep M; Guidi, Lionel; Hildebrand, Falk; Kokoszka, Florian; Lepoivre, Cyrille; Lima-Mendez, Gipsi; Poulain, Julie; Poulos, Bonnie T; Royo-Llonch, Marta; Sarmento, Hugo; Vieira-Silva, Sara; Dimier, Céline; Picheral, Marc; Searson, Sarah; Kandels-Lewis, Stefanie; Bowler, Chris; de Vargas, Colomban; Gorsky, Gabriel; Grimsley, Nigel; Hingamp, Pascal; Iudicone, Daniele; Jaillon, Olivier; Not, Fabrice; Ogata, Hiroyuki; Pesant, Stephane; Speich, Sabrina; Stemmann, Lars; Sullivan, Matthew B; Weissenbach, Jean; Wincker, Patrick; Karsenti, Eric; Raes, Jeroen; Acinas, Silvia G; Bork, Peer

    2015-05-22

    Microbes are dominant drivers of biogeochemical processes, yet drawing a global picture of functional diversity, microbial community structure, and their ecological determinants remains a grand challenge. We analyzed 7.2 terabases of metagenomic data from 243 Tara Oceans samples from 68 locations in epipelagic and mesopelagic waters across the globe to generate an ocean microbial reference gene catalog with >40 million nonredundant, mostly novel sequences from viruses, prokaryotes, and picoeukaryotes. Using 139 prokaryote-enriched samples, containing >35,000 species, we show vertical stratification with epipelagic community composition mostly driven by temperature rather than other environmental factors or geography. We identify ocean microbial core functionality and reveal that >73% of its abundance is shared with the human gut microbiome despite the physicochemical differences between these two ecosystems. Copyright © 2015, American Association for the Advancement of Science.

  10. Oceanic biogeochemical controls on global dynamics of persistent organic pollutants.

    PubMed

    Dachs, Jordi; Lohmann, Rainer; Ockenden, Wendy A; Méjanelle, Laurence; Eisenreich, Steven J; Jones, Kevin C

    2002-10-15

    Understanding and quantifying the global dynamics and sinks of persistent organic pollutants (POPs) is important to assess their environmental impact and fate. Air-surface exchange processes, where temperature plays a central role in controlling volatilization and deposition, are of key importance in controlling global POP dynamics. The present study is an assessment of the role of oceanic biogeochemical processes, notably phytoplankton uptake and vertical fluxes of particles, on the global dynamics of POPs. Field measurements of atmospheric polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and furans (PCDFs) are combined with remote sensing estimations of oceanic temperature, wind speed, and chlorophyll, to model the interactions between air-water exchange, phytoplankton uptake, and export of organic matter and POPs out of the mixed surface ocean layer. Deposition is enhanced in the mid-high latitudes and is driven by sinking marine particulate matter, rather than by a cold condensation effect. However, the relative contribution of the biological pump is a function of the physical-chemical properties of POPs. It is concluded that oceanic biogeochemical processes play a critical role in controlling the global dynamics and the ultimate sink of POPs.

  11. Global Ocean Circulation During Cretaceous Time

    NASA Astrophysics Data System (ADS)

    Haupt, B. J.; Seidov, D.

    2001-12-01

    Present--day global thermohaline ocean circulation (TOC) is usually associated with high--latitude deep-water formation due to surface cooling. In this understanding of the TOC driven by the deep--water production, the warm deep ocean during Mesozoic--Cenozoic time is a challenge. It may be questioned whether warm deep--ocean water, which is direct geologic evidence, does reflect warm polar surface--ocean regions. For the warm Cretaceous, it is difficult to maintain strong poleward heat transport in the case of reduced oceanic thermal contrasts. Usually, atmospheric feedbacks, in conjunction with the increase of atmospheric concentrations of greenhouse gases, are employed in order to explain the warm equable Cretaceous--Eocene climate. However, there is no feasible physical mechanism that could maintain warm subpolar surface oceans in both hemispheres, an assumption often used in atmospheric modeling. Our numerical experiments indicate that having a relatively cool but saltier high--latitude sea surface in at least one hemisphere is sufficient for driving a strong meridional overturning. Thus freshwater impacts in the high latitudes may be responsible for a vigorous conveyor capable of maintaining sufficient poleward oceanic heat transport needed to keep the polar oceans ice--free. These results imply that evaporation-precipitation patterns during warm climates are especially important climatic factors that can redistribute freshwater to create hemispheric asymmetry of sea surface conditions capable of generating a sufficiently strong TOC, otherwise impossible in warm climates.

  12. Measurement of global oceanic winds from Seasat-SMMR and its comparison with Seasat-SASS and ALT derived winds

    NASA Technical Reports Server (NTRS)

    Pandey, Prem C.

    1987-01-01

    The retrieval of ocean-surface wind speed from different channel combinations of Seasat SMMR measurements is demonstrated. Wind speeds derived using the best two channel subsets (10.6 H and 18.0 V) were compared with in situ data collected during the Joint Air-Sea Interaction (JASIN) experiment and an rms difference of 1.5 m/s was found. Global maps of wind speed generated with the present algorithm show that the averaged winds are arranged in well-ordered belts.

  13. The timescales of global surface-ocean connectivity.

    PubMed

    Jönsson, Bror F; Watson, James R

    2016-04-19

    Planktonic communities are shaped through a balance of local evolutionary adaptation and ecological succession driven in large part by migration. The timescales over which these processes operate are still largely unresolved. Here we use Lagrangian particle tracking and network theory to quantify the timescale over which surface currents connect different regions of the global ocean. We find that the fastest path between two patches--each randomly located anywhere in the surface ocean--is, on average, less than a decade. These results suggest that marine planktonic communities may keep pace with climate change--increasing temperatures, ocean acidification and changes in stratification over decadal timescales--through the advection of resilient types.

  14. Potential Increasing Dominance of Heterotrophy in the Global Ocean

    NASA Astrophysics Data System (ADS)

    Kvale, K.; Meissner, K. J.; Keller, D. P.

    2016-02-01

    Autotrophs are largely limited by resources in the modern ocean. However, standard metabolic theory suggests continued ocean warming could globally benefit heterotrophs, thereby reducing autotrophic nutrient limitation. The paleo record as well as modern observations offer evidence this has happened in the past and could happen again. Increasing dominance of heterotrophs would result in strong nutrient recycling in the upper ocean and high rates of net primary production (NPP), yet low carbon export to the deep ocean and sediments. We describe the transition towards such a state in the early 22nd century as a response to business-as-usual Representative Concentration Pathway forcing (RCP8.5) in an intermediate complexity Earth system model in three configurations: with and without an explicit calcifier phytoplankton class and calcite ballast model. In all models nutrient regeneration in the near surface becomes an increasingly important driver of primary production. The near-linear relationship between changes in NPP and global sea surface temperature (SST) found over the 21st century becomes exponential above a 2-4 °C global mean SST change. This transition to a more heterotrophic ocean agrees roughly with metabolic theory. Inclusion of small phytoplankton and calcifiers increase the model NPP:SST sensitivity because of their relatively higher nutrient affinity than general phytoplankton. Accounting for organic carbon "protected" from remineralization by carbonate ballast mitigates the exponential increase in NPP and provides an increasingly important pathway for deep carbon export with higher SST changes, despite simultaneous increasing carbonate dissolution rates due to ocean acidification.

  15. Towards the impact of eddies on the response of the global ocean circulation to Southern Ocean gateway opening

    NASA Astrophysics Data System (ADS)

    Viebahn, Jan; von der Heydt, Anna S.; Dijkstra, Henk A.

    2014-05-01

    During the past 65 Million (Ma) years, Earth's climate has undergone a major change from warm 'greenhouse' to colder 'icehouse' conditions with extensive ice sheets in the polar regions of both hemispheres. The Eocene-Oligocene (~34 Ma) and Oligocene-Miocene (~23 Ma) boundaries reflect major transitions in Cenozoic global climate change. Proposed mechanisms of these transitions include reorganization of ocean circulation due to critical gateway opening/deepening, changes in atmospheric CO2-concentration, and feedback mechanisms related to land-ice formation. A long-standing hypothesis is that the formation of the Antarctic Circumpolar Current due to opening/deepening of Southern Ocean gateways led to glaciation of the Antarctic continent. However, while this hypothesis remains controversial, its assessment via coupled climate model simulations depends crucially on the spatial resolution in the ocean component. More precisely, only high-resolution modeling of the turbulent ocean circulation is capable of adequately describing reorganizations in the ocean flow field and related changes in turbulent heat transport. In this study, for the first time results of a high-resolution (0.1° horizontally) realistic global ocean model simulation with a closed Drake Passage are presented. Changes in global ocean temperatures, heat transport, and ocean circulation (e.g., Meridional Overturning Circulation and Antarctic Coastal Current) are established by comparison with an open Drake Passage high-resolution reference simulation. Finally, corresponding low-resolution simulations are also analyzed. The results highlight the essential impact of the ocean eddy field in palaeoclimatic change.

  16. Ocean deoxygenation, the global phosphorus cycle and the possibility of human-caused large-scale ocean anoxia

    NASA Astrophysics Data System (ADS)

    Watson, Andrew J.; Lenton, Timothy M.; Mills, Benjamin J. W.

    2017-08-01

    The major biogeochemical cycles that keep the present-day Earth habitable are linked by a network of feedbacks, which has led to a broadly stable chemical composition of the oceans and atmosphere over hundreds of millions of years. This includes the processes that control both the atmospheric and oceanic concentrations of oxygen. However, one notable exception to the generally well-behaved dynamics of this system is the propensity for episodes of ocean anoxia to occur and to persist for 105-106 years, these ocean anoxic events (OAEs) being particularly associated with warm `greenhouse' climates. A powerful mechanism responsible for past OAEs was an increase in phosphorus supply to the oceans, leading to higher ocean productivity and oxygen demand in subsurface water. This can be amplified by positive feedbacks on the nutrient content of the ocean, with low oxygen promoting further release of phosphorus from ocean sediments, leading to a potentially self-sustaining condition of deoxygenation. We use a simple model for phosphorus in the ocean to explore this feedback, and to evaluate the potential for humans to bring on global-scale anoxia by enhancing P supply to the oceans. While this is not an immediate global change concern, it is a future possibility on millennial and longer time scales, when considering both phosphate rock mining and increased chemical weathering due to climate change. Ocean deoxygenation, once begun, may be self-sustaining and eventually could result in long-lasting and unpleasant consequences for the Earth's biosphere. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

  17. Tsunami Speed Variations in Density-stratified Compressible Global Oceans

    NASA Astrophysics Data System (ADS)

    Watada, S.

    2013-12-01

    Recent tsunami observations in the deep ocean have accumulated unequivocal evidence that tsunami traveltime delays compared with the linear long-wave tsunami simulations occur during tsunami propagation in the deep ocean. The delay is up to 2% of the tsunami traveltime. Watada et al. [2013] investigated the cause of the delay using the normal mode theory of tsunamis and attributed the delay to the compressibility of seawater, the elasticity of the solid earth, and the gravitational potential change associated with mass motion during the passage of tsunamis. Tsunami speed variations in the deep ocean caused by seawater density stratification is investigated using a newly developed propagator matrix method that is applicable to seawater with depth-variable sound speeds and density gradients. For a 4-km deep ocean, the total tsunami speed reduction is 0.45% compared with incompressible homogeneous seawater; two thirds of the reduction is due to elastic energy stored in the water and one third is due to water density stratification mainly by hydrostatic compression. Tsunami speeds are computed for global ocean density and sound speed profiles and characteristic structures are discussed. Tsunami speed reductions are proportional to ocean depth with small variations, except for in warm Mediterranean seas. The impacts of seawater compressibility and the elasticity effect of the solid earth on tsunami traveltime should be included for precise modeling of trans-oceanic tsunamis. Data locations where a vertical ocean profile deeper than 2500 m is available in World Ocean Atlas 2009. The dark gray area indicates the Pacific Ocean defined in WOA09. a) Tsunami speed variations. Red, gray and black bars represent global, Pacific, and Mediterranean Sea, respectively. b) Regression lines of the tsunami velocity reduction for all oceans. c)Vertical ocean profiles at grid points indicated by the stars in Figure 1.

  18. The Global Ocean Forecast System, Version 3.0 (GOFS 3.0) or the Hybrid Coordinate Ocean Model (HYCOM)

    DTIC Science & Technology

    2012-04-10

    System (GOFS) V3.0 – 1/12 HYCOM/NCODA: Phase I‖ by Metzger et al., dated 26 November 2008 (NRL/MR/7320—08- 9148). The HYbrid Coordinate Ocean...C. Lozano, H.L. Tolman, A. Srinivasan, S. Hankin, P. Cornillon, R. Weisberg, A. Barth, R. He, F. Werner, and J. Wilkin , 2009. U.S. GODAE: Global...E.J. Metzger, J.F. Shriver, O.M. Smedstad, A.J. Wallcraft, and C.N. Barron, 2008 : Eddy-resolving global ocean prediction. In "Eddy-Resolving Ocean

  19. Eddy Resolving Global Ocean Prediction including Tides

    DTIC Science & Technology

    2013-09-30

    atlantic meridional overturning circulation in the subpolar North Atlantic . Journal of Geophysical Research vol 118, doi:10.1002/jgrc,20065. [published, refereed] ...global ocean circulation model was examined using results from years 2005-2009 of a seven and a half year 1/12.5° global simulation that resolves...internal tides, along with barotropic tides and the eddying general circulation . We examined tidal amplitudes computed using 18 183-day windows that

  20. Global ocean conveyor lowers extinction risk in the deep sea

    USGS Publications Warehouse

    Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Weinberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Melanie; Morrison, Cheryl L.; Correa, Matthias Lopez; Rogers, Alex D.; Ruckelshausen, Mario; Roberts, J. Murray

    2014-01-01

    General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth׳s largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium–thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

  1. Global ocean conveyor lowers extinction risk in the deep sea

    NASA Astrophysics Data System (ADS)

    Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Wienberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Mélanie; Morrison, Cheryl L.; López Correa, Matthias; Rogers, Alex D.; Ruckelshausen, Mario; Roberts, J. Murray

    2014-06-01

    General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth's largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium-thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

  2. Combined constraints on global ocean primary production using observations and models

    NASA Astrophysics Data System (ADS)

    Buitenhuis, Erik T.; Hashioka, Taketo; Quéré, Corinne Le

    2013-09-01

    production is at the base of the marine food web and plays a central role for global biogeochemical cycles. Yet global ocean primary production is known to only a factor of 2, with previous estimates ranging from 38 to 65 Pg C yr-1 and no formal uncertainty analysis. Here, we present an improved global ocean biogeochemistry model that includes a mechanistic representation of photosynthesis and a new observational database of net primary production (NPP) in the ocean. We combine the model and observations to constrain particulate NPP in the ocean with statistical metrics. The PlankTOM5.3 model includes a new photosynthesis formulation with a dynamic representation of iron-light colimitation, which leads to a considerable improvement of the interannual variability of surface chlorophyll. The database includes a consistent set of 50,050 measurements of 14C primary production. The model best reproduces observations when global NPP is 58 ± 7 Pg C yr-1, with a most probable value of 56 Pg C yr-1. The most probable value is robust to the model used. The uncertainty represents 95% confidence intervals. It considers all random errors in the model and observations, but not potential biases in the observations. We show that tropical regions (23°S-23°N) contribute half of the global NPP, while NPPs in the Northern and Southern Hemispheres are approximately equal in spite of the larger ocean area in the South.

  3. Global negative emissions capacity of ocean macronutrient fertilization

    NASA Astrophysics Data System (ADS)

    Harrison, Daniel P.

    2017-03-01

    In order to meet the goal of limiting global average temperature increase to less than 2 °C, it is increasingly apparent that negative emissions technologies of up to 10 Pg C yr-1 will be needed before the end of the century. Recent research indicates that fertilization of the ocean with the macronutrients nitrogen and phosphorus where they limit primary production, may have sequestration advantages over fertilizing iron limited regions. Utilizing global datasets of oceanographic field measurements, and output from a high resolution global circulation model, the current study provides the first comprehensive assessment of the global potential for carbon sequestration from ocean macronutrient fertilization (OMF). Sufficient excess phosphate exists outside the iron limited surface ocean to support once-off sequestration of up to 3.6 Pg C by fertilization with nitrogen. Ongoing maximum capacity of nitrogen only fertilization is estimated at 0.7 ± 0.4 Pg C yr-1. Sequestration capacity is expected to decrease from the upper toward the lower bound over time under continued intense fertilization. If N and P were used in combination the capacity is ultimately limited by societies willingness to utilize phosphate resources. Doubling current phosphate production would allow an additional 0.9 Pg C yr-1 and consume 0.07% yr-1 of known global resources. Therefore offsetting up to around 15% (1.5 Pg C yr-1) of annual global CO2 emissions is assessed as being technically plausible. Environmental risks which to date have received little quantitative evaluation, could also limit the scale of implementation. These results reinforce the need to consider a multi-faceted approach to greenhouse gasses, including a reduction in emissions coupled with further research into negative emissions technologies.

  4. Ocean deoxygenation, the global phosphorus cycle and the possibility of human-caused large-scale ocean anoxia.

    PubMed

    Watson, Andrew J; Lenton, Timothy M; Mills, Benjamin J W

    2017-09-13

    The major biogeochemical cycles that keep the present-day Earth habitable are linked by a network of feedbacks, which has led to a broadly stable chemical composition of the oceans and atmosphere over hundreds of millions of years. This includes the processes that control both the atmospheric and oceanic concentrations of oxygen. However, one notable exception to the generally well-behaved dynamics of this system is the propensity for episodes of ocean anoxia to occur and to persist for 10 5 -10 6 years, these ocean anoxic events (OAEs) being particularly associated with warm 'greenhouse' climates. A powerful mechanism responsible for past OAEs was an increase in phosphorus supply to the oceans, leading to higher ocean productivity and oxygen demand in subsurface water. This can be amplified by positive feedbacks on the nutrient content of the ocean, with low oxygen promoting further release of phosphorus from ocean sediments, leading to a potentially self-sustaining condition of deoxygenation. We use a simple model for phosphorus in the ocean to explore this feedback, and to evaluate the potential for humans to bring on global-scale anoxia by enhancing P supply to the oceans. While this is not an immediate global change concern, it is a future possibility on millennial and longer time scales, when considering both phosphate rock mining and increased chemical weathering due to climate change. Ocean deoxygenation, once begun, may be self-sustaining and eventually could result in long-lasting and unpleasant consequences for the Earth's biosphere.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Authors.

  5. Ocean deoxygenation, the global phosphorus cycle and the possibility of human-caused large-scale ocean anoxia

    PubMed Central

    Lenton, Timothy M.; Mills, Benjamin J. W.

    2017-01-01

    The major biogeochemical cycles that keep the present-day Earth habitable are linked by a network of feedbacks, which has led to a broadly stable chemical composition of the oceans and atmosphere over hundreds of millions of years. This includes the processes that control both the atmospheric and oceanic concentrations of oxygen. However, one notable exception to the generally well-behaved dynamics of this system is the propensity for episodes of ocean anoxia to occur and to persist for 105–106 years, these ocean anoxic events (OAEs) being particularly associated with warm ‘greenhouse’ climates. A powerful mechanism responsible for past OAEs was an increase in phosphorus supply to the oceans, leading to higher ocean productivity and oxygen demand in subsurface water. This can be amplified by positive feedbacks on the nutrient content of the ocean, with low oxygen promoting further release of phosphorus from ocean sediments, leading to a potentially self-sustaining condition of deoxygenation. We use a simple model for phosphorus in the ocean to explore this feedback, and to evaluate the potential for humans to bring on global-scale anoxia by enhancing P supply to the oceans. While this is not an immediate global change concern, it is a future possibility on millennial and longer time scales, when considering both phosphate rock mining and increased chemical weathering due to climate change. Ocean deoxygenation, once begun, may be self-sustaining and eventually could result in long-lasting and unpleasant consequences for the Earth's biosphere. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’. PMID:28784709

  6. Coccolithophorid blooms in the global ocean

    NASA Technical Reports Server (NTRS)

    Brown, Christopher W.; Yoder, James A.

    1994-01-01

    The global distribution pattern of coccolithophrid blooms was mapped in order to ascertain the prevalence of these blooms in the world's oceans and to estimate their worldwide production of CaCO3 and dimethyl sulfide (DMS). Mapping was accomplished by classifying pixels of 5-day global composites of coastal zone color scanner imagery into bloom and nonbloom classes using a supervised, multispectral classification scheme. Surface waters with the spectral signature of coccolithophorid blooms annually covered an average of 1.4 x 10(exp 6) sq km in the world oceans from 1979 to 1985, with the subpolar latitudes accounting for 71% of this surface area. Classified blooms were most extensive in the Subartic North Atlantic. Large expanses of the bloom signal were also detected in the North Pacific, on the Argentine shelf and slope, and in numerous lower latitude marginal seas and shelf regions. The greatest spatial extent of classified blooms in subpolar oceanic regions occurred in the months from summer to early autumn, while those in lower latitude marginal seas occurred in midwinter to early spring. Though the classification scheme was effcient in separating bloom and nonbloom classes during test simulations, and biogeographical literature generally confirms the resulting distribution pattern of blooms in the subpolar regions, the cause of the bloom signal is equivocal in some geographic areas, particularly on shelf regions at lower latitudes. Standing stock estimates suggest that the presumed Emiliania huxleyi blooms act as a significant source of calcite carbon and DMS sulfur on a regional scale. On a global scale, however, the satellite-detected coccolithophorid blooms are estimated to play only a minor role in the annual production of these two compounds and their flux from the surface mixed layer.

  7. Global-Local Finite Element Analysis of Bonded Single-Lap Joints

    NASA Technical Reports Server (NTRS)

    Kilic, Bahattin; Madenci, Erdogan; Ambur, Damodar R.

    2004-01-01

    Adhesively bonded lap joints involve dissimilar material junctions and sharp changes in geometry, possibly leading to premature failure. Although the finite element method is well suited to model the bonded lap joints, traditional finite elements are incapable of correctly resolving the stress state at junctions of dissimilar materials because of the unbounded nature of the stresses. In order to facilitate the use of bonded lap joints in future structures, this study presents a finite element technique utilizing a global (special) element coupled with traditional elements. The global element includes the singular behavior at the junction of dissimilar materials with or without traction-free surfaces.

  8. The role stratification on Indian ocean mixing under global warming

    NASA Astrophysics Data System (ADS)

    Praveen, V.; Valsala, V.; Ravindran, A. M.

    2017-12-01

    The impact of changes in Indian ocean stratification on mixing under global warming is examined. Previous studies on global warming and associated weakening of winds reported to increase the stratification of the world ocean leading to a reduction in mixing, increased acidity, reduced oxygen and there by a reduction in productivity. However this processes is not uniform and are also modulated by changes in wind pattern of the future. Our study evaluate the role of stratification and surface fluxes on mixing focusing northern Indian ocean. A dynamical downscaling study using Regional ocean Modelling system (ROMS) forced with stratification and surface fluxes from selected CMIP5 models are presented. Results from an extensive set of historical and Representative Concentration Pathways 8.5 (rcp8.5) scenario simulations are used to quantify the distinctive role of stratification on mixing.

  9. Mapping Global Ocean Surface Albedo from Satellite Observations: Models, Algorithms, and Datasets

    NASA Astrophysics Data System (ADS)

    Li, X.; Fan, X.; Yan, H.; Li, A.; Wang, M.; Qu, Y.

    2018-04-01

    Ocean surface albedo (OSA) is one of the important parameters in surface radiation budget (SRB). It is usually considered as a controlling factor of the heat exchange among the atmosphere and ocean. The temporal and spatial dynamics of OSA determine the energy absorption of upper level ocean water, and have influences on the oceanic currents, atmospheric circulations, and transportation of material and energy of hydrosphere. Therefore, various parameterizations and models have been developed for describing the dynamics of OSA. However, it has been demonstrated that the currently available OSA datasets cannot full fill the requirement of global climate change studies. In this study, we present a literature review on mapping global OSA from satellite observations. The models (parameterizations, the coupled ocean-atmosphere radiative transfer (COART), and the three component ocean water albedo (TCOWA)), algorithms (the estimation method based on reanalysis data, and the direct-estimation algorithm), and datasets (the cloud, albedo and radiation (CLARA) surface albedo product, dataset derived by the TCOWA model, and the global land surface satellite (GLASS) phase-2 surface broadband albedo product) of OSA have been discussed, separately.

  10. Achieving Global Ocean Color Climate Data Records

    NASA Technical Reports Server (NTRS)

    Franz, Bryan

    2010-01-01

    Ocean color, or the spectral distribution of visible light upwelling from beneath the ocean surface, carries information on the composition and concentration of biological constituents within the water column. The CZCS mission in 1978 demonstrated that quantitative ocean color measurements could be. made from spaceborne sensors, given sufficient corrections for atmospheric effects and a rigorous calibration and validation program. The launch of SeaWiFS in 1997 represents the beginning of NASA's ongoing efforts to develop a continuous ocean color data record with sufficient coverage and fidelity for global change research. Achievements in establishing and maintaining the consistency of the time-series through multiple missions and varying instrument designs will be highlighted in this talk, including measurements from NASA'S MODIS instruments currently flying on the Terra and Aqua platforms, as well as the MERIS sensor flown by ESA and the OCM-2 sensor recently launched by ISRO.

  11. Seven-Year SSM/I-Derived Global Ocean Surface Turbulent Fluxes

    NASA Technical Reports Server (NTRS)

    Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Ardizzone, Joe

    2000-01-01

    A 7.5-year (July 1987-December 1994) dataset of daily surface specific humidity and turbulent fluxes (momentum, latent heat, and sensible heat) over global oceans has been retrieved from the Special Sensor Microwave/Imager (SSM/I) data and other data. It has a spatial resolution of 2.0 deg.x 2.5 deg. latitude-longitude. The retrieved surface specific humidity is generally accurate over global oceans as validated against the collocated radiosonde observations. The retrieved daily wind stresses and latent heat fluxes show useful accuracy as verified by those measured by the RV Moana Wave and IMET buoy in the western equatorial Pacific. The derived turbulent fluxes and input variables are also found to agree generally with the global distributions of annual-and seasonal-means of those based on 4-year (1990-93) comprehensive ocean-atmosphere data set (COADS) with adjustment in wind speeds and other climatological studies. The COADS has collected the most complete surface marine observations, mainly from merchant ships. However, ship measurements generally have poor accuracy, and variable spatial coverages. Significant differences between the retrieved and COADS-based are found in some areas of the tropical and southern extratropical oceans, reflecting the paucity of ship observations outside the northern extratropical oceans. Averaged over the global oceans, the retrieved wind stress is smaller but the latent heat flux is larger than those based on COADS. The former is suggested to be mainly due to overestimation of the adjusted ship-estimated wind speeds (depending on sea states), while the latter is suggested to be mainly due to overestimation of ship-measured dew point temperatures. The study suggests that the SSM/I-derived turbulent fluxes can be used for climate studies and coupled model validations.

  12. Marine defaunation: animal loss in the global ocean.

    PubMed

    McCauley, Douglas J; Pinsky, Malin L; Palumbi, Stephen R; Estes, James A; Joyce, Francis H; Warner, Robert R

    2015-01-16

    Marine defaunation, or human-caused animal loss in the oceans, emerged forcefully only hundreds of years ago, whereas terrestrial defaunation has been occurring far longer. Though humans have caused few global marine extinctions, we have profoundly affected marine wildlife, altering the functioning and provisioning of services in every ocean. Current ocean trends, coupled with terrestrial defaunation lessons, suggest that marine defaunation rates will rapidly intensify as human use of the oceans industrializes. Though protected areas are a powerful tool to harness ocean productivity, especially when designed with future climate in mind, additional management strategies will be required. Overall, habitat degradation is likely to intensify as a major driver of marine wildlife loss. Proactive intervention can avert a marine defaunation disaster of the magnitude observed on land. Copyright © 2015, American Association for the Advancement of Science.

  13. A Coupled Ocean General Circulation, Biogeochemical, and Radiative Model of the Global Oceans: Seasonal Distributions of Ocean Chlorophyll and Nutrients

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Busalacchi, Antonio (Technical Monitor)

    2000-01-01

    A coupled ocean general circulation, biogeochemical, and radiative model was constructed to evaluate and understand the nature of seasonal variability of chlorophyll and nutrients in the global oceans. Biogeochemical processes in the model are determined from the influences of circulation and turbulence dynamics, irradiance availability. and the interactions among three functional phytoplankton groups (diatoms. chlorophytes, and picoplankton) and three nutrients (nitrate, ammonium, and silicate). Basin scale (greater than 1000 km) model chlorophyll results are in overall agreement with CZCS pigments in many global regions. Seasonal variability observed in the CZCS is also represented in the model. Synoptic scale (100-1000 km) comparisons of imagery are generally in conformance although occasional departures are apparent. Model nitrate distributions agree with in situ data, including seasonal dynamics, except for the equatorial Atlantic. The overall agreement of the model with satellite and in situ data sources indicates that the model dynamics offer a reasonably realistic simulation of phytoplankton and nutrient dynamics on synoptic scales. This is especially true given that initial conditions are homogenous chlorophyll fields. The success of the model in producing a reasonable representation of chlorophyll and nutrient distributions and seasonal variability in the global oceans is attributed to the application of a generalized, processes-driven approach as opposed to regional parameterization and the existence of multiple phytoplankton groups with different physiological and physical properties. These factors enable the model to simultaneously represent many aspects of the great diversity of physical, biological, chemical, and radiative environments encountered in the global oceans.

  14. Sources of global warming of the upper ocean on decadal period scales

    USGS Publications Warehouse

    White, Warren B.; Dettinger, M.D.; Cayan, D.R.

    2003-01-01

    Recent studies find global climate variability in the upper ocean and lower atmosphere during the twentieth century dominated by quasi-biennial, interannual, quasi-decadal and interdecadal signals. The quasi-decadal signal in upper ocean temperature undergoes global warming/cooling of ???0.1??C, similar to that occuring with the interannual signal (i.e., El Nin??o-Southern Oscillation), both signals dominated by global warming/cooling in the tropics. From the National Centers for Environmental Prediction troposphere reanalysis and Scripps Institution of Oceanography upper ocean temperature reanalysis we examine the quasi-decadal global tropical diabetic heat storage (DHS) budget from 1975 to 2000. We find the anomalous DHS warming tendency of 0.3-0.9 W m-2 driven principally by a downward global tropical latent-plus-sensible heat flux anomaly into the ocean, overwhelming the tendency by weaker upward shortwave-minus-longwave heat flux anomaly to drive an anomalous DHS cooling tendency. During the peak quasi-decadal warming the estimated dissipation of DHS anomaly of 0.2-0.5 W m-2 into the deep ocean and a similar loss to the overlying atmosphere through air-sea heat flux anomaly are balanced by a decrease in the net poleward Ekman heat advection out of the tropics of 0.4-0.7 W m-2. This scenario is nearly the opposite of that accounting for global tropical warming during the El Nin??o. These diagnostics confirm that even though the global quasi-decadal signal is phase-locked to the 11-year signal in the Sun's surface radiative forcing of ???0.1 W m-2, the anomalous global tropical DHS tendency cannot be driven by it directly.

  15. CLIVAR-GSOP/GODAE Ocean Synthesis Inter-Comparison of Global Air-Sea Fluxes From Ocean and Coupled Reanalyses

    NASA Astrophysics Data System (ADS)

    Valdivieso, Maria

    2014-05-01

    The GODAE OceanView and CLIVAR-GSOP ocean synthesis program has been assessing the degree of consistency between global air-sea flux data sets obtained from ocean or coupled reanalyses (Valdivieso et al., 2014). So far, fifteen global air-sea heat flux products obtained from ocean or coupled reanalyses have been examined: seven are from low-resolution ocean reanalyses (BOM PEODAS, ECMWF ORAS4, JMA/MRI MOVEG2, JMA/MRI MOVECORE, Hamburg Univ. GECCO2, JPL ECCOv4, and NCEP GODAS), five are from eddy-permitting ocean reanalyses developed as part of the EU GMES MyOcean program (Mercator GLORYS2v1, Reading Univ. UR025.3, UR025.4, UKMO GloSea5, and CMCC C-GLORS), and the remaining three are couple reanalyses based on coupled climate models (JMA/MRI MOVE-C, GFDL ECDA and NCEP CFSR). The global heat closure in the products over the period 1993-2009 spanned by all data sets is presented in comparison with observational and atmospheric reanalysis estimates. Then, global maps of ensemble spread in the seasonal cycle, and of the Signal to Noise Ratio of interannual flux variability over the 17-yr common period are shown to illustrate the consistency between the products. We have also studied regional variability in the products, particularly at the OceanSITES project locations (such as, for instance, the TAO/TRITON and PIRATA arrays in the Tropical Pacific and Atlantic, respectively). Comparisons are being made with other products such as OAFlux latent and sensible heat fluxes (Yu et al., 2008) combined with ISCCP satellite-based radiation (Zhang et al., 2004), the ship-based NOC2.0 product (Berry and Kent, 2009), the Large and Yeager (2009) hybrid flux dataset CORE.2, and two atmospheric reanalysis products, the ECMWF ERA-Interim reanalysis (referred to as ERAi, Dee et al., 2011) and the NCEP/DOE reanalysis R2 (referred to as NCEP-R2, Kanamitsu et al., 2002). Preliminary comparisons with the observational flux products from OceanSITES are also underway. References Berry, D

  16. Equatorial Wave Line, Pacific Ocean

    NASA Image and Video Library

    1993-01-19

    STS054-95-042 (13-19 Jan 1993) --- The Equatorial Pacific Ocean is represented in this 70mm view. The international oceanographic research community is presently conducting a program called Joint Global Ocean Flux Study (JGOFS) to study the global ocean carbon budget. A considerable amount of effort within this program is presently being focused on the Equatorial Pacific Ocean because of the high annual average biological productivity. The high productivity is the result of nearly constant easterly winds causing cool, nutrient-rich water to well up at the equator. In this view of the sun glint pattern was photographed at about 2 degrees north latitude, 103 degrees west longitude, as the Space Shuttle passed over the Equatorial Pacific. The long narrow line is the equatorial front, which defines the boundary between warm surface equatorial water and cool, recently upwelled water. Such features are of interest to the JGOFS researchers and it is anticipated that photographs such as this will benefit the JGOFS program.

  17. Global Ocean Integrals and Means, with Trend Implications.

    PubMed

    Wunsch, Carl

    2016-01-01

    Understanding the ocean requires determining and explaining global integrals and equivalent average values of temperature (heat), salinity (freshwater and salt content), sea level, energy, and other properties. Attempts to determine means, integrals, and climatologies have been hindered by thinly and poorly distributed historical observations in a system in which both signals and background noise are spatially very inhomogeneous, leading to potentially large temporal bias errors that must be corrected at the 1% level or better. With the exception of the upper ocean in the current altimetric-Argo era, no clear documentation exists on the best methods for estimating means and their changes for quantities such as heat and freshwater at the levels required for anthropogenic signals. Underestimates of trends are as likely as overestimates; for example, recent inferences that multidecadal oceanic heat uptake has been greatly underestimated are plausible. For new or augmented observing systems, calculating the accuracies and precisions of global, multidecadal sampling densities for the full water column is necessary to avoid the irrecoverable loss of scientifically essential information.

  18. Spacebased Observation of Water Balance Over Global Oceans

    NASA Astrophysics Data System (ADS)

    Liu, W.; Xie, X.

    2008-12-01

    We demonstrated that ocean surface fresh water flux less the water discharge into the ocean from river and ice melt balances the mass loss in the ocean both in magnitude and in the phase of annual variation. The surface water flux was computed from the divergence of the water transport integrated over the depth of the atmosphere. The atmospheric water transport is estimated from the precipitable water measured by Special Sensor Microwave Imager, the surface wind vector by QuikSCAT, and the NOAA cloud drift wind through a statistical model. The transport has been extensively validated using global radiosonde and data and operational numerical weather prediction results. Its divergence has been shown to agree with the difference between evaporation estimated from the Advanced Microwave Scanning Radiometer data and the precipitation measured by Tropical Rain Measuring Mission over the global tropical and subtropical oceans both in magnitude and geographical distribution for temporal scales ranging from intraseasonal to interannual. The water loss rate in the ocean is estimated by two methods, one is from Gravity Recovery and Climate Experiment and the other is by subtracting the climatological steric change from the sea level change measured by radar altimeter on Jason. Only climatological river discharge and ice melt from in situ measurements are available and the lack of temporal variation may contribute to discrepancies in the balance. We have successfully used the spacebased surface fluxes to estimate to climatological mean heat transport in the Atlantic ocean and is attempting to estimate the meridional fresh water (or salt) transport from the surface flux. The approximate closure of the water balance gives a powerful indirect validation of the spacebased products.

  19. Variability in global ocean phytoplankton distribution over 1979-2007

    NASA Astrophysics Data System (ADS)

    Masotti, I.; Alvain, S.; Moulin, C.; Antoine, D.

    2009-04-01

    Recently, reanalysis of long-term ocean color data (CZCS and SeaWiFS; Antoine et al., 2005) has shown that world ocean average phytoplankton chlorophyll levels show an increase of 20% over the last two decades. It is however unknown whether this increase is associated with a change in the distribution of phytoplankton groups or if it simply corresponds to an increase of the productivity. Within the framework of the GLOBPHY project, the distribution of the phytoplankton groups was monitored by applying the PHYSAT method (Alvain et al., 2005) to the historical ocean color data series from CZCS, OCTS and SeaWiFS sensors. The PHYSAT algorithm allows identification of several phytoplankton, like nanoeucaryotes, prochlorococcus, synechococcus and diatoms. Because both sensors (OCTS-SeaWiFS) are very similar, OCTS data were processed with the standard PHYSAT algorithm to cover the 1996-1997 period during which a large El Niño event occurred, just before the SeaWiFS era. Our analysis of this dataset (1996-2006) evidences a strong variability in the distribution of phytoplankton groups at both regional and global scales. In the equatorial region (0°-5°S), a three-fold increase of nanoeucaryotes frequency was detected in opposition to a two-fold decrease of synechococcus during the early stages of El Niño conditions (May-June 1997, OCTS). The impact of this El Niño is however not confined to the Equatorial Pacific and has affected the global ocean. The processing of CZCS data with PHYSAT has required several adaptations of this algorithm due to the lower performances and the reduced number of spectral bands of the sensor. Despites higher uncertainties, the phytoplankton groups distribution obtained with CZCS is globally consistent with that of SeaWiFS. A comparison of variability in global phytoplankton distribution between 1979-1982 (CZCS) and 1999-2002 (SeaWiFS) suggests an increase in nanoeucaryotes at high latitudes (>40°) and in the equatorial region (10°S-10

  20. Global declines in oceanic nitrification rates as a consequence of ocean acidification.

    PubMed

    Beman, J Michael; Chow, Cheryl-Emiliane; King, Andrew L; Feng, Yuanyuan; Fuhrman, Jed A; Andersson, Andreas; Bates, Nicholas R; Popp, Brian N; Hutchins, David A

    2011-01-04

    Ocean acidification produced by dissolution of anthropogenic carbon dioxide (CO(2)) emissions in seawater has profound consequences for marine ecology and biogeochemistry. The oceans have absorbed one-third of CO(2) emissions over the past two centuries, altering ocean chemistry, reducing seawater pH, and affecting marine animals and phytoplankton in multiple ways. Microbially mediated ocean biogeochemical processes will be pivotal in determining how the earth system responds to global environmental change; however, how they may be altered by ocean acidification is largely unknown. We show here that microbial nitrification rates decreased in every instance when pH was experimentally reduced (by 0.05-0.14) at multiple locations in the Atlantic and Pacific Oceans. Nitrification is a central process in the nitrogen cycle that produces both the greenhouse gas nitrous oxide and oxidized forms of nitrogen used by phytoplankton and other microorganisms in the sea; at the Bermuda Atlantic Time Series and Hawaii Ocean Time-series sites, experimental acidification decreased ammonia oxidation rates by 38% and 36%. Ammonia oxidation rates were also strongly and inversely correlated with pH along a gradient produced in the oligotrophic Sargasso Sea (r(2) = 0.87, P < 0.05). Across all experiments, rates declined by 8-38% in low pH treatments, and the greatest absolute decrease occurred where rates were highest off the California coast. Collectively our results suggest that ocean acidification could reduce nitrification rates by 3-44% within the next few decades, affecting oceanic nitrous oxide production, reducing supplies of oxidized nitrogen in the upper layers of the ocean, and fundamentally altering nitrogen cycling in the sea.

  1. Global declines in oceanic nitrification rates as a consequence of ocean acidification

    PubMed Central

    Beman, J. Michael; Chow, Cheryl-Emiliane; King, Andrew L.; Feng, Yuanyuan; Fuhrman, Jed A.; Andersson, Andreas; Bates, Nicholas R.; Popp, Brian N.; Hutchins, David A.

    2011-01-01

    Ocean acidification produced by dissolution of anthropogenic carbon dioxide (CO2) emissions in seawater has profound consequences for marine ecology and biogeochemistry. The oceans have absorbed one-third of CO2 emissions over the past two centuries, altering ocean chemistry, reducing seawater pH, and affecting marine animals and phytoplankton in multiple ways. Microbially mediated ocean biogeochemical processes will be pivotal in determining how the earth system responds to global environmental change; however, how they may be altered by ocean acidification is largely unknown. We show here that microbial nitrification rates decreased in every instance when pH was experimentally reduced (by 0.05–0.14) at multiple locations in the Atlantic and Pacific Oceans. Nitrification is a central process in the nitrogen cycle that produces both the greenhouse gas nitrous oxide and oxidized forms of nitrogen used by phytoplankton and other microorganisms in the sea; at the Bermuda Atlantic Time Series and Hawaii Ocean Time-series sites, experimental acidification decreased ammonia oxidation rates by 38% and 36%. Ammonia oxidation rates were also strongly and inversely correlated with pH along a gradient produced in the oligotrophic Sargasso Sea (r2 = 0.87, P < 0.05). Across all experiments, rates declined by 8–38% in low pH treatments, and the greatest absolute decrease occurred where rates were highest off the California coast. Collectively our results suggest that ocean acidification could reduce nitrification rates by 3–44% within the next few decades, affecting oceanic nitrous oxide production, reducing supplies of oxidized nitrogen in the upper layers of the ocean, and fundamentally altering nitrogen cycling in the sea. PMID:21173255

  2. Does Ocean Color Data Assimilation Improve Estimates of Global Ocean Inorganic Carbon?

    NASA Technical Reports Server (NTRS)

    Gregg, Watson

    2012-01-01

    Ocean color data assimilation has been shown to dramatically improve chlorophyll abundances and distributions globally and regionally in the oceans. Chlorophyll is a proxy for phytoplankton biomass (which is explicitly defined in a model), and is related to the inorganic carbon cycle through the interactions of the organic carbon (particulate and dissolved) and through primary production where inorganic carbon is directly taken out of the system. Does ocean color data assimilation, whose effects on estimates of chlorophyll are demonstrable, trickle through the simulated ocean carbon system to produce improved estimates of inorganic carbon? Our emphasis here is dissolved inorganic carbon, pC02, and the air-sea flux. We use a sequential data assimilation method that assimilates chlorophyll directly and indirectly changes nutrient concentrations in a multi-variate approach. The results are decidedly mixed. Dissolved organic carbon estimates from the assimilation model are not meaningfully different from free-run, or unassimilated results, and comparisons with in situ data are similar. pC02 estimates are generally worse after data assimilation, with global estimates diverging 6.4% from in situ data, while free-run estimates are only 4.7% higher. Basin correlations are, however, slightly improved: r increase from 0.78 to 0.79, and slope closer to unity at 0.94 compared to 0.86. In contrast, air-sea flux of C02 is noticeably improved after data assimilation. Global differences decline from -0.635 mol/m2/y (stronger model sink from the atmosphere) to -0.202 mol/m2/y. Basin correlations are slightly improved from r=O.77 to r=0.78, with slope closer to unity (from 0.93 to 0.99). The Equatorial Atlantic appears as a slight sink in the free-run, but is correctly represented as a moderate source in the assimilation model. However, the assimilation model shows the Antarctic to be a source, rather than a modest sink and the North Indian basin is represented incorrectly as a sink

  3. Global Observations and Understanding of the General Circulation of the Oceans

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The workshop was organized to: (1) assess the ability to obtain ocean data on a global scale that could profoundly change our understanding of the circulation; (2) identify the primary and secondary elements needed to conduct a World Ocean Circulation Experiment (WOCE); (3) if the ability is achievable, to determine what the U.S. role in such an experiment should be; and (4) outline the steps necessary to assure that an appropriate program is conducted. The consensus of the workshop was that a World Ocean Circulation Experiment appears feasible, worthwhile, and timely. Participants did agree that such a program should have the overall goal of understanding the general circulation of the global ocean well enough to be able to predict ocean response and feedback to long-term changes in the atmosphere. The overall goal, specific objectives, and recommendations for next steps in planning such an experiment are included.

  4. Performance and quality assessment of the recent updated CMEMS global ocean monitoring and forecasting real-time system

    NASA Astrophysics Data System (ADS)

    Le Galloudec, Olivier; Lellouche, Jean-Michel; Greiner, Eric; Garric, Gilles; Régnier, Charly; Drévillon, Marie; Drillet, Yann

    2017-04-01

    Since May 2015, Mercator Ocean opened the Copernicus Marine Environment and Monitoring Service (CMEMS) and is in charge of the global eddy resolving ocean analyses and forecast. In this context, Mercator Ocean currently delivers in real-time daily services (weekly analyses and daily forecast) with a global 1/12° high resolution system. The model component is the NEMO platform driven at the surface by the IFS ECMWF atmospheric analyses and forecasts. Observations are assimilated by means of a reduced-order Kalman filter with a 3D multivariate modal decomposition of the forecast error. It includes an adaptive-error estimate and a localization algorithm. Along track altimeter data, satellite Sea Surface Temperature and in situ temperature and salinity vertical profiles are jointly assimilated to estimate the initial conditions for numerical ocean forecasting. A 3D-Var scheme provides a correction for the slowly-evolving large-scale biases in temperature and salinity. R&D activities have been conducted at Mercator Ocean these last years to improve the real-time 1/12° global system for recent updated CMEMS version in 2016. The ocean/sea-ice model and the assimilation scheme benefited of the following improvements: large-scale and objective correction of atmospheric quantities with satellite data, new Mean Dynamic Topography taking into account the last version of GOCE geoid, new adaptive tuning of some observational errors, new Quality Control on the assimilated temperature and salinity vertical profiles based on dynamic height criteria, assimilation of satellite sea-ice concentration, new freshwater runoff from ice sheets melting, … This presentation will show the impact of some updates separately, with a particular focus on adaptive tuning experiments of satellite Sea Level Anomaly (SLA) and Sea Surface Temperature (SST) observations errors. For the SLA, the a priori prescribed observation error is globally greatly reduced. The median value of the error changed

  5. El Nino and the Global Ocean Observing System

    NASA Technical Reports Server (NTRS)

    Halpern, David

    1999-01-01

    Until a decade ago, an often-quoted expression in oceanography is that very few observations are recorded throughout the ocean. Now, the sentiment is no longer valid in the uppermost 10% of the tropical Pacific Ocean nor at the surface of the global ocean. One of the remarkable legacies of the 1985-1994 Tropical Oceans Global Atmosphere (TOGA) Program is an in situ marine meteorological and upper oceanographic measurement array throughout the equatorial Pacific to monitor the development and maintenance of El Nino episodes. The TOGA Observing System, which initially consisted of moored- and drifting-buoy arrays, a network of commercial ships, and coastal and island stations, now includes a constellation of satellites and data-assimilating models to simulate subsurface oceanographic conditions. The El Nino and La Nina tropical Pacific Ocean observing system represents the initial phase of an integrated global ocean observing system. Remarkable improvements have been made in ocean model simulation of subsurface currents, but some problems persist. For example, the simulation of the South Equatorial Current (SEC) remains an important challenge in the 2S-2N Pacific equatorial wave guide. During El Nino the SEC at the equator is reduced and sometimes the direction is reversed, becoming eastward. Both conditions allow warm water stored in the western Pacific to invade the eastern region, creating an El Nino episode. Assimilation of data is a tenet of faith to correct simulation errors caused by deficiencies in surface fluxes (especially wind stress) and parameterizations of subgrid-scale physical processes. In the first of two numerical experiments, the Pacific SEC was simulated with and without assimilation of subsurface temperature data. Along the equator, a very weak SEC occurred throughout the eastern Pacific, independent of assimilation of data. However, as displayed in the diagram, in the western Pacific there was no satisfactory agreement between the two

  6. A daily global mesoscale ocean eddy dataset from satellite altimetry.

    PubMed

    Faghmous, James H; Frenger, Ivy; Yao, Yuanshun; Warmka, Robert; Lindell, Aron; Kumar, Vipin

    2015-01-01

    Mesoscale ocean eddies are ubiquitous coherent rotating structures of water with radial scales on the order of 100 kilometers. Eddies play a key role in the transport and mixing of momentum and tracers across the World Ocean. We present a global daily mesoscale ocean eddy dataset that contains ~45 million mesoscale features and 3.3 million eddy trajectories that persist at least two days as identified in the AVISO dataset over a period of 1993-2014. This dataset, along with the open-source eddy identification software, extract eddies with any parameters (minimum size, lifetime, etc.), to study global eddy properties and dynamics, and to empirically estimate the impact eddies have on mass or heat transport. Furthermore, our open-source software may be used to identify mesoscale features in model simulations and compare them to observed features. Finally, this dataset can be used to study the interaction between mesoscale ocean eddies and other components of the Earth System.

  7. A daily global mesoscale ocean eddy dataset from satellite altimetry

    PubMed Central

    Faghmous, James H.; Frenger, Ivy; Yao, Yuanshun; Warmka, Robert; Lindell, Aron; Kumar, Vipin

    2015-01-01

    Mesoscale ocean eddies are ubiquitous coherent rotating structures of water with radial scales on the order of 100 kilometers. Eddies play a key role in the transport and mixing of momentum and tracers across the World Ocean. We present a global daily mesoscale ocean eddy dataset that contains ~45 million mesoscale features and 3.3 million eddy trajectories that persist at least two days as identified in the AVISO dataset over a period of 1993–2014. This dataset, along with the open-source eddy identification software, extract eddies with any parameters (minimum size, lifetime, etc.), to study global eddy properties and dynamics, and to empirically estimate the impact eddies have on mass or heat transport. Furthermore, our open-source software may be used to identify mesoscale features in model simulations and compare them to observed features. Finally, this dataset can be used to study the interaction between mesoscale ocean eddies and other components of the Earth System. PMID:26097744

  8. Declining oxygen in the global ocean and coastal waters.

    PubMed

    Breitburg, Denise; Levin, Lisa A; Oschlies, Andreas; Grégoire, Marilaure; Chavez, Francisco P; Conley, Daniel J; Garçon, Véronique; Gilbert, Denis; Gutiérrez, Dimitri; Isensee, Kirsten; Jacinto, Gil S; Limburg, Karin E; Montes, Ivonne; Naqvi, S W A; Pitcher, Grant C; Rabalais, Nancy N; Roman, Michael R; Rose, Kenneth A; Seibel, Brad A; Telszewski, Maciej; Yasuhara, Moriaki; Zhang, Jing

    2018-01-05

    Oxygen is fundamental to life. Not only is it essential for the survival of individual animals, but it regulates global cycles of major nutrients and carbon. The oxygen content of the open ocean and coastal waters has been declining for at least the past half-century, largely because of human activities that have increased global temperatures and nutrients discharged to coastal waters. These changes have accelerated consumption of oxygen by microbial respiration, reduced solubility of oxygen in water, and reduced the rate of oxygen resupply from the atmosphere to the ocean interior, with a wide range of biological and ecological consequences. Further research is needed to understand and predict long-term, global- and regional-scale oxygen changes and their effects on marine and estuarine fisheries and ecosystems. Copyright © 2018, American Association for the Advancement of Science.

  9. A 3D parameterization of iron atmospheric deposition to the global ocean

    NASA Astrophysics Data System (ADS)

    Myriokefalitakis, Stelios; Krol, Maarten C.; van Noije, Twan P. C.; Le Sager, Philippe

    2017-04-01

    Atmospheric deposition of trace constituents, both of natural and anthropogenic origin, can act as a nutrient source into the open ocean and affect marine ecosystem functioning and subsequently the exchange of CO2 between the atmosphere and the global ocean. Dust is known as a major source of nutrients to the global ocean, but only a fraction of these nutrients is released in soluble form that can be assimilated by the ecosystems. Iron (Fe) is a key micronutrient that significantly modulates gross primary production in High-Nutrient-Low-Chlorophyll (HNLC) oceans, where macronutrients like nitrate are abundant but primary production is limited by Fe scarcity. The global atmospheric Fe cycle is here parameterized in the state-of-the-art global Earth System Model EC-Earth. The model takes into account the primary emissions of both insoluble and soluble Fe, associated with dusts and combustion processes. The impact of atmospheric acidity on mineral solubility is parameterized based on updated experimental and theoretical findings, and model results are evaluated against available observations. The link between the soluble Fe atmospheric deposition and anthropogenic sources is also investigated. Overall, the response of the chemical composition of nutrient containing aerosols to atmospheric composition changes is demonstrated and quantified. This work has been financed by the Marie-Curie H2020-MSCA-IF-2015 grant (ID 705652) ODEON (Online DEposition over OceaNs: Modeling the effect of air pollution on ocean bio-geochemistry in an Earth System Model).

  10. Are Global In-Situ Ocean Observations Fit-for-purpose? Applying the Framework for Ocean Observing in the Atlantic.

    NASA Astrophysics Data System (ADS)

    Visbeck, M.; Fischer, A. S.; Le Traon, P. Y.; Mowlem, M. C.; Speich, S.; Larkin, K.

    2015-12-01

    There are an increasing number of global, regional and local processes that are in need of integrated ocean information. In the sciences ocean information is needed to support physical ocean and climate studies for example within the World Climate Research Programme and its CLIVAR project, biogeochemical issues as articulated by the GCP, IMBER and SOLAS projects of ICSU-SCOR and Future Earth. This knowledge gets assessed in the area of climate by the IPCC and biodiversity by the IPBES processes. The recently released first World Ocean Assessment focuses more on ecosystem services and there is an expectation that the Sustainable Development Goals and in particular Goal 14 on the Ocean and Seas will generate new demands for integrated ocean observing from Climate to Fish and from Ocean Resources to Safe Navigation and on a healthy, productive and enjoyable ocean in more general terms. In recognition of those increasing needs for integrated ocean information we have recently launched the Horizon 2020 AtlantOS project to promote the transition from a loosely-coordinated set of existing ocean observing activities to a more integrated, more efficient, more sustainable and fit-for-purpose Atlantic Ocean Observing System. AtlantOS takes advantage of the Framework for Ocean observing that provided strategic guidance for the design of the project and its outcome. AtlantOS will advance the requirements and systems design, improving the readiness of observing networks and data systems, and engaging stakeholders around the Atlantic. AtlantOS will bring Atlantic nations together to strengthen their complementary contributions to and benefits from the internationally coordinated Global Ocean Observing System (GOOS) and the Blue Planet Initiative of the Global Earth Observation System of Systems (GEOSS). AtlantOS will fill gaps of the in-situ observing system networks and will ensure that their data are readily accessible and useable. AtlantOS will demonstrate the utility of

  11. Ocean Data Interoperability Platform (ODIP): using regional data systems for global ocean research

    NASA Astrophysics Data System (ADS)

    Schaap, D.; Thijsse, P.; Glaves, H.

    2017-12-01

    Ocean acidification, loss of coral reefs, sustainable exploitation of the marine environment are just a few of the challenges researchers around the world are currently attempting to understand and address. However, studies of these ecosystem level challenges are impossible unless researchers can discover and re-use the large volumes of interoperable multidisciplinary data that are currently only accessible through regional and global data systems that serve discreet, and often discipline specific, user communities. The plethora of marine data systems currently in existence are also using different standards, technologies and best practices making re-use of the data problematic for those engaged in interdisciplinary marine research. The Ocean Data Interoperability Platform (ODIP) is responding to this growing demand for discoverable, accessible and reusable data by establishing the foundations for a common global framework for marine data management. But creation of such an infrastructure is a major undertaking, and one that needs to be achieved in part by establishing different levels of interoperability across existing regional and global marine e-infrastructures. Workshops organised by ODIP II facilitate dialogue between selected regional and global marine data systems in an effort to identify potential solutions that integrate these marine e-infrastructures. The outcomes of these discussions have formed the basis for a number of prototype development tasks that aim to demonstrate effective sharing of data across multiple data systems, and allow users to access data from more than one system through a single access point. The ODIP II project is currently developing four prototype solutions that are establishing interoperability between selected regional marine data management infrastructures in Europe, the USA, Canada and Australia, and with the global POGO, IODE Ocean Data Portal (ODP) and GEOSS systems. The potential impact of implementing these solutions for

  12. Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming.

    PubMed

    Huang, Ping; Lin, I-I; Chou, Chia; Huang, Rong-Hui

    2015-05-18

    Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas.

  13. Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming

    PubMed Central

    Huang, Ping; Lin, I. -I; Chou, Chia; Huang, Rong-Hui

    2015-01-01

    Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas. PMID:25982028

  14. GLOBEC: Global Ocean Ecosystems Dynamics: A component of the US Global Change Research Program

    NASA Technical Reports Server (NTRS)

    1991-01-01

    GLOBEC (GLOBal ocean ECosystems dynamics) is a research initiative proposed by the oceanographic and fisheries communities to address the question of how changes in global environment are expected to affect the abundance and production of animals in the sea. The approach to this problem is to develop a fundamental understanding of the mechanisms that determine both the abundance of key marine animal populations and their variances in space and time. The assumption is that the physical environment is a major contributor to patterns of abundance and production of marine animals, in large part because the planktonic life stages typical of most marine animals are intrinsically at the mercy of the fluid motions of the medium in which they live. Consequently, the authors reason that a logical approach to predicting the potential impact of a globally changing environment is to understand how the physical environment, both directly and indirectly, contributes to animal abundance and its variability in marine ecosystems. The plans for this coordinated study of of the potential impact of global change on ocean ecosystems dynamics are discussed.

  15. Global variations in gravity-derived oceanic crustal thickness: Implications on oceanic crustal accretion and hotspot-lithosphere interactions

    NASA Astrophysics Data System (ADS)

    Lin, J.; Zhu, J.

    2012-12-01

    We present a new global model of oceanic crustal thickness based on inversion of global oceanic gravity anomaly with constrains from seismic crustal thickness profiles. We first removed from the observed marine free-air gravity anomaly all gravitational effects that can be estimated and removed using independent constraints, including the effects of seafloor topography, marine sediment thickness, and the age-dependent thermal structure of the oceanic lithosphere. We then calculated models of gravity-derived crustal thickness through inversion of the residual mantle Bouguer anomaly using best-fitting gravity-modeling parameters obtained from comparison with seismically determined crustal thickness profiles. Modeling results show that about 5% of the global crustal volume (or 9% of the global oceanic surface area) is associated with model crustal thickness <5.2 km (designated as "thin" crust), while 56% of the crustal volume (or 65% of the surface area) is associated with crustal thickness of 5.2-8.6 km thick (designated as "normal" crust). The remaining 39% of the crustal volume (or 26% of the surface area) is associated with crustal thickness >8.6 km and is interpreted to have been affected by excess magmatism. The percentage of oceanic crustal volume that is associated with thick crustal thickness (>8.6 km) varies greatly among tectonic plates: Pacific (33%), Africa (50%), Antarctic (33%), Australia (30%), South America (34%), Nazca (23%), North America (47%), India (74%), Eurasia (68%), Cocos (20%), Philippine (26%), Scotia (41%), Caribbean (89%), Arabian (82%), and Juan de Fuca (21%). We also found that distribution of thickened oceanic crust (>8.6 km) seems to depend on spreading rate and lithospheric age: (1) On ocean basins younger than 5 Ma, regions of thickened crust are predominantly associated with slow and ultraslow spreading ridges. The relatively strong lithospheric plate at slow and ultraslow ridges might facilitate the loading of large magmatic

  16. Assessment of Global Forecast Ocean Assimilation Model (FOAM) using new satellite SST data

    NASA Astrophysics Data System (ADS)

    Ascione Kenov, Isabella; Sykes, Peter; Fiedler, Emma; McConnell, Niall; Ryan, Andrew; Maksymczuk, Jan

    2016-04-01

    There is an increased demand for accurate ocean weather information for applications in the field of marine safety and navigation, water quality, offshore commercial operations, monitoring of oil spills and pollutants, among others. The Met Office, UK, provides ocean forecasts to customers from governmental, commercial and ecological sectors using the Global Forecast Ocean Assimilation Model (FOAM), an operational modelling system which covers the global ocean and runs daily, using the NEMO (Nucleus for European Modelling of the Ocean) ocean model with horizontal resolution of 1/4° and 75 vertical levels. The system assimilates salinity and temperature profiles, sea surface temperature (SST), sea surface height (SSH), and sea ice concentration observations on a daily basis. In this study, the FOAM system is updated to assimilate Advanced Microwave Scanning Radiometer 2 (AMSR2) and the Spinning Enhanced Visible and Infrared Imager (SEVIRI) SST data. Model results from one month trials are assessed against observations using verification tools which provide a quantitative description of model performance and error, based on statistical metrics, including mean error, root mean square error (RMSE), correlation coefficient, and Taylor diagrams. A series of hindcast experiments is used to run the FOAM system with AMSR2 and SEVIRI SST data, using a control run for comparison. Results show that all trials perform well on the global ocean and that largest SST mean errors were found in the Southern hemisphere. The geographic distribution of the model error for SST and temperature profiles are discussed using statistical metrics evaluated over sub-regions of the global ocean.

  17. Log-Normal Turbulence Dissipation in Global Ocean Models

    NASA Astrophysics Data System (ADS)

    Pearson, Brodie; Fox-Kemper, Baylor

    2018-03-01

    Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly log-normal distribution even at large horizontal scales O (10 km ) . As the horizontal scales of resolved turbulence are larger than the ocean is deep, the Kolmogorov-Yaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply; instead, the down-scale potential enstrophy cascade of quasigeostrophic turbulence should. Yet, energy dissipation obeys approximate log-normality—robustly across depths, seasons, regions, and subgrid schemes. The distribution parameters, skewness and kurtosis, show small systematic departures from log-normality with depth and subgrid friction schemes. Log-normality suggests that a few high-dissipation locations dominate the integrated energy and enstrophy budgets, which should be taken into account when making inferences from simplified models and inferring global energy budgets from sparse observations.

  18. Global equivalent magnetization of the oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Dyment, J.; Choi, Y.; Hamoudi, M.; Lesur, V.; Thebault, E.

    2015-11-01

    As a by-product of the construction of a new World Digital Magnetic Anomaly Map over oceanic areas, we use an original approach based on the global forward modeling of seafloor spreading magnetic anomalies and their comparison to the available marine magnetic data to derive the first map of the equivalent magnetization over the World's ocean. This map reveals consistent patterns related to the age of the oceanic lithosphere, the spreading rate at which it was formed, and the presence of mantle thermal anomalies which affects seafloor spreading and the resulting lithosphere. As for the age, the equivalent magnetization decreases significantly during the first 10-15 Myr after its formation, probably due to the alteration of crustal magnetic minerals under pervasive hydrothermal alteration, then increases regularly between 20 and 70 Ma, reflecting variations in the field strength or source effects such as the acquisition of a secondary magnetization. As for the spreading rate, the equivalent magnetization is twice as strong in areas formed at fast rate than in those formed at slow rate, with a threshold at ∼40 km/Myr, in agreement with an independent global analysis of the amplitude of Anomaly 25. This result, combined with those from the study of the anomalous skewness of marine magnetic anomalies, allows building a unified model for the magnetic structure of normal oceanic lithosphere as a function of spreading rate. Finally, specific areas affected by thermal mantle anomalies at the time of their formation exhibit peculiar equivalent magnetization signatures, such as the cold Australian-Antarctic Discordance, marked by a lower magnetization, and several hotspots, marked by a high magnetization.

  19. Ocean heat content and ocean energy budget: make better use of historical global subsurface temperature dataset

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Zhu, J.

    2016-02-01

    Ocean heat content (OHC) change contributes substantially to global sea level rise, also is a key metric of the ocean/global energy budget, so it is a vital task for the climate research community to estimate historical OHC. While there are large uncertainties regarding its value, here we review the OHC calculation by using the historical global subsurface temperature dataset, and discuss the sources of its uncertainty. The presentation briefly introduces how to correct to the systematic biases in expendable bathythermograph (XBT) data, a alternative way of filling data gaps (which is main focus of this talk), and how to choose a proper climatology. A new reconstruction of historical upper (0-700 m) OHC change will be presented, which is the Institute of Atmospheric Physics (IAP) version of historical upper OHC assessment. The authors also want to highlight the impact of observation system change on OHC calculation, which could lead to bias in OHC estimates. Furthermore, we will compare the updated observational-based estimates on ocean heat content change since 1970s with CMIP5 results. This comparison shows good agreement, increasing the confidence of the climate models in representing the climate history.

  20. The timescales of global surface-ocean connectivity

    PubMed Central

    Jönsson, Bror F.; Watson, James R.

    2016-01-01

    Planktonic communities are shaped through a balance of local evolutionary adaptation and ecological succession driven in large part by migration. The timescales over which these processes operate are still largely unresolved. Here we use Lagrangian particle tracking and network theory to quantify the timescale over which surface currents connect different regions of the global ocean. We find that the fastest path between two patches—each randomly located anywhere in the surface ocean—is, on average, less than a decade. These results suggest that marine planktonic communities may keep pace with climate change—increasing temperatures, ocean acidification and changes in stratification over decadal timescales—through the advection of resilient types. PMID:27093522

  1. Penetration of UV-visible solar radiation in the global oceans: Insights from ocean color remote sensing

    NASA Astrophysics Data System (ADS)

    Lee, Zhongping; Hu, Chuanmin; Shang, Shaoling; Du, Keping; Lewis, Marlon; Arnone, Robert; Brewin, Robert

    2013-09-01

    Penetration of solar radiation in the ocean is determined by the attenuation coefficient (Kd(λ)). Following radiative transfer theory, Kd is a function of angular distribution of incident light and water's absorption and backscattering coefficients. Because these optical products are now generated routinely from satellite measurements, it is logical to evolve the empirical Kd to a semianalytical Kd that is not only spectrally flexible, but also the sun-angle effect is accounted for explicitly. Here, the semianalytical model developed in Lee et al. (2005b) is revised to account for the shift of phase function between molecular and particulate scattering from the short to long wavelengths. Further, using field data collected independently from oligotrophic ocean to coastal waters covering >99% of the Kd range for the global oceans, the semianalytically derived Kd was evaluated and found to agree with measured data within ˜7-26%. The updated processing system was applied to MODIS measurements to reveal the penetration of UVA-visible radiation in the global oceans, where an empirical procedure to correct Raman effect was also included. The results indicated that the penetration of the blue-green radiation for most oceanic waters is ˜30-40% deeper than the commonly used euphotic zone depth; and confirmed that at a depth of 50-70 m there is still ˜10% of the surface UVA radiation (at 360 nm) in most oligotrophic waters. The results suggest a necessity to modify or expand the light attenuation product from satellite ocean-color measurements in order to be more applicable for studies of ocean physics and biogeochemistry.

  2. Retrieving Temperature Anomaly in the Global Subsurface and Deeper Ocean From Satellite Observations

    NASA Astrophysics Data System (ADS)

    Su, Hua; Li, Wene; Yan, Xiao-Hai

    2018-01-01

    Retrieving the subsurface and deeper ocean (SDO) dynamic parameters from satellite observations is crucial for effectively understanding ocean interior anomalies and dynamic processes, but it is challenging to accurately estimate the subsurface thermal structure over the global scale from sea surface parameters. This study proposes a new approach based on Random Forest (RF) machine learning to retrieve subsurface temperature anomaly (STA) in the global ocean from multisource satellite observations including sea surface height anomaly (SSHA), sea surface temperature anomaly (SSTA), sea surface salinity anomaly (SSSA), and sea surface wind anomaly (SSWA) via in situ Argo data for RF training and testing. RF machine-learning approach can accurately retrieve the STA in the global ocean from satellite observations of sea surface parameters (SSHA, SSTA, SSSA, SSWA). The Argo STA data were used to validate the accuracy and reliability of the results from the RF model. The results indicated that SSHA, SSTA, SSSA, and SSWA together are useful parameters for detecting SDO thermal information and obtaining accurate STA estimations. The proposed method also outperformed support vector regression (SVR) in global STA estimation. It will be a useful technique for studying SDO thermal variability and its role in global climate system from global-scale satellite observations.

  3. The self-consistent dynamic pole tide in global oceans

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1985-01-01

    The dynamic pole tide is characterized in a self-consistent manner by means of introducing a single nondifferential matrix equation compatible with the Liouville equation, modelling the ocean as global and of uniform depth. The deviations of the theory from the realistic ocean, associated with the nonglobality of the latter, are also given consideration, with an inference that in realistic oceans long-period modes of resonances would be increasingly likely to exist. The analysis of the nature of the pole tide and its effects on the Chandler wobble indicate that departures of the pole tide from the equilibrium may indeed be minimal.

  4. Dynamic biogeochemical provinces in the global ocean

    NASA Astrophysics Data System (ADS)

    Reygondeau, Gabriel; Longhurst, Alan; Martinez, Elodie; Beaugrand, Gregory; Antoine, David; Maury, Olivier

    2013-12-01

    In recent decades, it has been found useful to partition the pelagic environment using the concept of biogeochemical provinces, or BGCPs, within each of which it is assumed that environmental conditions are distinguishable and unique at global scale. The boundaries between provinces respond to features of physical oceanography and, ideally, should follow seasonal and interannual changes in ocean dynamics. But this ideal has not been fulfilled except for small regions of the oceans. Moreover, BGCPs have been used only as static entities having boundaries that were originally established to compute global primary production. In the present study, a new statistical methodology based on non-parametric procedures is implemented to capture the environmental characteristics within 56 BGCPs. Four main environmental parameters (bathymetry, chlorophyll a concentration, surface temperature, and salinity) are used to infer the spatial distribution of each BGCP over 1997-2007. The resulting dynamic partition allows us to integrate changes in the distribution of BGCPs at seasonal and interannual timescales, and so introduces the possibility of detecting spatial shifts in environmental conditions.

  5. Insights into global diatom distribution and diversity in the world's ocean.

    PubMed

    Malviya, Shruti; Scalco, Eleonora; Audic, Stéphane; Vincent, Flora; Veluchamy, Alaguraj; Poulain, Julie; Wincker, Patrick; Iudicone, Daniele; de Vargas, Colomban; Bittner, Lucie; Zingone, Adriana; Bowler, Chris

    2016-03-15

    Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 size-fractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.

  6. Sources of global warming in upper ocean temperature during El Niño

    USGS Publications Warehouse

    White, Warren B.; Cayan, Daniel R.; Dettinger, Mike; Auad, Guillermo

    2001-01-01

    Global average sea surface temperature (SST) from 40°S to 60°N fluctuates ±0.3°C on interannual period scales, with global warming (cooling) during El Niño (La Niña). About 90% of the global warming during El Niño occurs in the tropical global ocean from 20°S to 20°N, half because of large SST anomalies in the tropical Pacific associated with El Niño and the other half because of warm SST anomalies occurring over ∼80% of the tropical global ocean. From examination of National Centers for Environmental Prediction [Kalnay et al., 1996] and Comprehensive Ocean-Atmosphere Data Set [Woodruff et al., 1993] reanalyses, tropical global warming during El Niño is associated with higher troposphere moisture content and cloud cover, with reduced trade wind intensity occurring during the onset phase of El Niño. During this onset phase the tropical global average diabatic heat storage tendency in the layer above the main pycnocline is 1–3 W m−2above normal. Its principal source is a reduction in the poleward Ekman heat flux out of the tropical ocean of 2–5 W m−2. Subsequently, peak tropical global warming during El Niño is dissipated by an increase in the flux of latent heat to the troposphere of 2–5 W m−2, with reduced shortwave and longwave radiative fluxes in response to increased cloud cover tending to cancel each other. In the extratropical global ocean the reduction in poleward Ekman heat flux out of the tropics during the onset of El Niño tends to be balanced by reduction in the flux of latent heat to the troposphere. Thus global warming and cooling during Earth's internal mode of interannual climate variability arise from fluctuations in the global hydrological balance, not the global radiation balance. Since it occurs in the absence of extraterrestrial and anthropogenic forcing, global warming on decadal, interdecadal, and centennial period scales may also occur in association with Earth's internal modes of climate variability on those scales.

  7. Global View of the Arctic Ocean

    NASA Technical Reports Server (NTRS)

    2000-01-01

    together to create a time-lapsed view of this remote and inhospitable region. So far, they have processed one season's worth of images.

    'We can see large cracks in the ice cover, where most ice grows, ' said Kwok. 'These cracks are much longer than previously thought, some as long as 2,000 kilometers (1,200 miles),' Kwok continued. 'If the ice is thinning due to warming, we'll expect to see more of these long cracks over the Arctic Ocean. '

    Scientists believe this is one of the most significant breakthroughs in the last two decades of ice research. 'We are now in a position to better understand the sea ice cover and the role of the Arctic Ocean in global climate change, ' said Kwok.

    Radar can see through clouds and any kind of weather system, day or night, and as the Arctic regions are usually cloud-covered and subject to long, dark winters, radar is proving to be extremely useful. However, compiling these data into extremely detailed pictures of the Arctic is a challenging task.

    'This is truly a major innovation in terms of the quantities of data being processed and the novelty of the methods being used, ' said Verne Kaupp, director of the Alaska SAR Facility at the University of Alaska, Fairbanks.

    The mission is a joint project between JPL, the Alaska SAR Facility, and the Canadian Space Agency. Launched by NASA in 1995, the Radarsat satellite is operated by the Canadian Space Agency. JPL manages the Sea Ice Thickness Derived From High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced changes affect our global environment.

  8. Global Ocean Sedimentation Patterns: Plate Tectonic History Versus Climate Change

    NASA Astrophysics Data System (ADS)

    Goswami, A.; Reynolds, E.; Olson, P.; Hinnov, L. A.; Gnanadesikan, A.

    2014-12-01

    Global sediment data (Whittaker et al., 2013) and carbonate content data (Archer, 1996) allows examination of ocean sedimentation evolution with respect to age of the underlying ocean crust (Müller et al., 2008). From these data, we construct time series of ocean sediment thickness and carbonate deposition rate for the Atlantic, Pacific, and Indian ocean basins for the past 120 Ma. These time series are unique to each basin and reflect an integrated response to plate tectonics and climate change. The goal is to parameterize ocean sedimentation tied to crustal age for paleoclimate studies. For each basin, total sediment thickness and carbonate deposition rate from 0.1 x 0.1 degree cells are binned according to basement crustal age; area-corrected moments (mean, variance, etc.) are calculated for each bin. Segmented linear fits identify trends in present-day carbonate deposition rates and changes in ocean sedimentation from 0 to 120 Ma. In the North and South Atlantic and Indian oceans, mean sediment thickness versus crustal age is well represented by three linear segments, with the slope of each segment increasing with increasing crustal age. However, the transition age between linear segments varies among the three basins. In contrast, mean sediment thickness in the North and South Pacific oceans are numerically smaller and well represented by two linear segments with slopes that decrease with increasing crustal age. These opposing trends are more consistent with the plate tectonic history of each basin being the controlling factor in sedimentation rates, rather than climate change. Unlike total sediment thickness, carbonate deposition rates decrease smoothly with crustal age in all basins, with the primary controls being ocean chemistry and water column depth.References: Archer, D., 1996, Global Biogeochem. Cycles 10, 159-174.Müller, R.D., et al., 2008, Science, 319, 1357-1362.Whittaker, J., et al., 2013, Geochem., Geophys., Geosyst. DOI: 10.1002/ggge.20181

  9. Global biogeography of Prochlorococcus genome diversity in the surface ocean.

    PubMed

    Kent, Alyssa G; Dupont, Chris L; Yooseph, Shibu; Martiny, Adam C

    2016-08-01

    Prochlorococcus, the smallest known photosynthetic bacterium, is abundant in the ocean's surface layer despite large variation in environmental conditions. There are several genetically divergent lineages within Prochlorococcus and superimposed on this phylogenetic diversity is extensive gene gain and loss. The environmental role in shaping the global ocean distribution of genome diversity in Prochlorococcus is largely unknown, particularly in a framework that considers the vertical and lateral mechanisms of evolution. Here we show that Prochlorococcus field populations from a global circumnavigation harbor extensive genome diversity across the surface ocean, but this diversity is not randomly distributed. We observed a significant correspondence between phylogenetic and gene content diversity, including regional differences in both phylogenetic composition and gene content that were related to environmental factors. Several gene families were strongly associated with specific regions and environmental factors, including the identification of a set of genes related to lower nutrient and temperature regions. Metagenomic assemblies of natural Prochlorococcus genomes reinforced this association by providing linkage of genes across genomic backbones. Overall, our results show that the phylogeography in Prochlorococcus taxonomy is echoed in its genome content. Thus environmental variation shapes the functional capabilities and associated ecosystem role of the globally abundant Prochlorococcus.

  10. Improving Global Net Surface Heat Flux with Ocean Reanalysis

    NASA Astrophysics Data System (ADS)

    Carton, J.; Chepurin, G. A.; Chen, L.; Grodsky, S.

    2017-12-01

    This project addresses the current level of uncertainty in surface heat flux estimates. Time mean surface heat flux estimates provided by atmospheric reanalyses differ by 10-30W/m2. They are generally unbalanced globally, and have been shown by ocean simulation studies to be incompatible with ocean temperature and velocity measurements. Here a method is presented 1) to identify the spatial and temporal structure of the underlying errors and 2) to reduce them by exploiting hydrographic observations and the analysis increments produced by an ocean reanalysis using sequential data assimilation. The method is applied to fluxes computed from daily state variables obtained from three widely used reanalyses: MERRA2, ERA-Interim, and JRA-55, during an eight year period 2007-2014. For each of these seasonal heat flux errors/corrections are obtained. In a second set of experiments the heat fluxes are corrected and the ocean reanalysis experiments are repeated. This second round of experiments shows that the time mean error in the corrected fluxes is reduced to within ±5W/m2 over the interior subtropical and midlatitude oceans, with the most significant changes occuring over the Southern Ocean. The global heat flux imbalance of each reanalysis is reduced to within a few W/m2 with this single correction. Encouragingly, the corrected forms of the three sets of fluxes are also shown to converge. In the final discussion we present experiments beginning with a modified form of the ERA-Int reanalysis, produced by the DAKKAR program, in which state variables have been individually corrected based on independent measurements. Finally, we discuss the separation of flux error from model error.

  11. An operational global-scale ocean thermal analysis system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Clancy, R. M.; Pollak, K.D.; Phoebus, P.A.

    1990-04-01

    The Optimum Thermal Interpolation System (OTIS) is an ocean thermal analysis system designed for operational use at FNOC. It is based on the optimum interpolation of the assimilation technique and functions in an analysis-prediction-analysis data assimilation cycle with the TOPS mixed-layer model. OTIS provides a rigorous framework for combining real-time data, climatology, and predictions from numerical ocean prediction models to produce a large-scale synoptic representation of ocean thermal structure. The techniques and assumptions used in OTIS are documented and results of operational tests of global scale OTIS at FNOC are presented. The tests involved comparisons of OTIS against an existingmore » operational ocean thermal structure model and were conducted during February, March, and April 1988. Qualitative comparison of the two products suggests that OTIS gives a more realistic representation of subsurface anomalies and horizontal gradients and that it also gives a more accurate analysis of the thermal structure, with improvements largest below the mixed layer. 37 refs.« less

  12. The role of clouds and oceans in global greenhouse warming. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hoffert, M.I.

    1996-10-01

    This research focuses on assessing connections between anthropogenic greenhouse gas emissions and global climatic change. it has been supported since the early 1990s in part by the DOE ``Quantitative Links`` Program (QLP). A three-year effort was originally proposed to the QLP to investigate effects f global cloudiness on global climate and its implications for cloud feedback; and to continue the development and application of climate/ocean models, with emphasis on coupled effects of greenhouse warming and feedbacks by clouds and oceans. It is well-known that cloud and ocean processes are major sources of uncertainty in the ability to predict climatic changemore » from humankind`s greenhouse gas and aerosol emissions. And it has always been the objective to develop timely and useful analytical tools for addressing real world policy issues stemming from anthropogenic climate change.« less

  13. Patterns and Variability in Global Ocean Chlorophyll: Satellite Observations and Modeling

    NASA Technical Reports Server (NTRS)

    Gregg, Watson

    2004-01-01

    Recent analyses of SeaWiFS data have shown that global ocean chlorophyll has increased more than 4% since 1998. The North Pacific ocean basin has increased nearly 19%. These trend analyses follow earlier results showing decadal declines in global ocean chlorophyll and primary production. To understand the causes of these changes and trends we have applied the newly developed NASA Ocean Biogeochemical Assimilation Model (OBAM), which is driven in mechanistic fashion by surface winds, sea surface temperature, atmospheric iron deposition, sea ice, and surface irradiance. The model utilizes chlorophyll from SeaWiFS in a daily assimilation. The model has in place many of the climatic variables that can be expected to produce the changes observed in SeaWiFS data. This enables us to diagnose the model performance, the assimilation performance, and possible causes for the increase in chlorophyll. A full discussion of the changes and trends, possible causes, modeling approaches, and data assimilation will be the focus of the seminar.

  14. Tropical Ocean and Global Atmosphere (TOGA) heat exchange project: A summary report

    NASA Technical Reports Server (NTRS)

    Liu, W. T.; Niiler, P. P.

    1985-01-01

    A pilot data center to compute ocean atmosphere heat exchange over the tropical ocean is prposed at the Jet Propulsion Laboratory (JPL) in response to the scientific needs of the Tropical Ocean and Global Atmosphere (TOGA) Program. Optimal methods will be used to estimate sea surface temperature (SET), surface wind speed, and humidity from spaceborne observations. A monthly summary of these parameters will be used to compute ocean atmosphere latent heat exchanges. Monthly fields of surface heat flux over tropical oceans will be constructed using estimations of latent heat exchanges and short wave radiation from satellite data. Verification of all satellite data sets with in situ measurements at a few locations will be provided. The data center will be an experimental active archive where the quality and quantity of data required for TOGA flux computation are managed. The center is essential to facilitate the construction of composite data sets from global measurements taken from different sensors on various satellites. It will provide efficient utilization and easy access to the large volume of satellite data available for studies of ocean atmosphere energy exchanges.

  15. A Real-time 1/16° Global Ocean Nowcast/Forecast System

    NASA Astrophysics Data System (ADS)

    Shriver, J. F.; Rhodes, R. C.; Hurlburt, H. E.; Wallcraft, A. J.; Metzger, E. J.; Smedstad, O. M.; Kara, A. B.

    2001-05-01

    A 1/16° eddy-resolving global ocean prediction system that uses the NRL Layered Ocean Model (NLOM) has been transitioned to the Naval Oceanographic Office (NAVO), Stennis Space Center, MS. The system gives a real time view of the ocean down to the 50-100 mile scale of ocean eddies and the meandering of ocean currents and fronts, a view with unprecedented resolution and clarity, and demonstrated forecast skill for a month or more for many ocean features. It has been running in real time at NAVO since 19 Oct 2000 with assimilation of real-time altimeter sea surface height (SSH) data (currently ERS-2, GFO and TOPEX/POSEIDON) and sea surface temperature (SST). The model is updated daily and 4-day forecasts are made daily. 30-day forecasts are made once a week. Nowcasts and forecasts using this model are viewable on the web, including SSH, SST and 30-day forecast verification statistics for many zoom regions. The NRL web address is http://www7320.nrlssc.navy.mil/global_nlom/index.html. The NAVO web address is: http://www.navo.navy.mil. Click on "Operational Products", then "Product Search Form", then "Product Type View", then select "Model Navy Layered Ocean Model" and a region and click on "Submit Query". This system is used at NAVO for ocean front and eddy analyses and predictions and to provide accurate sea surface height for use in computing synthetic temperature and salinity profiles, among other applications.

  16. Multimillennium changes in dissolved oxygen under global warming: results from an AOGCM and offline ocean biogeochemical model

    NASA Astrophysics Data System (ADS)

    Yamamoto, A.; Abe-Ouchi, A.; Shigemitsu, M.; Oka, A.; Takahashi, K.; Ohgaito, R.; Yamanaka, Y.

    2016-12-01

    Long-term oceanic oxygen change due to global warming is still unclear; most future projections (such as CMIP5) are only performed until 2100. Indeed, few previous studies using conceptual models project oxygen change in the next thousands of years, showing persistent global oxygen reduction by about 30% in the next 2000 years, even after atmospheric carbon dioxide stops rising. Yet, these models cannot sufficiently represent the ocean circulation change: the key driver of oxygen change. Moreover, considering serious effect oxygen reduction has on marine life and biogeochemical cycling, long-term oxygen change should be projected for higher validity. Therefore, we used a coupled atmosphere-ocean general circulation model (AOGCM) and an offline ocean biogeochemical model, investigating realistic long-term changes in oceanic oxygen concentration and ocean circulation. We integrated these models for 2000 years under atmospheric CO2 doubling and quadrupling. After global oxygen reduction in the first 500 years, oxygen concentration in deep ocean globally recovers and overshoots, despite surface oxygen decrease and weaker Atlantic Meridional Overturning Circulation. Deep ocean convection in the Weddell Sea recovers and overshoots, after initial cessation. Thus, enhanced deep convection and associated Antarctic Bottom Water supply oxygen-rich surface waters to deep ocean, resulting global deep ocean oxygenation. We conclude that the change in ocean circulation in the Southern Ocean potentially drives millennial-scale oxygenation in the deep ocean; contrary to past reported long-term oxygen reduction and general expectation. In presentation, we will discuss the mechanism of response of deep ocean convection in the Weddell Sea and show the volume changes of hypoxic waters.

  17. Global Biogeochemical Fluxes Program for the Ocean Observatories Initiative: A Proposal. (Invited)

    NASA Astrophysics Data System (ADS)

    Ulmer, K. M.; Taylor, C.

    2010-12-01

    The overarching emphasis of the Global Biogeochemical Flux Ocean Observatories Initiative is to assess the role of oceanic carbon, both living and non-, in the Earth climate system. Modulation of atmospheric CO2 and its influence on global climate is a function of the quantitative capacity of the oceans to sequester organic carbon into deep waters. Critical to our understanding of the role of the oceans in the global cycling of carbon are the quantitative dynamics in both time and space of the fixation of CO2 into organic matter by surface ocean primary production and removal of this carbon to deep waters via the “biological pump”. To take the next major step forward in advancing our understanding of the oceanic biological pump, a global observation program is required that: (i) greatly improves constraints on estimates of global marine primary production (PP), a critical factor in understanding the global CO2 cycle and for developing accurate estimates of export production (EP); (ii) explores the spatiotemporal links between PP, EP and the biogeochemical processes that attenuate particulate organic carbon (POC) flux; (iii) characterizes microbial community structure and dynamics both in the surface and deep ocean; (iv) develops a comprehensive picture of the chemical and biological processes that take place from the surface ocean to the sea floor; (v) provides unique time-series samples for detailed laboratory-based chemical and biological characterization and tracer studies that will enable connections to be made between the operation of the biological pump at present and in the geologic past. The primary goal is to provide high quality biological and biogeochemical observational data for the modeling and prediction efforts of the global CO2 cycle research community. Crucial to the realization of the GBF-OOI is the development of reliable, long-term, time-series ocean observation platforms capable of precise

  18. Benchmarking the mesoscale variability in global ocean eddy-permitting numerical systems

    NASA Astrophysics Data System (ADS)

    Cipollone, Andrea; Masina, Simona; Storto, Andrea; Iovino, Doroteaciro

    2017-10-01

    The role of data assimilation procedures on representing ocean mesoscale variability is assessed by applying eddy statistics to a state-of-the-art global ocean reanalysis (C-GLORS), a free global ocean simulation (performed with the NEMO system) and an observation-based dataset (ARMOR3D) used as an independent benchmark. Numerical results are computed on a 1/4 ∘ horizontal grid (ORCA025) and share the same resolution with ARMOR3D dataset. This "eddy-permitting" resolution is sufficient to allow ocean eddies to form. Further to assessing the eddy statistics from three different datasets, a global three-dimensional eddy detection system is implemented in order to bypass the need of regional-dependent definition of thresholds, typical of commonly adopted eddy detection algorithms. It thus provides full three-dimensional eddy statistics segmenting vertical profiles from local rotational velocities. This criterion is crucial for discerning real eddies from transient surface noise that inevitably affects any two-dimensional algorithm. Data assimilation enhances and corrects mesoscale variability on a wide range of features that cannot be well reproduced otherwise. The free simulation fairly reproduces eddies emerging from western boundary currents and deep baroclinic instabilities, while underestimates shallower vortexes that populate the full basin. The ocean reanalysis recovers most of the missing turbulence, shown by satellite products , that is not generated by the model itself and consistently projects surface variability deep into the water column. The comparison with the statistically reconstructed vertical profiles from ARMOR3D show that ocean data assimilation is able to embed variability into the model dynamics, constraining eddies with in situ and altimetry observation and generating them consistently with local environment.

  19. Freshwater and its role in the Arctic Marine System: Sources, disposition, storage, export, and physical and biogeochemical consequences in the Arctic and global oceans

    NASA Astrophysics Data System (ADS)

    Carmack, E. C.; Yamamoto-Kawai, M.; Haine, T. W. N.; Bacon, S.; Bluhm, B. A.; Lique, C.; Melling, H.; Polyakov, I. V.; Straneo, F.; Timmermans, M.-L.; Williams, W. J.

    2016-03-01

    The Arctic Ocean is a fundamental node in the global hydrological cycle and the ocean's thermohaline circulation. We here assess the system's key functions and processes: (1) the delivery of fresh and low-salinity waters to the Arctic Ocean by river inflow, net precipitation, distillation during the freeze/thaw cycle, and Pacific Ocean inflows; (2) the disposition (e.g., sources, pathways, and storage) of freshwater components within the Arctic Ocean; and (3) the release and export of freshwater components into the bordering convective domains of the North Atlantic. We then examine physical, chemical, or biological processes which are influenced or constrained by the local quantities and geochemical qualities of freshwater; these include stratification and vertical mixing, ocean heat flux, nutrient supply, primary production, ocean acidification, and biogeochemical cycling. Internal to the Arctic the joint effects of sea ice decline and hydrological cycle intensification have strengthened coupling between the ocean and the atmosphere (e.g., wind and ice drift stresses, solar radiation, and heat and moisture exchange), the bordering drainage basins (e.g., river discharge, sediment transport, and erosion), and terrestrial ecosystems (e.g., Arctic greening, dissolved and particulate carbon loading, and altered phenology of biotic components). External to the Arctic freshwater export acts as both a constraint to and a necessary ingredient for deep convection in the bordering subarctic gyres and thus affects the global thermohaline circulation. Geochemical fingerprints attained within the Arctic Ocean are likewise exported into the neighboring subarctic systems and beyond. Finally, we discuss observed and modeled functions and changes in this system on seasonal, annual, and decadal time scales and discuss mechanisms that link the marine system to atmospheric, terrestrial, and cryospheric systems.

  20. An index to assess the health and benefits of the global ocean.

    PubMed

    Halpern, Benjamin S; Longo, Catherine; Hardy, Darren; McLeod, Karen L; Samhouri, Jameal F; Katona, Steven K; Kleisner, Kristin; Lester, Sarah E; O'Leary, Jennifer; Ranelletti, Marla; Rosenberg, Andrew A; Scarborough, Courtney; Selig, Elizabeth R; Best, Benjamin D; Brumbaugh, Daniel R; Chapin, F Stuart; Crowder, Larry B; Daly, Kendra L; Doney, Scott C; Elfes, Cristiane; Fogarty, Michael J; Gaines, Steven D; Jacobsen, Kelsey I; Karrer, Leah Bunce; Leslie, Heather M; Neeley, Elizabeth; Pauly, Daniel; Polasky, Stephen; Ris, Bud; St Martin, Kevin; Stone, Gregory S; Sumaila, U Rashid; Zeller, Dirk

    2012-08-30

    The ocean plays a critical role in supporting human well-being, from providing food, livelihoods and recreational opportunities to regulating the global climate. Sustainable management aimed at maintaining the flow of a broad range of benefits from the ocean requires a comprehensive and quantitative method to measure and monitor the health of coupled human–ocean systems. We created an index comprising ten diverse public goals for a healthy coupled human–ocean system and calculated the index for every coastal country. Globally, the overall index score was 60 out of 100 (range 36–86), with developed countries generally performing better than developing countries, but with notable exceptions. Only 5% of countries scored higher than 70, whereas 32% scored lower than 50. The index provides a powerful tool to raise public awareness, direct resource management, improve policy and prioritize scientific research.

  1. Global ocean monitoring for the World Climate Research Programme.

    PubMed

    Revelle, R; Bretherton, F

    1986-07-01

    Oceanic research and modelling for the World Climate Research Program will utilize several recently-developed instruments and measuring techniques as well as well-tested, long-used instruments. Ocean-scanning satellites will map the component of the ocean-surface topography related to ocean currents and mesoscale eddies and to fluctuating water volumes caused by ocean warming and cooling. Other satellite instruments will measure the direction and magnitude of wind stress on the sea surface, surface water temperatures, the distribution of chlorophyll and other photosynthetic pigments, the characteristics of internal waves, and possible precipitation over the ocean. Networks of acoustic transponders will obtain a three-dimensional picture of the distribution of temperature from the surface down to mid-depth and of long-term changes in temperature at depth. Ocean research vessels will determine the distribution and fate of geochemical tracers and will also make high-precision, deep hydrographic casts. Ships of opportunity, using expendable instruments, will measure temperature, salinity and currents in the upper water layers. Drifting and anchored buoys will also measure these properties as well as those of the air above the sea surface. Tide gauges installed on islands and exposed coastal locations will measure variations in monthly and shorter-period mean sea level. These tide gauges will provide 'ground truth' for the satellite maps of sea-surface topography, and will also determine variations in ocean currents and temperature.All these instruments will be used in several major programs, the most ambitious of which is the World Ocean Circulation Experiment (WOCE) designed to obtain global measurements of major currents throughout the world ocean, greater understanding of the transformation of water masses, and the role of advective, convective, and turbulent processes in exchange of properties between surface and deep-ocean layers.A five- to ten-year experiment

  2. Impact of Parameterized Lee Wave Drag on the Energy Budget of an Eddying Global Ocean Model

    DTIC Science & Technology

    2013-08-26

    Teixeira, J., Peng, M., Hogan, T.F., Pauley, R., 2002. Navy Operational Global Atmospheric Prediction System (NOGAPS): Forcing for ocean models...Impact of parameterized lee wave drag on the energy budget of an eddying global ocean model David S. Trossman a,⇑, Brian K. Arbic a, Stephen T...input and output terms in the total mechanical energy budget of a hybrid coordinate high-resolution global ocean general circulation model forced by winds

  3. C-GLORSv5: an improved multipurpose global ocean eddy-permitting physical reanalysis

    NASA Astrophysics Data System (ADS)

    Storto, Andrea; Masina, Simona

    2016-11-01

    Global ocean reanalyses combine in situ and satellite ocean observations with a general circulation ocean model to estimate the time-evolving state of the ocean, and they represent a valuable tool for a variety of applications, ranging from climate monitoring and process studies to downstream applications, initialization of long-range forecasts and regional studies. The purpose of this paper is to document the recent upgrade of C-GLORS (version 5), the latest ocean reanalysis produced at the Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC) that covers the meteorological satellite era (1980-present) and it is being updated in delayed time mode. The reanalysis is run at eddy-permitting resolution (1/4° horizontal resolution and 50 vertical levels) and consists of a three-dimensional variational data assimilation system, a surface nudging and a bias correction scheme. With respect to the previous version (v4), C-GLORSv5 contains a number of improvements. In particular, background- and observation-error covariances have been retuned, allowing a flow-dependent inflation in the globally averaged background-error variance. An additional constraint on the Arctic sea-ice thickness was introduced, leading to a realistic ice volume evolution. Finally, the bias correction scheme and the initialization strategy were retuned. Results document that the new reanalysis outperforms the previous version in many aspects, especially in representing the variability of global heat content and associated steric sea level in the last decade, the top 80 m ocean temperature biases and root mean square errors, and the Atlantic Ocean meridional overturning circulation; slight worsening in the high-latitude salinity and deep ocean temperature emerge though, providing the motivation for further tuning of the reanalysis system. The dataset is available in NetCDF format at doi:10.1594/PANGAEA.857995.

  4. Robust global ocean cooling trend for the pre-industrial Common Era

    USGS Publications Warehouse

    McGregor, Helen V.; Evans, Michael N.; Goosse, Hugues; Leduc, Guillaume; Martrat, Belen; Addison, Jason A.; Mortyn, P. Graham; Oppo, Delia W.; Seidenkrantz, Marit-Solveig; Sicre, Marie-Alexandrine; Phipps, Steven J.; Selvaraj, Kandasamy; Thirumalai, Kaustubh; Filipsson, Helena L.; Ersek, Vasile

    2015-01-01

    The oceans mediate the response of global climate to natural and anthropogenic forcings. Yet for the past 2,000 years — a key interval for understanding the present and future climate response to these forcings — global sea surface temperature changes and the underlying driving mechanisms are poorly constrained. Here we present a global synthesis of sea surface temperatures for the Common Era (CE) derived from 57 individual marine reconstructions that meet strict quality control criteria. We observe a cooling trend from 1 to 1800 CEthat is robust against explicit tests for potential biases in the reconstructions. Between 801 and 1800 CE, the surface cooling trend is qualitatively consistent with an independent synthesis of terrestrial temperature reconstructions, and with a sea surface temperature composite derived from an ensemble of climate model simulations using best estimates of past external radiative forcings. Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content.

  5. Robust global ocean cooling trend for the pre-industrial Common Era

    NASA Astrophysics Data System (ADS)

    McGregor, Helen V.; Evans, Michael N.; Goosse, Hugues; Leduc, Guillaume; Martrat, Belen; Addison, Jason A.; Mortyn, P. Graham; Oppo, Delia W.; Seidenkrantz, Marit-Solveig; Sicre, Marie-Alexandrine; Phipps, Steven J.; Selvaraj, Kandasamy; Thirumalai, Kaustubh; Filipsson, Helena L.; Ersek, Vasile

    2015-09-01

    The oceans mediate the response of global climate to natural and anthropogenic forcings. Yet for the past 2,000 years -- a key interval for understanding the present and future climate response to these forcings -- global sea surface temperature changes and the underlying driving mechanisms are poorly constrained. Here we present a global synthesis of sea surface temperatures for the Common Era (CE) derived from 57 individual marine reconstructions that meet strict quality control criteria. We observe a cooling trend from 1 to 1800 CE that is robust against explicit tests for potential biases in the reconstructions. Between 801 and 1800 CE, the surface cooling trend is qualitatively consistent with an independent synthesis of terrestrial temperature reconstructions, and with a sea surface temperature composite derived from an ensemble of climate model simulations using best estimates of past external radiative forcings. Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content.

  6. Emergence of a global science-business initiative for ocean stewardship.

    PubMed

    Österblom, Henrik; Jouffray, Jean-Baptiste; Folke, Carl; Rockström, Johan

    2017-08-22

    The ocean represents a fundamental source of micronutrients and protein for a growing world population. Seafood is a highly traded and sought after commodity on international markets, and is critically dependent on healthy marine ecosystems. A global trend of wild stocks being overfished and in decline, as well as multiple sustainability challenges associated with a rapid growth of aquaculture, represent key concerns in relation to the United Nations Sustainable Development Goals. Existing efforts aimed to improve the sustainability of seafood production have generated important progress, primarily at the local and national levels, but have yet to effectively address the global challenges associated with the ocean. This study highlights the importance of transnational corporations in enabling transformative change, and thereby contributes to advancing the limited understanding of large-scale private actors within the sustainability science literature. We describe how we engaged with large seafood producers to coproduce a global science-business initiative for ocean stewardship. We suggest that this initiative is improving the prospects for transformative change by providing novel links between science and business, between wild-capture fisheries and aquaculture, and across geographical space. We argue that scientists can play an important role in facilitating change by connecting knowledge to action among global actors, while recognizing risks associated with such engagement. The methods developed through this case study contribute to identifying key competences in sustainability science and hold promises for other sectors as well.

  7. Emergence of a global science–business initiative for ocean stewardship

    PubMed Central

    Jouffray, Jean-Baptiste; Folke, Carl; Rockström, Johan

    2017-01-01

    The ocean represents a fundamental source of micronutrients and protein for a growing world population. Seafood is a highly traded and sought after commodity on international markets, and is critically dependent on healthy marine ecosystems. A global trend of wild stocks being overfished and in decline, as well as multiple sustainability challenges associated with a rapid growth of aquaculture, represent key concerns in relation to the United Nations Sustainable Development Goals. Existing efforts aimed to improve the sustainability of seafood production have generated important progress, primarily at the local and national levels, but have yet to effectively address the global challenges associated with the ocean. This study highlights the importance of transnational corporations in enabling transformative change, and thereby contributes to advancing the limited understanding of large-scale private actors within the sustainability science literature. We describe how we engaged with large seafood producers to coproduce a global science–business initiative for ocean stewardship. We suggest that this initiative is improving the prospects for transformative change by providing novel links between science and business, between wild-capture fisheries and aquaculture, and across geographical space. We argue that scientists can play an important role in facilitating change by connecting knowledge to action among global actors, while recognizing risks associated with such engagement. The methods developed through this case study contribute to identifying key competences in sustainability science and hold promises for other sectors as well. PMID:28784792

  8. How well-connected is the surface of the global ocean?

    PubMed

    Froyland, Gary; Stuart, Robyn M; van Sebille, Erik

    2014-09-01

    The Ekman dynamics of the ocean surface circulation is known to contain attracting regions such as the great oceanic gyres and the associated garbage patches. Less well-known are the extents of the basins of attractions of these regions and how strongly attracting they are. Understanding the shape and extent of the basins of attraction sheds light on the question of the strength of connectivity of different regions of the ocean, which helps in understanding the flow of buoyant material like plastic litter. Using short flow time trajectory data from a global ocean model, we create a Markov chain model of the surface ocean dynamics. The surface ocean is not a conservative dynamical system as water in the ocean follows three-dimensional pathways, with upwelling and downwelling in certain regions. Using our Markov chain model, we easily compute net surface upwelling and downwelling, and verify that it matches observed patterns of upwelling and downwelling in the real ocean. We analyze the Markov chain to determine multiple attracting regions. Finally, using an eigenvector approach, we (i) identify the five major ocean garbage patches, (ii) partition the ocean into basins of attraction for each of the garbage patches, and (iii) partition the ocean into regions that demonstrate transient dynamics modulo the attracting garbage patches.

  9. The CAFE model: A net production model for global ocean phytoplankton

    NASA Astrophysics Data System (ADS)

    Silsbe, Greg M.; Behrenfeld, Michael J.; Halsey, Kimberly H.; Milligan, Allen J.; Westberry, Toby K.

    2016-12-01

    The Carbon, Absorption, and Fluorescence Euphotic-resolving (CAFE) net primary production model is an adaptable framework for advancing global ocean productivity assessments by exploiting state-of-the-art satellite ocean color analyses and addressing key physiological and ecological attributes of phytoplankton. Here we present the first implementation of the CAFE model that incorporates inherent optical properties derived from ocean color measurements into a mechanistic and accurate model of phytoplankton growth rates (μ) and net phytoplankton production (NPP). The CAFE model calculates NPP as the product of energy absorption (QPAR), and the efficiency (ϕμ) by which absorbed energy is converted into carbon biomass (CPhyto), while μ is calculated as NPP normalized to CPhyto. The CAFE model performance is evaluated alongside 21 other NPP models against a spatially robust and globally representative set of direct NPP measurements. This analysis demonstrates that the CAFE model explains the greatest amount of variance and has the lowest model bias relative to other NPP models analyzed with this data set. Global oceanic NPP from the CAFE model (52 Pg C m-2 yr-1) and mean division rates (0.34 day-1) are derived from climatological satellite data (2002-2014). This manuscript discusses and validates individual CAFE model parameters (e.g., QPAR and ϕμ), provides detailed sensitivity analyses, and compares the CAFE model results and parameterization to other widely cited models.

  10. Perfluoroalkylated substances in the global tropical and subtropical surface oceans.

    PubMed

    González-Gaya, Belén; Dachs, Jordi; Roscales, Jose L; Caballero, Gemma; Jiménez, Begoña

    2014-11-18

    In this study, perfluoroalkylated substances (PFASs) were analyzed in 92 surface seawater samples taken during the Malaspina 2010 expedition which covered all the tropical and subtropical Atlantic, Pacific and Indian oceans. Nine ionic PFASs including C6-C10 perfluoroalkyl carboxylic acids (PFCAs), C4 and C6-C8 perfluoroalkyl sulfonic acids (PFSAs) and two neutral precursors perfluoroalkyl sulfonamides (PFASAs), were identified and quantified. The Atlantic Ocean presented the broader range in concentrations of total PFASs (131-10900 pg/L, median 645 pg/L, n = 45) compared to the other oceanic basins, probably due to a better spatial coverage. Total concentrations in the Pacific ranged from 344 to 2500 pg/L (median = 527 pg/L, n = 27) and in the Indian Ocean from 176 to 1976 pg/L (median = 329, n = 18). Perfluorooctanesulfonic acid (PFOS) was the most abundant compound, accounting for 33% of the total PFASs globally, followed by perfluorodecanoic acid (PFDA, 22%) and perfluorohexanoic acid (PFHxA, 12%), being the rest of the individual congeners under 10% of total PFASs, even for perfluorooctane carboxylic acid (PFOA, 6%). PFASAs accounted for less than 1% of the total PFASs concentration. This study reports the ubiquitous occurrence of PFCAs, PFSAs, and PFASAs in the global ocean, being the first attempt, to our knowledge, to show a comprehensive assessment in surface water samples collected in a single oceanic expedition covering tropical and subtropical oceans. The potential factors affecting their distribution patterns were assessed including the distance to coastal regions, oceanic subtropical gyres, currents and biogeochemical processes. Field evidence of biogeochemical controls on the occurrence of PFASs was tentatively assessed considering environmental variables (solar radiation, temperature, chlorophyll a concentrations among others), and these showed significant correlations with some PFASs, but explaining small to moderate percentages of variability

  11. Deep oceans may acidify faster than anticipated due to global warming

    NASA Astrophysics Data System (ADS)

    Chen, Chen-Tung Arthur; Lui, Hon-Kit; Hsieh, Chia-Han; Yanagi, Tetsuo; Kosugi, Naohiro; Ishii, Masao; Gong, Gwo-Ching

    2017-12-01

    Oceans worldwide are undergoing acidification due to the penetration of anthropogenic CO2 from the atmosphere1-4. The rate of acidification generally diminishes with increasing depth. Yet, slowing down of the thermohaline circulation due to global warming could reduce the pH in the deep oceans, as more organic material would decompose with a longer residence time. To elucidate this process, a time-series study at a climatically sensitive region with sufficient duration and resolution is needed. Here we show that deep waters in the Sea of Japan are undergoing reduced ventilation, reducing the pH of seawater. As a result, the acidification rate near the bottom of the Sea of Japan is 27% higher than the rate at the surface, which is the same as that predicted assuming an air-sea CO2 equilibrium. This reduced ventilation may be due to global warming and, as an oceanic microcosm with its own deep- and bottom-water formations, the Sea of Japan provides an insight into how future warming might alter the deep-ocean acidification.

  12. Insights into global diatom distribution and diversity in the world’s ocean

    PubMed Central

    Malviya, Shruti; Scalco, Eleonora; Audic, Stéphane; Vincent, Flora; Veluchamy, Alaguraj; Poulain, Julie; Wincker, Patrick; Iudicone, Daniele; de Vargas, Colomban; Bittner, Lucie; Zingone, Adriana; Bowler, Chris

    2016-01-01

    Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 size-fractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered. PMID:26929361

  13. Integrated studies of uncultured microbes in the global ocean (Invited)

    NASA Astrophysics Data System (ADS)

    Dupont, C.; Rusch, D.; Martiny, A.; Lasken, R.

    2010-12-01

    The Global Ocean Sampling (GOS) initiative at the J. Craig Venter Institute represents the most extensive metagenomic study of a single environment. Early findings highlighted the potential of shotgun metagenomics to expand our knowledge of marine microbial biodiversity and physiology. However, it also became clear that many of the abundant marine microbes remain uncultured, hindering a direct connection between phylogeny and ecophysiology. In two recent studies, a combination of single cell genomics and aggressive assembly of binned metagenomic data have resulted in the acquisition of multiple genomes for two uncultured but globally relevant organisms. Metabolic reconstructions of the whole genomes revealed unique physiological adaptations in marine Prochlorococcus to high nutrient, low Fe regions of the global ocean and illuminated the potential ecological role of the gamma-proteobacterial 16S clade SAR86. The internal reference genomes also facilitate fragment recruitment based biogeographical studies, both at the whole genome level and the protein level.

  14. Producing a Climate-Quality Database of Global Upper Ocean Profile Temperatures - The IQuOD (International Quality-controlled Ocean Database) Project.

    NASA Astrophysics Data System (ADS)

    Sprintall, J.; Cowley, R.; Palmer, M. D.; Domingues, C. M.; Suzuki, T.; Ishii, M.; Boyer, T.; Goni, G. J.; Gouretski, V. V.; Macdonald, A. M.; Thresher, A.; Good, S. A.; Diggs, S. C.

    2016-02-01

    Historical ocean temperature profile observations provide a critical element for a host of ocean and climate research activities. These include providing initial conditions for seasonal-to-decadal prediction systems, evaluating past variations in sea level and Earth's energy imbalance, ocean state estimation for studying variability and change, and climate model evaluation and development. The International Quality controlled Ocean Database (IQuOD) initiative represents a community effort to create the most globally complete temperature profile dataset, with (intelligent) metadata and assigned uncertainties. With an internationally coordinated effort organized by oceanographers, with data and ocean instrumentation expertise, and in close consultation with end users (e.g., climate modelers), the IQuOD initiative will assess and maximize the potential of an irreplaceable collection of ocean temperature observations (tens of millions of profiles collected at a cost of tens of billions of dollars, since 1772) to fulfil the demand for a climate-quality global database that can be used with greater confidence in a vast range of climate change related research and services of societal benefit. Progress towards version 1 of the IQuOD database, ongoing and future work will be presented. More information on IQuOD is available at www.iquod.org.

  15. A Global Ocean Tide Model From TOPEX/POSEIDON Altimetry: GOT99.2

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    1999-01-01

    Goddard Ocean Tide model GOT99.2 is a new solution for the amplitudes and phases of the global oceanic tides, based on over six years of sea-surface height measurements by the TOPEX/POSEIDON satellite altimeter. Comparison with deep-ocean tide-gauge measurements show that this new tidal solution is an improvement over previous global models, with accuracies for the main semidiurnal lunar constituent M2 now below 1.5 cm (deep water only). The new solution benefits from use of prior hydrodynamic models, several in shallow and inland seas as well as the global finite-element model FES94.1. This report describes some of the data processing details involved in handling the altimetry, and it provides a comprehensive set of global cotidal charts of the resulting solutions. Various derived tidal charts are also provided, including tidal loading deformation charts, tidal gravimetric charts, and tidal current velocity (or transport) charts. Finally, low-degree spherical harmonic coefficients are computed by numerical quadrature and are tabulated for the major short-period tides; these are useful for a variety of geodetic and geophysical purposes, especially in combination with similar estimates from satellite laser ranging.

  16. A 3D parameterization of nutrients atmospheric deposition to the global ocean

    NASA Astrophysics Data System (ADS)

    Myriokefalitakis, S.; Nenes, A.; Baker, A. R.; Mihalopoulos, N.; Kanakidou, M.

    2016-12-01

    Atmospheric deposition of trace constituents, both of natural and anthropogenic origin, can act as a nutrient source into the open ocean and affect marine ecosystem functioning and subsequently the exchange of CO2 between the atmosphere and the global ocean. Dust is known as a major source of nutrients (such as iron and phosphorus) to the global ocean, but only a fraction of these nutrients is released in soluble form that can be assimilated by the ecosystems. The global atmospheric iron (Fe) and phosphorus (P) cycles are here parameterized in a global 3-D chemical transport model. Both primary emissions of total and soluble Fe and P associated with dust and combustion processes are taken into account. The impact of atmospheric acidity on nutrient solubility is parameterised based on experimental findings and model results are evaluated by comparison with available observations. The effect of air-quality changes on soluble nutrient deposition is studied by performing sensitivity simulations using preindustrial, present and future emission scenarios. The link between the soluble Fe and P atmospheric deposition and anthropogenic sources is also investigated. Overall, the response of the chemical composition of nutrient-containing aerosols to environmental changes is demonstrated and quantified.

  17. Global Isotopic Signatures of Oceanic Island Basalts.

    DTIC Science & Technology

    1991-08-01

    and the__ WOODS HOLE OCEANOGRAPHIC INSTITUTION August 1991 ©Lynn A. Oschmann 1991 The author hereby grants to MIT, WHOI, and the U.S. Government...Massachusetts Institute of Technology! Woods Hole Oceanographic Institution Certified 1W ___ ____________________ Dr. Staidlc\\ R. I L, rt Senior Scientik, Woods ...Institute of T’echnology! Woods Hole Oceanographic Institution 3 GLOBAL ISOTOPIC SIGNATURES OF OCEANIC ISLAND BASALTS by LYNN A. OSCHMANN Submitted to the

  18. Changes of the Oceanic Long-term and seasonal variation in a Global-warming Climate

    NASA Astrophysics Data System (ADS)

    Xia, Q.; He, Y.; Dong, C.

    2015-12-01

    Abstract: Gridded absolute dynamic topography (ADT) from AVISO and outputs of sea surface height above geoid from a series of climate models run for CMIP5 are used to analysis global sea level variation. Variance has been calculated to determine the magnitude of change in sea level variation over two decades. Increasing trend of variance of ADT suggests an enhanced fluctuation as well as geostrophic shear of global ocean. To further determine on what scale does the increasing fluctuation dominate, the global absolute dynamic topography (ADT) has been separated into two distinguished parts: the global five-year mean sea surface (MSS) and the residual absolute dynamic topography (RADT). Increased variance of MSS can be ascribed to the nonuniform rising of global sea level and an enhancement of ocean gyres in the Pacific Ocean. While trend in the variance of RADT is found to be close to zero which suggests an unchanged ocean mesoscale variability. The Gaussian-like distribution of global ADT are used to study the change in extreme sea levels. Information entropy has also been adapted in our study. Increasing trend of information entropy which measures the degree of dispersion of a probability distribution suggests more appearance of extreme sea levels. Extreme high sea levels are increasing with a higher growing rate than the mean sea level rise.

  19. Simple global carbon model: The atmosphere-terrestrial biosphere-ocean interaction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kwon, O.Y.; Schnoor, J.L.

    A simple global carbon model has been developed for scenario analysis, and research needs prioritization. CO{sub 2} fertilization and temperature effects are included in the terrestrial biosphere compartment, and the ocean compartment includes inorganic chemistry which, with ocean water circulation, enables the calculation of time-variable oceanic carbon uptake. Model-derived Q{sub 10} values (the increasing rate for every 10{degrees}C increase of temperature) are 1.37 for land biota photosynthesis, 1.89 for land biota respiration, and 1.95 for soil respiration, and feedback temperature is set at 0.01{degrees}C/ppm of CO{sub 2}. These could be the important parameters controlling the carbon cycle in potential globalmore » warming scenarios. Scenario analysis, together with sensitivity analysis of temperature feedback, suggests that if CO{sub 2} emissions from fossil fuel combustion continue at the present increasing rate of {approximately}1.5% per year, a CO{sub 2} doubling (to 560 ppm) will appear in year 2060. Global warming would be responsible for 40 Gt as carbon (Gt C) accumulation in the land biota, 88 Gt C depletion from the soil carbon, a 7 Gt C accumulation in the oceans, and a 19 ppm increase in atmospheric CO{sub 2}. The ocean buffering capacity to take up the excess CO{sub 2} will decrease with the increasing atmospheric CO{sub 2} concentration. 51 refs., 8 figs., 3 tabs.« less

  20. OceanNOMADS: Real-time and retrospective access to operational U.S. ocean prediction products

    NASA Astrophysics Data System (ADS)

    Harding, J. M.; Cross, S. L.; Bub, F.; Ji, M.

    2011-12-01

    The National Oceanic and Atmospheric Administration (NOAA) National Operational Model Archive and Distribution System (NOMADS) provides both real-time and archived atmospheric model output from servers at the National Centers for Environmental Prediction (NCEP) and National Climatic Data Center (NCDC) respectively (http://nomads.ncep.noaa.gov/txt_descriptions/marRutledge-1.pdf). The NOAA National Ocean Data Center (NODC) with NCEP is developing a complementary capability called OceanNOMADS for operational ocean prediction models. An NCEP ftp server currently provides real-time ocean forecast output (http://www.opc.ncep.noaa.gov/newNCOM/NCOM_currents.shtml) with retrospective access through NODC. A joint effort between the Northern Gulf Institute (NGI; a NOAA Cooperative Institute) and the NOAA National Coastal Data Development Center (NCDDC; a division of NODC) created the developmental version of the retrospective OceanNOMADS capability (http://www.northerngulfinstitute.org/edac/ocean_nomads.php) under the NGI Ecosystem Data Assembly Center (EDAC) project (http://www.northerngulfinstitute.org/edac/). Complementary funding support for the developmental OceanNOMADS from U.S. Integrated Ocean Observing System (IOOS) through the Southeastern University Research Association (SURA) Model Testbed (http://testbed.sura.org/) this past year provided NODC the analogue that facilitated the creation of an NCDDC production version of OceanNOMADS (http://www.ncddc.noaa.gov/ocean-nomads/). Access tool development and storage of initial archival data sets occur on the NGI/NCDDC developmental servers with transition to NODC/NCCDC production servers as the model archives mature and operational space and distribution capability grow. Navy operational global ocean forecast subsets for U.S waters comprise the initial ocean prediction fields resident on the NCDDC production server. The NGI/NCDDC developmental server currently includes the Naval Research Laboratory Inter-America Seas

  1. The Tara Oceans voyage reveals global diversity and distribution patterns of marine planktonic ciliates

    PubMed Central

    Gimmler, Anna; Korn, Ralf; de Vargas, Colomban; Audic, Stéphane; Stoeck, Thorsten

    2016-01-01

    Illumina reads of the SSU-rDNA-V9 region obtained from the circumglobal Tara Oceans expedition allow the investigation of protistan plankton diversity patterns on a global scale. We analyzed 6,137,350 V9-amplicons from ocean surface waters and the deep chlorophyll maximum, which were taxonomically assigned to the phylum Ciliophora. For open ocean samples global planktonic ciliate diversity is relatively low (ca. 1,300 observed and predicted ciliate OTUs). We found that 17% of all detected ciliate OTUs occurred in all oceanic regions under study. On average, local ciliate OTU richness represented 27% of the global ciliate OTU richness, indicating that a large proportion of ciliates is widely distributed. Yet, more than half of these OTUs shared <90% sequence similarity with reference sequences of described ciliates. While alpha-diversity measures (richness and exp(Shannon H)) are hardly affected by contemporary environmental conditions, species (OTU) turnover and community similarity (β-diversity) across taxonomic groups showed strong correlation to environmental parameters. Logistic regression models predicted significant correlations between the occurrence of specific ciliate genera and individual nutrients, the oceanic carbonate system and temperature. Planktonic ciliates displayed distinct vertical distributions relative to chlorophyll a. In contrast, the Tara Oceans dataset did not reveal any evidence that latitude is structuring ciliate communities. PMID:27633177

  2. Is low frequency ocean sound increasing globally?

    PubMed

    Miksis-Olds, Jennifer L; Nichols, Stephen M

    2016-01-01

    Low frequency sound has increased in the Northeast Pacific Ocean over the past 60 yr [Ross (1993) Acoust. Bull. 18, 5-8; (2005) IEEE J. Ocean. Eng. 30, 257-261; Andrew, Howe, Mercer, and Dzieciuch (2002) J. Acoust. Soc. Am. 129, 642-651; McDonald, Hildebrand, and Wiggins (2006) J. Acoust. Soc. Am. 120, 711-717; Chapman and Price (2011) J. Acoust. Soc. Am. 129, EL161-EL165] and in the Indian Ocean over the past decade, [Miksis-Olds, Bradley, and Niu (2013) J. Acoust. Soc. Am. 134, 3464-3475]. More recently, Andrew, Howe, and Mercer's [(2011) J. Acoust. Soc. Am. 129, 642-651] observations in the Northeast Pacific show a level or slightly decreasing trend in low frequency noise. It remains unclear what the low frequency trends are in other regions of the world. In this work, data from the Comprehensive Nuclear-Test Ban Treaty Organization International Monitoring System was used to examine the rate and magnitude of change in low frequency sound (5-115 Hz) over the past decade in the South Atlantic and Equatorial Pacific Oceans. The dominant source observed in the South Atlantic was seismic air gun signals, while shipping and biologic sources contributed more to the acoustic environment at the Equatorial Pacific location. Sound levels over the past 5-6 yr in the Equatorial Pacific have decreased. Decreases were also observed in the ambient sound floor in the South Atlantic Ocean. Based on these observations, it does not appear that low frequency sound levels are increasing globally.

  3. New features of global climatology revealed by satellite-derived oceanic rainfall maps

    NASA Technical Reports Server (NTRS)

    Rao, M. S. V.; Theon, J. S.

    1977-01-01

    Quantitative rainfall maps over the oceanic areas of the globe were derived from the Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR) data. Analysis of satellite derived oceanic rainfall maps reveal certain distinctive characteristics of global patterns for the years 1973-74. The main ones are (1) the forking of the Intertropical Convergence Zone in the Pacific, (2) a previously unrecognized rain area in the South Atlantic, (3) the bimodal behavior of rainbelts in the Indian Ocean and (4) the large interannual variability in oceanic rainfall. These features are discussed.

  4. Estimating Particulate Inorganic Carbon Concentrations of the Global Ocean From Ocean Color Measurements Using a Reflectance Difference Approach

    NASA Astrophysics Data System (ADS)

    Mitchell, C.; Hu, C.; Bowler, B.; Drapeau, D.; Balch, W. M.

    2017-11-01

    A new algorithm for estimating particulate inorganic carbon (PIC) concentrations from ocean color measurements is presented. PIC plays an important role in the global carbon cycle through the oceanic carbonate pump, therefore accurate estimations of PIC concentrations from satellite remote sensing are crucial for observing changes on a global scale. An extensive global data set was created from field and satellite observations for investigating the relationship between PIC concentrations and differences in the remote sensing reflectance (Rrs) at green, red, and near-infrared (NIR) wavebands. Three color indices were defined: two as the relative height of Rrs(667) above a baseline running between Rrs(547) and an Rrs in the NIR (either 748 or 869 nm), and one as the difference between Rrs(547) and Rrs(667). All three color indices were found to explain over 90% of the variance in field-measured PIC. But, due to the lack of availability of Rrs(NIR) in the standard ocean color data products, most of the further analysis presented here was done using the color index determined from only two bands. The new two-band color index algorithm was found to retrieve PIC concentrations more accurately than the current standard algorithm used in generating global PIC data products. Application of the new algorithm to satellite imagery showed patterns on the global scale as revealed from field measurements. The new algorithm was more resistant to atmospheric correction errors and residual errors in sun glint corrections, as seen by a reduction in the speckling and patchiness in the satellite-derived PIC images.

  5. Stochastic Modeling and Global Warming Trend Extraction For Ocean Acoustic Travel Times.

    DTIC Science & Technology

    1995-01-06

    consideration and that these models can not currently be relied upon by themselves to predict global warming . Experimental data is most certainly needed, not...only to measure global warming itself, but to help improve the ocean model themselves. (AN)

  6. Estimates of Gelatinous Zooplankton Carbon Flux in the Global Oceans

    NASA Astrophysics Data System (ADS)

    Luo, J. Y.; Condon, R.; Cowen, R. K.

    2016-02-01

    Gelatinous zooplankton (GZ), which include the cnidarians, ctenophores, and pelagic tunicates, are a common feature of marine ecosystems worldwide, but their contribution to global biogeochemical fluxes has never been assessed. We constructed a carbon-cycle model with a single, annual time-step and resolved to a 5° spatial grid for the three major GZ groups in order to evaluate the GZ-mediated carbon fluxes and export to depth. Biomass inputs (totaling 0.149 Pg C) were based off of Lucas et al. (2014) and updated using the JeDI database (Condon et al. 2015). From the upper ocean, biomass export flux from cnidarians, ctenophores, and tunicates totaled 2.96 ± 2.82 Pg C y-1, though only 0.199 ± 0.023 Pg C y-1 of GZ carbon were transferred to upper trophic levels, roughly amounting to one-quarter of all mesozooplankton production flux. In contrast, GZ fluxes to DOC only comprised ca. 2% of labile DOC flux. Egestion flux from the upper ocean totaled 2.56 ± 3.35 Pg C y-1, with over 80% being fast-sinking tunicate fecal pellets. Due to fast sinking rates of carcasses and fecal pellets, 26% of all C export from the upper ocean reached the seafloor, such that GZ fecal matter is estimated to comprise between 20-30% of global POC surface export and 11-30% of POC seafloor deposition. Finally, results from sensitivity analyses showed no increase in cnidarian and ctenophore export fluxes with increased temperature and jelly biomass, though tunicate export fluxes showed some increase with both temperature and biomass. These results suggest that current estimates of global POC flux from the surface oceans, which range between 8.6 - 12.9 Pg C y-1, may be underestimated by as much as 20 - 25%, implying a definite need to incorporate GZ mediated flux in estimating the biological pump transfer efficiency. Our study represents the first effort to quantify the role of gelatinous zooplankton in the global marine carbon cycle.

  7. Global decadal climate variability driven by Southern Ocean convection

    NASA Astrophysics Data System (ADS)

    Marinov, I.; Cabre, A.

    2016-02-01

    Here we suggest a set of new "teleconnections" by which the Southern Ocean (SO) can induce anomalies in the tropical oceans and atmosphere. A 5000-year long control simulation in a coupled atmosphere-ocean model (CM2Mc, a low-resolution GFDL model) shows a natural, highly regular multi-decadal oscillation between periods of SO open sea convection and non-convective periods. This process happens naturally, with different frequencies and durations of convection across the majority of CMIP5 under preindustrial forcing (deLavergne et al., 2014). In our model, oscillations in Weddell Sea convection drive multidecadal variability in SO and global SSTs, as well as SO heat storage, with convective decades warm due to the heat released from the Circumpolar Deep Water and non-convective decades cold due to subsurface heat storage. Convective pulses drive local SST and sea ice variations south of 60S, immediately triggering changes in the Ferrell and Hadley cells, atmospheric energy budget and cross-equatorial heat exchange, ultimately influencing the position of the Intertropical Convergence Zone and rain patterns in the tropics. Additionally, the SO convection pulse is propagated to the tropics and the North Atlantic MOC via oceanic pathways on relatively fast (decadal) timescales, in agreement with recent observational constraints. Open sea convection is the major mode of Antarctic Bottom Water (AABW) formation in the CMIP5 models. Future improvements in the representation of shelf convection and sea-ice interaction in the SO are a clear necessity. These model improvements should render the AABW representation more realistic, and might influence (a) the connectivity of the SO with the rest of the planet, as described above and (b) the oceanic and global carbon cycle, of which the AABW is a fundamental conduit.

  8. Respiration of new and old carbon in the surface ocean: Implications for estimates of global oceanic gross primary productivity

    NASA Astrophysics Data System (ADS)

    Carvalho, Matheus C.; Schulz, Kai G.; Eyre, Bradley D.

    2017-06-01

    New respiration (Rnew, of freshly fixated carbon) and old respiration (Rold, of storage carbon) were estimated for different regions of the global surface ocean using published data on simultaneous measurements of the following: (1) primary productivity using 14C (14PP); (2) gross primary productivity (GPP) based on 18O or O2; and (3) net community productivity (NCP) using O2. The ratio Rnew/GPP in 24 h incubations was typically between 0.1 and 0.3 regardless of depth and geographical area, demonstrating that values were almost constant regardless of large variations in temperature (0 to 27°C), irradiance (surface to 100 m deep), nutrients (nutrient-rich and nutrient-poor waters), and community composition (diatoms, flagellates, etc,). As such, between 10 and 30% of primary production in the surface ocean is respired in less than 24 h, and most respiration (between 55 and 75%) was of older carbon. Rnew was most likely associated with autotrophs, with minor contribution from heterotrophic bacteria. Patterns were less clear for Rold. Short 14C incubations are less affected by respiratory losses. Global oceanic GPP is estimated to be between 70 and 145 Gt C yr-1.Plain Language SummaryHere we present a comprehensive coverage of <span class="hlt">ocean</span> new and old respiration. Our results show that nearly 20% of <span class="hlt">oceanic</span> gross primary production is consumed in the first 24 h. However, most (about 60%) respiration is of older carbon fixed at least 24 h before its consumption. Rates of new respiration relative to gross primary production were remarkably constant for the entire <span class="hlt">ocean</span>, which allowed a preliminary estimation of <span class="hlt">global</span> primary productivity as between 70 and 145 gt C yr-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010069509','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010069509"><span>A Multilayer Dataset of SSM/I-Derived <span class="hlt">Global</span> <span class="hlt">Ocean</span> Surface Turbulent Fluxes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Ardizzone, Joe; Nelkin, Eric; Einaud, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>A dataset including daily- and monthly-mean turbulent fluxes (momentum, latent heat, and sensible heat) and some relevant parameters over <span class="hlt">global</span> <span class="hlt">oceans</span>, derived from the Special Sensor Microwave/Imager (SSM/I) data, for the period July 1987-December 1994 and the 1988-94 annual and monthly-mean climatologies of the same variables is created. It has a spatial resolution of 2.0deg x 2.5deg latitude-longitude. The retrieved surface air humidity is found to be generally accurate as compared to the collocated radiosonde observations over <span class="hlt">global</span> <span class="hlt">oceans</span>. The retrieved wind stress and latent heat flux show useful accuracy as verified against research quality measurements of ship and buoy in the western equatorial Pacific. The 1988-94 seasonal-mean wind stress and latent heat flux show reasonable patterns related to seasonal variations of the atmospheric general circulation. The patterns of 1990-93 annual-mean turbulent fluxes and input variables are generally in good agreement with one of the best <span class="hlt">global</span> analyzed flux datasets that based on COADS (comprehensive <span class="hlt">ocean</span>-atmosphere data set) with corrections on wind speeds and covered the same period. The retrieved wind speed is generally within +/-1 m/s of the COADS-based, but is stronger by approx. 1-2 m/s in the northern extratropical <span class="hlt">oceans</span>. The discrepancy is suggested to be mainly due to higher COADS-modified wind speeds resulting from underestimation of anemometer heights. Compared to the COADS-based, the retrieved latent heat flux and sea-air humidity difference are generally larger with significant differences in the trade wind zones and the <span class="hlt">ocean</span> south of 40degS (up to approx. 40-60 W/sq m and approx. 1-1.5 g/kg). The discrepancy is believed to be mainly caused by higher COADS-based surface air humidity arising from the overestimation of dew point temperatures and from the extrapolation of observed high humidity southward into data-void regions south of 40degS. The retrieved sensible heat flux is generally within +/-5</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013615','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013615"><span>TOPEX/POSEIDON <span class="hlt">joint</span> verification plan</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1992-01-01</p> <p>TOPEX/POSEIDON is a satellite mission that will use altimetry to make precise measurements of sea level with the primary goal of studying <span class="hlt">global</span> <span class="hlt">ocean</span> circulation. The mission is <span class="hlt">jointly</span> conducted by the United States' National Aeronautics and Space Administration (NASA) and the French space agency, Centre National d'Etudes Spatiales (CNES). The current plans call for a launch of the satellite in August 1992. The primary mission will last 3 years, and provisions were made to extend the mission for an additional 2 years. The mission was coordinated with a number of international oceanographic and meteorological programs, including the World <span class="hlt">Ocean</span> Circulation Experiment and the Tropical <span class="hlt">Ocean</span> and <span class="hlt">Global</span> Atmosphere Program, both of which are sponsored by the World Climate Research Program. The observations of TOPEX/POSEIDON are timed to provide a <span class="hlt">global</span> perspective for interpreting the in situ measurements collected by these programs and in turn will be combined with observations of other satellites to achieve a <span class="hlt">global</span>, four-dimensional description of the circulation of the world's <span class="hlt">oceans</span>. In the autumn of 1987, an international team of 38 Principal Investigators was selected to participate in the mission. These scientists have been working closely with the TOPEX/POSEIDON Project to refine the mission design and science plans. During the first 6 months after launch, a number of these investigators will join with the project to conduct a wide range of oceanographic and geophysical investigations using the TOPEX/POSEIDON data. The purpose of these investigations is to demonstrate the scientific utility of the mission to the international scientific community.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988JGR....9315502S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988JGR....9315502S"><span>A simulation of the <span class="hlt">global</span> <span class="hlt">ocean</span> circulation with resolved eddies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semtner, Albert J.; Chervin, Robert M.</p> <p>1988-12-01</p> <p>A multilevel primitive-equation model has been constructed for the purpose of simulating <span class="hlt">ocean</span> circulation on modern supercomputing architectures. The model is designed to take advantage of faster clock speeds, increased numbers of processors, and enlarged memories of machines expected to be available over the next decade. The model allows <span class="hlt">global</span> eddy-resolving simulations to be conducted in support of the World <span class="hlt">Ocean</span> Circulation Experiment. Furthermore, <span class="hlt">global</span> <span class="hlt">ocean</span> modeling is essential for proper representation of the full range of <span class="hlt">oceanic</span> and climatic phenomena. The first such <span class="hlt">global</span> eddy-resolving <span class="hlt">ocean</span> calculation is reported here. A 20-year integration of a <span class="hlt">global</span> <span class="hlt">ocean</span> model with ½° grid spacing and 20 vertical levels has been carried out with realistic geometry and annual mean wind forcing. The temperature and salinity are constrained to Levitus gridded data above 25-m depth and below 710-m depth (on time scales of 1 month and 3 years, respectively), but the values in the main thermocline are unconstrained for the last decade of the calculation. The final years of the simulation allow the spontaneous formation of waves and eddies through the use of scale-selective viscosity and diffusion. A quasi-equilibrium state shows many realistic features of <span class="hlt">ocean</span> circulation, including unstable separating western boundary currents, the known anomalous northward heat transport in the South Atlantic, and a <span class="hlt">global</span> compensation for the abyssal spread of North Atlantic Deep Water via a long chain of thermocline mass transport from the tropical Pacific, through the Indonesian archipelago, across the Indian <span class="hlt">Ocean</span>, and around the southern tip of Africa. This chain of thermocline transport is perhaps the most striking result from the model, and eddies and waves are evident along the entire 20,000-km path of the flow. The modeled Gulf Stream separates somewhat north of Cape Hatteras, produces warm- and cold-core rings, and maintains its integrity as a meadering thermal front</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9277E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9277E"><span>Monitoring and Predicting the Export and Fate of <span class="hlt">Global</span> <span class="hlt">Ocean</span> Net Primary Production: The EXPORTS Field Program</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Exports Science Definition Team</p> <p>2016-04-01</p> <p><span class="hlt">Ocean</span> ecosystems play a critical role in the Earth's carbon cycle and its quantification on <span class="hlt">global</span> scales remains one of the greatest challenges in <span class="hlt">global</span> <span class="hlt">ocean</span> biogeochemistry. The goal of the EXport Processes in the <span class="hlt">Ocean</span> from Remote Sensing (EXPORTS) science plan is to develop a predictive understanding of the export and fate of <span class="hlt">global</span> <span class="hlt">ocean</span> primary production and its implications for the Earth's carbon cycle in present and future climates. NASA's satellite <span class="hlt">ocean</span>-color data record has revolutionized our understanding of <span class="hlt">global</span> marine systems. EXPORTS is designed to advance the utility of NASA <span class="hlt">ocean</span> color assets to predict how changes in <span class="hlt">ocean</span> primary production will impact the <span class="hlt">global</span> carbon cycle. EXPORTS will create a predictive understanding of both the export of organic carbon from the euphotic zone and its fate in the underlying "twilight zone" (depths of 500 m or more) where variable fractions of exported organic carbon are respired back to CO2. Ultimately, it is the sequestration of deep organic carbon transport that defines the impact of <span class="hlt">ocean</span> biota on atmospheric CO2 levels and hence climate. EXPORTS will generate a new, detailed understanding of <span class="hlt">ocean</span> carbon transport processes and pathways linking upper <span class="hlt">ocean</span> phytoplankton processes to the export and fate of organic matter in the underlying twilight zone using a combination of field campaigns, remote sensing and numerical modeling. The overarching objective for EXPORTS is to ensure the success of future satellite missions by establishing mechanistic relationships between remotely sensed signals and carbon cycle processes. Through a process-oriented approach, EXPORTS will foster new insights on <span class="hlt">ocean</span> carbon cycling that will maximize its societal relevance and be a key component in the U.S. investment to understand Earth as an integrated system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27935174','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27935174"><span>Going with the flow: the role of <span class="hlt">ocean</span> circulation in <span class="hlt">global</span> marine ecosystems under a changing climate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Gennip, Simon J; Popova, Ekaterina E; Yool, Andrew; Pecl, Gretta T; Hobday, Alistair J; Sorte, Cascade J B</p> <p>2017-07-01</p> <p><span class="hlt">Ocean</span> warming, acidification, deoxygenation and reduced productivity are widely considered to be the major stressors to <span class="hlt">ocean</span> ecosystems induced by emissions of CO 2 . However, an overlooked stressor is the change in <span class="hlt">ocean</span> circulation in response to climate change. Strong changes in the intensity and position of the western boundary currents have already been observed, and the consequences of such changes for ecosystems are beginning to emerge. In this study, we address climatically induced changes in <span class="hlt">ocean</span> circulation on a <span class="hlt">global</span> scale but relevant to propagule dispersal for species inhabiting <span class="hlt">global</span> shelf ecosystems, using a high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> model run under the IPCC RCP 8.5 scenario. The ¼ degree model resolution allows improved regional realism of the <span class="hlt">ocean</span> circulation beyond that of available CMIP5-class models. We use a Lagrangian approach forced by modelled <span class="hlt">ocean</span> circulation to simulate the circulation pathways that disperse planktonic life stages. Based on trajectory backtracking, we identify present-day coastal retention, dominant flow and dispersal range for coastal regions at the <span class="hlt">global</span> scale. Projecting into the future, we identify areas of the strongest projected circulation change and present regional examples with the most significant modifications in their dominant pathways. Climatically induced changes in <span class="hlt">ocean</span> circulation should be considered as an additional stressor of marine ecosystems in a similar way to <span class="hlt">ocean</span> warming or acidification. © 2017 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23746709','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23746709"><span>Dispersion of Fukushima radionuclides in the <span class="hlt">global</span> atmosphere and the <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Povinec, P P; Gera, M; Holý, K; Hirose, K; Lujaniené, G; Nakano, M; Plastino, W; Sýkora, I; Bartok, J; Gažák, M</p> <p>2013-11-01</p> <p>Large quantities of radionuclides were released in March-April 2011 during the accident of the Fukushima Dai-ichi Nuclear Power Plant to the atmosphere and the <span class="hlt">ocean</span>. Atmospheric and marine modeling has been carried out to predict the dispersion of radionuclides worldwide, to compare the predicted and measured radionuclide concentrations, and to assess the impact of the accident on the environment. Atmospheric Lagrangian dispersion modeling was used to simulate the dispersion of (137)Cs over America and Europe. <span class="hlt">Global</span> <span class="hlt">ocean</span> circulation model was applied to predict the dispersion of (137)Cs in the Pacific <span class="hlt">Ocean</span>. The measured and simulated (137)Cs concentrations in atmospheric aerosols and in seawater are compared with <span class="hlt">global</span> fallout and the Chernobyl accident, which represent the main sources of the pre-Fukushima radionuclide background in the environment. The radionuclide concentrations in the atmosphere have been negligible when compared with the Chernobyl levels. The maximum (137)Cs concentration in surface waters of the open Pacific <span class="hlt">Ocean</span> will be around 20 Bq/m(3). The plume will reach the US coast 4-5 y after the accident, however, the levels will be below 3 Bq/m(3). All the North Pacific <span class="hlt">Ocean</span> will be labeled with Fukushima (137)Cs 10 y after the accident with concentration bellow 1 Bq/m(3). Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA537113','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA537113"><span>Synthesis and Assimilation Systems - Essential Adjuncts to the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Observing System</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-02-16</p> <p>34, Elisabeth Remy󈧢’, Anthony Rosati*3", Andreas Schiller󈧤’, Doug M. Smith’"’, Detlef Stammer 󈧦’, Nozomi Sugiura𔃽", Kevin E. Trenberth "*’, Yan...and Beyond ENSO. In these proceedings (Vol. 2). 10. Stammer D. & Co-Authors (2002). The <span class="hlt">Global</span> <span class="hlt">Ocean</span> Circulation During 1992-1997 Estimated from...GODAE. Oceanography 22(3), 128-143. 25. Stammer , D. & Co-Authors (2010). <span class="hlt">Ocean</span> Information Provided through Ensemble <span class="hlt">Ocean</span> Syntheses. In these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28769035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28769035"><span>Spiraling pathways of <span class="hlt">global</span> deep waters to the surface of the Southern <span class="hlt">Ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tamsitt, Veronica; Drake, Henri F; Morrison, Adele K; Talley, Lynne D; Dufour, Carolina O; Gray, Alison R; Griffies, Stephen M; Mazloff, Matthew R; Sarmiento, Jorge L; Wang, Jinbo; Weijer, Wilbert</p> <p>2017-08-02</p> <p>Upwelling of <span class="hlt">global</span> deep waters to the sea surface in the Southern <span class="hlt">Ocean</span> closes the <span class="hlt">global</span> overturning circulation and is fundamentally important for <span class="hlt">oceanic</span> uptake of carbon and heat, nutrient resupply for sustaining <span class="hlt">oceanic</span> biological production, and the melt rate of ice shelves. However, the exact pathways and role of topography in Southern <span class="hlt">Ocean</span> upwelling remain largely unknown. Here we show detailed upwelling pathways in three dimensions, using hydrographic observations and particle tracking in high-resolution models. The analysis reveals that the northern-sourced deep waters enter the Antarctic Circumpolar Current via southward flow along the boundaries of the three <span class="hlt">ocean</span> basins, before spiraling southeastward and upward through the Antarctic Circumpolar Current. Upwelling is greatly enhanced at five major topographic features, associated with vigorous mesoscale eddy activity. Deep water reaches the upper <span class="hlt">ocean</span> predominantly south of the Antarctic Circumpolar Current, with a spatially nonuniform distribution. The timescale for half of the deep water to upwell from 30° S to the mixed layer is ~60-90 years.Deep waters of the Atlantic, Pacific and Indian <span class="hlt">Oceans</span> upwell in the Southern Oceanbut the exact pathways are not fully characterized. Here the authors present a three dimensional view showing a spiralling southward path, with enhanced upwelling by eddy-transport at topographic hotspots.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ESSD....8..297O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ESSD....8..297O"><span>The <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project version 2 (GLODAPv2) - an internally consistent data product for the world <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olsen, Are; Key, Robert M.; van Heuven, Steven; Lauvset, Siv K.; Velo, Anton; Lin, Xiaohua; Schirnick, Carsten; Kozyr, Alex; Tanhua, Toste; Hoppema, Mario; Jutterström, Sara; Steinfeldt, Reiner; Jeansson, Emil; Ishii, Masao; Pérez, Fiz F.; Suzuki, Toru</p> <p>2016-08-01</p> <p>Version 2 of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the <span class="hlt">global</span> <span class="hlt">ocean</span>. It includes data assembled during the previous efforts GLODAPv1.1 (<span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic <span class="hlt">ocean</span> Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl4) have been subjected to extensive quality control, including systematic evaluation of bias. The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. This compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg-1 in dissolved inorganic carbon, 6 µmol kg-1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.The original data and their documentation and doi codes are available at the Carbon Dioxide Information Analysis Center (<a href="http://cdiac.ornl.gov/<span class="hlt">oceans</span>/GLODAPv2/" target="_blank">http://cdiac.ornl.gov/<span class="hlt">oceans</span>/GLODAPv2/</a>). This site also provides access to the calibrated data product, which is provided as a single <span class="hlt">global</span> file or four regional ones - the Arctic, Atlantic, Indian, and Pacific <span class="hlt">oceans</span> - under the <a href="http://dx.doi.org/10.3334/CDIAC/OTG.NDP093_GLODAPv2" target="_blank">doi:10.3334/CDIAC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090027894','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090027894"><span>Declining <span class="hlt">Global</span> Per Capita Agricultural Production and Warming <span class="hlt">Oceans</span> Threaten Food Security</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Funk, Chris C.; Brown, Molly E.</p> <p>2009-01-01</p> <p>Despite accelerating <span class="hlt">globalization</span>, most people still eat food that was grown locally. Developing countries with weak purchasing power tend to import as little food as possible from <span class="hlt">global</span> markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be controlled by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices, and policies. In this paper we discuss several emerging threats to <span class="hlt">global</span> and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian <span class="hlt">Ocean</span> and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia, and Central and Southern America will experience substantial declines in per capita cereal production. <span class="hlt">Global</span> per capita cereal production will potentially decline by 14 percent between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific <span class="hlt">Oceans</span>, may also reduce 21 st century food availability by disrupting Indian <span class="hlt">Ocean</span> moisture transports and tilting the 21 st century climate toward a more El Nino-like state. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian <span class="hlt">Ocean</span> warming appears to have already reduced main growing season rainfall along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, we present an analysis of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1082686','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1082686"><span>TARA <span class="hlt">OCEANS</span>: A <span class="hlt">Global</span> Analysis of <span class="hlt">Oceanic</span> Plankton Ecosystems (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Karsenti, Eric</p> <p>2013-03-01</p> <p>Eric Karsenti of EMBL delivers the closing keynote on "TARA <span class="hlt">OCEANS</span>: A <span class="hlt">Global</span> Analysis of <span class="hlt">Oceanic</span> Plankton Ecosystems" at the 8th Annual Genomics of Energy & Environment Meeting on March 28, 2013 in Walnut Creek, California.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/1082686','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/1082686"><span>TARA <span class="hlt">OCEANS</span>: A <span class="hlt">Global</span> Analysis of <span class="hlt">Oceanic</span> Plankton Ecosystems (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a></p> <p>Karsenti, Eric [European Molecular Biology Lab. (EMBL), Heidelberg (Germany)</p> <p>2018-05-23</p> <p>Eric Karsenti of EMBL delivers the closing keynote on "TARA <span class="hlt">OCEANS</span>: A <span class="hlt">Global</span> Analysis of <span class="hlt">Oceanic</span> Plankton Ecosystems" at the 8th Annual Genomics of Energy & Environment Meeting on March 28, 2013 in Walnut Creek, California.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24361115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24361115"><span><span class="hlt">Global</span> assessment of <span class="hlt">oceanic</span> lead pollution using sperm whales (Physeter macrocephalus) as an indicator species.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Savery, Laura C; Wise, Sandra S; Falank, Carolyne; Wise, James; Gianios, Christy; Douglas Thompson, W; Perkins, Christopher; Zheng, Tongzhang; Zhu, Cairong; Wise, John Pierce</p> <p>2014-02-15</p> <p>Lead (Pb) is an <span class="hlt">oceanic</span> pollutant of <span class="hlt">global</span> concern. Anthropogenic activities are increasing <span class="hlt">oceanic</span> levels, but to an unknown extent. The sperm whale (Physeter macrocephalus) has a <span class="hlt">global</span> distribution and high trophic level. The aim of this study was to establish a <span class="hlt">global</span> baseline of <span class="hlt">oceanic</span> Pb concentrations using free-ranging sperm whales as an indicator species. Skin biopsies (n=337) were collected during the voyage of the Odyssey (2000-2005) from 17 regions considering gender and age. Pb was detectable in 315 samples with a <span class="hlt">global</span> mean of 1.6 ug/gww ranging from 0.1 to 129.6 ug/gww. Papua New Guinea, Bahamas and Australia had the highest regional mean with 6.1, 3.4, and 3.1 ug/gww, respectively. Pb concentrations were not significantly different between sex and age in males. This is the first <span class="hlt">global</span> toxicological dataset for Pb in a marine mammal and confirms Pb is widely distributed with hotspots in some regions. Copyright © 2014. Published by Elsevier Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790015713','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790015713"><span>Atmospheric and oceanographic research review, 1978. [<span class="hlt">global</span> weather, <span class="hlt">ocean</span>/air interactions, and climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1978-01-01</p> <p>Research activities related to <span class="hlt">global</span> weather, <span class="hlt">ocean</span>/air interactions, and climate are reported. The <span class="hlt">global</span> weather research is aimed at improving the assimilation of satellite-derived data in weather forecast models, developing analysis/forecast models that can more fully utilize satellite data, and developing new measures of forecast skill to properly assess the impact of satellite data on weather forecasting. The oceanographic research goal is to understand and model the processes that determine the general circulation of the <span class="hlt">oceans</span>, focusing on those processes that affect sea surface temperature and <span class="hlt">oceanic</span> heat storage, which are the oceanographic variables with the greatest influence on climate. The climate research objective is to support the development and effective utilization of space-acquired data systems in climate forecast models and to conduct sensitivity studies to determine the affect of lower boundary conditions on climate and predictability studies to determine which <span class="hlt">global</span> climate features can be modeled either deterministically or statistically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060041407&hterms=Doing+better+Doing+Good&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D80%26Ntt%3DDoing%2Bbetter%2Bat%2BDoing%2BGood','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060041407&hterms=Doing+better+Doing+Good&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D80%26Ntt%3DDoing%2Bbetter%2Bat%2BDoing%2BGood"><span>Assimilation of TOPEX/POSEIDON Altimeter Data into a <span class="hlt">Global</span> <span class="hlt">Ocean</span> Circulation Model: Are the Results Any Good?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fukumori, I.; Fu, L. L.; Chao, Y.</p> <p>1998-01-01</p> <p>The feasibility of assimilating satellite altimetry data into a <span class="hlt">global</span> <span class="hlt">ocean</span> general <span class="hlt">ocean</span> general circulation model is studied. Three years of TOPEX/POSEIDON data is analyzed using a <span class="hlt">global</span>, three-dimensional, nonlinear primitive equation model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912915K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912915K"><span>Impact of biomass burning on nutrient deposition to the <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kanakidou, Maria; Myriokefalitakis, Stelios; Daskalakis, Nikos; Mihalopoulos, Nikolaos; Nenes, Athanasios</p> <p>2017-04-01</p> <p>Atmospheric deposition of trace constituents, both of natural and anthropogenic origin, can act as a nutrient source into the open <span class="hlt">ocean</span> and affect marine ecosystem functioning and subsequently the exchange of CO2 between the atmosphere and the <span class="hlt">global</span> <span class="hlt">ocean</span>. Dust is known as a major source of nutrients (Fe and P) into the atmosphere, but only a fraction of these nutrients is released in soluble form that can be assimilated by the ecosystems. Dust is also known to enhance N deposition by interacting with anthropogenic pollutants and neutralisation of part of the acidity of the atmosphere by crustal alkaline species. These nutrients have also primary anthropogenic sources including combustion emissions. The <span class="hlt">global</span> atmospheric N [1], Fe [2] and P [3] cycles have been parameterized in the <span class="hlt">global</span> 3-D chemical transport model TM4-ECPL, accounting for inorganic and organic forms of these nutrients, for all natural and anthropogenic sources of these nutrients including biomass burning, as well as for the link between the soluble forms of Fe and P atmospheric deposition and atmospheric acidity. The impact of atmospheric acidity on nutrient solubility has been parameterised based on experimental findings and the model results have been evaluated by extensive comparison with available observations. In the present study we isolate the significant impact of biomass burning emissions on these nutrients deposition by comparing <span class="hlt">global</span> simulations that consider or neglect biomass burning emissions. The investigated impact integrates changes in the emissions of the nutrients as well as in atmospheric oxidants and acidity and thus in atmospheric processing and secondary sources of these nutrients. The results are presented and thoroughly discussed. References [1] Kanakidou M, S. Myriokefalitakis, N. Daskalakis, G. Fanourgakis, A. Nenes, A. Baker, K. Tsigaridis, N. Mihalopoulos, Past, Present and Future Atmospheric Nitrogen Deposition, Journal of the Atmospheric Sciences (JAS-D-15</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28978724','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28978724"><span>The growth of finfish in <span class="hlt">global</span> open-<span class="hlt">ocean</span> aquaculture under climate change.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klinger, Dane H; Levin, Simon A; Watson, James R</p> <p>2017-10-11</p> <p>Aquaculture production is projected to expand from land-based operations to the open <span class="hlt">ocean</span> as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-<span class="hlt">ocean</span> aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the <span class="hlt">oceans</span>. We employ a novel spatial model to estimate the potential of open-<span class="hlt">ocean</span> finfish aquaculture <span class="hlt">globally</span>, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds-Atlantic salmon ( Salmo salar ), gilthead seabream ( Sparus aurata ) and cobia ( Rachycentron canadum )-is compared across species and regions and with climate change, based on outputs of a high-resolution <span class="hlt">global</span> climate model. <span class="hlt">Globally</span>, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses. © 2017 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040034037&hterms=oceans+tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Doceans%2Btide','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040034037&hterms=oceans+tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Doceans%2Btide"><span>The <span class="hlt">Global</span> S$_1$ <span class="hlt">Ocean</span> Tide</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ray, Richard D.; Egbert, G. D.</p> <p>2003-01-01</p> <p>The small S$_1$ <span class="hlt">ocean</span> tide is caused primarily by diurnal atmospheric pressure loading. Its excitation is therefore unlike any other diurnal tide. The <span class="hlt">global</span> character of $S-1$ is here determined by numerical modeling and by analysis of Topex/Poseidon satellite altimeter data. The two approaches yield reasonably consistent results, and large ( $ greater than $l\\cm) amplitudes in several regions are further confirmed by comparison with coastal tide gauges. Notwithstanding their excitation differences, S$-1$ and other diurnal tides are found to share several common features, such as relatively large amplitudes in the Arabian Sea, the Sea of Okhotsk, and the Gulf of Alaska. The most noticeable difference is the lack of an S$-1$ Antarctic Kelvin wave. These similarities and differences can be explained in terms of the coherences between near-diurnal <span class="hlt">oceanic</span> normal modes and the underlying tidal forcings. While gravitational diurnal tidal forces excite primarily a 28-hour Antarctic-Pacific mode, the S$_1$ air tide excites several other near-diurnal modes, none of which has large amplitudes near Antarctica.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28580419','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28580419"><span>Light penetration structures the deep acoustic scattering layers in the <span class="hlt">global</span> <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aksnes, Dag L; Røstad, Anders; Kaartvedt, Stein; Martinez, Udane; Duarte, Carlos M; Irigoien, Xabier</p> <p>2017-05-01</p> <p>The deep scattering layer (DSL) is a ubiquitous acoustic signature found across all <span class="hlt">oceans</span> and arguably the dominant feature structuring the pelagic open <span class="hlt">ocean</span> ecosystem. It is formed by mesopelagic fishes and pelagic invertebrates. The DSL animals are an important food source for marine megafauna and contribute to the biological carbon pump through the active flux of organic carbon transported in their daily vertical migrations. They occupy depths from 200 to 1000 m at daytime and migrate to a varying degree into surface waters at nighttime. Their daytime depth, which determines the migration amplitude, varies across the <span class="hlt">global</span> <span class="hlt">ocean</span> in concert with water mass properties, in particular the oxygen regime, but the causal underpinning of these correlations has been unclear. We present evidence that the broad variability in the <span class="hlt">oceanic</span> DSL daytime depth observed during the Malaspina 2010 Circumnavigation Expedition is governed by variation in light penetration. We find that the DSL depth distribution conforms to a common optical depth layer across the <span class="hlt">global</span> <span class="hlt">ocean</span> and that a correlation between dissolved oxygen and light penetration provides a parsimonious explanation for the association of shallow DSL distributions with hypoxic waters. In enhancing understanding of this phenomenon, our results should improve the ability to predict and model the dynamics of one of the largest animal biomass components on earth, with key roles in the <span class="hlt">oceanic</span> biological carbon pump and food web.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS43C1283J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS43C1283J"><span>On Verifying Currents and Other Features in the Hawaiian Islands Region Using Fully Coupled <span class="hlt">Ocean</span>/Atmosphere Mesoscale Prediction System Compared to <span class="hlt">Global</span> <span class="hlt">Ocean</span> Model and <span class="hlt">Ocean</span> Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jessen, P. G.; Chen, S.</p> <p>2014-12-01</p> <p>This poster introduces and evaluates features concerning the Hawaii, USA region using the U.S. Navy's fully Coupled <span class="hlt">Ocean</span>/Atmosphere Mesoscale Prediction System (COAMPS-OS™) coupled to the Navy Coastal <span class="hlt">Ocean</span> Model (NCOM). It also outlines some challenges in verifying <span class="hlt">ocean</span> currents in the open <span class="hlt">ocean</span>. The system is evaluated using in situ <span class="hlt">ocean</span> data and initial forcing fields from the operational <span class="hlt">global</span> Hybrid Coordinate <span class="hlt">Ocean</span> Model (HYCOM). Verification shows difficulties in modelling downstream currents off the Hawaiian islands (Hawaii's wake). Comparing HYCOM to NCOM current fields show some displacement of small features such as eddies. Generally, there is fair agreement from HYCOM to NCOM in salinity and temperature fields. There is good agreement in SSH fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23676754','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23676754"><span>Signature of <span class="hlt">ocean</span> warming in <span class="hlt">global</span> fisheries catch.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheung, William W L; Watson, Reg; Pauly, Daniel</p> <p>2013-05-16</p> <p>Marine fishes and invertebrates respond to <span class="hlt">ocean</span> warming through distribution shifts, generally to higher latitudes and deeper waters. Consequently, fisheries should be affected by 'tropicalization' of catch (increasing dominance of warm-water species). However, a signature of such climate-change effects on <span class="hlt">global</span> fisheries catch has so far not been detected. Here we report such an index, the mean temperature of the catch (MTC), that is calculated from the average inferred temperature preference of exploited species weighted by their annual catch. Our results show that, after accounting for the effects of fishing and large-scale oceanographic variability, <span class="hlt">global</span> MTC increased at a rate of 0.19 degrees Celsius per decade between 1970 and 2006, and non-tropical MTC increased at a rate of 0.23 degrees Celsius per decade. In tropical areas, MTC increased initially because of the reduction in the proportion of subtropical species catches, but subsequently stabilized as scope for further tropicalization of communities became limited. Changes in MTC in 52 large marine ecosystems, covering the majority of the world's coastal and shelf areas, are significantly and positively related to regional changes in sea surface temperature. This study shows that <span class="hlt">ocean</span> warming has already affected <span class="hlt">global</span> fisheries in the past four decades, highlighting the immediate need to develop adaptation plans to minimize the effect of such warming on the economy and food security of coastal communities, particularly in tropical regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA537743','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA537743"><span>Salinity Boundary Conditions and the Atlantic Meridional Overturning Circulation in Depth and Quasi-Isopycnic Coordinate <span class="hlt">Global</span> <span class="hlt">Ocean</span> Models</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-06-30</p> <p>Atlantic Meridional Overturning Circulation in Depth and Quasi-Isopycnic Coordinate <span class="hlt">Global</span> <span class="hlt">Ocean</span>...2009 4. TITLE AND SUBTITLE Salinity Boundary Conditions and the Atlantic Meridional Overturning Circulation in Depth and Quasi-Isopycnic Coordinate... Atlantic Meridional Overturning Circulation (AMOC) in <span class="hlt">global</span> simulations performed with the depth coordinate Parallel <span class="hlt">Ocean</span> Program (POP) <span class="hlt">ocean</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2671968','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2671968"><span><span class="hlt">Global</span> Body Posture Evaluation in Patients with Temporomandibular <span class="hlt">Joint</span> Disorder</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Saito, Eliza Tiemi; Akashi, Paula Marie Hanai; de Camargo Neves Sacco, Isabel</p> <p>2009-01-01</p> <p>AIM: To identify the relationship between anterior disc displacement and <span class="hlt">global</span> posture (plantar arches, lower limbs, shoulder and pelvic girdle, vertebral spine, head and mandibles). Common signs and symptoms of anterior disc displacement were also identified. INTRODUCTION: <span class="hlt">Global</span> posture deviations cause body adaptation and realignment, which may interfere with the organization and function of the temporomandibular <span class="hlt">joint</span>. METHODS : <span class="hlt">Global</span> posture evaluation was performed in a group of 10 female patients (20 to 30 years of age) with temporomandibular <span class="hlt">joint</span> disc displacement and in a control group of 16 healthy female volunteers matched for age, weight and height. Anterior disc displacement signs, symptoms and the presence of parafunctional habits were also identified through interview. RESULTS: Patients with disc displacement showed a higher incidence of pain in the temporomandibular <span class="hlt">joint</span> area, but there were no differences in parafunctional habits between the groups. In the disc displacement group, postural deviations were found in the pelvis (posterior rotation), lumbar spine (hyperlordosis), thoracic spine (rectification), head (deviation to the right) and mandibles (deviation to the left with open mouth). There were no differences in the longitudinal plantar arches between the groups. CONCLUSION: Our results suggest a close relationship between body posture and temporomandibular disorder, though it is not possible to determine whether postural deviations are the cause or the result of the disorder. Hence, postural evaluation could be an important component in the overall approach to providing accurate prevention and treatment in the management of patients with temporomandibular disorder. PMID:19142549</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28073022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28073022"><span><span class="hlt">Ocean</span> Depths: The Mesopelagic and Implications for <span class="hlt">Global</span> Warming.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Costello, Mark J; Breyer, Sean</p> <p>2017-01-09</p> <p>The mesopelagic or 'twilight zone' of the <span class="hlt">oceans</span> occurs too deep for photosynthesis, but is a major part of the world's carbon cycle. Depth boundaries for the mesopelagic have now been shown on a <span class="hlt">global</span> scale using the distribution of pelagic animals detected by compiling echo-soundings from ships around the world, and been used to predict the effect of <span class="hlt">global</span> warming on regional fish production. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GBioC..28..181S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GBioC..28..181S"><span><span class="hlt">Global</span> assessment of <span class="hlt">ocean</span> carbon export by combining satellite observations and food-web models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siegel, D. A.; Buesseler, K. O.; Doney, S. C.; Sailley, S. F.; Behrenfeld, M. J.; Boyd, P. W.</p> <p>2014-03-01</p> <p>The export of organic carbon from the surface <span class="hlt">ocean</span> by sinking particles is an important, yet highly uncertain, component of the <span class="hlt">global</span> carbon cycle. Here we introduce a mechanistic assessment of the <span class="hlt">global</span> <span class="hlt">ocean</span> carbon export using satellite observations, including determinations of net primary production and the slope of the particle size spectrum, to drive a food-web model that estimates the production of sinking zooplankton feces and algal aggregates comprising the sinking particle flux at the base of the euphotic zone. The synthesis of observations and models reveals fundamentally different and ecologically consistent regional-scale patterns in export and export efficiency not found in previous <span class="hlt">global</span> carbon export assessments. The model reproduces regional-scale particle export field observations and predicts a climatological mean <span class="hlt">global</span> carbon export from the euphotic zone of 6 Pg C yr-1. <span class="hlt">Global</span> export estimates show small variation (typically < 10%) to factor of 2 changes in model parameter values. The model is also robust to the choices of the satellite data products used and enables interannual changes to be quantified. The present synthesis of observations and models provides a path for quantifying the <span class="hlt">ocean</span>'s biological pump.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17813287','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17813287"><span><span class="hlt">Global</span> climate change and intensification of coastal <span class="hlt">ocean</span> upwelling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bakun, A</p> <p>1990-01-12</p> <p>A mechanism exists whereby <span class="hlt">global</span> greenhouse warning could, by intensifying the alongshore wind stress on the <span class="hlt">ocean</span> surface, lead to acceleration of coastal upwelling. Evidence from several different regions suggests that the major coastal upwelling systems of the world have been growing in upwelling intensity as greenhouse gases have accumulated in the earth's atmosphere. Thus the cool foggy summer conditions that typify the coastlands of northern California and other similar upwelling regions might, under <span class="hlt">global</span> warming, become even more pronounced. Effects of enhanced upwelling on the marine ecosystem are uncertain but potentially dramatic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171552&hterms=kaufman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dkaufman','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171552&hterms=kaufman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dkaufman"><span>Internally Consistent MODIS Estimate of Aerosol Clear-Sky Radiative Effect Over the <span class="hlt">Global</span> <span class="hlt">Oceans</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, Lorraine A.; Kaufman, Yoram J.</p> <p>2004-01-01</p> <p>Modern satellite remote sensing, and in particular the MODerate resolution Imaging Spectroradiometer (MODIS), offers a measurement-based pathway to estimate <span class="hlt">global</span> aerosol radiative effects and aerosol radiative forcing. Over the <span class="hlt">Oceans</span>, MODIS retrieves the total aerosol optical thickness, but also reports which combination of the 9 different aerosol models was used to obtain the retrieval. Each of the 9 models is characterized by a size distribution and complex refractive index, which through Mie calculations correspond to a unique set of single scattering albedo, assymetry parameter and spectral extinction for each model. The combination of these sets of optical parameters weighted by the optical thickness attributed to each model in the retrieval produces the best fit to the observed radiances at the top of the atmosphere. Thus the MODIS <span class="hlt">Ocean</span> aerosol retrieval provides us with (1) An observed distribution of <span class="hlt">global</span> aerosol loading, and (2) An internally-consistent, observed, distribution of aerosol optical models that when used in combination will best represent the radiances at the top of the atmosphere. We use these two observed <span class="hlt">global</span> distributions to initialize the column climate model by Chou and Suarez to calculate the aerosol radiative effect at top of the atmosphere and the radiative efficiency of the aerosols over the <span class="hlt">global</span> <span class="hlt">oceans</span>. We apply the analysis to 3 years of MODIS retrievals from the Terra satellite and produce <span class="hlt">global</span> and regional, seasonally varying, estimates of aerosol radiative effect over the clear-sky <span class="hlt">oceans</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GBioC..28..553Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GBioC..28..553Z"><span>Natural biogeochemical cycle of mercury in a <span class="hlt">global</span> three-dimensional <span class="hlt">ocean</span> tracer model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yanxu; Jaeglé, Lyatt; Thompson, LuAnne</p> <p>2014-05-01</p> <p>We implement mercury (Hg) biogeochemistry in the offline <span class="hlt">global</span> 3-D <span class="hlt">ocean</span> tracer model (OFFTRAC) to investigate the natural Hg cycle, prior to any anthropogenic input. The simulation includes three Hg tracers: dissolved elemental (Hg0aq), dissolved divalent (HgIIaq), and particle-bound mercury (HgPaq). Our Hg parameterization takes into account redox chemistry in <span class="hlt">ocean</span> waters, air-sea exchange of Hg0, scavenging of HgIIaq onto sinking particles, and resupply of HgIIaq at depth by remineralization of sinking particles. Atmospheric boundary conditions are provided by a <span class="hlt">global</span> simulation of the natural atmospheric Hg cycle in the GEOS-Chem model. In the surface <span class="hlt">ocean</span>, the OFFTRAC model predicts <span class="hlt">global</span> mean concentrations of 0.16 pM for total Hg, partitioned as 80% HgIIaq, 14% Hg0aq, and 6% HgPaq. Total Hg concentrations increase to 0.38 pM in the thermocline/intermediate waters (between the mixed layer and 1000 m depth) and 0.82 pM in deep waters (below 1000 m), reflecting removal of Hg from the surface to the subsurface <span class="hlt">ocean</span> by particle sinking followed by remineralization at depth. Our model predicts that Hg concentrations in the deep North Pacific <span class="hlt">Ocean</span> (>2000 m) are a factor of 2-3 higher than in the deep North Atlantic <span class="hlt">Ocean</span>. This is the result of cumulative input of Hg from particle remineralization as deep waters transit from the North Atlantic to the North Pacific on their ~2000 year journey. The model is able to reproduce the relatively uniform concentrations of total Hg observed in the old deep waters of the North Pacific <span class="hlt">Ocean</span> (observations: 1.2 ± 0.4 pM; model: 1.1 ± 0.04 pM) and Southern <span class="hlt">Ocean</span> (observations: 1.1 ± 0.2 pM; model: 0.8 ± 0.02 pM). However, the modeled concentrations are factors of 5-6 too low compared to observed concentrations in the surface <span class="hlt">ocean</span> and in the young water masses of the deep North Atlantic <span class="hlt">Ocean</span>. This large underestimate for these regions implies a factor of 5-6 anthropogenic enhancement in Hg concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990092375','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990092375"><span>Seasonal Distributions of <span class="hlt">Global</span> <span class="hlt">Ocean</span> Chlorophyll and Nutrients: Analysis with a Coupled <span class="hlt">Ocean</span> General Circulation Biogeochemical, and Radiative Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Watson W.</p> <p>1999-01-01</p> <p>A coupled general <span class="hlt">ocean</span> circulation, biogeochemical, and radiative model was constructed to evaluate and understand the nature of seasonal variability of chlorophyll and nutrients in the <span class="hlt">global</span> <span class="hlt">oceans</span>. The model is driven by climatological meteorological conditions, cloud cover, and sea surface temperature. Biogeochemical processes in the model are determined from the influences of circulation and turbulence dynamics, irradiance availability, and the interactions among three functional phytoplankton groups (diatoms, chorophytes, and picoplankton) and three nutrient groups (nitrate, ammonium, and silicate). Phytoplankton groups are initialized as homogeneous fields horizontally and vertically, and allowed to distribute themselves according to the prevailing conditions. Basin-scale model chlorophyll results are in very good agreement with CZCS pigments in virtually every <span class="hlt">global</span> region. Seasonal variability observed in the CZCS is also well represented in the model. Synoptic scale (100-1000 km) comparisons of imagery are also in good conformance, although occasional departures are apparent. Agreement of nitrate distributions with in situ data is even better, including seasonal dynamics, except for the equatorial Atlantic. The good agreement of the model with satellite and in situ data sources indicates that the model dynamics realistically simulate phytoplankton and nutrient dynamics on synoptic scales. This is especially true given that initial conditions are homogenous chlorophyll fields. The success of the model in producing a reasonable representation of chlorophyll and nutrient distributions and seasonal variability in the <span class="hlt">global</span> <span class="hlt">oceans</span> is attributed to the application of a generalized, processes-driven approach as opposed to regional parameterization, and the existence of multiple phytoplankton groups with different physiological and physical properties. These factors enable the model to simultaneously represent the great diversity of physical, biological</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA521562','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA521562"><span><span class="hlt">Global</span> <span class="hlt">Ocean</span> Forecast System (GOFS) Version 2.6. User’s Manual</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-03-31</p> <p>odimens.D, which takes the rivers.dat flow levels, inputs an SST and sea surface salinity (SSS) climatology from GDEM , and outputs the orivs_1.D...Center for Medium-range Weather Forecast GB GigaByte GDEM <span class="hlt">Global</span> Digital Elevation Map GOFS <span class="hlt">Global</span> <span class="hlt">Ocean</span> Forecast System HPCMP High Performance</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711768P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711768P"><span><span class="hlt">Ocean</span>SITES format and <span class="hlt">Ocean</span> Observatory Output harmonisation: past, present and future</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pagnani, Maureen; Galbraith, Nan; Diggs, Stephen; Lankhorst, Matthias; Hidas, Marton; Lampitt, Richard</p> <p>2015-04-01</p> <p>The <span class="hlt">Global</span> <span class="hlt">Ocean</span> Observing System (GOOS) initiative was launched in 1991, and was the first step in creating a <span class="hlt">global</span> view of <span class="hlt">ocean</span> observations. In 1999 oceanographers at the <span class="hlt">Ocean</span>Obs conference envisioned a '<span class="hlt">global</span> system of eulerian observatories' which evolved into the <span class="hlt">Ocean</span>SITES project. <span class="hlt">Ocean</span>SITES has been generously supported by individual oceanographic institutes and agencies across the globe, as well as by the WMO-IOC <span class="hlt">Joint</span> Technical Commission for Oceanography and Marine Meteorology (under JCOMMOPS). The project is directed by the needs of research scientists, but has a strong data management component, with an international team developing content standards, metadata specifications, and NetCDF templates for many types of in situ oceanographic data. The <span class="hlt">Ocean</span>SITES NetCDF format specification is intended as a robust data exchange and archive format specifically for time-series observatory data from the deep <span class="hlt">ocean</span>. First released in February 2006, it has evolved to build on and extend internationally recognised standards such as the Climate and Forecast (CF) standard, BODC vocabularies, ISO formats and vocabularies, and in version 1.3, released in 2014, ACDD (Attribute Convention for Dataset Discovery). The success of the <span class="hlt">Ocean</span>SITES format has inspired other observational groups, such as autonomous vehicles and ships of opportunity, to also use the format and today it is fulfilling the original concept of providing a coherent set of data from eurerian observatories. Data in the <span class="hlt">Ocean</span>SITES format is served by 2 <span class="hlt">Global</span> Data Assembly Centres (GDACs), one at Coriolis, in France, at ftp://ftp.ifremer.fr/ifremer/oceansites/ and one at the US NDBC, at ftp://data.ndbc.noaa.gov/data/oceansites/. These two centres serve over 26,800 <span class="hlt">Ocean</span>SITES format data files from 93 moorings. The use of standardised and controlled features enables the files held at the <span class="hlt">Ocean</span>SITES GDACs to be electronically discoverable and ensures the widest access to the data. The <span class="hlt">Ocean</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020001784','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020001784"><span>A 7.5-Year Dataset of SSM/I-Derived Surface Turbulent Fluxes Over <span class="hlt">Global</span> <span class="hlt">Oceans</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Adizzone, Joe; Nelkin, Eric; Starr, David OC. (Technical Monitor)</p> <p>2001-01-01</p> <p>The <span class="hlt">global</span> air-sea turbulent fluxes are needed for driving <span class="hlt">ocean</span> models and validating coupled <span class="hlt">ocean</span>-atmosphere <span class="hlt">global</span> models. A method was developed to retrieve surface air humidity from the radiances measured by the Special Sensor Microwave/Imager (SSM/I) Using both SSM/I-retrieved surface wind and air humidity, they computed daily turbulent fluxes over <span class="hlt">global</span> <span class="hlt">oceans</span> with a stability-dependent bulk scheme. Based on this method, we have produced Version 1 of Goddard Satellite-Based Surface Turbulent Fluxes (GSSTF) dataset from the SSM/I data and other data. It provides daily- and monthly-mean surface turbulent fluxes and some relevant parameters over <span class="hlt">global</span> <span class="hlt">oceans</span> for individual F8, F10, and F11 satellites covering the period July 1987-December 1994. It also provides 1988-94 annual- and monthly-mean climatologies of the same variables, using only F8 and F1 1 satellite data. It has a spatial resolution of 2.0 degrees x 2.5 degrees lat-long and is archived at the NASA/GSFC DAAC. The purpose of this paper is to present an updated assessment of the GSSTF 1.0 dataset.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSOD24B2464B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSOD24B2464B"><span>World <span class="hlt">Ocean</span> Database and the <span class="hlt">Global</span> Temperature and Salinity Profile Program Database: Synthesis of historical and near real-time <span class="hlt">ocean</span> profile data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boyer, T.; Sun, L.; Locarnini, R. A.; Mishonov, A. V.; Hall, N.; Ouellet, M.</p> <p>2016-02-01</p> <p>The World <span class="hlt">Ocean</span> Database (WOD) contains systematically quality controlled historical and recent <span class="hlt">ocean</span> profile data (temperature, salinity, oxygen, nutrients, carbon cycle variables, biological variables) ranging from Captain Cooks second voyage (1773) to this year's Argo floats. The US National Centers for Environmental Information (NCEI) also hosts the <span class="hlt">Global</span> Temperature and Salinity Profile Program (GTSPP) Continuously Managed Database (CMD) which provides quality controlled near-real time <span class="hlt">ocean</span> profile data and higher level quality controlled temperature and salinity profiles from 1990 to present. Both databases are used extensively for <span class="hlt">ocean</span> and climate studies. Synchronization of these two databases will allow easier access and use of comprehensive regional and <span class="hlt">global</span> <span class="hlt">ocean</span> profile data sets for <span class="hlt">ocean</span> and climate studies. Synchronizing consists of two distinct phases: 1) a retrospective comparison of data in WOD and GTSPP to ensure that the most comprehensive and highest quality data set is available to researchers without the need to individually combine and contrast the two datasets and 2) web services to allow the constantly accruing near-real time data in the GTSPP CMD and the continuous addition and quality control of historical data in WOD to be made available to researchers together, seamlessly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010022696&hterms=correlation+coefficient&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcorrelation%2Bcoefficient','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010022696&hterms=correlation+coefficient&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcorrelation%2Bcoefficient"><span>The Correlation Between Atmospheric Dust Deposition to the Surface <span class="hlt">Ocean</span> and SeaWiFS <span class="hlt">Ocean</span> Color: A <span class="hlt">Global</span> Satellite-Based Analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Erickson, D. J., III; Hernandez, J.; Ginoux, P.; Gregg, W.; Kawa, R.; Behrenfeld, M.; Esaias, W.; Einaudi, Franco (Technical Monitor)</p> <p>2000-01-01</p> <p>Since the atmospheric deposition of iron has been linked to primary productivity in various <span class="hlt">oceanic</span> regions, we have conducted an objective study of the correlation of dust deposition and satellite remotely sensed surface <span class="hlt">ocean</span> chlorophyll concentrations. We present a <span class="hlt">global</span> analysis of the correlation between atmospheric dust deposition derived from a satellite-based 3-D atmospheric transport model and SeaWiFs estimates of <span class="hlt">ocean</span> color. We use the monthly mean dust deposition fields of Ginoux et al. which are based on a <span class="hlt">global</span> model of dust generation and transport. This model is driven by atmospheric circulation from the Data Assimilation Office (DAO) for the period 1995-1998. This <span class="hlt">global</span> dust model is constrained by several satellite estimates of standard circulation characteristics. We then perform an analysis of the correlation between the dust deposition and the 1998 SeaWIFS <span class="hlt">ocean</span> color data for each 2.0 deg x 2.5 deg lat/long grid point, for each month of the year. The results are surprisingly robust. The region between 40 S and 60 S has correlation coefficients from 0.6 to 0.95, statistically significant at the 0.05 level. There are swaths of high correlation at the edges of some major <span class="hlt">ocean</span> current systems. We interpret these correlations as reflecting areas that have shear related turbulence bringing nitrogen and phosphorus from depth into the surface <span class="hlt">ocean</span>, and the atmospheric supply of iron provides the limiting nutrient and the correlation between iron deposition and surface <span class="hlt">ocean</span> chlorophyll is high. There is a region in the western North Pacific with high correlation, reflecting the input of Asian dust to that region. The southern hemisphere has an average correlation coefficient of 0.72 compared that in the northern hemisphere of 0.42 consistent with present conceptual models of where atmospheric iron deposition may play a role in surface <span class="hlt">ocean</span> biogeochemical cycles. The spatial structure of the correlation fields will be discussed within the context</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=33376&Lab=ORD&keyword=tourism&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=33376&Lab=ORD&keyword=tourism&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">GLOBAL</span> ENVIRONMENTAL CHANGE ISSUES IN THE WESTERN INDIAN <span class="hlt">OCEAN</span> REGION</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Mounting evidence from both instrumental and proxy records shows <span class="hlt">global</span> climate continues to change. nalysis of near-surface temperatures over land and <span class="hlt">oceans</span> during the past 130 years shows marked warming during the first half of this century with relatively steady temperatures ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912760C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912760C"><span>The <span class="hlt">Global</span> Drifter Program Currents, Sea Surface Temperature, Atmospheric Pressure and Waves in the World's <span class="hlt">Ocean</span>The <span class="hlt">Global</span> Drifter Program Currents, Sea Surface Temperature, Atmospheric Pressure and Waves in the World's <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Centurioni, Luca</p> <p>2017-04-01</p> <p>The <span class="hlt">Global</span> Drifter Program is the principal component of the <span class="hlt">Global</span> Surface Drifting Buoy Array, a branch of NOAA's <span class="hlt">Global</span> <span class="hlt">Ocean</span> Observing System and a scientific project of the Data Buoy Cooperation Panel (DBCP). The DBCP is an international program coordinating the use of autonomous data buoys to observe atmospheric and oceanographic conditions over <span class="hlt">ocean</span> areas where few other measurements are taken. The <span class="hlt">Global</span> Drifter Program maintains an array of over 1,250 Lagrangian drifters, reporting in near real-time and designed measure 15 m depth Lagrangian currents, sea surface temperature (SST) and sea level atmospheric pressure (SLP), among others, to fulfill the needs to observe the air-sea interface at temporal and spatial scales adequate to support short to medium-range weather forecasting, <span class="hlt">ocean</span> state estimates and climate science. This overview talk will discuss the main achievements of the program, the main impacts for satellite SST calibration and validation, for numerical weather prediction, and it will review the main scientific findings based on the use of Lagrangian currents. Finally, we will present new developments in Lagrangian drifter technology, which include special drifters designed to measure sea surface salinity, wind and directional wave spectra. New opportunities for expanding the scope of the <span class="hlt">Global</span> Drifter Program will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H42C..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H42C..03M"><span>Investigating the Control of <span class="hlt">Ocean</span>-Atmospheric Oscillations on <span class="hlt">Global</span> Terrestrial Evaporation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martens, B.; Waegeman, W.; Dorigo, W.; Verhoest, N.; Miralles, D. G.</p> <p>2017-12-01</p> <p>Intra-annual and multi-decadal variability in Earth's climate is strongly driven by periodic oscillations in the coupled state of our atmosphere and <span class="hlt">ocean</span>. These oscillations do not only impact climate in nearby regions, but can also have an effect on the climate in remote areas, a phenomenon that is often referred to as teleconnection. Because changes in local climate immediately affect terrestrial ecosystems through a series of complex processes, <span class="hlt">ocean</span>-atmospheric oscillations are expected to influence land evaporation; i.e. the return flux of water from land into the atmosphere. In this presentation, the effects of <span class="hlt">ocean</span>-atmospheric oscillations on <span class="hlt">global</span> terrestrial evaporation are analysed. We use multi-decadal, satellite-based observations of different climate variables (air temperature, radiation, precipitation) in combination with a simple supervised learning method - the Least Absolute Shrinkage and Selection Operator - to detect the impact of sixteen leading <span class="hlt">ocean</span>-atmospheric oscillations on terrestrial evaporation. The latter is retrieved using the <span class="hlt">Global</span> Land Evaporation Amsterdam Model (GLEAM). The analysis reveals hotspot regions in which more than 30% of the inter-annual variability in terrestrial evaporation can be explained by <span class="hlt">ocean</span>-atmospheric oscillations. The impact is different per region and season, and can typically be attributed to a small subset of oscillations. For instance, the dynamics in terrestrial evaporation over eastern Australia are substantially impacted by both the El Niño Southern Oscillation (ENSO) and the Indian <span class="hlt">Ocean</span> Dipole (IOD) during Austral spring. Using the same learning method, but targeting terrestrial evaporation based on its local climatic drivers (air temperature, precipitation, and radiation), shows the dominant control of precipitation on terrestrial evaporation in Australia, suggesting that both ENSO and IOD affect the precipitation, in his turn influencing evaporation. The latter is confirmed by regressing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008cosp...37.1036G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008cosp...37.1036G"><span>The <span class="hlt">ocean</span> quasi-homogeneous layer model and <span class="hlt">global</span> cycle of carbon dioxide in system of atmosphere-<span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glushkov, Alexander; Glushkov, Alexander; Loboda, Nataliya; Khokhlov, Valery; Serbov, Nikoly; Svinarenko, Andrey</p> <p></p> <p>The purpose of this paper is carrying out the detailed model of the CO2 <span class="hlt">global</span> turnover in system of "atmosphere-<span class="hlt">ocean</span>" with using the <span class="hlt">ocean</span> quasi-homogeneous layer model. Practically all carried out models are functioning in the average annual regime and accounting for the carbon distribution in bio-sphere in most general form (Glushkov et al, 2003). We construct a modified model for cycle of the carbon dioxide, which allows to reproduce a season dynamics of carbon turnover in <span class="hlt">ocean</span> with account of zone <span class="hlt">ocean</span> structure (up quasi-homogeneous layer, thermocline and deepest layer). It is taken into account dependence of the CO2 transfer through the bounder between atmosphere and <span class="hlt">ocean</span> upon temperature of water and air, wind velocity, buffer mechanism of the CO2 dissolution. The same program is realized for atmosphere part of whole system. It is obtained a tempo-ral and space distribution for concentration of non-organic carbon in <span class="hlt">ocean</span>, partial press of dissolute CO2 and value of exchange on the border between atmosphere and <span class="hlt">ocean</span>. It is estimated a role of the wind intermixing of the up <span class="hlt">ocean</span> layer. The increasing of this effect leads to increasing the plankton mass and further particles, which are transferred by wind, contribute to more quick immersion of microscopic shells and organic material. It is fulfilled investigation of sen-sibility of the master differential equations system solutions from the model parameters. The master differential equa-tions system, describing a dynamics of the CO2 cycle, is numerically integrated by the four order Runge-Cutt method under given initial values of valuables till output of solution on periodic regime. At first it is indicated on possible real-zation of the chaos scenario in system. On our data, the difference of the average annual values for the non-organic car-bon concentration in the up quasi-homogeneous layer between equator and extreme southern zone is 0.15 mol/m3, be-tween the equator and extreme northern zone is 0</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ESSDD...5..221B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ESSDD...5..221B"><span>Picophytoplankton biomass distribution in the <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buitenhuis, E. T.; Li, W. K. W.; Vaulot, D.; Lomas, M. W.; Landry, M.; Partensky, F.; Karl, D. M.; Ulloa, O.; Campbell, L.; Jacquet, S.; Lantoine, F.; Chavez, F.; Macias, D.; Gosselin, M.; McManus, G. B.</p> <p>2012-04-01</p> <p>The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s, during cruises throughout most of the world <span class="hlt">ocean</span>. We compiled a database of 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the <span class="hlt">ocean</span> surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins. The average picophytoplankton biomass is 12 ± 22 μg C l-1 or 1.9 g C m-2. We estimate a total <span class="hlt">global</span> picophytoplankton biomass of 0.53-0.74 Pg C (17-39% Prochlorococcus, 12-15% Synechococcus and 49-69% picoeukaryotes). Future efforts in this area of research should focus on reporting calibrated cell size, and collecting data in undersampled regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2964215','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2964215"><span>Satellite-based <span class="hlt">global-ocean</span> mass balance estimates of interannual variability and emerging trends in continental freshwater discharge</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Syed, Tajdarul H.; Famiglietti, James S.; Chambers, Don P.; Willis, Josh K.; Hilburn, Kyle</p> <p>2010-01-01</p> <p>Freshwater discharge from the continents is a key component of Earth’s water cycle that sustains human life and ecosystem health. Surprisingly, owing to a number of socioeconomic and political obstacles, a comprehensive <span class="hlt">global</span> river discharge observing system does not yet exist. Here we use 13 years (1994–2006) of satellite precipitation, evaporation, and sea level data in an <span class="hlt">ocean</span> mass balance to estimate freshwater discharge into the <span class="hlt">global</span> <span class="hlt">ocean</span>. Results indicate that <span class="hlt">global</span> freshwater discharge averaged 36,055 km3/y for the study period while exhibiting significant interannual variability driven primarily by El Niño Southern Oscillation cycles. The method described here can ultimately be used to estimate long-term <span class="hlt">global</span> discharge trends as the records of sea level rise and <span class="hlt">ocean</span> temperature lengthen. For the relatively short 13-year period studied here, <span class="hlt">global</span> discharge increased by 540 km3/y2, which was largely attributed to an increase of <span class="hlt">global-ocean</span> evaporation (768 km3/y2). Sustained growth of these flux rates into long-term trends would provide evidence for increasing intensity of the hydrologic cycle. PMID:20921364</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7170P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7170P"><span>The CONCEPTS <span class="hlt">Global</span> Ice-<span class="hlt">Ocean</span> Prediction System: Establishing an Environmental Prediction Capability in Canada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pellerin, Pierre; Smith, Gregory; Testut, Charles-Emmanuel; Surcel Colan, Dorina; Roy, Francois; Reszka, Mateusz; Dupont, Frederic; Lemieux, Jean-Francois; Beaudoin, Christiane; He, Zhongjie; Belanger, Jean-Marc; Deacu, Daniel; Lu, Yimin; Buehner, Mark; Davidson, Fraser; Ritchie, Harold; Lu, Youyu; Drevillon, Marie; Tranchant, Benoit; Garric, Gilles</p> <p>2015-04-01</p> <p>Here we describe a new system implemented recently at the Canadian Meteorological Centre (CMC) entitled the <span class="hlt">Global</span> Ice <span class="hlt">Ocean</span> Prediction System (GIOPS). GIOPS provides ice and <span class="hlt">ocean</span> analyses and 10 day forecasts daily at 00GMT on a <span class="hlt">global</span> 1/4° resolution grid. GIOPS includes a full multivariate <span class="hlt">ocean</span> data assimilation system that combines satellite observations of sea level anomaly and sea surface temperature (SST) together with in situ observations of temperature and salinity. In situ observations are obtained from a variety of sources including: the Argo network of autonomous profiling floats, moorings, ships of opportunity, marine mammals and research cruises. <span class="hlt">Ocean</span> analyses are blended with sea ice analyses produced by the <span class="hlt">Global</span> Ice Analysis System.. GIOPS has been developed as part of the Canadian Operational Network of Coupled Environmental PredicTion Systems (CONCEPTS) tri-departmental initiative between Environment Canada, Fisheries and <span class="hlt">Oceans</span> Canada and National Defense. The development of GIOPS was made through a partnership with Mercator-Océan, a French operational oceanography group. Mercator-Océan provided the <span class="hlt">ocean</span> data assimilation code and assistance with the system implementation. GIOPS has undergone a rigorous evaluation of the analysis, trial and forecast fields demonstrating its capacity to provide high-quality products in a robust and reliable framework. In particular, SST and ice concentration forecasts demonstrate a clear benefit with respect to persistence. These results support the use of GIOPS products within other CMC operational systems, and more generally, as part of a Government of Canada marine core service. Impact of a two-way coupling between the GEM atmospheric model and NEMO-CICE <span class="hlt">ocean</span>-ice model will also be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28054561','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28054561"><span>Pliocene <span class="hlt">oceanic</span> seaways and <span class="hlt">global</span> climate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karas, Cyrus; Nürnberg, Dirk; Bahr, André; Groeneveld, Jeroen; Herrle, Jens O; Tiedemann, Ralf; deMenocal, Peter B</p> <p>2017-01-05</p> <p>Tectonically induced changes in <span class="hlt">oceanic</span> seaways had profound effects on <span class="hlt">global</span> and regional climate during the Late Neogene. The constriction of the Central American Seaway reached a critical threshold during the early Pliocene ~4.8-4 million years (Ma) ago. Model simulations indicate the strengthening of the Atlantic Meridional Overturning Circulation (AMOC) with a signature warming response in the Northern Hemisphere and cooling in the Southern Hemisphere. Subsequently, between ~4-3 Ma, the constriction of the Indonesian Seaway impacted regional climate and might have accelerated the Northern Hemisphere Glaciation. We here present Pliocene Atlantic interhemispheric sea surface temperature and salinity gradients (deduced from foraminiferal Mg/Ca and stable oxygen isotopes, δ 18 O) in combination with a recently published benthic stable carbon isotope (δ 13 C) record from the southernmost extent of North Atlantic Deep Water to reconstruct gateway-related changes in the AMOC mode. After an early reduction of the AMOC at ~5.3 Ma, we show in agreement with model simulations of the impacts of Central American Seaway closure a strengthened AMOC with a <span class="hlt">global</span> climate signature. During ~3.8-3 Ma, we suggest a weakening of the AMOC in line with the <span class="hlt">global</span> cooling trend, with possible contributions from the constriction of the Indonesian Seaway.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25631682','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25631682"><span>Turnover time of fluorescent dissolved organic matter in the dark <span class="hlt">global</span> <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Catalá, Teresa S; Reche, Isabel; Fuentes-Lema, Antonio; Romera-Castillo, Cristina; Nieto-Cid, Mar; Ortega-Retuerta, Eva; Calvo, Eva; Álvarez, Marta; Marrasé, Cèlia; Stedmon, Colin A; Álvarez-Salgado, X Antón</p> <p>2015-01-29</p> <p>Marine dissolved organic matter (DOM) is one of the largest reservoirs of reduced carbon on Earth. In the dark <span class="hlt">ocean</span> (>200 m), most of this carbon is refractory DOM. This refractory DOM, largely produced during microbial mineralization of organic matter, includes humic-like substances generated in situ and detectable by fluorescence spectroscopy. Here we show two ubiquitous humic-like fluorophores with turnover times of 435±41 and 610±55 years, which persist significantly longer than the ~350 years that the dark <span class="hlt">global</span> <span class="hlt">ocean</span> takes to renew. In parallel, decay of a tyrosine-like fluorophore with a turnover time of 379±103 years is also detected. We propose the use of DOM fluorescence to study the cycling of resistant DOM that is preserved at centennial timescales and could represent a mechanism of carbon sequestration (humic-like fraction) and the decaying DOM injected into the dark <span class="hlt">global</span> <span class="hlt">ocean</span>, where it decreases at centennial timescales (tyrosine-like fraction).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150000330','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150000330"><span>Sensitivity of Simulated <span class="hlt">Global</span> <span class="hlt">Ocean</span> Carbon Flux Estimates to Forcing by Reanalysis Products</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Watson W.; Casey, Nancy W.; Rousseaux, Cecile S.</p> <p>2015-01-01</p> <p>Reanalysis products from MERRA, NCEP2, NCEP1, and ECMWF were used to force an established <span class="hlt">ocean</span> biogeochemical model to estimate air-sea carbon fluxes (FCO2) and partial pressure of carbon dioxide (pCO2) in the <span class="hlt">global</span> <span class="hlt">oceans</span>. <span class="hlt">Global</span> air-sea carbon fluxes and pCO2 were relatively insensitive to the choice of forcing reanalysis. All <span class="hlt">global</span> FCO2 estimates from the model forced by the four different reanalyses were within 20% of in situ estimates (MERRA and NCEP1 were within 7%), and all models exhibited statistically significant positive correlations with in situ estimates across the 12 major oceanographic basins. <span class="hlt">Global</span> pCO2 estimates were within 1% of in situ estimates with ECMWF being the outlier at 0.6%. Basin correlations were similar to FCO2. There were, however, substantial departures among basin estimates from the different reanalysis forcings. The high latitudes and tropics had the largest ranges in estimated fluxes among the reanalyses. Regional pCO2 differences among the reanalysis forcings were muted relative to the FCO2 results. No individual reanalysis was uniformly better or worse in the major oceanographic basins. The results provide information on the characterization of uncertainty in <span class="hlt">ocean</span> carbon models due to choice of reanalysis forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611457M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611457M"><span>Estimating the numerical diapycnal mixing in the GO5.0 <span class="hlt">ocean</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Megann, Alex; Nurser, George</p> <p>2014-05-01</p> <p>Constant-depth (or "z-coordinate") <span class="hlt">ocean</span> models such as MOM and NEMO have become the de facto workhorse in climate applications, and have attained a mature stage in their development and are well understood. A generic shortcoming of this model type, however, is a tendency for the advection scheme to produce unphysical numerical diapycnal mixing, which in some cases may exceed the explicitly parameterised mixing based on observed physical processes (e.g. Hofmann and Maqueda, 2006), and this is likely to have effects on the long-timescale evolution of the simulated climate system. Despite this, few quantitative estimations have been made of the typical magnitude of the effective diapycnal diffusivity due to numerical mixing in these models. GO5.0 is the latest <span class="hlt">ocean</span> model configuration developed <span class="hlt">jointly</span> by the UK Met Office and the National Oceanography Centre (Megann et al, 2013). It uses version 3.4 of the NEMO model, on the ORCA025 <span class="hlt">global</span> tripolar grid. Two approaches to quantifying the numerical diapycnal mixing in this model are described: the first is based on the isopycnal watermass analysis of Lee et al (2002), while the second uses a passive tracer to diagnose mixing across density surfaces. Results from these two methods will be compared and contrasted. Hofmann, M. and Maqueda, M. A. M., 2006. Performance of a second-order moments advection scheme in an <span class="hlt">ocean</span> general circulation model. JGR-<span class="hlt">Oceans</span>, 111(C5). Lee, M.-M., Coward, A.C., Nurser, A.G., 2002. Spurious diapycnal mixing of deep waters in an eddy-permitting <span class="hlt">global</span> <span class="hlt">ocean</span> model. JPO 32, 1522-1535 Megann, A., Storkey, D., Aksenov, Y., Alderson, S., Calvert, D., Graham, T., Hyder, P., Siddorn, J., and Sinha, B., 2013: GO5.0: The <span class="hlt">joint</span> NERC-Met Office NEMO <span class="hlt">global</span> <span class="hlt">ocean</span> model for use in coupled and forced applications, Geosci. Model Dev. Discuss., 6, 5747-5799,.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032852','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032852"><span><span class="hlt">Joint</span> variability of <span class="hlt">global</span> runoff and <span class="hlt">global</span> sea surface temperatures</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McCabe, G.J.; Wolock, D.M.</p> <p>2008-01-01</p> <p><span class="hlt">Global</span> land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with <span class="hlt">global</span> monthly temperature and precipitation data to compute time series of annual gridded runoff for the analysis period. The annual runoff time series data are combined with gridded annual sea surface temperature data, and the combined dataset is subjected to a principal components analysis (PCA) to identify the primary modes of variability. The first three components from the PCA explain 29% of the total variability in the combined runoff/SST dataset. The first component explains 15% of the total variance and primarily represents long-term trends in the data. The long-term trends in SSTs are evident as warming in all of the <span class="hlt">oceans</span>. The associated long-term trends in runoff suggest increasing flows for parts of North America, South America, Eurasia, and Australia; decreasing runoff is most notable in western Africa. The second principal component explains 9% of the total variance and reflects variability of the El Ni??o-Southern Oscillation (ENSO) and its associated influence on <span class="hlt">global</span> annual runoff patterns. The third component explains 5% of the total variance and indicates a response of <span class="hlt">global</span> annual runoff to variability in North Aflantic SSTs. The association between runoff and North Atlantic SSTs may explain an apparent steplike change in runoff that occurred around 1970 for a number of continental regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO14C2799G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO14C2799G"><span><span class="hlt">Global</span> <span class="hlt">Ocean</span> Circulation in Thermohaline Coordinates and Small-scale and Mesoscale mixing: An Inverse Estimate.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Groeskamp, S.; Zika, J. D.; McDougall, T. J.; Sloyan, B.</p> <p>2016-02-01</p> <p>I will present results of a new inverse technique that infers small-scale turbulent diffusivities and mesoscale eddy diffusivities from an <span class="hlt">ocean</span> climatology of Salinity (S) and Temperature (T) in combination with surface freshwater and heat fluxes.First, the <span class="hlt">ocean</span> circulation is represented in (S,T) coordinates, by the diathermohaline streamfunction. Framing the <span class="hlt">ocean</span> circulation in (S,T) coordinates, isolates the component of the circulation that is directly related to water-mass transformation.Because water-mass transformation is directly related to fluxes of salt and heat, this framework allows for the formulation of an inverse method in which the diathermohaline streamfunction is balanced with known air-sea forcing and unknown mixing. When applying this inverse method to observations, we obtain observationally based estimates for both the streamfunction and the mixing. The results reveal new information about the component of the <span class="hlt">global</span> <span class="hlt">ocean</span> circulation due to water-mass transformation and its relation to surface freshwater and heat fluxes and small-scale and mesoscale mixing. The results provide <span class="hlt">global</span> constraints on spatially varying patterns of diffusivities, in order to obtain a realistic overturning circulation. We find that mesoscale isopycnal mixing is much smaller than expected. These results are important for our understanding of the relation between <span class="hlt">global</span> <span class="hlt">ocean</span> circulation and mixing and may lead to improved parameterisations in numerical <span class="hlt">ocean</span> models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001OcMod...3...51G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001OcMod...3...51G"><span>The sources of Antarctic bottom water in a <span class="hlt">global</span> ice <span class="hlt">ocean</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goosse, Hugues; Campin, Jean-Michel; Tartinville, Benoı̂t</p> <p></p> <p>Two mechanisms contribute to the formation of Antarctic bottom water (AABW). The first, and probably the most important, is initiated by the brine released on the Antarctic continental shelf during ice formation which is responsible for an increase in salinity. After mixing with ambient water at the shelf break, this salty and dense water sinks along the shelf slope and invades the deepest part of the <span class="hlt">global</span> <span class="hlt">ocean</span>. For the second one, the increase of surface water density is due to strong cooling at the <span class="hlt">ocean</span>-atmosphere interface, together with a contribution from brine release. This induces deep convection and the renewal of deep waters. The relative importance of these two mechanisms is investigated in a <span class="hlt">global</span> coupled ice-<span class="hlt">ocean</span> model. Chlorofluorocarbon (CFC) concentrations simulated by the model compare favourably with observations, suggesting a reasonable deep water ventilation in the Southern <span class="hlt">Ocean</span>, except close to Antarctica where concentrations are too high. Two artificial passive tracers released at surface on the Antarctic continental shelf and in the open-<span class="hlt">ocean</span> allow to show clearly that the two mechanisms contribute significantly to the renewal of AABW in the model. This indicates that open-<span class="hlt">ocean</span> convection is overestimated in our simulation. Additional experiments show that the amount of AABW production due to the export of dense shelf waters is quite sensitive to the parameterisation of the effect of downsloping and meso-scale eddies. Nevertheless, shelf waters always contribute significantly to deep water renewal. Besides, increasing the P.R. Gent, J.C. McWilliams [Journal of Physical Oceanography 20 (1990) 150-155] thickness diffusion can nearly suppress the AABW formation by open-<span class="hlt">ocean</span> convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B22C..06C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B22C..06C"><span><span class="hlt">Ocean</span> Fertilization and <span class="hlt">Ocean</span> Acidification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, L.; Caldeira, K.</p> <p>2008-12-01</p> <p>It has been suggested that <span class="hlt">ocean</span> fertilization could help diminish <span class="hlt">ocean</span> acidification. Here, we quantitatively evaluate this suggestion. <span class="hlt">Ocean</span> fertilization is one of several <span class="hlt">ocean</span> methods proposed to mitigate atmospheric CO2 concentrations. The basic idea of this method is to enhance the biological uptake of atmospheric CO2 by stimulating net phytoplankton growth through the addition of iron to the surface <span class="hlt">ocean</span>. Concern has been expressed that <span class="hlt">ocean</span> fertilization may not be very effective at reducing atmospheric CO2 concentrations and may produce unintended environmental consequences. The rationale for thinking that <span class="hlt">ocean</span> fertilization might help diminish <span class="hlt">ocean</span> acidification is that dissolved inorganic carbon concentrations in the near-surface equilibrate with the atmosphere in about a year. If <span class="hlt">ocean</span> fertilization could reduce atmospheric CO2 concentrations, it would also reduce surface <span class="hlt">ocean</span> dissolved inorganic carbon concentrations, and thus diminish the degree of <span class="hlt">ocean</span> acidification. To evaluate this line of thinking, we use a <span class="hlt">global</span> <span class="hlt">ocean</span> carbon cycle model with a simple representation of marine biology and investigate the maximum potential effect of <span class="hlt">ocean</span> fertilization on <span class="hlt">ocean</span> carbonate chemistry. We find that the effect of <span class="hlt">ocean</span> fertilization on <span class="hlt">ocean</span> acidification depends, in part, on the context in which <span class="hlt">ocean</span> fertilization is performed. With fixed emissions of CO2 to the atmosphere, <span class="hlt">ocean</span> fertilization moderately mitigates changes in <span class="hlt">ocean</span> carbonate chemistry near the <span class="hlt">ocean</span> surface, but at the expense of further acidifying the deep <span class="hlt">ocean</span>. Under the SRES A2 CO2 emission scenario, by year 2100 simulated atmospheric CO2, <span class="hlt">global</span> mean surface pH, and saturation state of aragonite is 965 ppm, 7.74, and 1.55 for the scenario without fertilization and 833 ppm, 7.80, and 1.71 for the scenario with 100-year (between 2000 and 2100) continuous fertilization for the <span class="hlt">global</span> <span class="hlt">ocean</span> (For comparison, pre-industrial <span class="hlt">global</span> mean surface pH and saturation state of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMOS52A..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMOS52A..02S"><span>Seasonal and Inter-Annual Changes in the Distribution of Dominant Phytoplancton Groups in the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Severine, A.; Cyril, M.; Yves, D.; Laurent, B.; Hubert, L.</p> <p>2006-12-01</p> <p>The fate of fixed organic carbon in the <span class="hlt">ocean</span> strongly varies with the phytoplankton group that makes photosynthesis. The monitoring of phytoplankton groups in the <span class="hlt">global</span> <span class="hlt">ocean</span> is thus of primary importance to evaluate and improve <span class="hlt">ocean</span> carbon models. A new method (PHYSAT; Alvain et al., 2005) enables to distinguish between four different groups from space using SeaWiFS <span class="hlt">ocean</span> color measurements. In addition to these four initial phytoplankton groups, which are diatoms, Prochlorococcus, Synecochoccus and haptophytes, we show that PHYSAT is also capable of identifying blooms of phaeocystis and coccolithophorids. Daily <span class="hlt">global</span> SeaWiFS level-3 data from September 1997 to December 2004 were processed using PHYSAT. We present here the first monthly mean <span class="hlt">global</span> climatology of the dominant phytoplankton groups. The seasonal cycle is discussed, with particular emphasis on the succession of phytoplankton groups during the North Atlantic spring bloom and on the coexistence of large phaeocystis and diatoms blooms during winter in the Austral <span class="hlt">Ocean</span>. We also present the inter-annual variability for the 1998-2004 period. The contribution of diatoms to the total chlorophyll is highly variable (up to a factor of two) from one year to the other in both Atlantic and Austral <span class="hlt">Oceans</span>, suggesting a significant variability in organic carbon export by diatoms in these regions. On the opposite, the phaeocystis contribution is less variable in the Austral <span class="hlt">Ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1111151I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1111151I"><span><span class="hlt">Global</span> patterns of changes in underwater sound transmission caused by <span class="hlt">ocean</span> acidification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ilyina, T.; Zeebe, R. E.; Brewer, P. G.</p> <p>2009-04-01</p> <p><span class="hlt">Oceanic</span> uptake of man-made CO2 leads to a decrease in the <span class="hlt">ocean</span> pH and carbonate saturation state. This processes, known as <span class="hlt">ocean</span> acidification is expected to have adverse effects on a variety of marine organisms. A surprising consequence of <span class="hlt">ocean</span> acidification, which has gone widely unrecognized, is its effect on underwater sound transmission. Low-frequency sound absorption in the <span class="hlt">ocean</span> occurs due to chemical relaxation of the pH-dependent boric acid-borate ion reaction. As <span class="hlt">ocean</span> pH drops, sound absorption in the audible range decreases. The decreased sound absorption will amplify ambient noise levels, and enhance long distance sound transmission, although its exact environmental impact is uncertain. Changes in the underwater sound absorption will affect the operation of scientific, commercial, and naval applications that are based on <span class="hlt">ocean</span> acoustics, with yet unknown consequences for marine life. We project these changes using a <span class="hlt">global</span> biogeochemical model (HAMOCC), which is forced by the anthropogenic CO2 emissions during the years 1800-2300. Based on model projections, we quantify when and where in the <span class="hlt">ocean</span> these <span class="hlt">ocean</span> chemistry induced perturbations in sound absorption will occur.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO14C2805A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO14C2805A"><span>The internal gravity wave spectrum in two high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arbic, B. K.; Ansong, J. K.; Buijsman, M. C.; Kunze, E. L.; Menemenlis, D.; Müller, M.; Richman, J. G.; Savage, A.; Shriver, J. F.; Wallcraft, A. J.; Zamudio, L.</p> <p>2016-02-01</p> <p>We examine the internal gravity wave (IGW) spectrum in two sets of high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> simulations that are forced concurrently by atmospheric fields and the astronomical tidal potential. We analyze <span class="hlt">global</span> 1/12th and 1/25th degree HYCOM simulations, and <span class="hlt">global</span> 1/12th, 1/24th, and 1/48th degree simulations of the MITgcm. We are motivated by the central role that IGWs play in <span class="hlt">ocean</span> mixing, by operational considerations of the US Navy, which runs HYCOM as an <span class="hlt">ocean</span> forecast model, and by the impact of the IGW continuum on the sea surface height (SSH) measurements that will be taken by the planned NASA/CNES SWOT wide-swath altimeter mission. We (1) compute the IGW horizontal wavenumber-frequency spectrum of kinetic energy, and interpret the results with linear dispersion relations computed from the IGW Sturm-Liouville problem, (2) compute and similarly interpret nonlinear spectral kinetic energy transfers in the IGW band, (3) compute and similarly interpret IGW contributions to SSH variance, (4) perform comparisons of modeled IGW kinetic energy frequency spectra with moored current meter observations, and (5) perform comparisons of modeled IGW kinetic energy vertical wavenumber-frequency spectra with moored observations. This presentation builds upon our work in Muller et al. (2015, GRL), who performed tasks (1), (2), and (4) in 1/12th and 1/25th degree HYCOM simulations, for one region of the North Pacific. New for this presentation are tasks (3) and (5), the inclusion of MITgcm solutions, and the analysis of additional <span class="hlt">ocean</span> regions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ESASP.710E...9E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ESASP.710E...9E"><span>Twenty Years of Progress on <span class="hlt">Global</span> <span class="hlt">Ocean</span> Tide: The Impact of Satellite Altimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Egbert, Gary D.; Ray, Richard D.</p> <p>2013-09-01</p> <p>At the dawn of the era of high-precision altimetry, before the launch of TOPEX/Poseidon, <span class="hlt">ocean</span> tides were properly viewed as a source of noise-tidal variations in <span class="hlt">ocean</span> height would represent a very substantial fraction of what the altimeter measures, and would have to be accurately predicted and subtracted if altimetry were to achieve its potential for <span class="hlt">ocean</span> and climate studies. But to the extent that the altimetry could be severely contaminated by tides, it also represented an unprecedented <span class="hlt">global</span>-scale tidal data set. These new data, together with research stimulated by the need for accurate tidal corrections, led to a renaissance in tidal studies in the oceanographic community. In this paper we review contributions of altimetry to tidal science over the past 20 years, emphasizing recent progress. Mapping of tides has now been extended from the early focus on major constituents in the open <span class="hlt">ocean</span> to include minor constituents, (e.g., long-period tides; non-linear tides in shelf waters, and in the open <span class="hlt">ocean</span>), and into shallow and coastal waters. <span class="hlt">Global</span> and spatially local estimates of tidal energy balance have been refined, and the role of internal tide conversion in dissipating barotropic tidal energy is now well established through modeling, altimetry, and in situ observations. However, energy budgets for internal tides, and the role of tidal dissipation in vertical <span class="hlt">ocean</span> mixing remain controversial topics. Altimetry may contribute to resolving some of these important questions through improved mapping of low-mode internal tides. This area has advanced significantly in recent years, with several <span class="hlt">global</span> maps now available, and progress on constraining temporally incoherent components. For the future, new applications of altimetry (e.g., in the coastal <span class="hlt">ocean</span>, where barotropic tidal models remain inadequate), and new mission concepts (studies of the sub-mesoscale with SWOT, which will require correction for internal tides) may bring us full circle, again pushing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009634','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009634"><span>Twenty Years of Progress on <span class="hlt">Global</span> <span class="hlt">Ocean</span> Tides: The Impact of Satellite Altimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Egbert, Gary; Ray, Richard</p> <p>2012-01-01</p> <p>At the dawn of the era of high-precision altimetry, before the launch of TOPEX/Poseidon, <span class="hlt">ocean</span> tides were properly viewed as a source of noise--tidal variations in <span class="hlt">ocean</span> height would represent a very substantial fraction of what the altimeter measures, and would have to be accurately predicted and subtracted if altimetry were to achieve its potential for <span class="hlt">ocean</span> and climate studies. But to the extent that the altimetry could be severely contaminated by tides, it also represented an unprecedented <span class="hlt">global</span>-scale tidal data set. These new data, together with research stimulated by the need for accurate tidal corrections, led to a renaissance in tidal studies in the oceanographic community. In this paper we review contributions of altimetry to tidal science over the past 20 years, emphasizing recent progress. Mapping of tides has now been extended from the early focus on major constituents in the open <span class="hlt">ocean</span> to include minor constituents, (e.g., long-period tides; non-linear tides in shelf waters, and in the open <span class="hlt">ocean</span>), and into shallow and coastal waters. <span class="hlt">Global</span> and spatially local estimates of tidal energy balance have been refined, and the role of internal tide conversion in dissipating barotropic tidal energy is now well established through modeling, altimetry, and in situ observations. However, energy budgets for internal tides, and the role of tidal dissipation in vertical <span class="hlt">ocean</span> mixing remain controversial topics. Altimetry may contribute to resolving some of these important questions through improved mapping of low-mode internal tides. This area has advanced significantly in recent years, with several <span class="hlt">global</span> maps now available, and progress on constraining temporally incoherent components. For the future, new applications of altimetry (e.g., in the coastal <span class="hlt">ocean</span>, where barotropic tidal models remain inadequate), and new mission concepts (studies of the submesoscale with SWOT, which will require correction for internal tides) may bring us full circle, again pushing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5133693','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5133693"><span><span class="hlt">Global</span> warming-induced upper-<span class="hlt">ocean</span> freshening and the intensification of super typhoons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Balaguru, Karthik; Foltz, Gregory R.; Leung, L. Ruby; Emanuel, Kerry A.</p> <p>2016-01-01</p> <p>Super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards <span class="hlt">globally</span>. The violent winds of these storms induce deep mixing of the upper <span class="hlt">ocean</span>, resulting in strong sea surface cooling and making STYs highly sensitive to <span class="hlt">ocean</span> density stratification. Although a few studies examined the potential impacts of changes in <span class="hlt">ocean</span> thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper <span class="hlt">ocean</span>, caused by greater rainfall in places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper <span class="hlt">ocean</span>. We further demonstrate that the strengthening effect of this freshening over the period 1961–2008 is ∼53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of <span class="hlt">ocean</span> temperature changes. PMID:27886199</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27886199','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27886199"><span><span class="hlt">Global</span> warming-induced upper-<span class="hlt">ocean</span> freshening and the intensification of super typhoons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Balaguru, Karthik; Foltz, Gregory R; Leung, L Ruby; Emanuel, Kerry A</p> <p>2016-11-25</p> <p>Super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards <span class="hlt">globally</span>. The violent winds of these storms induce deep mixing of the upper <span class="hlt">ocean</span>, resulting in strong sea surface cooling and making STYs highly sensitive to <span class="hlt">ocean</span> density stratification. Although a few studies examined the potential impacts of changes in <span class="hlt">ocean</span> thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper <span class="hlt">ocean</span>, caused by greater rainfall in places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper <span class="hlt">ocean</span>. We further demonstrate that the strengthening effect of this freshening over the period 1961-2008 is ∼53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of <span class="hlt">ocean</span> temperature changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100033200','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100033200"><span>Synthesis and Assimilation Systems - Essential Adjuncts to the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Observing System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rienecker, Michele M.; Balmaseda, Magdalena; Awaji, Toshiyuki; Barnier, Bernard; Behringer, David; Bell, Mike; Bourassa, Mark; Brasseur, Pierre; Breivik, Lars-Anders; Carton, James; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20100033200'); toggleEditAbsImage('author_20100033200_show'); toggleEditAbsImage('author_20100033200_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20100033200_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20100033200_hide"></p> <p>2009-01-01</p> <p><span class="hlt">Ocean</span> assimilation systems synthesize diverse in situ and satellite data streams into four-dimensional state estimates by combining the various observations with the model. Assimilation is particularly important for the <span class="hlt">ocean</span> where subsurface observations, even today, are sparse and intermittent compared with the scales needed to represent <span class="hlt">ocean</span> variability and where satellites only sense the surface. Developments in assimilation and in the observing system have advanced our understanding and prediction of <span class="hlt">ocean</span> variations at mesoscale and climate scales. Use of these systems for assessing the observing system helps identify the strengths of each observation type. Results indicate that the <span class="hlt">ocean</span> remains under-sampled and that further improvements in the observing system are needed. Prospects for future advances lie in improved models and better estimates of error statistics for both models and observations. Future developments will be increasingly towards consistent analyses across components of the Earth system. However, even today <span class="hlt">ocean</span> synthesis and assimilation systems are providing products that are useful for many applications and should be considered an integral part of the <span class="hlt">global</span> <span class="hlt">ocean</span> observing and information system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GBioC..31..492E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GBioC..31..492E"><span>A <span class="hlt">global</span> estimate of the full <span class="hlt">oceanic</span> 13C Suess effect since the preindustrial</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eide, Marie; Olsen, Are; Ninnemann, Ulysses S.; Eldevik, Tor</p> <p>2017-03-01</p> <p>We present the first estimate of the full <span class="hlt">global</span> <span class="hlt">ocean</span> 13C Suess effect since preindustrial times, based on observations. This has been derived by first using the method of Olsen and Ninnemann (2010) to calculate 13C Suess effect estimates on sections spanning the world <span class="hlt">ocean</span>, which were next mapped on a <span class="hlt">global</span> 1° × 1° grid. We find a strong 13C Suess effect in the upper 1000 m of all basins, with strongest decrease in the subtropical gyres of the Northern Hemisphere, where δ13C of dissolved inorganic carbon has decreased by more than 0.8‰ since the industrial revolution. At greater depths, a significant 13C Suess effect can only be detected in the northern parts of the North Atlantic <span class="hlt">Ocean</span>. The relationship between the 13C Suess effect and the concentration of anthropogenic carbon varies strongly between water masses, reflecting the degree to which source waters are equilibrated with the atmospheric 13C Suess effect before sinking. Finally, we estimate a <span class="hlt">global</span> <span class="hlt">ocean</span> inventory of anthropogenic CO2 of 92 ± 46 Gt C. This provides an estimate that is almost independent of and consistent, within the uncertainties, with previous estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010GGG....11.8001R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010GGG....11.8001R"><span>An intermediate-complexity model for simulating marine biogeochemistry in deep time: Validation against the modern <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romaniello, Stephen J.; Derry, Louis A.</p> <p>2010-08-01</p> <p>We present a new high-resolution 1-D intermediate-complexity box model (ICBM) of <span class="hlt">ocean</span> biogeochemical processes for paleoceanographic applications. The model contains 79 reservoirs in three regions that should be generally applicable throughout much of Earth history: (1) a stratified gyre region, (2) a high-latitude convective region, and (3) an upwelling region analogous to those found associated with eastern boundary currents. Transport processes are modeled as exchange fluxes between boxes and by eddy diffusion terms. Significant improvement in the representation of middepth oxygen budgets was achieved by implementing nonlocal mixing between the high-latitude surface and gyre thermocline reservoirs. The biogeochemical submodel simulates coupled C, N, P, O, and S systematics with explicit representation of microbial populations, using a process-based approach. Primary production follows Redfield stoichiometry, while water column remineralization is depth- and redox couple-dependent. Settling particulate organic matter is incorporated into a benthic submodel that accounts for burial and remineralization. The C/P ratio of burial depends on bottom water oxygen. Denitrification takes place both by classical and anammox pathways. The ICBM was tested against modern oceanographic observations from the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project, <span class="hlt">Joint</span> <span class="hlt">Global</span> <span class="hlt">Ocean</span> Flux Study, and other databases. Comparisons of model output with circulation tracers including θ, salinity, CFC-12, and radiocarbon permit a test of the physical exchange scheme. Vertical profiles of biogeochemically reactive components in each of the three regions are in good agreement with observations. Under modern conditions the upwelling zone displays a pronounced oxygen minimum zone and water column denitrification, while these are not present in the high-latitude or gyre regions. Model-generated <span class="hlt">global</span> fluxes also compare well to independent estimates of primary production, burial, and phosphorous and nitrogen</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1338547-global-ocean-data-analysis-project-version-glodapv2-internally-consistent-data-product-world-ocean','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1338547-global-ocean-data-analysis-project-version-glodapv2-internally-consistent-data-product-world-ocean"><span>The <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project version 2 (GLODAPv2) – an internally consistent data product for the world <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Olsen, Are; Key, Robert M.; van Heuven, Steven; ...</p> <p>2016-08-15</p> <p>Version 2 of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the <span class="hlt">global</span> <span class="hlt">ocean</span>. It includes data assembled during the previous efforts GLODAPv1.1 (<span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic <span class="hlt">ocean</span> Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl 4) have been subjected to extensive quality control, including systematic evaluation of bias.more » The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. In conclusion, this compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg -1 in dissolved inorganic carbon, 6 µmol kg -1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1338547','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1338547"><span>The <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project version 2 (GLODAPv2) – an internally consistent data product for the world <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Olsen, Are; Key, Robert M.; van Heuven, Steven</p> <p></p> <p>Version 2 of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the <span class="hlt">global</span> <span class="hlt">ocean</span>. It includes data assembled during the previous efforts GLODAPv1.1 (<span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic <span class="hlt">ocean</span> Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl 4) have been subjected to extensive quality control, including systematic evaluation of bias.more » The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. In conclusion, this compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg -1 in dissolved inorganic carbon, 6 µmol kg -1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A52B..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A52B..08S"><span>A Parallel Icosahedral, Higher Order Discontinuous Galerkin, <span class="hlt">Global</span> Shallow Water Model: <span class="hlt">Global</span> <span class="hlt">Ocean</span> Tides and Aquaplanet Benchmarks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salehipour, H.; Stuhne, G.; Peltier, W. R.</p> <p>2012-12-01</p> <p>The development of models of the <span class="hlt">ocean</span> tides with higher resolution near the coastlines and courser mesh offshore, has been required due to the significant impacts of coastline configuration and bathymetry (associated with sea level rise) on the amplitude and phase of tidal constituents, not only under present conditions but also in the deep past [Griffiths and Peltier GRL 2008, Griffiths and Peltier AMS 2009, Hill et al. JGR 2011]. A <span class="hlt">global</span> tidal model with enhanced resolution at the poles has been developed by Griffiths and Peltier [2008, 2009], which, although capable of highly resolving polar <span class="hlt">ocean</span> tides , is based upon a standard structured Arakawa C grid and hence is not capable of resolving coastlines locally. Furthermore the use of a nested modelling approach, although it may enable local spatial refinement [Hill et al. 2011], nevertheless suffers from its inherent dependence on the availability of a <span class="hlt">global</span> tidal model with necessarily low spatial resolution to provide the open boundary conditions required for the local high resolution model. On the other hand, an unstructured triangulation of the <span class="hlt">global</span> domain provides a standalone framework that may be employed to study highly resolved regions without relying on secondary models. The first step in the development of the structure we are employing was described in Stuhne and Peltier [<span class="hlt">Ocean</span> Modeling, 2009]. In further extending this modelling structure we are employing a new discontinuous Galerkin (DG) discretization of the governing equations in order to provide very high order of accuracy while also ensuring that momentum transport is locally conserved [Giraldo et al. JCP 2002]. After validating the 2D shallow water model with several test suites appropriate to aquaplanets [Williamson et al. JCP 1992, Galewsky et al. Tellus 2004, Nair and Lauritzen JCP 2010], the governing equations are extended to include the influence of internal tide drag in the deep <span class="hlt">ocean</span> as well as the drag in shallow marginal seas</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930001663','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930001663"><span>Morning-evening differences in <span class="hlt">global</span> and regional <span class="hlt">oceanic</span> precipitation as observed by the SSM/I</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Petty, Grant W.; Katsaros, Kristina B.</p> <p>1992-01-01</p> <p>For the present preliminary analysis of <span class="hlt">oceanic</span> rainfall statistics, <span class="hlt">global</span> <span class="hlt">oceanic</span> SSM/I data were simply scanned for pixels which exhibited a 37 GHz polarization difference (vertically polarized brightness temperatures minus horizontally polarized brightness temperatures) of less than 15 K. Such a low polarization difference over the open <span class="hlt">ocean</span> is a completely unambiguous indication of moderate to intense precipitation. Co-located brightness temperatures from all seven channels of the SSM/I were saved for each pixel so identified. Bad scans and geographically mislocated block of data were objectively identified and removed from the resulting data base. We collected <span class="hlt">global</span> <span class="hlt">oceanic</span> rainfall data for two time periods, each one month in length. The first period (20 July-19 August 1987) coincides with the peak of the Northern Hemisphere summer. The second period (13 January-12 February 1988) coincides with the Northern Hemisphere winter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916429L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916429L"><span>A Southern <span class="hlt">Ocean</span> variability study using the Argo-based Model for Investigation of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> (AMIGO)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lebedev, Konstantin</p> <p>2017-04-01</p> <p>The era of satellite observations of the <span class="hlt">ocean</span> surface that started at the end of the 20th century and the development of the Argo project in the first years of the 21st century, designed to collect information of the upper 2000 m of the <span class="hlt">ocean</span> using satellites, provides unique opportunities for continuous monitoring of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> state. Starting from 2005, measurements with the Argo floats have been performed over the majority of the World <span class="hlt">Ocean</span>. In November 2007, the Argo program reached coverage of 3000 simultaneously operating floats (one float in a three-degree square) planned during the development of the program. Currently, 4000 Argo floats autonomously profile the upper 2000-m water column of the <span class="hlt">ocean</span> from Antarctica to Spitsbergen increasing World <span class="hlt">Ocean</span> temperature and salinity databases by 12000 profiles per month. This makes it possible to solve problems on reconstructing and monitoring the <span class="hlt">ocean</span> state on an almost real-time basis, study the <span class="hlt">ocean</span> dynamics, obtain reasonable estimates of the climatic state of the <span class="hlt">ocean</span> in the last decade and estimate existing intraclimatic trends. We present the newly developed Argo-Based Model for Investigation of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> (AMIGO), which consists of a block for variational interpolation of the profiles of drifting Argo floats to a regular grid and a block for model hydrodynamic adjustment of variationally interpolated fields. Such a method makes it possible to obtain a full set of oceanographic characteristics - temperature, salinity, density, and current velocity - using irregularly located Argo measurements (the principle of the variational interpolation technique entails minimization of the misfit between the interpolated fields defined on the regular grid and irregularly distributed data; hence the optimal solution passes as close to the data as possible). The simulations were performed for the entire globe limited in the north by 85.5° N using 1° grid spacing in both longitude and latitude. At the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996GBioC..10...57A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996GBioC..10...57A"><span><span class="hlt">Oceanic</span> primary production 2. Estimation at <span class="hlt">global</span> scale from satellite (coastal zone color scanner) chlorophyll</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antoine, David; André, Jean-Michel; Morel, André</p> <p></p> <p>A fast method has been proposed [Antoine and Morel, this issue] to compute the <span class="hlt">oceanic</span> primary production from the upper <span class="hlt">ocean</span> chlorophyll-like pigment concentration, as it can be routinely detected by a spaceborne <span class="hlt">ocean</span> color sensor. This method is applied here to the monthly <span class="hlt">global</span> maps of the photosynthetic pigments that were derived from the coastal zone color scanner (CZCS) data archive [Feldman et al., 1989]. The photosynthetically active radiation (PAR) field is computed from the astronomical constant and by using an atmospheric model, thereafter combined with averaged cloud information, derived from the International Satellite Cloud Climatology Project (ISCCP). The aim is to assess the seasonal evolution, as well as the spatial distribution of the photosynthetic carbon fixation within the world <span class="hlt">ocean</span> and for a ``climatological year,'' to the extent that both the chlorophyll information and the cloud coverage statistics actually are averages obtained over several years. The computed <span class="hlt">global</span> annual production actually ranges between 36.5 and 45.6 Gt C yr-1 according to the assumption which is made (0.8 or 1) about the ratio of active-to-total pigments (recall that chlorophyll and pheopigments are not radiometrically resolved by CZCS). The relative contributions to the <span class="hlt">global</span> productivity of the various <span class="hlt">oceans</span> and zonal belts are examined. By considering the hypotheses needed in such computations, the nature of the data used as inputs, and the results of the sensitivity studies, the <span class="hlt">global</span> numbers have to be cautiously considered. Improving the reliability of the primary production estimates implies (1) new <span class="hlt">global</span> data sets allowing a higher temporal resolution and a better coverage, (2) progress in the knowledge of physiological responses of phytoplankton and therefore refinements of the time and space dependent parameterizations of these responses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29784792','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29784792"><span>Abrupt <span class="hlt">global-ocean</span> anoxia during the Late Ordovician-early Silurian detected using uranium isotopes of marine carbonates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bartlett, Rick; Elrick, Maya; Wheeley, James R; Polyak, Victor; Desrochers, André; Asmerom, Yemane</p> <p>2018-05-21</p> <p>Widespread marine anoxia is hypothesized as the trigger for the second pulse of the Late Ordovician (Hirnantian) mass extinction based on lithologic and geochemical proxies that record local bottom waters or porewaters. We test the anoxia hypothesis using δ 238 U values of marine limestones as a <span class="hlt">global</span> seawater redox proxy. The δ 238 U trends at Anticosti Island, Canada, document an abrupt late Hirnantian ∼0.3‰ negative shift continuing through the early Silurian indicating more reducing seawater conditions. The lack of observed anoxic facies and no covariance among δ 238 U values and other local redox proxies suggests that the δ 238 U trends represent a <span class="hlt">global-ocean</span> redox record. The Hirnantian <span class="hlt">ocean</span> anoxic event (HOAE) onset is coincident with the extinction pulse indicating its importance in triggering it. Anoxia initiated during high sea levels before peak Hirnantian glaciation, and continued into the subsequent lowstand and early Silurian deglacial eustatic rise, implying that major climatic and eustatic changes had little effect on <span class="hlt">global-ocean</span> redox conditions. The HOAE occurred during a <span class="hlt">global</span> δ 13 C positive excursion, but lasted longer indicating that controls on the C budget were partially decoupled from <span class="hlt">global-ocean</span> redox trends. U cycle modeling suggests that there was a ∼15% increase in anoxic seafloor area and ∼80% of seawater U was sequestered into anoxic sediments during the HOAE. Unlike other <span class="hlt">ocean</span> anoxic events (OAE), the HOAE occurred during peak and waning icehouse conditions rather than during greenhouse climates. We interpret that anoxia was driven by <span class="hlt">global</span> cooling, which reorganized thermohaline circulation, decreased deep-<span class="hlt">ocean</span> ventilation, enhanced nutrient fluxes, stimulated productivity, which lead to expanded oxygen minimum zones. Copyright © 2018 the Author(s). Published by PNAS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26213675','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26213675"><span>Decadal trends in <span class="hlt">global</span> pelagic <span class="hlt">ocean</span> chlorophyll: A new assessment integrating multiple satellites, in situ data, and models.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gregg, Watson W; Rousseaux, Cécile S</p> <p>2014-09-01</p> <p>Quantifying change in <span class="hlt">ocean</span> biology using satellites is a major scientific objective. We document trends <span class="hlt">globally</span> for the period 1998-2012 by integrating three diverse methodologies: <span class="hlt">ocean</span> color data from multiple satellites, bias correction methods based on in situ data, and data assimilation to provide a consistent and complete <span class="hlt">global</span> representation free of sampling biases. The results indicated no significant trend in <span class="hlt">global</span> pelagic <span class="hlt">ocean</span> chlorophyll over the 15 year data record. These results were consistent with previous findings that were based on the first 6 years and first 10 years of the SeaWiFS mission. However, all of the Northern Hemisphere basins (north of 10° latitude), as well as the Equatorial Indian basin, exhibited significant declines in chlorophyll. Trend maps showed the local trends and their change in percent per year. These trend maps were compared with several other previous efforts using only a single sensor (SeaWiFS) and more limited time series, showing remarkable consistency. These results suggested the present effort provides a path forward to quantifying <span class="hlt">global</span> <span class="hlt">ocean</span> trends using multiple satellite missions, which is essential if we are to understand the state, variability, and possible changes in the <span class="hlt">global</span> <span class="hlt">oceans</span> over longer time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25999517','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25999517"><span><span class="hlt">Ocean</span> plankton. Determinants of community structure in the <span class="hlt">global</span> plankton interactome.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lima-Mendez, Gipsi; Faust, Karoline; Henry, Nicolas; Decelle, Johan; Colin, Sébastien; Carcillo, Fabrizio; Chaffron, Samuel; Ignacio-Espinosa, J Cesar; Roux, Simon; Vincent, Flora; Bittner, Lucie; Darzi, Youssef; Wang, Jun; Audic, Stéphane; Berline, Léo; Bontempi, Gianluca; Cabello, Ana M; Coppola, Laurent; Cornejo-Castillo, Francisco M; d'Ovidio, Francesco; De Meester, Luc; Ferrera, Isabel; Garet-Delmas, Marie-José; Guidi, Lionel; Lara, Elena; Pesant, Stéphane; Royo-Llonch, Marta; Salazar, Guillem; Sánchez, Pablo; Sebastian, Marta; Souffreau, Caroline; Dimier, Céline; Picheral, Marc; Searson, Sarah; Kandels-Lewis, Stefanie; Gorsky, Gabriel; Not, Fabrice; Ogata, Hiroyuki; Speich, Sabrina; Stemmann, Lars; Weissenbach, Jean; Wincker, Patrick; Acinas, Silvia G; Sunagawa, Shinichi; Bork, Peer; Sullivan, Matthew B; Karsenti, Eric; Bowler, Chris; de Vargas, Colomban; Raes, Jeroen</p> <p>2015-05-22</p> <p>Species interaction networks are shaped by abiotic and biotic factors. Here, as part of the Tara <span class="hlt">Oceans</span> project, we studied the photic zone interactome using environmental factors and organismal abundance profiles and found that environmental factors are incomplete predictors of community structure. We found associations across plankton functional types and phylogenetic groups to be nonrandomly distributed on the network and driven by both local and <span class="hlt">global</span> patterns. We identified interactions among grazers, primary producers, viruses, and (mainly parasitic) symbionts and validated network-generated hypotheses using microscopy to confirm symbiotic relationships. We have thus provided a resource to support further research on <span class="hlt">ocean</span> food webs and integrating biological components into <span class="hlt">ocean</span> models. Copyright © 2015, American Association for the Advancement of Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21502171','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21502171"><span>Warming up, turning sour, losing breath: <span class="hlt">ocean</span> biogeochemistry under <span class="hlt">global</span> change.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gruber, Nicolas</p> <p>2011-05-28</p> <p>In the coming decades and centuries, the <span class="hlt">ocean</span>'s biogeochemical cycles and ecosystems will become increasingly stressed by at least three independent factors. Rising temperatures, <span class="hlt">ocean</span> acidification and <span class="hlt">ocean</span> deoxygenation will cause substantial changes in the physical, chemical and biological environment, which will then affect the <span class="hlt">ocean</span>'s biogeochemical cycles and ecosystems in ways that we are only beginning to fathom. <span class="hlt">Ocean</span> warming will not only affect organisms and biogeochemical cycles directly, but will also increase upper <span class="hlt">ocean</span> stratification. The changes in the <span class="hlt">ocean</span>'s carbonate chemistry induced by the uptake of anthropogenic carbon dioxide (CO(2)) (i.e. <span class="hlt">ocean</span> acidification) will probably affect many organisms and processes, although in ways that are currently not well understood. <span class="hlt">Ocean</span> deoxygenation, i.e. the loss of dissolved oxygen (O(2)) from the <span class="hlt">ocean</span>, is bound to occur in a warming and more stratified <span class="hlt">ocean</span>, causing stress to macro-organisms that critically depend on sufficient levels of oxygen. These three stressors-warming, acidification and deoxygenation-will tend to operate <span class="hlt">globally</span>, although with distinct regional differences. The impacts of <span class="hlt">ocean</span> acidification tend to be strongest in the high latitudes, whereas the low-oxygen regions of the low latitudes are most vulnerable to <span class="hlt">ocean</span> deoxygenation. Specific regions, such as the eastern boundary upwelling systems, will be strongly affected by all three stressors, making them potential hotspots for change. Of additional concern are synergistic effects, such as <span class="hlt">ocean</span> acidification-induced changes in the type and magnitude of the organic matter exported to the <span class="hlt">ocean</span>'s interior, which then might cause substantial changes in the oxygen concentration there. <span class="hlt">Ocean</span> warming, acidification and deoxygenation are essentially irreversible on centennial time scales, i.e. once these changes have occurred, it will take centuries for the <span class="hlt">ocean</span> to recover. With the emission of CO(2) being the primary driver</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930060288&hterms=oceans+tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Doceans%2Btide','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930060288&hterms=oceans+tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Doceans%2Btide"><span><span class="hlt">Global</span> <span class="hlt">ocean</span> tide models on the eve of Topex/Poseidon</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ray, Richard D.</p> <p>1993-01-01</p> <p>Some existing <span class="hlt">global</span> <span class="hlt">ocean</span> tide models that can provide tide corrections to Topex/Poseidon altimeter data are described. Emphasis is given to the Schwiderski and Cartwright-Ray models, as these are the most comprehensive, highest resolution models, but other models that will soon appear are mentioned. Differences between models for M2 often exceed 10 cm over vast stretches of the <span class="hlt">ocean</span>. Comparisons to 80 selected pelagic and island gauge measurements indicate the Schwiderski model is more accurate for the major solar tides, Cartwright-Ray for the major lunar tides. The adequacy of available tide models for studying basin-scale motions is probably marginal at best.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1414450H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1414450H"><span><span class="hlt">Global</span> patterns of organic carbon export and sequestration in the <span class="hlt">ocean</span> (Arne Richter Award for Outstanding Young Scientists)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henson, S.; Sanders, R.; Madsen, E.; Le Moigne, F.; Quartly, G.</p> <p>2012-04-01</p> <p>A major term in the <span class="hlt">global</span> carbon cycle is the <span class="hlt">ocean</span>'s biological carbon pump which is dominated by sinking of small organic particles from the surface <span class="hlt">ocean</span> to its interior. Here we examine <span class="hlt">global</span> patterns in particle export efficiency (PEeff), the proportion of primary production that is exported from the surface <span class="hlt">ocean</span>, and transfer efficiency (Teff), the fraction of exported organic matter that reaches the deep <span class="hlt">ocean</span>. This is achieved through extrapolating from in situ estimates of particulate organic carbon export to the <span class="hlt">global</span> scale using satellite-derived data. <span class="hlt">Global</span> scale estimates derived from satellite data show, in keeping with earlier studies, that PEeff is high at high latitudes and low at low latitudes, but that Teff is low at high latitudes and high at low latitudes. However, in contrast to the relationship observed for deep biomineral fluxes in previous studies, we find that Teff is strongly negatively correlated with opal export flux from the upper <span class="hlt">ocean</span>, but uncorrelated with calcium carbonate export flux. We hypothesise that the underlying factor governing the spatial patterns observed in Teff is ecosystem function, specifically the degree of recycling occurring in the upper <span class="hlt">ocean</span>, rather than the availability of calcium carbonate for ballasting. Finally, our estimate of <span class="hlt">global</span> integrated carbon export is only 50% of previous estimates. The lack of consensus amongst different methodologies on the strength of the biological carbon pump emphasises that our knowledge of a major planetary carbon flux remains incomplete.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://link.springer.com/content/pdf/10.1007%2Fs12571-009-0026-y','USGSPUBS'); return false;" href="http://link.springer.com/content/pdf/10.1007%2Fs12571-009-0026-y"><span>Declining <span class="hlt">global</span> per capita agricultural production and warming <span class="hlt">oceans</span> threaten food security</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Funk, Christopher C.; Brown, Molly E.</p> <p>2009-01-01</p> <p>Despite accelerating <span class="hlt">globalization</span>, most people still eat food that is grown locally. Developing countries with weak purchasing power tend to import as little food as possible from <span class="hlt">global</span> markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be determined by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices and policies. This paper discusses several emerging threats to <span class="hlt">global</span> and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian <span class="hlt">Ocean</span> and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia and Central and Southern America will experience substantial declines in per capita cereal production. <span class="hlt">Global</span> per capita cereal production will potentially decline by 14% between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific <span class="hlt">Oceans</span>, may also reduce 21st century food availability in some countries by disrupting moisture transports and bringing down dry air over crop growing areas. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian <span class="hlt">Ocean</span> warming appears to have already reduced rainfall during the main growing season along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, this study presents an analysis of emerging</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......198W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......198W"><span>Poseidon's paintbox : historical archives of <span class="hlt">ocean</span> colour in <span class="hlt">global</span>-change perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wernand, M. R.</p> <p>2011-11-01</p> <p>In the thesis introduction issues are discussed on the historical background of marine optics and on marine optical devices that were used over the past centuries to observe and measure; as in all sciences, in marine optics we can see a steady development: that of ‘measuring’, beginning many centuries ago, to 'knowing' and since less than a century to the understanding of the phenomenon. Hereafter, six themes are treated successively. The first theme, ‘<span class="hlt">Ocean</span> optics from 1600 (Hudson) to 1930 (Raman), shift in interpretation of natural water colouring’, addresses the question of why it took so long a time to explain the phenomenon ‘the colouring of the sea’, especially the blue colour, despite the age-long interest of sailors, for practical purposes of navigation and detection of fish - of which more later. The second theme ‘On the history of the Secchi disc’, describes the search to establish methods for the determination of (sea) water clarity concerning purposes of navigation (near coast colour changes) just mentioned to detect shoals, and for a more basic purpose, tracing lost objects. The search to determine the clarity of lakes and seas culminated in the invention of the Secchi disc, used since the late 19th century. The third theme, ‘Spectral analysis of the Forel-Ule <span class="hlt">ocean</span> colour comparator scale’, addresses the accuracy of a colour scale proposed, used in limnology and oceanography. Scale observations are put into perspective with contemporary measurements on the colour of the sea. The fourth theme, ‘<span class="hlt">Ocean</span> colour changes in the North Pacific since 1930’, handles the question whether long-term <span class="hlt">ocean</span> colour changes using historic Forel-Ule observations, in this part of the <span class="hlt">ocean</span> made very frequently over time, can be determined in relation to <span class="hlt">global</span> change. In principal <span class="hlt">global</span> warming may cause a gradual change in <span class="hlt">ocean</span> colour due to the effect of biological, chemical and physical aspects of the <span class="hlt">ocean</span>-surface. The fifth theme, </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO34B3062F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO34B3062F"><span><span class="hlt">Global</span> Variability and Changes in <span class="hlt">Ocean</span> Total Alkalinity from Aquarius Satellite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fine, R. A.; Willey, D. A.; Millero, F. J., Jr.</p> <p>2016-02-01</p> <p>To document effects of <span class="hlt">ocean</span> acidification it is important to have an understanding of the processes and parameters that influence alkalinity. Alkalinity is a gauge on the ability of seawater to neutralize acids. We use Aquarius satellite data, which allow unprecedented <span class="hlt">global</span> mapping of surface total alkalinity as it correlates strongly with salinity and to a lesser extent with temperature. Spatial variability in total alkalinity and salinity exceed temporal variability, the latter includes seasonal and differences compared to climatological data. The northern hemisphere has more spatial and monthly variability in total alkalinity and salinity, while less variability in Southern <span class="hlt">Ocean</span> alkalinity is due to less salinity variability and upwelling of waters enriched in alkalinity. Satellite alkalinity data are providing a <span class="hlt">global</span> baseline that can be used for comparing with future carbon data, and for evaluating spatial and temporal variability and past trends. For the first time it is shown that recent satellite derived total alkalinity in the subtropics have increased as compared with climatological data; this is reflective of large scale changes in the <span class="hlt">global</span> water cycle. Total alkalinity increases imply increased dissolution of calcareous minerals and difficulty for calcifying organisms to make their shells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1420141','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1420141"><span>Exploring the sensitivity of <span class="hlt">global</span> <span class="hlt">ocean</span> circulation to future ice loss from Antarctica</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Condron, Alan</p> <p></p> <p>The sensitivity of the <span class="hlt">global</span> <span class="hlt">ocean</span> circulation and climate to large increases in iceberg calving and meltwater discharges from the Antarctic Ice Sheet (AIS) are rarely studied and poorly understood. The requirement to investigate this topic is heightened by growing evidence that the West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse on multidecadal-to-centennial timescales. Observations collected over the last 30 years indicate that the WAIS is now losing mass at an accelerated and that a collapse may have already begun in the Amundsen Sea sector. In addition, some recent future model simulations of the AIS showmore » the potential for rapid ice sheet retreat in the next 50 – 300 years. Such a collapse would be associated with the discharge of enormous volumes of ice and meltwater to the Southern <span class="hlt">Ocean</span>. This project funds PI Condron to begin assessing the sensitivity of the <span class="hlt">global</span> <span class="hlt">ocean</span> circulation to projected increases in meltwater discharge and iceberg calving from the AIS for the next 50 – 100 years. A series of climate model simulations will determine changes in <span class="hlt">ocean</span> circulation and temperature at the ice sheet grounding line, the role of mesoscale <span class="hlt">ocean</span> eddies in mixing and transporting freshwater away from the continent to deep water formation regions, and the likely impact on the northward transport of heat to Europe and North America.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1339813','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1339813"><span><span class="hlt">Global</span> warming-induced upper-<span class="hlt">ocean</span> freshening and the intensification of super typhoons</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Balaguru, Karthik; Foltz, Gregory R.; Leung, L. Ruby</p> <p></p> <p>Here, super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards <span class="hlt">globally</span>. The violent winds of these storms induce deep mixing of the upper <span class="hlt">ocean</span>, resulting in strong sea surface cooling and making STYs highly sensitive to <span class="hlt">ocean</span> density stratification. Although a few studies examined the potential impacts of changes in <span class="hlt">ocean</span> thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper <span class="hlt">ocean</span>, caused by greater rainfall inmore » places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper <span class="hlt">ocean</span>. We further demonstrate that the strengthening effect of this freshening over the period 1961–2008 is ~53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of <span class="hlt">ocean</span> temperature changes.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1339813-global-warming-induced-upper-ocean-freshening-intensification-super-typhoons','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1339813-global-warming-induced-upper-ocean-freshening-intensification-super-typhoons"><span><span class="hlt">Global</span> warming-induced upper-<span class="hlt">ocean</span> freshening and the intensification of super typhoons</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Balaguru, Karthik; Foltz, Gregory R.; Leung, L. Ruby; ...</p> <p>2016-11-25</p> <p>Here, super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards <span class="hlt">globally</span>. The violent winds of these storms induce deep mixing of the upper <span class="hlt">ocean</span>, resulting in strong sea surface cooling and making STYs highly sensitive to <span class="hlt">ocean</span> density stratification. Although a few studies examined the potential impacts of changes in <span class="hlt">ocean</span> thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper <span class="hlt">ocean</span>, caused by greater rainfall inmore » places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper <span class="hlt">ocean</span>. We further demonstrate that the strengthening effect of this freshening over the period 1961–2008 is ~53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of <span class="hlt">ocean</span> temperature changes.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002GeoRL..29.1800S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002GeoRL..29.1800S"><span>On the role of inter-basin surface salinity contrasts in <span class="hlt">global</span> <span class="hlt">ocean</span> circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seidov, D.; Haupt, B. J.</p> <p>2002-08-01</p> <p>The role of sea surface salinity (SSS) contrasts in maintaining vigorous <span class="hlt">global</span> <span class="hlt">ocean</span> thermohaline circulation (TOC) is revisited. Relative importance of different generalizations of sea surface conditions in climate studies is explored. <span class="hlt">Ocean</span>-wide inter-basin SSS contrasts serve as the major controlling element in <span class="hlt">global</span> TOC. These contrasts are shown to be at least as important as high-latitudinal freshwater impacts. It is also shown that intra-basin longitudinal distribution of sea surface salinity, as well as intra- and inter-basin longitudinal distribution of sea surface temperature, is not crucial to conveyor functionality if only inter-basin contrasts in sea surface salinity are retained. This is especially important for paleoclimate and future climate simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP34A..04O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP34A..04O"><span>Assessing <span class="hlt">global</span> carbon burial during <span class="hlt">Oceanic</span> Anoxic Event 2, Cenomanian-Turonian boundary event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Owens, J. D.; Lyons, T. W.; Lowery, C. M.</p> <p>2017-12-01</p> <p>Reconstructing the areal extent and total amount of organic carbon burial during ancient events remains elusive even for the best documented <span class="hlt">oceanic</span> anoxic event (OAE) in Earth history, the Cenomanian-Turonian boundary event ( 93.9 Ma), or OAE 2. Reports from 150 OAE 2 localities provide a wide <span class="hlt">global</span> distribution. However, despite the large number of sections, the majority are found within the proto-Atlantic and Tethyan <span class="hlt">oceans</span> and interior seaways. Considering these gaps in spatial coverage, the pervasive increase in organic carbon (OC) burial during OAE2 that drove carbon isotope values more positive (average of 4‰) can provide additional insight. These isotope data allow us to estimate the total <span class="hlt">global</span> burial of OC, even for unstudied portions of the <span class="hlt">global</span> <span class="hlt">ocean</span>. Thus, we can solve for any `missing' OC sinks by comparing our estimates from a forward carbon-isotope box model with the known, mapped distribution of OC for OAE 2 sediments. Using the known OC distribution and reasonably extrapolating to the surrounding regions of analogous depositional conditions accounts for only 13% of the total seafloor, mostly in marginal marine settings. This small geographic area accounts for more OC burial than the entire modern <span class="hlt">ocean</span>, but significantly less than the amount necessary to produce the observed isotope record. Using modern and OAE 2 average OC rates we extrapolate further to appropriate depositional settings in the unknown portions of seafloor, mostly deep abyssal plains. This addition significantly increases the predicted amount buried but still does not account for total burial. Additional sources, including hydrocarbon migration, lacustrine, and coal also cannot account for the missing OC. This difference points to unknown portions of the open <span class="hlt">ocean</span> with high TOC contents or exceptionally high TOC in productive marginal marine regions, which are underestimated in our extrapolations. This difference might be explained by highly productive margins within the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRE..122.1258J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRE..122.1258J"><span>The impact of a pressurized regional sea or <span class="hlt">global</span> <span class="hlt">ocean</span> on stresses on Enceladus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnston, Stephanie A.; Montési, Laurent G. J.</p> <p>2017-06-01</p> <p>Liquid water is likely present in the interior of Enceladus, but it is still debated whether this water forms a <span class="hlt">global</span> <span class="hlt">ocean</span> or a regional sea and whether the present-day situation is stable. As the heat flux of Enceladus exceeds most heat source estimates, the liquid water is likely cooling and crystallizing, which results in expansion and pressurization of the sea or <span class="hlt">ocean</span>. We determine, using an axisymmetric Finite Element Model, the tectonic patterns that pressurization of a regional sea or <span class="hlt">global</span> <span class="hlt">ocean</span> might produce at the surface of Enceladus. Tension is always predicted above where the ice is thinnest and generates cracks that might be at the origin of the Tiger Stripes. Tectonic activity is also expected in an annulus around the sea if the ice shell is in contact with but slips freely along the rocky core of the satellite. Cracks at the north pole are expected if the shell slips along the core or if there is a <span class="hlt">global</span> <span class="hlt">ocean</span> with thin ice at the pole. Water is likely injected along the base of the ice when the shell is grounded, which may lead to cycles of tectonic activity with the shell alternating between floating and grounded states and midlatitude faulting occurring at the transition from a grounded to a floating state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6283V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6283V"><span>Effects of Drake Passage on a strongly eddying <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viebahn, Jan; von der Heydt, Anna S.; Dijkstra, Henk A.</p> <p>2015-04-01</p> <p>During the past 65 Million (Ma) years, Earth's climate has undergone a major change from warm 'greenhouse' to colder 'icehouse' conditions with extensive ice sheets in the polar regions of both hemispheres. The Eocene-Oligocene (~34 Ma) and Oligocene-Miocene (~23 Ma) boundaries reflect major transitions in Cenozoic <span class="hlt">global</span> climate change. Proposed mechanisms of these transitions include reorganization of <span class="hlt">ocean</span> circulation due to critical gateway opening/deepening, changes in atmospheric CO2-concentration, and feedback mechanisms related to land-ice formation. Drake Passage (DP) is an intensively studied gateway because it plays a central role in closing the transport pathways of heat and chemicals in the <span class="hlt">ocean</span>. The climate response to a closed DP has been explored with a variety of general circulation models, however, all of these models employ low model-grid resolutions such that the effects of subgrid-scale fluctuations ('eddies') are parameterized. We present results of the first high-resolution (0.1° horizontally) realistic <span class="hlt">global</span> <span class="hlt">ocean</span> model simulation with a closed DP in which the eddy field is largely resolved. The simulation extends over more than 200 years such that the strong transient adjustment process is passed and a near-equilibrium <span class="hlt">ocean</span> state is reached. The effects of DP are diagnosed by comparing with both an open DP high-resolution control simulation (of same length) and corresponding low-resolution simulations. By focussing on the heat/tracer transports we demonstrate that the results are twofold: Considering spatially integrated transports the overall response to a closed DP is well captured by low-resolution simulations. However, looking at the actual spatial distributions drastic differences appear between far-scattered high-resolution and laminar-uniform low-resolution fields. We conclude that sparse and highly localized tracer proxy observations have to be interpreted carefully with the help of high-resolution model simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSOD12A..07G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSOD12A..07G"><span><span class="hlt">Globalizing</span> Lessons Learned from Regional-scale Observatories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glenn, S. M.</p> <p>2016-02-01</p> <p>The Mid Atlantic Regional Association Coastal <span class="hlt">Ocean</span> Observing System (MARACOOS) has accumulated a decade of experience designing, building and operating a Regional Coastal <span class="hlt">Ocean</span> Observing System for the U.S. Integrated <span class="hlt">Ocean</span> Observing System (IOOS). MARACOOS serves societal goals and supports scientific discovery at the scale of a Large Marine Ecosystem (LME). Societal themes include maritime safety, ecosystem decision support, coastal inundation, water quality and offshore energy. Scientific results that feed back on societal goals with better products include improved understanding of seasonal transport pathways and their impact on phytoplankton blooms and hypoxia, seasonal evolution of the subsurface Mid Atlantic Cold Pool and its impact on fisheries, biogeochemical transformations in coastal plumes, coastal <span class="hlt">ocean</span> evolution and impact on hurricane intensities, and storm sediment transport pathways. As the <span class="hlt">global</span> <span class="hlt">ocean</span> observing requirements grow to support additional societal needs for information on fisheries and aquaculture, <span class="hlt">ocean</span> acidification and deoxygenation, water quality and offshore development, <span class="hlt">global</span> observing will necessarily evolve to include more coastal observations and forecast models at the scale of the world's many LMEs. Here we describe our efforts to share lessons learned between the observatory operators at the regional-scale of the LMEs. Current collaborators are spread across Europe, and also include Korea, Indonesia, Australia, Brazil and South Africa. Specific examples include the development of a world standard QA/QC approach for HF Radar data that will foster the sharing of data between countries, basin-scale underwater glider missions between internationally-distributed glider ports to developed a shared understanding of operations and an ongoing evaluation of the <span class="hlt">global</span> <span class="hlt">ocean</span> models in which the regional models for the LME will be nested, and <span class="hlt">joint</span> training programs to develop the distributed teams of scientists and technicians</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ESD.....9..339L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ESD.....9..339L"><span>Assessing carbon dioxide removal through <span class="hlt">global</span> and regional <span class="hlt">ocean</span> alkalinization under high and low emission pathways</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lenton, Andrew; Matear, Richard J.; Keller, David P.; Scott, Vivian; Vaughan, Naomi E.</p> <p>2018-04-01</p> <p>Atmospheric carbon dioxide (CO2) levels continue to rise, increasing the risk of severe impacts on the Earth system, and on the ecosystem services that it provides. Artificial <span class="hlt">ocean</span> alkalinization (AOA) is capable of reducing atmospheric CO2 concentrations and surface warming and addressing <span class="hlt">ocean</span> acidification. Here, we simulate <span class="hlt">global</span> and regional responses to alkalinity (ALK) addition (0.25 PmolALK yr-1) over the period 2020-2100 using the CSIRO-Mk3L-COAL Earth System Model, under high (Representative Concentration Pathway 8.5; RCP8.5) and low (RCP2.6) emissions. While regionally there are large changes in alkalinity associated with locations of AOA, <span class="hlt">globally</span> we see only a very weak dependence on where and when AOA is applied. On a <span class="hlt">global</span> scale, while we see that under RCP2.6 the carbon uptake associated with AOA is only ˜ 60 % of the total, under RCP8.5 the relative changes in temperature are larger, as are the changes in pH (140 %) and aragonite saturation state (170 %). The simulations reveal AOA is more effective under lower emissions, therefore the higher the emissions the more AOA is required to achieve the same reduction in <span class="hlt">global</span> warming and <span class="hlt">ocean</span> acidification. Finally, our simulated AOA for 2020-2100 in the RCP2.6 scenario is capable of offsetting warming and ameliorating <span class="hlt">ocean</span> acidification increases at the <span class="hlt">global</span> scale, but with highly variable regional responses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760011888&hterms=abuse+right&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dabuse%2Bright','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760011888&hterms=abuse+right&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dabuse%2Bright"><span>Contamination, misuse and abuse of the <span class="hlt">global</span> <span class="hlt">oceans</span> leading to ecosystem damage and destruction, health consequences and international conflict</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1975-01-01</p> <p>Unregulated uses of the <span class="hlt">oceans</span> may threaten the <span class="hlt">global</span> ecological balance, alter plant and animal life and significantly impact the <span class="hlt">global</span> climatic systems. Recent plans to locate large scale structures on the <span class="hlt">oceans</span> and to exploit the mineral riches of the seas pose even greater risk to the ecological system. Finally, increasing use of the <span class="hlt">oceans</span> for large scale transport greatly enhances the probability of collision, polluting spills and international conflict.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70044191','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70044191"><span>Antarctic and Southern <span class="hlt">Ocean</span> influences on Late Pliocene <span class="hlt">global</span> cooling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McKay, Robert; Naish, Tim; Carter, Lionel; Riesselman, Christina; Dunbar, Robert; Sjunneskog, Charlotte; Winter, Diane; Sangiorgi, Francesca; Warren, Courtney; Pagani, Mark; Schouten, Stefan; Willmott, Veronica; Levy, Richard; DeConto, Robert; Powell, Ross D.</p> <p>2012-01-01</p> <p>The influence of Antarctica and the Southern <span class="hlt">Ocean</span> on Late Pliocene <span class="hlt">global</span> climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1B sediment core recovered from beneath the Ross Ice Shelf. We provide evidence for a major expansion of an ice sheet in the Ross Sea that began at ~3.3 Ma, followed by a coastal sea surface temperature cooling of ~2.5 °C, a stepwise expansion of sea ice, and polynya-style deep mixing in the Ross Sea between 3.3 and 2.5 Ma. The intensification of Antarctic cooling resulted in strengthened westerly winds and invigorated <span class="hlt">ocean</span> circulation. The associated northward migration of Southern <span class="hlt">Ocean</span> fronts has been linked with reduced Atlantic Meridional Overturning Circulation by restricting surface water connectivity between the <span class="hlt">ocean</span> basins, with implications for heat transport to the high latitudes of the North Atlantic. While our results do not exclude low-latitude mechanisms as drivers for Pliocene cooling, they indicate an additional role played by southern high-latitude cooling during development of the bipolar world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001DSRI...48.1169P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001DSRI...48.1169P"><span>Production and export in a <span class="hlt">global</span> <span class="hlt">ocean</span> ecosystem model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palmer, J. R.; Totterdell, I. J.</p> <p>2001-05-01</p> <p>The Hadley Centre <span class="hlt">Ocean</span> Carbon Cycle (HadOCC) model is a coupled physical-biogeochemical model of the <span class="hlt">ocean</span> carbon cycle. It features an explicit representation of the marine ecosystem, which is assumed to be limited by nitrogen availability. The biogeochemical compartments are dissolved nutrient, total CO 2, total alkalinity, phytoplankton, zooplankton and detritus. The results of the standard simulation are presented. The annual primary production predicted by the model ( 47.7 Gt C yr -1) compares well to the estimates made by Longhurst et al. (1995, J. Plankton Res., 17, 1245) and Antoine et al. (1996, <span class="hlt">Global</span> Biogeochem. Cycles, 10, 57). The HadOCC model finds high production in the sub-polar North Pacific and North Atlantic <span class="hlt">Oceans</span>, and around the Antarctic convergence, and low production in the sub-tropical gyres. However in disagreement with the observations of Longhurst et al. and Antoine et al., the model predicts very high production in the eastern equatorial Pacific <span class="hlt">Ocean</span>. The export flux of carbon in the model agrees well with data from deep-water sediment traps. In order to examine the factors controlling production in the <span class="hlt">ocean</span>, additional simulations have been run. A nutrient-restoring simulation confirms that the areas with the highest primary production are those with the greatest nutrient supply. A reduced wind-stress experiment demonstrates that the high production found in the equatorial Pacific is driven by excessive upwelling of nutrient-rich water. Three further simulations show that nutrient supply at high latitudes, and hence production there, is sensitive to the parameters and climatological forcings of the mixed layer sub-model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040140836&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dworlds%2Boceans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040140836&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dworlds%2Boceans"><span>Tropical <span class="hlt">Ocean</span> <span class="hlt">Global</span> Atmosphere (TOGA) Meteorological and Oceanographic Data Sets for 1985 and 1986</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Halpern, D.; Ashby, H.; Finch, C.; Smith, E.; Robles, J.</p> <p>1990-01-01</p> <p>The Tropical <span class="hlt">Ocean</span> <span class="hlt">Global</span> Atmosphere (TOGA) Program is a component of the World Meteorological Organization (WMO)/International Council of Scientific Unions (ICSU) World Climate Research Program (WCRP). One of the objectives of TOGA, which began in 1985, is to determine the limits of predictability of monthly mean sea surface temperature variations in tropical regions. The TOGA program created a raison d'etre for an explosive growth of the tropical <span class="hlt">ocean</span> observing system and a substantial improvement in numerical simulations from atmospheric and <span class="hlt">oceanic</span> general circulation models. Institutions located throughout the world are involved in the TOGA-distributed active data archive system. The diverse TOGA data sets for 1985 and 1986, including results from general circulation models, are included on a CD-ROM. Variables on the CD-ROM are barometric pressure, surface air temperature, dewpoint temperature Cartesian components of surface wind, surface sensible and latent heat fluxes,Cartesian components of surface wind stress and of an index of surface wind stress, sea level, sea surface temperature, and depth profiles of temperature and current in the upper <span class="hlt">ocean</span>. Some data sets are <span class="hlt">global</span> in extent, some are regional and cover portions of an <span class="hlt">ocean</span> basin. Data on the CD-ROM can be extracted with an Apple Macintosh or an IBM PC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ACP....17..595G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ACP....17..595G"><span>The G4Foam Experiment: <span class="hlt">global</span> climate impacts of regional <span class="hlt">ocean</span> albedo modification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gabriel, Corey J.; Robock, Alan; Xia, Lili; Zambri, Brian; Kravitz, Ben</p> <p>2017-01-01</p> <p>Reducing insolation has been proposed as a geoengineering response to <span class="hlt">global</span> warming. Here we present the results of climate model simulations of a unique Geoengineering Model Intercomparison Project Testbed experiment to investigate the benefits and risks of a scheme that would brighten certain <span class="hlt">oceanic</span> regions. The National Center for Atmospheric Research CESM CAM4-Chem <span class="hlt">global</span> climate model was modified to simulate a scheme in which the albedo of the <span class="hlt">ocean</span> surface is increased over the subtropical <span class="hlt">ocean</span> gyres in the Southern Hemisphere. In theory, this could be accomplished using a stable, nondispersive foam, comprised of tiny, highly reflective microbubbles. Such a foam has been developed under idealized conditions, although deployment at a large scale is presently infeasible. We conducted three ensemble members of a simulation (G4Foam) from 2020 through to 2069 in which the albedo of the <span class="hlt">ocean</span> surface is set to 0.15 (an increase of 150 %) over the three subtropical <span class="hlt">ocean</span> gyres in the Southern Hemisphere, against a background of the RCP6.0 (representative concentration pathway resulting in +6 W m-2 radiative forcing by 2100) scenario. After 2069, geoengineering is ceased, and the simulation is run for an additional 20 years. <span class="hlt">Global</span> mean surface temperature in G4Foam is 0.6 K lower than RCP6.0, with statistically significant cooling relative to RCP6.0 south of 30° N. There is an increase in rainfall over land, most pronouncedly in the tropics during the June-July-August season, relative to both G4SSA (specified stratospheric aerosols) and RCP6.0. Heavily populated and highly cultivated regions throughout the tropics, including the Sahel, southern Asia, the Maritime Continent, Central America, and much of the Amazon experience a statistically significant increase in precipitation minus evaporation. The temperature response to the relatively modest <span class="hlt">global</span> average forcing of -1.5 W m-2 is amplified through a series of positive cloud feedbacks, in which more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1349159','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1349159"><span>The G4Foam Experiment: <span class="hlt">Global</span> climate impacts of regional <span class="hlt">ocean</span> albedo modification</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gabriel, Corey J.; Robock, Alan; Xia, Lili</p> <p></p> <p>Reducing insolation has been proposed as a geoengineering response to <span class="hlt">global</span> warming. Here we present the results of climate model simulations of a unique Geoengineering Model Intercomparison Project Testbed experiment to investigate the benefits and risks of a scheme that would brighten certain <span class="hlt">oceanic</span> regions. The National Center for Atmospheric Research CESM CAM4-Chem <span class="hlt">global</span> climate model was modified to simulate a scheme in which the albedo of the <span class="hlt">ocean</span> surface is increased over the subtropical <span class="hlt">ocean</span> gyres in the Southern Hemisphere. In theory, this could be accomplished using a stable, nondispersive foam, comprised of tiny, highly reflective microbubbles. Such amore » foam has been developed under idealized conditions, although deployment at a large scale is presently infeasible. We conducted three ensemble members of a simulation (G4Foam) from 2020 through to 2069 in which the albedo of the <span class="hlt">ocean</span> surface is set to 0.15 (an increase of 150%) over the three subtropical <span class="hlt">ocean</span> gyres in the Southern Hemisphere, against a background of the RCP6.0 (representative concentration pathway resulting in +6Wm -2 radiative forcing by 2100) scenario. After 2069, geoengineering is ceased, and the simulation is run for an additional 20 years. <span class="hlt">Global</span> mean surface temperature in G4Foam is 0.6 K lower than RCP6.0, with statistically significant cooling relative to RCP6.0 south of 30°N. There is an increase in rainfall over land, most pronouncedly in the tropics during the June–July–August season, relative to both G4SSA (specified stratospheric aerosols) and RCP6.0. Heavily populated and highly cultivated regions throughout the tropics, including the Sahel, southern Asia, the Maritime Continent, Central America, and much of the Amazon experience a statistically significant increase in precipitation minus evaporation. The temperature response to the relatively modest <span class="hlt">global</span> average forcing of -1.5 W m -2 is amplified through a series of positive cloud feedbacks, in which</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1349159-g4foam-experiment-global-climate-impacts-regional-ocean-albedo-modification','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1349159-g4foam-experiment-global-climate-impacts-regional-ocean-albedo-modification"><span>The G4Foam Experiment: <span class="hlt">Global</span> climate impacts of regional <span class="hlt">ocean</span> albedo modification</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Gabriel, Corey J.; Robock, Alan; Xia, Lili; ...</p> <p>2017-01-12</p> <p>Reducing insolation has been proposed as a geoengineering response to <span class="hlt">global</span> warming. Here we present the results of climate model simulations of a unique Geoengineering Model Intercomparison Project Testbed experiment to investigate the benefits and risks of a scheme that would brighten certain <span class="hlt">oceanic</span> regions. The National Center for Atmospheric Research CESM CAM4-Chem <span class="hlt">global</span> climate model was modified to simulate a scheme in which the albedo of the <span class="hlt">ocean</span> surface is increased over the subtropical <span class="hlt">ocean</span> gyres in the Southern Hemisphere. In theory, this could be accomplished using a stable, nondispersive foam, comprised of tiny, highly reflective microbubbles. Such amore » foam has been developed under idealized conditions, although deployment at a large scale is presently infeasible. We conducted three ensemble members of a simulation (G4Foam) from 2020 through to 2069 in which the albedo of the <span class="hlt">ocean</span> surface is set to 0.15 (an increase of 150%) over the three subtropical <span class="hlt">ocean</span> gyres in the Southern Hemisphere, against a background of the RCP6.0 (representative concentration pathway resulting in +6Wm -2 radiative forcing by 2100) scenario. After 2069, geoengineering is ceased, and the simulation is run for an additional 20 years. <span class="hlt">Global</span> mean surface temperature in G4Foam is 0.6 K lower than RCP6.0, with statistically significant cooling relative to RCP6.0 south of 30°N. There is an increase in rainfall over land, most pronouncedly in the tropics during the June–July–August season, relative to both G4SSA (specified stratospheric aerosols) and RCP6.0. Heavily populated and highly cultivated regions throughout the tropics, including the Sahel, southern Asia, the Maritime Continent, Central America, and much of the Amazon experience a statistically significant increase in precipitation minus evaporation. The temperature response to the relatively modest <span class="hlt">global</span> average forcing of -1.5 W m -2 is amplified through a series of positive cloud feedbacks, in which</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009DSRII..56..554T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009DSRII..56..554T"><span>Climatological mean and decadal change in surface <span class="hlt">ocean</span> pCO 2, and net sea-air CO 2 flux over the <span class="hlt">global</span> <span class="hlt">oceans</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takahashi, Taro; Sutherland, Stewart C.; Wanninkhof, Rik; Sweeney, Colm; Feely, Richard A.; Chipman, David W.; Hales, Burke; Friederich, Gernot; Chavez, Francisco; Sabine, Christopher; Watson, Andrew; Bakker, Dorothee C. E.; Schuster, Ute; Metzl, Nicolas; Yoshikawa-Inoue, Hisayuki; Ishii, Masao; Midorikawa, Takashi; Nojiri, Yukihiro; Körtzinger, Arne; Steinhoff, Tobias; Hoppema, Mario; Olafsson, Jon; Arnarson, Thorarinn S.; Tilbrook, Bronte; Johannessen, Truls; Olsen, Are; Bellerby, Richard; Wong, C. S.; Delille, Bruno; Bates, N. R.; de Baar, Hein J. W.</p> <p>2009-04-01</p> <p>A climatological mean distribution for the surface water pCO 2 over the <span class="hlt">global</span> <span class="hlt">oceans</span> in non-El Niño conditions has been constructed with spatial resolution of 4° (latitude) ×5° (longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO 2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. <span class="hlt">Global</span> sea-air CO 2 flux based on climatological surface <span class="hlt">ocean</span> pCO 2, and seasonal biological and temperature effects. Deep-Sea Res. II, 49, 1601-1622]. A time-trend analysis using deseasonalized surface water pCO 2 data in portions of the North Atlantic, North and South Pacific and Southern <span class="hlt">Oceans</span> (which cover about 27% of the <span class="hlt">global</span> <span class="hlt">ocean</span> areas) indicates that the surface water pCO 2 over these <span class="hlt">oceanic</span> areas has increased on average at a mean rate of 1.5 μatm y -1 with basin-specific rates varying between 1.2±0.5 and 2.1±0.4 μatm y -1. A <span class="hlt">global</span> <span class="hlt">ocean</span> database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Niño periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO 2 and the sea-air pCO 2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern <span class="hlt">Oceans</span> are presented. Over the Southern <span class="hlt">Ocean</span> seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO 2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net air-sea CO 2 flux is estimated using the sea-air pCO 2 difference and the air-sea gas transfer rate that is parameterized as a function of (wind speed) 2 with a scaling factor of 0.26. This is estimated by inverting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27096373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27096373"><span>In situ imaging reveals the biomass of giant protists in the <span class="hlt">global</span> <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Biard, Tristan; Stemmann, Lars; Picheral, Marc; Mayot, Nicolas; Vandromme, Pieter; Hauss, Helena; Gorsky, Gabriel; Guidi, Lionel; Kiko, Rainer; Not, Fabrice</p> <p>2016-04-28</p> <p>Planktonic organisms play crucial roles in <span class="hlt">oceanic</span> food webs and <span class="hlt">global</span> biogeochemical cycles. Most of our knowledge about the ecological impact of large zooplankton stems from research on abundant and robust crustaceans, and in particular copepods. A number of the other organisms that comprise planktonic communities are fragile, and therefore hard to sample and quantify, meaning that their abundances and effects on <span class="hlt">oceanic</span> ecosystems are poorly understood. Here, using data from a worldwide in situ imaging survey of plankton larger than 600 μm, we show that a substantial part of the biomass of this size fraction consists of giant protists belonging to the Rhizaria, a super-group of mostly fragile unicellular marine organisms that includes the taxa Phaeodaria and Radiolaria (for example, orders Collodaria and Acantharia). <span class="hlt">Globally</span>, we estimate that rhizarians in the top 200 m of world <span class="hlt">oceans</span> represent a standing stock of 0.089 Pg carbon, equivalent to 5.2% of the total <span class="hlt">oceanic</span> biota carbon reservoir. In the vast oligotrophic intertropical open <span class="hlt">oceans</span>, rhizarian biomass is estimated to be equivalent to that of all other mesozooplankton (plankton in the size range 0.2-20 mm). The photosymbiotic association of many rhizarians with microalgae may be an important factor in explaining their distribution. The previously overlooked importance of these giant protists across the widest ecosystem on the planet changes our understanding of marine planktonic ecosystems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140001061','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140001061"><span>Technical Report Series on <span class="hlt">Global</span> Modeling and Data Assimilation. Volume 31; <span class="hlt">Global</span> Surface <span class="hlt">Ocean</span> Carbon Estimates in a Model Forced by MERRA</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Watson W.; Casey, Nancy W.; Rousseaux, Cecile S.</p> <p>2013-01-01</p> <p>MERRA products were used to force an established <span class="hlt">ocean</span> biogeochemical model to estimate surface carbon inventories and fluxes in the <span class="hlt">global</span> <span class="hlt">oceans</span>. The results were compared to public archives of in situ carbon data and estimates. The model exhibited skill for <span class="hlt">ocean</span> dissolved inorganic carbon (DIC), partial pressure of <span class="hlt">ocean</span> CO2 (pCO2) and air-sea fluxes (FCO2). The MERRA-forced model produced <span class="hlt">global</span> mean differences of 0.02% (approximately 0.3 microns) for DIC, -0.3% (about -1.2 (micro) atm; model lower) for pCO2, and -2.3% (-0.003 mol C/sq m/y) for FCO2 compared to in situ estimates. Basin-scale distributions were significantly correlated with observations for all three variables (r=0.97, 0.76, and 0.73, P<0.05, respectively for DIC, pCO2, and FCO2). All major oceanographic basins were represented as sources to the atmosphere or sinks in agreement with in situ estimates. However, there were substantial basin-scale and local departures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHI41A..07W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHI41A..07W"><span>Finding the missing plastic -resolving the <span class="hlt">global</span> mass (im)balance for plastic pollution in the <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilcox, C.; van Sebille, E.</p> <p>2016-02-01</p> <p>Several <span class="hlt">global</span> studies have attempted to estimate the standing stock of plastic debris in the <span class="hlt">oceans</span> at the <span class="hlt">global</span> scale. However, recent work estimating the amount lost from land on an annual basis suggests that the standing stock should be several orders of magnitude larger than the <span class="hlt">global</span> estimates. We investigate the role of coastal deposition within the first few weeks after plastic enters the <span class="hlt">ocean</span> and very near its sources, one of the hypothesized sinks for the missing plastic in this mass balance. We utilize a continental scale dataset of plastics collected along Australia's coast and in the offshore regions together with models of plastic release and transport based on Lagrangian tracking to investigate the role of local deposition in the coastal environment. Our models predict that the vast majority of positively buoyant plastic is deposited within a very short distance from its release point, with only a small fraction escaping into the open <span class="hlt">ocean</span>. These predictions match our coastal and offshore observations, providing clear evidence that this mechanism of immediate coastal deposition is, at least in part, driving the apparent mismatch between coastal emissions and the standing stock in the <span class="hlt">ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSOD12A..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSOD12A..03M"><span>Developing a <span class="hlt">global</span> <span class="hlt">ocean</span> observing system that prioritises ecosystem variables from a political and societal point of view</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miloslavich, P.; Bax, N. J.; Simmons, S. E.; Appeltans, W.; Garcia, M.</p> <p>2016-02-01</p> <p>The Biology and Ecosystems Panel of GOOS aims to develop and coordinate efforts to implement a sustained and targeted <span class="hlt">global</span> <span class="hlt">ocean</span> observation system. This system will be driven by societal needs (including the Sustainable Development Goals), and identify Essential <span class="hlt">Ocean</span> Variables (EOVs) to inform priority scientific and societal questions that will facilitate critical policy development and management decision-making on <span class="hlt">ocean</span> and coastal resource sustainability and health. Mature EOVs need to have <span class="hlt">global</span> relevance and the capacity for <span class="hlt">global</span> measurement. Our goal is to implement at least one (set of) mature EOVs by 2019, and identify a further three (sets of) pilot EOVs with a clear pathway to maturity. Our initial work includes (1) identifying drivers and pressures of societal and scientific needs, and (2) identifying internationally agreed goals that need sustained <span class="hlt">global</span> observations of <span class="hlt">ocean</span> biological & ecosystem variables for a healthy <span class="hlt">ocean</span>. We reviewed 24 major conventions/international organizations (including the CBD and 16 UN related) to identify the societal needs these organizations address through their goals, and to produce a set of overlapping objectives. Main drivers identified in these conventions were: knowledge (science/data access), development (sustainable economic growth), conservation (biodiversity & ecosystems), sustainable use (biodiversity & resources), environmental quality (health), capacity building (technology transfer), food security, threat prevention and impact mitigation (to different pressures) and improved management (integrated ecosystem approach). The main pressures identified were climate change, <span class="hlt">ocean</span> acidification, extreme weather events, overfishing/ overexploitation, pollution/ eutrophication, mining, solid wastes. Our next step will be to develop consensus with the observing community about the EOVs that will meet these needs and support the expansion of these identified EOVs into successful <span class="hlt">global</span> observing systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5497940','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5497940"><span>Drivers and implications of change in <span class="hlt">global</span> <span class="hlt">ocean</span> health over the past five years</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Frazier, Melanie; Afflerbach, Jamie; O’Hara, Casey; Katona, Steven; Stewart Lowndes, Julia S.; Jiang, Ning; Pacheco, Erich; Scarborough, Courtney; Polsenberg, Johanna</p> <p>2017-01-01</p> <p>Growing international and national focus on quantitatively measuring and improving <span class="hlt">ocean</span> health has increased the need for comprehensive, scientific, and repeated indicators to track progress towards achieving policy and societal goals. The <span class="hlt">Ocean</span> Health Index (OHI) is one of the few indicators available for this purpose. Here we present results from five years of annual <span class="hlt">global</span> assessment for 220 countries and territories, evaluating potential drivers and consequences of changes and presenting lessons learned about the challenges of using composite indicators to measure sustainability goals. <span class="hlt">Globally</span> scores have shown little change, as would be expected. However, individual countries have seen notable increases or declines due in particular to improvements in the harvest and management of wild-caught fisheries, the creation of marine protected areas (MPAs), and decreases in natural product harvest. Rapid loss of sea ice and the consequent reduction of coastal protection from that sea ice was also responsible for declines in overall <span class="hlt">ocean</span> health in many Arctic and sub-Arctic countries. The OHI performed reasonably well at predicting near-term future scores for many of the ten goals measured, but data gaps and limitations hindered these predictions for many other goals. Ultimately, all indicators face the substantial challenge of informing policy for progress toward broad goals and objectives with insufficient monitoring and assessment data. If countries and the <span class="hlt">global</span> community hope to achieve and maintain healthy <span class="hlt">oceans</span>, we will need to dedicate significant resources to measuring what we are trying to manage. PMID:28678881</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1292X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1292X"><span>Schwarz-Christoffel Conformal Mapping based Grid Generation for <span class="hlt">Global</span> <span class="hlt">Oceanic</span> Circulation Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Shiming</p> <p>2015-04-01</p> <p>We propose new grid generation algorithms for <span class="hlt">global</span> <span class="hlt">ocean</span> general circulation models (OGCMs). Contrary to conventional, analytical forms based dipolar or tripolar grids, the new algorithm are based on Schwarz-Christoffel (SC) conformal mapping with prescribed boundary information. While dealing with the conventional grid design problem of pole relocation, it also addresses more advanced issues of computational efficiency and the new requirements on OGCM grids arisen from the recent trend of high-resolution and multi-scale modeling. The proposed grid generation algorithm could potentially achieve the alignment of grid lines to coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the generated grids are still orthogonal curvilinear, they can be readily 10 utilized in existing Bryan-Cox-Semtner type <span class="hlt">ocean</span> models. The proposed methodology can also be applied to the grid generation task for regional <span class="hlt">ocean</span> modeling when complex land-<span class="hlt">ocean</span> distribution is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790022736','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790022736"><span>M2, S2, K1 models of the <span class="hlt">global</span> <span class="hlt">ocean</span> tide</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parke, M. E.; Hendershott, M. C.</p> <p>1979-01-01</p> <p><span class="hlt">Ocean</span> tidal signals appear in many geophysical measurements. Geophysicists need realistic tidal models to aid in interpretation of their data. Because of the closeness to resonance of dissipationless <span class="hlt">ocean</span> tides, it is difficult for numerical models to correctly represent the actual open <span class="hlt">ocean</span> tide. As an approximate solution to this problem, test functions derived by solving Laplace's Tidal Equations with <span class="hlt">ocean</span> loading and self gravitation are used as a basis for least squares dynamic interpolation of coastal and island tidal data for the constituents M2, S2, and Kl. The resulting representations of the <span class="hlt">global</span> tide are stable over at least a ?5% variation in the mean depth of the model basin, and they conserve mass. Maps of the geocentric tide, the induced free space potential, the induced vertical component of the solid earth tide, and the induced vertical component of the gravitational field for each contituent are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17829533','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17829533"><span>Dimethyl sulfide in the surface <span class="hlt">ocean</span> and the marine atmosphere: a <span class="hlt">global</span> view.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andreae, M O; Raemdonck, H</p> <p>1983-08-19</p> <p>Dimethyl sulfide (DMS) has been identified as the major volatile sulfur compound in 628 samples of surface seawater representing most of the major <span class="hlt">oceanic</span> ecozones. In at least three respects, its vertical distribution, its local patchiness, and its distribution in <span class="hlt">oceanic</span> ecozones, the concentration of DMS in the sea exhibits a pattern similar to that of primary production. The <span class="hlt">global</span> weightedaverage concentration of DMS in surface seawater is 102 nanograms of sulfur (DMS) per liter, corresponding to a <span class="hlt">global</span> sea-to-air flux of 39 x 10(12) grams of sulfur per year. When the biogenic sulfur contributions from the land surface are added, the biogenic sulfur gas flux is approximately equal to the anthropogenic flux of sulfur dioxide. The DMS concentration in air over the equatorial Pacific varies diurnally between 120 and 200 nanograms of sulfur (DMS) per cubic meter, in agreement with the predictions of photochemical models. The estimated source flux of DMS from the <span class="hlt">oceans</span> to the marine atmosphere is in agreement with independently obtained estimates of the removal fluxes of DMS and its oxidation products from the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983Sci...221..744A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983Sci...221..744A"><span>Dimethyl Sulfide in the Surface <span class="hlt">Ocean</span> and the Marine Atmosphere: A <span class="hlt">Global</span> View</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andreae, Meinrat O.; Raemdonck, Hans</p> <p>1983-08-01</p> <p>Dimethyl sulfide (DMS) has been identified as the major volatile sulfur compound in 628 samples of surface seawater representing most of the major <span class="hlt">oceanic</span> ecozones. In at least three respects, its vertical distribution, its local patchiness, and its distribution in <span class="hlt">oceanic</span> ecozones, the concentration of DMS in the sea exhibits a pattern similar to that of primary production. The <span class="hlt">global</span> weighted-average concentration of DMS in surface seawater is 102 nanograms of sulfur (DMS) per liter, corresponding to a <span class="hlt">global</span> sea-to-air flux of 39 × 1012 grams of sulfur per year. When the biogenic sulfur contributions from the land surface are added, the biogenic sulfur gas flux is approximately equal to the anthropogenic flux of sulfur dioxide. The DMS concentration in air over the equatorial Pacific varies diurnally between 120 and 200 nanograms of sulfur (DMS) per cubic meter, in agreement with the predictions of photochemical models. The estimated source flux of DMS from the <span class="hlt">oceans</span> to the marine atmosphere is in agreement with independently obtained estimates of the removal fluxes of DMS and its oxidation products from the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25100482','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25100482"><span>A <span class="hlt">global</span> <span class="hlt">ocean</span> inventory of anthropogenic mercury based on water column measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lamborg, Carl H; Hammerschmidt, Chad R; Bowman, Katlin L; Swarr, Gretchen J; Munson, Kathleen M; Ohnemus, Daniel C; Lam, Phoebe J; Heimbürger, Lars-Eric; Rijkenberg, Micha J A; Saito, Mak A</p> <p>2014-08-07</p> <p>Mercury is a toxic, bioaccumulating trace metal whose emissions to the environment have increased significantly as a result of anthropogenic activities such as mining and fossil fuel combustion. Several recent models have estimated that these emissions have increased the <span class="hlt">oceanic</span> mercury inventory by 36-1,313 million moles since the 1500s. Such predictions have remained largely untested owing to a lack of appropriate historical data and natural archives. Here we report oceanographic measurements of total dissolved mercury and related parameters from several recent expeditions to the Atlantic, Pacific, Southern and Arctic <span class="hlt">oceans</span>. We find that deep North Atlantic waters and most intermediate waters are anomalously enriched in mercury relative to the deep waters of the South Atlantic, Southern and Pacific <span class="hlt">oceans</span>, probably as a result of the incorporation of anthropogenic mercury. We estimate the total amount of anthropogenic mercury present in the <span class="hlt">global</span> <span class="hlt">ocean</span> to be 290 ± 80 million moles, with almost two-thirds residing in water shallower than a thousand metres. Our findings suggest that anthropogenic perturbations to the <span class="hlt">global</span> mercury cycle have led to an approximately 150 per cent increase in the amount of mercury in thermocline waters and have tripled the mercury content of surface waters compared to pre-anthropogenic conditions. This information may aid our understanding of the processes and the depths at which inorganic mercury species are converted into toxic methyl mercury and subsequently bioaccumulated in marine food webs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5643P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5643P"><span>Combined simulation of carbon and water isotopes in a <span class="hlt">global</span> <span class="hlt">ocean</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paul, André; Krandick, Annegret; Gebbie, Jake; Marchal, Olivier; Dutkiewicz, Stephanie; Losch, Martin; Kurahashi-Nakamura, Takasumi; Tharammal, Thejna</p> <p>2013-04-01</p> <p>Carbon and water isotopes are included as passive tracers in the MIT general circulation model (MITgcm). The implementation of the carbon isotopes is based on the existing MITgcm carbon cycle component and involves the fractionation processes during photosynthesis and air-sea gas exchange. Special care is given to the use of a real freshwater flux boundary condition in conjunction with the nonlinear free surface of the <span class="hlt">ocean</span> model. The isotopic content of precipitation and water vapor is obtained from an atmospheric GCM (the NCAR CAM3) and mapped onto the MITgcm grid system, but the kinetic fractionation during evaporation is treated explicitly in the <span class="hlt">ocean</span> model. In a number of simulations, we test the sensitivity of the carbon isotope distributions to the formulation of fractionation during photosynthesis and compare the results to modern observations of δ13C and Δ14C from GEOSECS, WOCE and CLIVAR. Similarly, we compare the resulting distribution of oxygen isotopes to modern δ18O data from the NASA GISS <span class="hlt">Global</span> Seawater Oxygen-18 Database. The overall agreement is good, but there are discrepancies in the carbon isotope composition of the surface water and the oxygen isotope composition of the intermediate and deep waters. The combined simulation of carbon and water isotopes in a <span class="hlt">global</span> <span class="hlt">ocean</span> model will provide a framework for studying present and past states of <span class="hlt">ocean</span> circulation such as postulated from deep-sea sediment records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME51A..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME51A..05S"><span>An Accurate Absorption-Based Net Primary Production Model for the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silsbe, G.; Westberry, T. K.; Behrenfeld, M. J.; Halsey, K.; Milligan, A.</p> <p>2016-02-01</p> <p>As a vital living link in the <span class="hlt">global</span> carbon cycle, understanding how net primary production (NPP) varies through space, time, and across climatic oscillations (e.g. ENSO) is a key objective in oceanographic research. The continual improvement of <span class="hlt">ocean</span> observing satellites and data analytics now present greater opportunities for advanced understanding and characterization of the factors regulating NPP. In particular, the emergence of spectral inversion algorithms now permits accurate retrievals of the phytoplankton absorption coefficient (aΦ) from space. As NPP is the efficiency in which absorbed energy is converted into carbon biomass, aΦ measurements circumvents chlorophyll-based empirical approaches by permitting direct and accurate measurements of phytoplankton energy absorption. It has long been recognized, and perhaps underappreciated, that NPP and phytoplankton growth rates display muted variability when normalized to aΦ rather than chlorophyll. Here we present a novel absorption-based NPP model that parameterizes the underlying physiological mechanisms behind this muted variability, and apply this physiological model to the <span class="hlt">global</span> <span class="hlt">ocean</span>. Through a comparison against field data from the Hawaii and Bermuda <span class="hlt">Ocean</span> Time Series, we demonstrate how this approach yields more accurate NPP measurements than other published NPP models. By normalizing NPP to satellite estimates of phytoplankton carbon biomass, this presentation also explores the seasonality of phytoplankton growth rates across several <span class="hlt">oceanic</span> regions. Finally, we discuss how future advances in remote-sensing (e.g. hyperspectral satellites, LIDAR, autonomous profilers) can be exploited to further improve absorption-based NPP models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMED51B0818P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMED51B0818P"><span>Community Observatories: Fostering Ideas that STEM From <span class="hlt">Ocean</span> Sense: Local Observations. <span class="hlt">Global</span> Connections.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pelz, M. S.; Ewing, N.; Hoeberechts, M.; Riddell, D. J.; McLean, M. A.; Brown, J. C. K.</p> <p>2015-12-01</p> <p><span class="hlt">Ocean</span> Networks Canada (ONC) uses education and communication to inspire, engage and educate via innovative "meet them where they are, and take them where they need to go" programs. ONC data are accessible via the internet allowing for the promotion of programs wherever the learners are located. We use technologies such as web portals, mobile apps and citizen science to share <span class="hlt">ocean</span> science data with many different audiences. Here we focus specifically on one of ONC's most innovative programs: community observatories and the accompanying <span class="hlt">Ocean</span> Sense program. The approach is based on equipping communities with the same technology enabled on ONC's large cabled observatories. ONC operates the world-leading NEPTUNE and VENUS cabled <span class="hlt">ocean</span> observatories and they collect data on physical, chemical, biological, and geological aspects of the <span class="hlt">ocean</span> over long time periods, supporting research on complex Earth processes in ways not previously possible. Community observatories allow for similar monitoring on a smaller scale, and support STEM efforts via a teacher-led program: <span class="hlt">Ocean</span> Sense. This program, based on local observations and <span class="hlt">global</span> connections improves data-rich teaching and learning via visualization tools, interactive plotting interfaces and lesson plans for teachers that focus on student inquiry and exploration. For example, students use all aspects of STEM by accessing, selecting, and interpreting data in multiple dimensions, from their local community observatories to the larger VENUS and NEPTUNE networks. The students make local observations and <span class="hlt">global</span> connections in all STEM areas. The first year of the program with teachers and students who use this innovative technology is described. Future community observatories and their technological applications in education, communication and STEM efforts are also described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DSRI..109..137S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DSRI..109..137S"><span>A <span class="hlt">global</span> seasonal surface <span class="hlt">ocean</span> climatology of phytoplankton types based on CHEMTAX analysis of HPLC pigments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swan, Chantal M.; Vogt, Meike; Gruber, Nicolas; Laufkoetter, Charlotte</p> <p>2016-03-01</p> <p>Much advancement has been made in recent years in field data assimilation, remote sensing and ecosystem modeling, yet our <span class="hlt">global</span> view of phytoplankton biogeography beyond chlorophyll biomass is still a cursory taxonomic picture with vast areas of the open <span class="hlt">ocean</span> requiring field validations. High performance liquid chromatography (HPLC) pigment data combined with inverse methods offer an advantage over many other phytoplankton quantification measures by way of providing an immediate perspective of the whole phytoplankton community in a sample as a function of chlorophyll biomass. Historically, such chemotaxonomic analysis has been conducted mainly at local spatial and temporal scales in the <span class="hlt">ocean</span>. Here, we apply a widely tested inverse approach, CHEMTAX, to a <span class="hlt">global</span> climatology of pigment observations from HPLC. This study marks the first systematic and objective <span class="hlt">global</span> application of CHEMTAX, yielding a seasonal climatology comprised of ~1500 1°×1° <span class="hlt">global</span> grid points of the major phytoplankton pigment types in the <span class="hlt">ocean</span> characterizing cyanobacteria, haptophytes, chlorophytes, cryptophytes, dinoflagellates, and diatoms, with results validated against prior regional studies where possible. Key findings from this new <span class="hlt">global</span> view of specific phytoplankton abundances from pigments are a) the large <span class="hlt">global</span> proportion of marine haptophytes (comprising 32±5% of total chlorophyll), whose biogeochemical functional roles are relatively unknown, and b) the contrasting spatial scales of complexity in <span class="hlt">global</span> community structure that can be explained in part by regional oceanographic conditions. The results are publically accessible via</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGeod.tmp..480A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGeod.tmp..480A"><span>On the assimilation of absolute geodetic dynamic topography in a <span class="hlt">global</span> <span class="hlt">ocean</span> model: impact on the deep <span class="hlt">ocean</span> state</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Androsov, Alexey; Nerger, Lars; Schnur, Reiner; Schröter, Jens; Albertella, Alberta; Rummel, Reiner; Savcenko, Roman; Bosch, Wolfgang; Skachko, Sergey; Danilov, Sergey</p> <p>2018-05-01</p> <p>General <span class="hlt">ocean</span> circulation models are not perfect. Forced with observed atmospheric fluxes they gradually drift away from measured distributions of temperature and salinity. We suggest data assimilation of absolute dynamical <span class="hlt">ocean</span> topography (DOT) observed from space geodetic missions as an option to reduce these differences. Sea surface information of DOT is transferred into the deep <span class="hlt">ocean</span> by defining the analysed <span class="hlt">ocean</span> state as a weighted average of an ensemble of fully consistent model solutions using an error-subspace ensemble Kalman filter technique. Success of the technique is demonstrated by assimilation into a <span class="hlt">global</span> configuration of the <span class="hlt">ocean</span> circulation model FESOM over 1 year. The dynamic <span class="hlt">ocean</span> topography data are obtained from a combination of multi-satellite altimetry and geoid measurements. The assimilation result is assessed using independent temperature and salinity analysis derived from profiling buoys of the AGRO float data set. The largest impact of the assimilation occurs at the first few analysis steps where both the model <span class="hlt">ocean</span> topography and the steric height (i.e. temperature and salinity) are improved. The continued data assimilation over 1 year further improves the model state gradually. Deep <span class="hlt">ocean</span> fields quickly adjust in a sustained manner: A model forecast initialized from the model state estimated by the data assimilation after only 1 month shows that improvements induced by the data assimilation remain in the model state for a long time. Even after 11 months, the modelled <span class="hlt">ocean</span> topography and temperature fields show smaller errors than the model forecast without any data assimilation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA526438','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA526438"><span>Concurrent Simulation of the Eddying General Circulation and Tides in a <span class="hlt">Global</span> <span class="hlt">Ocean</span> Model</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-01-01</p> <p>Eddying General Circulation and Tides in a <span class="hlt">Global</span> <span class="hlt">Ocean</span> Model 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 0602435N 6...STATEMENT Approved for public release, distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT This paper presents a five-year <span class="hlt">global</span> ...running 25-h average to approximately separate tidal and non-tidal components of the near-bottom flow. In contrast to earlier high-resolution <span class="hlt">global</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhDT.......129W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhDT.......129W"><span>The <span class="hlt">Oceanic</span> Cycle and <span class="hlt">Global</span> Atmospheric Budget of Carbonyl Sulfide.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weiss, Peter Scott</p> <p>1995-01-01</p> <p>A significant portion of stratospheric air chemistry is influenced by the existence of carbonyl sulfide (COS). This ubiquitous sulfur gas represents a major source of sulfur to the stratosphere where it is converted to sulfuric acid aerosol particles. Stratospheric aerosols are climatically important because they scatter incoming solar radiation back to space and are able to increase the catalytic destruction of ozone through gas phase reactions on particle surfaces. COS is primarily formed at the surface of the earth, in both marine and terrestrial environments, and is strongly linked to natural biological processes. However, many gaps in the understanding of the <span class="hlt">global</span> COS cycle still exist, which has led to a <span class="hlt">global</span> atmospheric budget that is out of balance by a factor of two or more, and a lack of understanding of how human activity has affected the cycling of this gas. The goal of this study was to focus on COS in the marine environment by investigating production/destruction mechanisms and recalculating the <span class="hlt">ocean</span>-atmosphere flux. Analytical work was carried out using the electron capture sulfur detector (ECD-S) for gas chromatography. This system was optimized for COS so that air and seawater-equilibrated air samples could be directly injected without preconcentration. This research was carried out on two cruises aboard the NOAA ship Surveyor during long meridional transects between 55^circN and 70 ^circS along 140^circ W in the Pacific <span class="hlt">Ocean</span>. The major findings of these research activities are: (1) Photoproduction of COS is at a maximum between 313 and 336 nm in natural sunlit waters. Tropical water surface and column production rates are 68 pM/day and 360 nmol/m^2/day, respectively. Antarctic surface and column production rates are 101 pM/day and 620 nmol/m^2/day, respectively. (2) Wide regions of the open <span class="hlt">ocean</span> were found to be undersaturated with respect to atmospheric equilibrium of COS. The <span class="hlt">global</span> open <span class="hlt">ocean</span> sea-air flux of COS was found to be -0</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GBioC..25.1004L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GBioC..25.1004L"><span>An updated climatology of surface dimethlysulfide concentrations and emission fluxes in the <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lana, A.; Bell, T. G.; Simó, R.; Vallina, S. M.; Ballabrera-Poy, J.; Kettle, A. J.; Dachs, J.; Bopp, L.; Saltzman, E. S.; Stefels, J.; Johnson, J. E.; Liss, P. S.</p> <p>2011-03-01</p> <p>The potentially significant role of the biogenic trace gas dimethylsulfide (DMS) in determining the Earth's radiation budget makes it necessary to accurately reproduce seawater DMS distribution and quantify its <span class="hlt">global</span> flux across the sea/air interface. Following a threefold increase of data (from 15,000 to over 47,000) in the <span class="hlt">global</span> surface <span class="hlt">ocean</span> DMS database over the last decade, new <span class="hlt">global</span> monthly climatologies of surface <span class="hlt">ocean</span> DMS concentration and sea-to-air emission flux are presented as updates of those constructed 10 years ago. Interpolation/extrapolation techniques were applied to project the discrete concentration data onto a first guess field based on Longhurst's biogeographic provinces. Further objective analysis allowed us to obtain the final monthly maps. The new climatology projects DMS concentrations typically in the range of 1-7 nM, with higher levels occurring in the high latitudes, and with a general trend toward increasing concentration in summer. The increased size and distribution of the observations in the DMS database have produced in the new climatology substantially lower DMS concentrations in the polar latitudes and generally higher DMS concentrations in regions that were severely undersampled 10 years ago, such as the southern Indian <span class="hlt">Ocean</span>. Using the new DMS concentration climatology in conjunction with state-of-the-art parameterizations for the sea/air gas transfer velocity and climatological wind fields, we estimate that 28.1 (17.6-34.4) Tg of sulfur are transferred from the <span class="hlt">oceans</span> into the atmosphere annually in the form of DMS. This represents a <span class="hlt">global</span> emission increase of 17% with respect to the equivalent calculation using the previous climatology. This new DMS climatology represents a valuable tool for atmospheric chemistry, climate, and Earth System models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3340021','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3340021"><span>Antarctic and Southern <span class="hlt">Ocean</span> influences on Late Pliocene <span class="hlt">global</span> cooling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McKay, Robert; Naish, Tim; Carter, Lionel; Riesselman, Christina; Dunbar, Robert; Sjunneskog, Charlotte; Winter, Diane; Sangiorgi, Francesca; Warren, Courtney; Pagani, Mark; Schouten, Stefan; Willmott, Veronica; Levy, Richard; DeConto, Robert; Powell, Ross D.</p> <p>2012-01-01</p> <p>The influence of Antarctica and the Southern <span class="hlt">Ocean</span> on Late Pliocene <span class="hlt">global</span> climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1B sediment core recovered from beneath the Ross Ice Shelf. We provide evidence for a major expansion of an ice sheet in the Ross Sea that began at ∼3.3 Ma, followed by a coastal sea surface temperature cooling of ∼2.5 °C, a stepwise expansion of sea ice, and polynya-style deep mixing in the Ross Sea between 3.3 and 2.5 Ma. The intensification of Antarctic cooling resulted in strengthened westerly winds and invigorated <span class="hlt">ocean</span> circulation. The associated northward migration of Southern <span class="hlt">Ocean</span> fronts has been linked with reduced Atlantic Meridional Overturning Circulation by restricting surface water connectivity between the <span class="hlt">ocean</span> basins, with implications for heat transport to the high latitudes of the North Atlantic. While our results do not exclude low-latitude mechanisms as drivers for Pliocene cooling, they indicate an additional role played by southern high-latitude cooling during development of the bipolar world. PMID:22496594</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp...35H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp...35H"><span>Uncertainty in Indian <span class="hlt">Ocean</span> Dipole response to <span class="hlt">global</span> warming: the role of internal variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hui, Chang; Zheng, Xiao-Tong</p> <p>2018-01-01</p> <p>The Indian <span class="hlt">Ocean</span> Dipole (IOD) is one of the leading modes of interannual sea surface temperature (SST) variability in the tropical Indian <span class="hlt">Ocean</span> (TIO). The response of IOD to <span class="hlt">global</span> warming is quite uncertain in climate model projections. In this study, the uncertainty in IOD change under <span class="hlt">global</span> warming, especially that resulting from internal variability, is investigated based on the community earth system model large ensemble (CESM-LE). For the IOD amplitude change, the inter-member uncertainty in CESM-LE is about 50% of the intermodel uncertainty in the phase 5 of the coupled model intercomparison project (CMIP5) multimodel ensemble, indicating the important role of internal variability in IOD future projection. In CESM-LE, both the ensemble mean and spread in mean SST warming show a zonal positive IOD-like (pIOD-like) pattern in the TIO. This pIOD-like mean warming regulates <span class="hlt">ocean</span>-atmospheric feedbacks of the interannual IOD mode, and weakens the skewness of the interannual variability. However, as the changes in <span class="hlt">oceanic</span> and atmospheric feedbacks counteract each other, the inter-member variability in IOD amplitude change is not correlated with that of the mean state change. Instead, the ensemble spread in IOD amplitude change is correlated with that in ENSO amplitude change in CESM-LE, reflecting the close inter-basin relationship between the tropical Pacific and Indian <span class="hlt">Ocean</span> in this model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.7909V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.7909V"><span>Hiatus-like decades in the absence of equatorial Pacific cooling and accelerated <span class="hlt">global</span> <span class="hlt">ocean</span> heat uptake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>von Känel, Lukas; Frölicher, Thomas L.; Gruber, Nicolas</p> <p>2017-08-01</p> <p>A surface cooling pattern in the equatorial Pacific associated with a negative phase of the Interdecadal Pacific Oscillation is the leading hypothesis to explain the smaller rate of <span class="hlt">global</span> warming during 1998-2012, with these cooler than normal conditions thought to have accelerated the <span class="hlt">oceanic</span> heat uptake. Here using a 30-member ensemble simulation of a <span class="hlt">global</span> Earth system model, we show that in 10% of all simulated decades with a <span class="hlt">global</span> cooling trend, the eastern equatorial Pacific actually warms. This implies that there is a 1 in 10 chance that decadal hiatus periods may occur without the equatorial Pacific being the dominant pacemaker. In addition, the <span class="hlt">global</span> <span class="hlt">ocean</span> heat uptake tends to slow down during hiatus decades implying a fundamentally different <span class="hlt">global</span> climate feedback factor on decadal time scales than on centennial time scales and calling for caution inferring climate sensitivity from decadal-scale variability.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS12A..07M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS12A..07M"><span>The Indonesian Throughflow (ITF) and its impacts on the Indian <span class="hlt">Ocean</span> during the <span class="hlt">global</span> warming slowdown period</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makarim, S.; Liu, Z.; Yu, W.; Yan, X.; Sprintall, J.</p> <p>2016-12-01</p> <p>The <span class="hlt">global</span> warming slowdown indicated by a slower warming rate at the surface layer accompanied by stronger heat transport into the deeper layers has been explored in the Indian <span class="hlt">Ocean</span>. Although the mechanisms of the <span class="hlt">global</span> warming slowdown are still under warm debate, some clues have been recognized that decadal La Nina like-pattern induced decadal cooling in the Pacific <span class="hlt">Ocean</span> and generated an increase of the Indonesian Throughflow (ITF) transport in 2004-2010. However, how the ITF spreading to the interior of the Indian <span class="hlt">Ocean</span> and the impact of ITF changes on the Indian <span class="hlt">Ocean</span>, in particular its water mass transformation and current system are still unknown. To this end, we analyzed thermohaline structure and current system at different depths in the Indian <span class="hlt">Ocean</span> both during and just before the <span class="hlt">global</span> warming slowdown period using the ORAS4 and ARGO dataset. Here, we found the new edge of ITF at off Sumatra presumably as northward deflection of ITF Lombok Strait, and The Monsoon Onset Monitoring and Social Ecology Impact (MOMSEI) and Java Upwelling Variation Observation (JUVO) dataset confirmed this evident. An isopycnal mixing method initially proposed by Du et al. (2013) is adopted to quantify the spreading of ITF water in the Indian <span class="hlt">Ocean</span>, and therefore the impacts of ITF changes on the variation of the Agulhas Current, Leuween Current, Bay of Bengal Water. This study also prevailed the fresher salinity in the Indian <span class="hlt">Ocean</span> during the slowdown warming period were not only contributed by stronger transport of the ITF, but also by freshening Arabian Sea and infiltrating Antartic Intermediate Water (AAIW).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171617"><span><span class="hlt">Global</span> Autocorrelation Scales of the Partial Pressure of <span class="hlt">Oceanic</span> CO2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Li, Zhen; Adamec, David; Takahashi, Taro; Sutherland, Stewart C.</p> <p>2004-01-01</p> <p>A <span class="hlt">global</span> database of approximately 1.7 million observations of the partial pressure of carbon dioxide in surface <span class="hlt">ocean</span> waters (pCO2) collected between 1970 and 2003 is used to estimate its spatial autocorrelation structure. The patterns of the lag distance where the autocorrelation exceeds 0.8 is similar to patterns in the spatial distribution of the first baroclinic Rossby radius of deformation indicating that <span class="hlt">ocean</span> circulation processes play a significant role in determining the spatial variability of pCO2. For example, the <span class="hlt">global</span> maximum of the distance at which autocorrelations exceed 0.8 averages about 140 km in the equatorial Pacific. Also, the lag distance at which the autocorrelation exceed 0.8 is greater in the vicinity of the Gulf Stream than it is near the Kuroshio, approximately 50 km near the Gulf Stream as opposed to 20 km near the Kuroshio. Separate calculations for times when the sun is north and south of the equator revealed no obvious seasonal dependence of the spatial autocorrelation scales. The pCO2 measurements at <span class="hlt">Ocean</span> Weather Station (OWS) 'P', in the eastern subarctic Pacific (50 N, 145 W) is the only fixed location where an uninterrupted time series of sufficient length exists to calculate a meaningful temporal autocorrelation function for lags greater than a few days. The estimated temporal autocorrelation function at OWS 'P', is highly variable. A spectral analysis of the longest four pCO2 time series indicates a high level of variability occurring over periods from the atmospheric synoptic to the maximum length of the time series, in this case 42 days. It is likely that a relative peak in variability with a period of 3-6 days is related to atmospheric synoptic period variability and <span class="hlt">ocean</span> mixing events due to wind stirring. However, the short length of available time series makes identifying temporal relationships between pCO2 and atmospheric or <span class="hlt">ocean</span> processes problematic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980007178','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980007178"><span><span class="hlt">Global</span>-Local Finite Element Analysis for Thermo-Mechanical Stresses in Bonded <span class="hlt">Joints</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shkarayev, S.; Madenci, Erdogan; Camarda, C. J.</p> <p>1997-01-01</p> <p>An analysis of adhesively bonded <span class="hlt">joints</span> using conventional finite elements does not capture the singular behavior of the stress field in regions where two or three dissimilar materials form a junction with or without free edges. However, these regions are characteristic of the bonded <span class="hlt">joints</span> and are prone to failure initiation. This study presents a method to capture the singular stress field arising from the geometric and material discontinuities in bonded composites. It is achieved by coupling the local (conventional) elements with <span class="hlt">global</span> (special) elements whose interpolation functions are constructed from the asymptotic solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GBioC..32..654C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GBioC..32..654C"><span>The eMLR(C*) Method to Determine Decadal Changes in the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Storage of Anthropogenic CO2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clement, Dominic; Gruber, Nicolas</p> <p>2018-04-01</p> <p>The determination of the decadal change in anthropogenic CO2 in the <span class="hlt">global</span> <span class="hlt">ocean</span> from repeat hydrographic surveys represents a formidable challenge, which we address here by introducing a seamless new method. This method builds on the extended multiple linear regression (eMLR) approach to identify the anthropogenic CO2 signal, but in order to improve the robustness of this method, we fit C∗ rather than dissolved inorganic carbon and use a probabilistic method for the selection of the predictors. In order to account for the multiyear nature of the surveys, we adjust all C∗ observations of a particular observing period to a common reference year by assuming a transient steady state. We finally use the eMLR models together with <span class="hlt">global</span> gridded climatological distributions of the predictors to map the estimated change in anthropogenic CO2 to the <span class="hlt">global</span> <span class="hlt">ocean</span>. Testing this method with synthetic data generated from a hindcast simulation with an <span class="hlt">ocean</span> model reveals that the method is able to reconstruct the change in anthropogenic CO2 with only a small <span class="hlt">global</span> bias (<5%). Within <span class="hlt">ocean</span> basins, the errors can be larger, mostly driven by changes in <span class="hlt">ocean</span> circulation. Overall, we conclude from the model that the method has an accuracy of retrieving the column integrated change in anthropogenic CO2 of about ±10% at the scale of whole <span class="hlt">ocean</span> basins. We expect that this uncertainty needs to be doubled to about ±20% when the change in anthropogenic CO2 is reconstructed from observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000034263','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000034263"><span>NASA/GSFC Research Activities for the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Carbon Cycle: A Prospectus for the 21st Century</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, W. W.; Behrenfield, M. J.; Hoge, F. E.; Esaias, W. E.; Huang, N. E.; Long, S. R.; McClain, C. R.</p> <p>2000-01-01</p> <p>There are increasing concerns that anthropogenic inputs of carbon dioxide into the Earth system have the potential for climate change. In response to these concerns, the GSFC Laboratory for Hydrospheric Processes has formed the <span class="hlt">Ocean</span> Carbon Science Team (OCST) to contribute to greater understanding of the <span class="hlt">global</span> <span class="hlt">ocean</span> carbon cycle. The overall goals of the OCST are to: 1) detect changes in biological components of the <span class="hlt">ocean</span> carbon cycle through remote sensing of biooptical properties, 2) refine understanding of <span class="hlt">ocean</span> carbon uptake and sequestration through application of basic research results, new satellite algorithms, and improved model parameterizations, 3) develop and implement new sensors providing critical missing environmental information related to the <span class="hlt">oceanic</span> carbon cycle and the flux of CO2 across the air-sea interface. The specific objectives of the OCST are to: 1) establish a 20-year time series of <span class="hlt">ocean</span> color, 2) develop new remote sensing technologies, 3) validate <span class="hlt">ocean</span> remote sensing observations, 4) conduct <span class="hlt">ocean</span> carbon cycle scientific investigations directly related to remote sensing data, emphasizing physiological, empirical and coupled physical/biological models, satellite algorithm development and improvement, and analysis of satellite data sets. These research and mission objectives are intended to improve our understanding of <span class="hlt">global</span> <span class="hlt">ocean</span> carbon cycling and contribute to national goals by maximizing the use of remote sensing data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V34B..06B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V34B..06B"><span>Did the Chicxulub meteorite impact trigger eruptions at mid-<span class="hlt">ocean</span> ridges <span class="hlt">globally</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Byrnes, J. S.; Karlstrom, L.</p> <p>2017-12-01</p> <p>Are there causal links between the eruption of large igneous provinces, meteorite impacts, and mass extinctions? Recent dating suggests that state shifts in Deccan Traps eruptions, including erupted volumes, feeder dike orientations, and magma chemistry, occurred shortly after the Chicxulub impact. A proposed explanation for this observation is an increase in upper mantle permeability following the Chicxulub impact that accelerated the pace of Deccan volcanism [Richards et al., 2015]. If such triggering occurred, at <span class="hlt">global</span> distances not associated with the impact antipode, it is reasonable to hypothesize that other reservoirs of stored melt may have been perturbed as well. We present evidence that mid-<span class="hlt">ocean</span> ridge activity increased <span class="hlt">globally</span> following the impact. Anomalously concentrated free-air gravity and sea-floor topographic roughness suggest volumes of excess <span class="hlt">oceanic</span> ridge magmatism in the range of 2 x 105 to 106 km3 within 1 Myrs of the Chicxulub impact. This signal is only clearly observed for half-spreading rates above 35 mm/yr, possibly because crust formed at slower spreading rates is too complex to preserve the signal. Because similar anomalies are observed separately in the Indian and Pacific <span class="hlt">Oceans</span>, and because the timing of the signal does not clearly align with changes in spreading rates, we do not favor plume activity as an explanation. Widespread mobilization of existing mantle melt by post-impact seismic radiation, and subsequent emplacement of melt as crustal intrusions and eruptions, can explain the volume and distribution of anomalous crust without invoking impact-induced melt production. Although the mechanism for increasing permeability is not clear at either Deccan or mid-<span class="hlt">ocean</span> ridges, these results support the hypothesis that the causes and consequences of the Deccan Traps, Chicxulub impact, and K-Pg mass extinction should not be considered in isolation. We conclude by discussing several enigmatic observations from K-Pg time that heightened</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ESSD....4...37B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ESSD....4...37B"><span>Picophytoplankton biomass distribution in the <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buitenhuis, E. T.; Li, W. K. W.; Vaulot, D.; Lomas, M. W.; Landry, M. R.; Partensky, F.; Karl, D. M.; Ulloa, O.; Campbell, L.; Jacquet, S.; Lantoine, F.; Chavez, F.; Macias, D.; Gosselin, M.; McManus, G. B.</p> <p>2012-08-01</p> <p>The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s during cruises throughout most of the world <span class="hlt">ocean</span>. We compiled a database of 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the <span class="hlt">ocean</span> surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins, and at least some data in all other basins. The average picophytoplankton biomass is 12 ± 22 μg C l-1 or 1.9 g C m-2. We estimate a total <span class="hlt">global</span> picophytoplankton biomass of 0.53-1.32 Pg C (17-39% Prochlorococcus, 12-15% Synechococcus and 49-69% picoeukaryotes), with an intermediate/best estimate of 0.74 Pg C. Future efforts in this area of research should focus on reporting calibrated cell size and collecting data in undersampled regions. <a href="http://doi.pangaea.de/10.1594/PANGAEA.777385"target="_blank">http://doi.pangaea.de/10.1594/PANGAEA.777385</a></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP33C2323W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP33C2323W"><span>Testing the Deglacial <span class="hlt">Global</span> <span class="hlt">Ocean</span> Alkalization Hypothesis Using Foraminifer-based Mg/Ca, Shell Weight, and MFI</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ward, B. M.; Mekik, F.; Pourmand, A.</p> <p>2015-12-01</p> <p>In light of evidence for extensive modern <span class="hlt">ocean</span> acidification, it has become imperative to better understand the <span class="hlt">global</span> carbon cycle by reconstructing past <span class="hlt">ocean</span> acidification/alkalization events. Our goal is to test the deglacial <span class="hlt">global</span> alkalization hypothesis using a multi-proxy approach by reconstructing the pH, temperature, and [CO32-] of thermocline waters and the dissolution in deep sea sediments over the last 25,000 years in core ME-27 from the eastern equatorial Pacific. Our specific research questions are: Is there unequivocal evidence for a deglacial <span class="hlt">ocean</span> alkalization event? If yes, what was the magnitude of the alkalization event? If no, how can we explain why evidence of this event is missing from our core? We inferred temperature from Mg/Ca, and habitat water [CO32-] from sized-normalized shell weight in Neogloboquadrina dutertrei. Dissolution in sediments was estimated using the Globorotalia menardii Fragmentation Index (MFI). We see no clear indication of a deglacial <span class="hlt">ocean</span> alkalization event with our proxies. Neither our shell weight, nor MFI data show a more alkaline deglacial <span class="hlt">ocean</span> compared to the Last Glacial Maximum and the modern Interglacial. Instead, we observe a steady decrease in thermocline [CO32-], and increase in deep sea calcite preservation since the LGM. Our results may indicate that the <span class="hlt">global</span> alkalization event was obscured in ME-27 due to higher organic carbon fluxes during the deglacial, and/or due to yet undetermined effects of temperature on the foraminifer shell weight proxy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020043988','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020043988"><span>The Change in <span class="hlt">Oceanic</span> O2 Inventory Associated with Recent <span class="hlt">Global</span> Warming</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keeling, Ralph; Garcia, Hernan</p> <p>2002-01-01</p> <p><span class="hlt">Oceans</span> general circulation models predict that <span class="hlt">global</span> warming may cause a decrease in the <span class="hlt">oceanic</span> O2 inventory and an associated O2 outgassing. An independent argument is presented here in support of this prediction based on observational evidence of the <span class="hlt">ocean</span>'s biogeochemical response to natural warming. On time scales from seasonal to centennial, natural O2 flux/heat flux ratios are shown to occur in a range of 2 to 10 nmol O2 per Joule of warming, with larger ratios typically occurring at higher latitudes and over longer time scales. The ratios are several times larger than would be expected solely from the effect of heating on the O2 solubility, indicating that most of the O2 exchange is biologically mediated through links between heating and stratification. The change in <span class="hlt">oceanic</span> O2 inventory through the 1990's is estimated to be 0.3 - 0.4 x 10(exp 14) mol O2 per year based on scaling the observed anomalous long-term <span class="hlt">ocean</span> warming by natural O2 flux/heating ratios and allowing for uncertainty due to decadal variability. Implications are discussed for carbon budgets based on observed changes in atmospheric O2/N2 ratio and based on observed changes in <span class="hlt">ocean</span> dissolved inorganic carbon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010048424&hterms=dataset&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddataset','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010048424&hterms=dataset&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddataset"><span>A 7.5-Year Dataset of SSM/I-Derived Surface Turbulent Fluxes Over <span class="hlt">Global</span> <span class="hlt">Oceans</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Ardizzone, Joe; Nelkin, Eric; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>The surface turbulent fluxes of momentum, latent heat, and sensible heat over <span class="hlt">global</span> <span class="hlt">oceans</span> are essential to weather, climate and <span class="hlt">ocean</span> problems. Wind stress is the major forcing for driving the <span class="hlt">oceanic</span> circulation, while Evaporation is a key component of hydrological cycle and surface heat budget. We have produced a 7.5-year (July 1987-December 1994) dataset of daily, individual monthly-mean and climatological (1988-94) monthly-mean surface turbulent fluxes over the <span class="hlt">global</span> <span class="hlt">oceans</span> from measurements of the Special Sensor Microwave/Imager (SSM/I) on board the US Defense Meteorological Satellite Program F8, F10, and F11 satellites. It has a spatial resolution of 2.0x2.5 latitude-longitude. Daily turbulent fluxes are derived from daily data of SSM/I surface winds and specific humidity, National Centers for Environmental Prediction (NCEP) sea surface temperatures, and European Centre for Medium-Range Weather Forecasts (ECMWF) air-sea temperature differences, using a stability-dependent bulk scheme. The retrieved instantaneous surface air humidity (with a 25-km resolution) IS found to be generally accurate as compared to the collocated radiosonde observations over <span class="hlt">global</span> <span class="hlt">oceans</span>. The surface wind speed and specific humidity (latent heat flux) derived from the F10 SSM/I are found to be -encrally smaller (larger) than those retrieved from the F11 SSM/I. The F11 SSM/I appears to have slightly better retrieval accuracy for surface wind speed and humidity as compared to the F10 SSM/I. This difference may be due to the orbital drift of the F10 satellite. The daily wind stresses and latent heat fluxes retrieved from F10 and F11 SSM/Is show useful accuracy as verified against the research quality in si -neasurerrients (IMET buoy, RV Moana Wave, and RV Wecoma) in the western Pacific warm pool during the TOGA COARE Intensive observing period (November 1992-February 1993). The 1988-94 seasonal-mean turbulent fluxes and input variables derived from FS and F11 SSM/Is show reasonable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.7732G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7732G"><span>Euro-Argo: The European contribution to the <span class="hlt">global</span> Argo <span class="hlt">ocean</span> observations network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gourcuff, Claire</p> <p>2017-04-01</p> <p>The international Argo programme is a major element of the <span class="hlt">global</span> in-situ <span class="hlt">ocean</span> observing system. More than 3900 floats are now <span class="hlt">globally</span> measuring temperature and salinity throughout the <span class="hlt">global</span> <span class="hlt">oceans</span>, down to 2,000 meters depth and delivering data both in real time for operational users and after careful scientific quality control for climate change research and monitoring. Argo is the single most important in-situ observing system for the Copernicus Marine Service. The Euro-Argo research infrastructure organizes and federates European contribution to Argo. A legal and governance framework (Euro-Argo ERIC) was set up in May 2014; it allows European countries to consolidate and improve their contribution to Argo international. We will provide an overview of the development of Euro-Argo over the past years and present the now agreed Euro-Argo long term organization. The capability of the Euro-Argo infrastructure to organize Argo floats procurement, deployment and processing at European level and to conduct R&D driven by Copernicus needs will be highlighted. During the recent years, within the H2020 E-AIMS project, Euro-Argo carried R&D activities on new Argo floats, equipped with biogeochemical sensors or able to dive up to 4000m, from the floats design up to the analysis of their measurements. European Argo data centers were adapted so that they can handle the new data. Observing System Evaluations and Simulation Experiments were also conducted to provide robust recommendations for the next phase of Argo. One of the main challenges for Euro-Argo is now to implement the next phase of Argo with an extension towards biogeochemistry (e.g. oxygen, biology), the polar <span class="hlt">oceans</span>, the marginal seas and the deep <span class="hlt">ocean</span>. Meeting such challenges is essential for the long term sustainability and evolution of the Copernicus Marine Service. We will present Euro-Argo strategy and provide some highlights on the implementation-plan for the years to come and the Argo extensions for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080046909','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080046909"><span>Recent Short Term <span class="hlt">Global</span> Aerosol Trends over Land and <span class="hlt">Ocean</span> Dominated by Biomass Burning</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remer, Lorraine A.; Koren, Ilan; Kleidman, RIchard G.; Levy, Robert C.; Martins, J. Vanderlei; Kim, Kyu-Myong; Tanre, Didier; Mattoo, Shana; Yu, Hongbin</p> <p>2007-01-01</p> <p>NASA's MODIS instrument on board the Terra satellite is one of the premier tools to assess aerosol over land and <span class="hlt">ocean</span> because of its high quality calibration and consistency. We analyze Terra-MODIS's seven year record of aerosol optical depth (AOD) observations to determine whether <span class="hlt">global</span> aerosol has increased or decreased during this period. This record shows that AOD has decreased over land and increased over <span class="hlt">ocean</span>. Only the <span class="hlt">ocean</span> trend is statistically significant and corresponds to an increase in AOD of 0.009, or a 15% increase from background conditions. The strongest increasing trends occur over regions and seasons noted for strong biomass burning. This suggests that biomass burning aerosol dominates the increasing trend over <span class="hlt">oceans</span> and mitigates the otherwise mostly negative trend over the continents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMOS13A1002L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMOS13A1002L"><span>Regional variability of sea level change using a <span class="hlt">global</span> <span class="hlt">ocean</span> model.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lombard, A.; Garric, G.; Cazenave, A.; Penduff, T.; Molines, J.</p> <p>2007-12-01</p> <p>We analyse different runs of a <span class="hlt">global</span> eddy-permitting (1/4 degree) <span class="hlt">ocean</span> model driven by atmospheric forcing to evaluate regional variability of sea level change over 1993-2001, 1998-2006 and over the long period 1958-2004. No data assimilation is performed in the model, contrarily to previous similar studies (Carton et al., 2005; Wunsch et al., 2007; Koehl and Stammer, 2007). We compare the model-based regional sea level trend patterns with the one deduced from satellite altimetry data. We examine respective contributions of steric and bottom pressure changes to total regional sea level changes. For the steric component, we analyze separately the contributions of temperature and salinity changes as well as upper and lower <span class="hlt">ocean</span> contributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/820629','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/820629"><span>NSF final project report planning and implementation of the U.S. <span class="hlt">Joint</span> <span class="hlt">Global</span> <span class="hlt">Ocean</span> Flux Study (U.S. JGOFS)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Livingston, Hugh D.</p> <p>1996-07-01</p> <p>Conducted planning and implementation of <span class="hlt">ocean</span> carbon dioxide hydrographic surveys <span class="hlt">ocean</span> process studies, time-series studies of Bermuda and Hawaii, and sponsored scientific workshops for those activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19970003722&hterms=mit&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmit','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19970003722&hterms=mit&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmit"><span><span class="hlt">Oceanic</span> Fluxes of Mass, Heat and Freshwater: A <span class="hlt">Global</span> Estimate and Perspective</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>MacDonald, Alison Marguerite</p> <p>1995-01-01</p> <p>Data from fifteen <span class="hlt">globally</span> distributed, modern, high resolution, hydrographic <span class="hlt">oceanic</span> transects are combined in an inverse calculation using large scale box models. The models provide estimates of the <span class="hlt">global</span> meridional heat and freshwater budgets and are used to examine the sensitivity of the <span class="hlt">global</span> circulation, both inter and intra-basin exchange rates, to a variety of external constraints provided by estimates of Ekman, boundary current and throughflow transports. A solution is found which is consistent with both the model physics and the <span class="hlt">global</span> data set, despite a twenty five year time span and a lack of seasonal consistency among the data. The overall pattern of the <span class="hlt">global</span> circulation suggested by the models is similar to that proposed in previously published local studies and regional reviews. However, significant qualitative and quantitative differences exist. These differences are due both to the model definition and to the <span class="hlt">global</span> nature of the data set.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28779070','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28779070"><span>Long-range transport of airborne microbes over the <span class="hlt">global</span> tropical and subtropical <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mayol, Eva; Arrieta, Jesús M; Jiménez, Maria A; Martínez-Asensio, Adrián; Garcias-Bonet, Neus; Dachs, Jordi; González-Gaya, Belén; Royer, Sarah-J; Benítez-Barrios, Verónica M; Fraile-Nuez, Eugenio; Duarte, Carlos M</p> <p>2017-08-04</p> <p>The atmosphere plays a fundamental role in the transport of microbes across the planet but it is often neglected as a microbial habitat. Although the <span class="hlt">ocean</span> represents two thirds of the Earth's surface, there is little information on the atmospheric microbial load over the open <span class="hlt">ocean</span>. Here we provide a <span class="hlt">global</span> estimate of microbial loads and air-sea exchanges over the tropical and subtropical <span class="hlt">oceans</span> based on the data collected along the Malaspina 2010 Circumnavigation Expedition. Total loads of airborne prokaryotes and eukaryotes were estimated at 2.2 × 10 21 and 2.1 × 10 21 cells, respectively. Overall 33-68% of these microorganisms could be traced to a marine origin, being transported thousands of kilometres before re-entering the <span class="hlt">ocean</span>. Moreover, our results show a substantial load of terrestrial microbes transported over the <span class="hlt">oceans</span>, with abundances declining exponentially with distance from land and indicate that islands may act as stepping stones facilitating the transoceanic transport of terrestrial microbes.The extent to which the <span class="hlt">ocean</span> acts as a sink and source of airborne particles to the atmosphere is unresolved. Here, the authors report high microbial loads over the tropical Atlantic, Pacific and Indian <span class="hlt">oceans</span> and propose islands as stepping stones for the transoceanic transport of terrestrial microbes..</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS21A1361J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS21A1361J"><span>Isolating Tracers of Phytoplankton with Allometric Zooplankton (TOPAZ) from Modular <span class="hlt">Ocean</span> Model (MOM5) to Couple it with a <span class="hlt">Global</span> <span class="hlt">Ocean</span> Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jung, H. C.; Moon, B. K.; Wie, J.; Park, H. S.; Kim, K. Y.; Lee, J.; Byun, Y. H.</p> <p>2017-12-01</p> <p>This research is motivated by a need to develop a new coupled <span class="hlt">ocean</span>-biogeochemistry model, a key tool for climate projections. The Modular <span class="hlt">Ocean</span> Model (MOM5) is a <span class="hlt">global</span> <span class="hlt">ocean</span>/ice model developed by the Geophysical Fluid Dynamics Laboratory (GFDL) in the US, and it incorporates Tracers of Phytoplankton with Allometric Zooplankton (TOPAZ), which simulates the marine biota associated with carbon cycles. We isolated TOPAZ from MOM5 into a stand-alone version (TOPAZ-SA), and had it receive initial data and <span class="hlt">ocean</span> physical fields required. Then, its reliability was verified by comparing the simulation results from the TOPAZ-SA with the MOM5/TOPAZ. This stand-alone version of TOPAZ is to be coupled to the Nucleus for European Modelling of the <span class="hlt">Ocean</span> (NEMO). Here we present the preliminary results. Acknowledgements This research was supported by the project "Research and Development for KMA Weather, Climate, and Earth system Services" (NIMS-2016-3100) of the National Institute of Meteorological Sciences/Korea Meteorological Administration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA463189','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA463189"><span>Validation Test Report for the 1/8 deg <span class="hlt">Global</span> Navy Coastal <span class="hlt">Ocean</span> Model Nowcast/Forecast System</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-01-24</p> <p>Test Report for the 1/8° <span class="hlt">Global</span> Navy Coastal <span class="hlt">Ocean</span> Model Nowcast/Forecast System Charlie N. BarroN a. Birol Kara roBert C. rhodes ClarK rowley......OF ACRONYMS ......................................................................48 VALIDATION TEST REPORT FOR THE 1/8° <span class="hlt">GLOBAL</span> NAVY COASTAL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.G11A..11R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.G11A..11R"><span>Real-time Assimilation of Altimeter Derived Synthetic Profiles Into a <span class="hlt">Global</span> version of the Naval Research Laboratory's Coastal <span class="hlt">Ocean</span> Model (NCOM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rhodes, R. C.; Barron, C. N.; Fox, D. N.; Smedstad, L. F.</p> <p>2001-12-01</p> <p>A <span class="hlt">global</span> implementation of the Navy Coastal <span class="hlt">Ocean</span> Model (NCOM), developed by the Naval Research Laboratory (NRL) at Stennis Space Center is currently running in real-time and is planned for transition to the Naval Oceanographic Office (NAVOCEANO) in 2002. The model encompasses the open <span class="hlt">ocean</span> to 5 m depth on a curvilinear <span class="hlt">global</span> model grid with 1/8 degree grid spacing at 45N, extending from 80 S to a complete arctic cap with grid singularities mapped into Canada and Russia. Vertically, the model employs 41 sigma-z levels with sigma in the upper-<span class="hlt">ocean</span> and coastal regions and z in the deeper <span class="hlt">ocean</span>. The Navy Operational <span class="hlt">Global</span> Atmospheric Prediction System (NOGAPS) provides 6-hourly wind stresses and heat fluxes for forcing, while the operational Modular <span class="hlt">Ocean</span> Data Assimilation System (MODAS) provides the background climatology and tools for data pre-processing. Operationally available sea surface temperature (SST) and altimetry (SSH) data are assimilated into the NAVOCEANO <span class="hlt">global</span> 1/8 degree MODAS 2-D analysis and the 1/16 degree Navy Layered <span class="hlt">Ocean</span> Model (NLOM) to provide analyses and forecasts of SSH and SST. The 2-D SSH and SST nowcast fields are used as input to the MODAS synthetic climatology database to yield three-dimensional fields of synthetic temperature and salinity for assimilation into <span class="hlt">global</span> NCOM. The synthetic profiles are weighted higher at depth in the assimilation process to allow the numerical model to properly develop the mixed-layer structure driven by the real-time atmospheric forcing. <span class="hlt">Global</span> NCOM nowcasts and forecasts provide a valuable resource for rapid response to the varied and often unpredictable operational requests for 3-dimensional fields of <span class="hlt">ocean</span> temperature, salinity, and currents. In some cases, the resolution of the <span class="hlt">global</span> product is sufficient for guidance. In cases requiring higher resolution, the <span class="hlt">global</span> product offers a quick overview of local circulation and provides initial and boundary conditions for higher resolution coastal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28533519','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28533519"><span><span class="hlt">Ocean</span> acidification compromises a planktic calcifier with implications for <span class="hlt">global</span> carbon cycling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Davis, Catherine V; Rivest, Emily B; Hill, Tessa M; Gaylord, Brian; Russell, Ann D; Sanford, Eric</p> <p>2017-05-22</p> <p>Anthropogenically-forced changes in <span class="hlt">ocean</span> chemistry at both the <span class="hlt">global</span> and regional scale have the potential to negatively impact calcifying plankton, which play a key role in ecosystem functioning and marine carbon cycling. We cultured a <span class="hlt">globally</span> important calcifying marine plankter (the foraminifer, Globigerina bulloides) under an ecologically relevant range of seawater pH (7.5 to 8.3 total scale). Multiple metrics of calcification and physiological performance varied with pH. At pH > 8.0, increased calcification occurred without a concomitant rise in respiration rates. However, as pH declined from 8.0 to 7.5, calcification and oxygen consumption both decreased, suggesting a reduced ability to precipitate shell material accompanied by metabolic depression. Repair of spines, important for both buoyancy and feeding, was also reduced at pH < 7.7. The dependence of calcification, respiration, and spine repair on seawater pH suggests that foraminifera will likely be challenged by future <span class="hlt">ocean</span> conditions. Furthermore, the nature of these effects has the potential to actuate changes in vertical transport of organic and inorganic carbon, perturbing feedbacks to regional and <span class="hlt">global</span> marine carbon cycling. The biological impacts of seawater pH have additional, important implications for the use of foraminifera as paleoceanographic indicators.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E1828D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E1828D"><span>Dynamic <span class="hlt">ocean</span> provinces: a multi-sensor approach to <span class="hlt">global</span> marine ecophysiology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dowell, M.; Campbell, J.; Moore, T.</p> <p></p> <p>The concept of <span class="hlt">oceanic</span> provinces or domains has existed for well over a century. Such systems, whether real or only conceptual, provide a useful framework for understanding the mechanisms controlling biological, physical and chemical processes and their interactions. Criteria have been established for defining provinces based on physical forcings, availability of light and nutrients, complexity of the marine food web, and other factors. In general, such classification systems reflect the heterogeneous nature of the <span class="hlt">ocean</span> environment, and the effort of scientists to comprehend the whole system by understanding its various homogeneous components. If provinces are defined strictly on the basis of geospatial or temporal criteria (e.g., latitude zones, bathymetry, or season), the resulting maps exhibit discontinuities that are uncharacteristic of the <span class="hlt">ocean</span>. While this may be useful for many purposes, it is unsatisfactory in that it does not capture the dynamic nature of fluid boundaries in the <span class="hlt">ocean</span>. Boundaries fixed in time and space do not allow us to observe interannual or longer-term variability (e.g., regime shifts) that may result from climate change. The current study illustrates the potential of using fuzzy logic as a means of classifying the <span class="hlt">ocean</span> into objectively defined provinces using properties measurable from satellite sensors (MODIS and SeaWiFS). This approach accommodates the dynamic variability of provinces which can be updated as each image is processed. We adopt this classification as the basis for parameterizing specific algorithms for each of the classes. Once the class specific algorithms have been applied, retrievals are then recomposed into a single blended product based on the "weighted" fuzzy memberships. This will be demonstrated through animations of multi-year time- series of monthly composites of the individual classes or provinces. The provinces themselves are identified on the basis of <span class="hlt">global</span> fields of chlorophyll, sea surface temperature</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSCT44B0242P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSCT44B0242P"><span>Iron control on <span class="hlt">global</span> productivity: an efficient inverse model of the <span class="hlt">ocean</span>'s coupled phosphate and iron cycles.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pasquier, B.; Holzer, M.; Frants, M.</p> <p>2016-02-01</p> <p>We construct a data-constrained mechanistic inverse model of the <span class="hlt">ocean</span>'s coupled phosphorus and iron cycles. The nutrient cycling is embedded in a data-assimilated steady <span class="hlt">global</span> circulation. Biological nutrient uptake is parameterized in terms of nutrient, light, and temperature limitations on growth for two classes of phytoplankton that are not transported explicitly. A matrix formulation of the discretized nutrient tracer equations allows for efficient numerical solutions, which facilitates the objective optimization of the key biogeochemical parameters. The optimization minimizes the misfit between the modelled and observed nutrient fields of the current climate. We systematically assess the nonlinear response of the biological pump to changes in the aeolian iron supply for a variety of scenarios. Specifically, Green-function techniques are employed to quantify in detail the pathways and timescales with which those perturbations are propagated throughout the world <span class="hlt">oceans</span>, determining the <span class="hlt">global</span> teleconnections that mediate the response of the <span class="hlt">global</span> <span class="hlt">ocean</span> ecosystem. We confirm previous findings from idealized studies that increased iron fertilization decreases biological production in the subtropical gyres and we quantify the counterintuitive and asymmetric response of <span class="hlt">global</span> productivity to increases and decreases in the aeolian iron supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.489..228T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.489..228T"><span>Controls on the <span class="hlt">global</span> distribution of contourite drifts: Insights from an eddy-resolving <span class="hlt">ocean</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thran, Amanda C.; Dutkiewicz, Adriana; Spence, Paul; Müller, R. Dietmar</p> <p>2018-05-01</p> <p>Contourite drifts are anomalously high sediment accumulations that form due to reworking by bottom currents. Due to the lack of a comprehensive contourite database, the link between vigorous bottom water activity and drift occurrence has yet to be demonstrated on a <span class="hlt">global</span> scale. Using an eddy-resolving <span class="hlt">ocean</span> model and a new georeferenced database of 267 contourites, we show that the <span class="hlt">global</span> distribution of modern contourite drifts strongly depends on the configuration of the world's most powerful bottom currents, many of which are associated with <span class="hlt">global</span> meridional overturning circulation. Bathymetric obstacles frequently modify flow direction and intensity, imposing additional finer-scale control on drift occurrence. Mean bottom current speed over contourite-covered areas is only slightly higher (2.2 cm/s) than the rest of the <span class="hlt">global</span> <span class="hlt">ocean</span> (1.1 cm/s), falling below proposed thresholds deemed necessary to re-suspend and redistribute sediments (10-15 cm/s). However, currents fluctuate more frequently and intensely over areas with drifts, highlighting the role of intermittent, high-energy bottom current events in sediment erosion, transport, and subsequent drift accumulation. We identify eddies as a major driver of these bottom current fluctuations, and we find that simulated bottom eddy kinetic energy is over three times higher in contourite-covered areas in comparison to the rest of the <span class="hlt">ocean</span>. Our work supports previous hypotheses which suggest that contourite deposition predominantly occurs due to repeated acute events as opposed to continuous reworking under average-intensity background flow conditions. This suggests that the contourite record should be interpreted in terms of a bottom current's susceptibility to experiencing periodic, high-speed current events. Our results also highlight the potential role of upper <span class="hlt">ocean</span> dynamics in contourite sedimentation through its direct influence on deep eddy circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040034110','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040034110"><span>A Comparison of Latent Heat Fluxes over <span class="hlt">Global</span> <span class="hlt">Oceans</span> for Four Flux Products</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Nelkin, Eric; Ardizzone, Joe; Atlas, Robert M.</p> <p>2003-01-01</p> <p>To improve our understanding of <span class="hlt">global</span> energy and water cycle variability, and to improve model simulations of climate variations, it is vital to have accurate latent heat fluxes (LHF) over <span class="hlt">global</span> <span class="hlt">oceans</span>. Monthly LHF, 10-m wind speed (U10m), 10-m specific humidity (Q10h), and sea-air humidity difference (Qs-Q10m) of GSSTF2 (version 2 Goddard Satellite-based Surface Turbulent Fluxes) over <span class="hlt">global</span> <span class="hlt">Oceans</span> during 1992-93 are compared with those of HOAPS (Hamburg <span class="hlt">Ocean</span> Atmosphere Parameters and Fluxes from Satellite Data), NCEP (NCEP/NCAR reanalysis). The mean differences, standard deviations of differences, and temporal correlation of these monthly variables over <span class="hlt">global</span> <span class="hlt">Oceans</span> during 1992-93 between GSSTF2 and each of the three datasets are analyzed. The large-scale patterns of the 2yr-mean fields for these variables are similar among these four datasets, but significant quantitative differences are found. The temporal correlation is higher in the northern extratropics than in the south for all variables, with the contrast being especially large for da Silva as a result of more missing ship data in the south. The da Silva has extremely low temporal correlation and large differences with GSSTF2 for all variables in the southern extratropics, indicating that da Silva hardly produces a realistic variability in these variables. The NCEP has extremely low temporal correlation (0.27) and large spatial variations of differences with GSSTF2 for Qs-Q10m in the tropics, which causes the low correlation for LHF. Over the tropics, the HOAPS LHF is significantly smaller than GSSTF2 by approx. 31% (37 W/sq m), whereas the other two datasets are comparable to GSSTF2. This is because the HOAPS has systematically smaller LHF than GSSTF2 in space, while the other two datasets have very large spatial variations of large positive and negative LHF differences with GSSTF2 to cancel and to produce smaller regional-mean differences. Our analyses suggest that the GSSTF2 latent heat flux</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ISPAr42W7.1521L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ISPAr42W7.1521L"><span>Accuracy Assessment of Recent <span class="hlt">Global</span> <span class="hlt">Ocean</span> Tide Models around Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lei, J.; Li, F.; Zhang, S.; Ke, H.; Zhang, Q.; Li, W.</p> <p>2017-09-01</p> <p>Due to the coverage limitation of T/P-series altimeters, the lack of bathymetric data under large ice shelves, and the inaccurate definitions of coastlines and grounding lines, the accuracy of <span class="hlt">ocean</span> tide models around Antarctica is poorer than those in deep <span class="hlt">oceans</span>. Using tidal measurements from tide gauges, gravimetric data and GPS records, the accuracy of seven state-of-the-art <span class="hlt">global</span> <span class="hlt">ocean</span> tide models (DTU10, EOT11a, GOT4.8, FES2012, FES2014, HAMTIDE12, TPXO8) is assessed, as well as the most widely-used conventional model FES2004. Four regions (Antarctic Peninsula region, Amery ice shelf region, Filchner-Ronne ice shelf region and Ross ice shelf region) are separately reported. The standard deviations of eight main constituents between the selected models are large in polar regions, especially under the big ice shelves, suggesting that the uncertainty in these regions remain large. Comparisons with in situ tidal measurements show that the most accurate model is TPXO8, and all models show worst performance in Weddell sea and Filchner-Ronne ice shelf regions. The accuracy of tidal predictions around Antarctica is gradually improving.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC54A..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC54A..05K"><span>Geophysical <span class="hlt">Global</span> Modeling for Extreme Crop Production Using Photosynthesis Models Coupled to <span class="hlt">Ocean</span> SST Dipoles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaneko, D.</p> <p>2016-12-01</p> <p>Climate change appears to have manifested itself along with abnormal meteorological disasters. Instability caused by drought and flood disasters is producing poor harvests because of poor photosynthesis and pollination. Fluctuations of extreme phenomena are increasing rapidly because amplitudes of change are much greater than average trends. A fundamental cause of these phenomena derives from increased stored energy inside <span class="hlt">ocean</span> waters. Geophysical and biochemical modeling of crop production can elucidate complex mechanisms under seasonal climate anomalies. The models have progressed through their combination with <span class="hlt">global</span> climate reanalysis, environmental satellite data, and harvest data on the ground. This study examined adaptation of crop production to advancing abnormal phenomena related to <span class="hlt">global</span> climate change. <span class="hlt">Global</span> environmental surface conditions, i.e., vegetation, surface air temperature, and sea surface temperature observed by satellites, enable <span class="hlt">global</span> modeling of crop production and monitoring. Basic streams of the concepts of modeling rely upon continental energy flow and carbon circulation among crop vegetation, land surface atmosphere combining energy advection from <span class="hlt">ocean</span> surface anomalies. <span class="hlt">Global</span> environmental surface conditions, e.g., vegetation, surface air temperature, and sea surface temperature observed by satellites, enable <span class="hlt">global</span> modeling of crop production and monitoring. The method of validating the modeling relies upon carbon partitioning in biomass and grains through carbon flow by photosynthesis using carbon dioxide unit in photosynthesis. Results of computations done for this study show <span class="hlt">global</span> distributions of actual evaporation, stomata opening, and photosynthesis, presenting mechanisms related to advection effects from SST anomalies in the Pacific, Atlantic, and Indian <span class="hlt">oceans</span> on <span class="hlt">global</span> and continental croplands. For North America, climate effects appear clearly in severe atmospheric phenomena, which have caused drought and forest fires</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ThApC.tmp..226S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ThApC.tmp..226S"><span>Cycles in <span class="hlt">oceanic</span> teleconnections and <span class="hlt">global</span> temperature change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seip, Knut L.; Grøn, Øyvind</p> <p>2018-06-01</p> <p>Three large <span class="hlt">ocean</span> currents are represented by proxy time series: the North Atlantic Oscillation (NAO), the Southern Oscillation Index (SOI), and the Pacific Decadal Oscillation (PDO). We here show how proxies for the currents interact with each other and with the <span class="hlt">global</span> temperature anomaly (GTA). Our results are obtained by a novel method, which identifies running average leading-lagging (LL) relations, between paired series. We find common cycle times for a paired series of 6-7 and 25-28 years and identify years when the LL relations switch. Switching occurs with 18.4 ± 14.3-year intervals for the short 6-7-year cycles and with 27 ± 15-year intervals for the 25-28-year cycles. During the period 1940-1950, the LL relations for the long cycles were circular (nomenclature x leads y: x → y): GTA → NAO → SOI → PDO → GTA. However, after 1960, the LL relations become more complex and there are indications that GTA leads to both NAO and PDO. The switching years are related to <span class="hlt">ocean</span> current tie points and reversals reported in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRB..122.2328H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRB..122.2328H"><span><span class="hlt">Oceanic</span> residual depth measurements, the plate cooling model, and <span class="hlt">global</span> dynamic topography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoggard, Mark J.; Winterbourne, Jeff; Czarnota, Karol; White, Nicky</p> <p>2017-03-01</p> <p>Convective circulation of the mantle causes deflections of the Earth's surface that vary as a function of space and time. Accurate measurements of this dynamic topography are complicated by the need to isolate and remove other sources of elevation, arising from flexure and lithospheric isostasy. The complex architecture of continental lithosphere means that measurement of present-day dynamic topography is more straightforward in the <span class="hlt">oceanic</span> realm. Here we present an updated methodology for calculating <span class="hlt">oceanic</span> residual bathymetry, which is a proxy for dynamic topography. Corrections are applied that account for the effects of sedimentary loading and compaction, for anomalous crustal thickness variations, for subsidence of <span class="hlt">oceanic</span> lithosphere as a function of age and for non-hydrostatic geoid height variations. Errors are formally propagated to estimate measurement uncertainties. We apply this methodology to a <span class="hlt">global</span> database of 1936 seismic surveys located on <span class="hlt">oceanic</span> crust and generate 2297 spot measurements of residual topography, including 1161 with crustal corrections. The resultant anomalies have amplitudes of ±1 km and wavelengths of ˜1000 km. Spectral analysis of our database using cross-validation demonstrates that spherical harmonics up to and including degree 30 (i.e., wavelengths down to 1300 km) are required to accurately represent these observations. Truncation of the expansion at a lower maximum degree erroneously increases the amplitude of inferred long-wavelength dynamic topography. There is a strong correlation between our observations and free-air gravity anomalies, magmatism, ridge seismicity, vertical motions of adjacent rifted margins, and <span class="hlt">global</span> tomographic models. We infer that shorter wavelength components of the observed pattern of dynamic topography may be attributable to the presence of thermal anomalies within the shallow asthenospheric mantle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22539717','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22539717"><span><span class="hlt">Ocean</span> salinities reveal strong <span class="hlt">global</span> water cycle intensification during 1950 to 2000.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Durack, Paul J; Wijffels, Susan E; Matear, Richard J</p> <p>2012-04-27</p> <p>Fundamental thermodynamics and climate models suggest that dry regions will become drier and wet regions will become wetter in response to warming. Efforts to detect this long-term response in sparse surface observations of rainfall and evaporation remain ambiguous. We show that <span class="hlt">ocean</span> salinity patterns express an identifiable fingerprint of an intensifying water cycle. Our 50-year observed <span class="hlt">global</span> surface salinity changes, combined with changes from <span class="hlt">global</span> climate models, present robust evidence of an intensified <span class="hlt">global</span> water cycle at a rate of 8 ± 5% per degree of surface warming. This rate is double the response projected by current-generation climate models and suggests that a substantial (16 to 24%) intensification of the <span class="hlt">global</span> water cycle will occur in a future 2° to 3° warmer world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4644973','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4644973"><span>The coastal <span class="hlt">ocean</span> response to the <span class="hlt">global</span> warming acceleration and hiatus</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liao, Enhui; Lu, Wenfang; Yan, Xiao-Hai; Jiang, Yuwu; Kidwell, Autumn</p> <p>2015-01-01</p> <p>Coastlines are fundamental to humans for habitation, commerce, and natural resources. Many coastal ecosystem disasters, caused by extreme sea surface temperature (SST), were reported when the <span class="hlt">global</span> climate shifted from <span class="hlt">global</span> warming to <span class="hlt">global</span> surface warming hiatus after 1998. The task of understanding the coastal SST variations within the <span class="hlt">global</span> context is an urgent matter. Our study on the <span class="hlt">global</span> coastal SST from 1982 to 2013 revealed a significant cooling trend in the low and mid latitudes (31.4% of the <span class="hlt">global</span> coastlines) after 1998, while 17.9% of the <span class="hlt">global</span> coastlines changed from a cooling trend to a warming trend concurrently. The trend reversals in the Northern Pacific and Atlantic coincided with the phase shift of Pacific Decadal Oscillation and North Atlantic Oscillation, respectively. These coastal SST changes are larger than the changes of the <span class="hlt">global</span> mean and open <span class="hlt">ocean</span>, resulting in a fast increase of extremely hot/cold days, and thus extremely hot/cold events. Meanwhile, a continuous increase of SST was detected for a considerable portion of coastlines (46.7%) with a strengthened warming along the coastlines in the high northern latitudes. This suggests the warming still continued and strengthened in some regions after 1998, but with a weaker pattern in the low and mid latitudes. PMID:26568024</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26568024','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26568024"><span>The coastal <span class="hlt">ocean</span> response to the <span class="hlt">global</span> warming acceleration and hiatus.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liao, Enhui; Lu, Wenfang; Yan, Xiao-Hai; Jiang, Yuwu; Kidwell, Autumn</p> <p>2015-11-16</p> <p>Coastlines are fundamental to humans for habitation, commerce, and natural resources. Many coastal ecosystem disasters, caused by extreme sea surface temperature (SST), were reported when the <span class="hlt">global</span> climate shifted from <span class="hlt">global</span> warming to <span class="hlt">global</span> surface warming hiatus after 1998. The task of understanding the coastal SST variations within the <span class="hlt">global</span> context is an urgent matter. Our study on the <span class="hlt">global</span> coastal SST from 1982 to 2013 revealed a significant cooling trend in the low and mid latitudes (31.4% of the <span class="hlt">global</span> coastlines) after 1998, while 17.9% of the <span class="hlt">global</span> coastlines changed from a cooling trend to a warming trend concurrently. The trend reversals in the Northern Pacific and Atlantic coincided with the phase shift of Pacific Decadal Oscillation and North Atlantic Oscillation, respectively. These coastal SST changes are larger than the changes of the <span class="hlt">global</span> mean and open <span class="hlt">ocean</span>, resulting in a fast increase of extremely hot/cold days, and thus extremely hot/cold events. Meanwhile, a continuous increase of SST was detected for a considerable portion of coastlines (46.7%) with a strengthened warming along the coastlines in the high northern latitudes. This suggests the warming still continued and strengthened in some regions after 1998, but with a weaker pattern in the low and mid latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS23A1367Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS23A1367Z"><span>A Unified Model for Methylmercury Formation and Bioaccumulation in the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Y.; Schartup, A. T.; Soerensen, A.; Dutkiewicz, S.; Sunderland, E. M.</p> <p>2017-12-01</p> <p>Marine fish consumption is the main exposure pathway for methylmercury (MeHg), a neurotoxin, in many countries. The Hg in the <span class="hlt">ocean</span> is mainly from atmospheric deposition in inorganic forms. How the deposited Hg is methylated and accumulated in biota remain an open question. We develop a 3D model (MITgcm) for MeHg formation and bioaccumulation in the <span class="hlt">global</span> <span class="hlt">ocean</span> and evaluate the driving factors. The model is based on a previous published inorganic Hg model and is coupled with the bioaccumulation model for marine methylmercury (BAM3) with <span class="hlt">ocean</span> biogeochemistry from DARWIN model. We develop a unified scheme that scales methylation by microbe activity and assumes demethylation a function of short wave radiation and temperature. The model result agrees well with currently available observations at the 0-100 m (mod.: 43±52 fM vs obs.: 69±67 fM, 1 fM = 10-15 mol/L), 500 m (360±280 fM vs 340±260 fM), and 1000 m depth (260±170 fM vs 290±210 fM). In the surface <span class="hlt">ocean</span>, we find the MeHg concentrations are a function of latitude, resulting from photodemethylation. The model reproduces the high concentrations observed over the sub-thermocline of Pacific Subarctic Gyre, which is associated with active microbe activity. On the other hand, both the model and observations suggest low concentrations over oligotrophic regions such as Indian <span class="hlt">Ocean</span> Gyre. In the tropical <span class="hlt">oceans</span>, the model predicts the highest MeHg concentrations, consistent with observation, and it is caused by the overlapping high atmospheric deposition and active microbe activities. The model captures the high concentrations in the subsurface of the Arctic and Southern <span class="hlt">Ocean</span> where low temperature slows down abiotic demethylation. The modeled <span class="hlt">global</span> average MeHg concentration in phytoplankton is 2.0 ng/g (by wet weight), within the same range of observations. High concentrations are modeled over tropical and high-latitude regions due to the dominance of small sized prochlorococcus and high seawater concentrations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.P41E1973B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.P41E1973B"><span>Clathrate hydrate stability models for Titan: implications for a <span class="hlt">global</span> subsurface <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Basu Sarkar, D.; Elwood Madden, M.</p> <p>2013-12-01</p> <p>Titan is the only planetary body in the solar system, apart from the Earth, with liquid at its surface. Titan's changing rotational period suggests that a <span class="hlt">global</span> subsurface <span class="hlt">ocean</span> decouples the icy crust from the interior. Several studies predict the existence of such an internal <span class="hlt">ocean</span> below an Ice I layer, ranging in depth between a few tens of kilometers to a few hundreds of kilometers, depending on the composition of the icy crust and liquid-<span class="hlt">ocean</span>. While the overall density of Titan is well constrained, the degree of differentiation within the interior is unclear. These uncertainties lead to poor understanding of the volatile content of the moon. However, unlike other similar large icy moons like Ganymede and Callisto, Titan has a thick nitrogen atmosphere, with methane as the second most abundant constituent - 5% near the surface. Titan's atmosphere, surface, and interior are likely home to various compounds such as C2H6, CO2, Ar, N2 and CH4, capable of forming clathrate hydrates. In addition, the moon has low temperature and low-to-high pressure conditions required for clathrate formation. Therefore the occurrence of extensive multicomponent hydrates may effect the composition of near-surface materials, the subsurface <span class="hlt">ocean</span>, as well as the atmosphere. This work uses models of hydrate stability for a number of plausible hydrate formers including CH4, C2H6, CH4 + C2H6 and CH4 + NH3, and equilibrium geothermal gradients for probable near-surface materials to delineate the lateral and vertical extent of clathrate hydrate stability zones for Titan. By comparing geothermal gradients with clathrate stability fields for these systems we investigate possible compositions of Titan's <span class="hlt">global</span> subsurface <span class="hlt">ocean</span>. Preliminary model results indicate that ethane hydrates or compound hydrates of ethane and methane could be destabilized within the proposed depth range of the internal <span class="hlt">ocean</span>, while methane/ammonia or pure methane hydrates may not be affected. Therefore, ethane or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29276053','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29276053"><span>Inter-observer agreement of standard <span class="hlt">joint</span> count examination and disease <span class="hlt">global</span> assessment in a cohort of Egyptian Rheumatoid Arthritis patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>El-Hadidi, Khaled; Gamal, Sherif M; Saad, Sahar</p> <p>2017-12-21</p> <p>To assess the inter-observer agreement of standard <span class="hlt">joint</span> count between experienced Rheumatology professor (Prof) and young Rheumatology fellow (candidate), and to compare disease <span class="hlt">global</span> assessment between professor, young candidate and patients. This study included one hundred rheumatoid arthritis patients. For all patients independent clinical evaluation was done by two rheumatologists (professor and candidate) for detection of tenderness in 28 <span class="hlt">joints</span> and swelling in 26 <span class="hlt">joints</span>. The study also involved <span class="hlt">global</span> assessment of disease activity by the provider (Prof and candidate) (EGA) as well as by the patient (PGA). The EGA was determined without previous knowledge of the patient's laboratory test results. A highly significant accordance (correlation) between professor and candidate was found in both the number of tender <span class="hlt">joints</span> (p<0.001) (r=0.946), and the number of swollen <span class="hlt">joints</span> (p<0.001) (r=0.797). Regarding swollen <span class="hlt">joints</span>, the highest agreement was in right knee (0.929), while poor agreement was found in the right 5th MCP (0.049). Regarding tender <span class="hlt">joints</span>, the highest analogy was in the right elbow (0.899), in contrast to the left 3rd PIP (0.462) which showed the least congruence. Agreement study using kappa measurement for disease <span class="hlt">global</span> assessment showed: moderate agreement (between professor and candidate) (0.405), fair agreement between (professor and patient) (0.213), fair agreement between (candidate and patient) (0.367). Inter-observer reliability was better for TJCs than SJCs. Regarding SJCs agreement was better in large <span class="hlt">joints</span> such as the knees compared to the small <span class="hlt">joints</span> such as the MCPs. Disease <span class="hlt">global</span> assessment may show discrepancy between patients and physicians. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GMD....11.1229W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GMD....11.1229W"><span>A 4.5 km resolution Arctic <span class="hlt">Ocean</span> simulation with the <span class="hlt">global</span> multi-resolution model FESOM 1.4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Qiang; Wekerle, Claudia; Danilov, Sergey; Wang, Xuezhu; Jung, Thomas</p> <p>2018-04-01</p> <p>In the framework of developing a <span class="hlt">global</span> modeling system which can facilitate modeling studies on Arctic <span class="hlt">Ocean</span> and high- to midlatitude linkage, we evaluate the Arctic <span class="hlt">Ocean</span> simulated by the multi-resolution Finite Element Sea ice-<span class="hlt">Ocean</span> Model (FESOM). To explore the value of using high horizontal resolution for Arctic <span class="hlt">Ocean</span> modeling, we use two <span class="hlt">global</span> meshes differing in the horizontal resolution only in the Arctic <span class="hlt">Ocean</span> (24 km vs. 4.5 km). The high resolution significantly improves the model's representation of the Arctic <span class="hlt">Ocean</span>. The most pronounced improvement is in the Arctic intermediate layer, in terms of both Atlantic Water (AW) mean state and variability. The deepening and thickening bias of the AW layer, a common issue found in coarse-resolution simulations, is significantly alleviated by using higher resolution. The topographic steering of the AW is stronger and the seasonal and interannual temperature variability along the <span class="hlt">ocean</span> bottom topography is enhanced in the high-resolution simulation. The high resolution also improves the <span class="hlt">ocean</span> surface circulation, mainly through a better representation of the narrow straits in the Canadian Arctic Archipelago (CAA). The representation of CAA throughflow not only influences the release of water masses through the other gateways but also the circulation pathways inside the Arctic <span class="hlt">Ocean</span>. However, the mean state and variability of Arctic freshwater content and the variability of freshwater transport through the Arctic gateways appear not to be very sensitive to the increase in resolution employed here. By highlighting the issues that are independent of model resolution, we address that other efforts including the improvement of parameterizations are still required.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984SPIE..481..159P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984SPIE..481..159P"><span>Spaceborne Studies Of <span class="hlt">Ocean</span> Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patzert, William C.</p> <p>1984-08-01</p> <p>The <span class="hlt">global</span> view of the <span class="hlt">oceans</span> seen by Seasat during its 1978 flight demonstrated the feasibility of <span class="hlt">ocean</span> remote sensing. These first-ever <span class="hlt">global</span> data sets of sea surface topography (altimeter) and marine winds (scatterometer) laid the foundation for two satellite missions planned for the late 1980's. The future missions are the next generation of altimeter and scatterometer to be flown aboard TOPEX (Topography Experiment) and NROSS (Navy Remote <span class="hlt">Ocean</span> Sensing System), respectively. The data from these satellites will be coordinated with measurements made at sea to determine the driving forces of <span class="hlt">ocean</span> circulation and to study the <span class="hlt">oceans</span> role in climate variability. Sea surface winds (calculated from scatterometer measurements) are the fundamental driving force for <span class="hlt">ocean</span> waves and currents (estimated from altimeter measurements). On a <span class="hlt">global</span> scale, the winds and currents are approximately equal partners in redistributing the excess heat gained in the tropics from solar radiation to the cooler polar regions. Small perturbations in this system can dramatically alter <span class="hlt">global</span> weather, such as the El Niho event of 1982-83. During an El Ni?io event, <span class="hlt">global</span> wind patterns and <span class="hlt">ocean</span> currents are perturbed causing unusual <span class="hlt">ocean</span> warming in the tropical Pacfic <span class="hlt">Ocean</span>. These <span class="hlt">ocean</span> events are coupled to complex fluctuations in <span class="hlt">global</span> weather. Only with satellites will we be able to collect the <span class="hlt">global</span> data sets needed to study events such as El Ni?o. When TOPEX and NROSS fly, oceanographers will have the equivalent of meteorological high and low pressure charts of <span class="hlt">ocean</span> topography as well as the surface winds to study <span class="hlt">ocean</span> "weather." This ability to measure <span class="hlt">ocean</span> circulation and its driving forces is a critical element in understanding the influence of <span class="hlt">oceans</span> on society. Climatic changes, fisheries, commerce, waste disposal, and national defense are all involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14.2321A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14.2321A"><span>Variable reactivity of particulate organic matter in a <span class="hlt">global</span> <span class="hlt">ocean</span> biogeochemical model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aumont, Olivier; van Hulten, Marco; Roy-Barman, Matthieu; Dutay, Jean-Claude; Éthé, Christian; Gehlen, Marion</p> <p>2017-05-01</p> <p>The marine biological carbon pump is dominated by the vertical transfer of particulate organic carbon (POC) from the surface <span class="hlt">ocean</span> to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the <span class="hlt">ocean</span>. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which, such as iron, are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. However, this variable reactivity of POC has never been extensively considered, especially in modelling studies. Here, we introduced in the <span class="hlt">global</span> <span class="hlt">ocean</span> biogeochemical model <span style="" class="text smallcaps">NEMO-PISCES a description of the variable composition of POC based on the theoretical reactivity continuum model proposed by Boudreau and Ruddick (1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the <span class="hlt">ocean</span>'s interior by 1 to 2 orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of 2, which is in better agreement with <span class="hlt">global</span> estimates of the sediment oxygen demand. The impact on the major macronutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: vertical gradients in Fe are milder in the upper <span class="hlt">ocean</span>, which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMED33A0718B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMED33A0718B"><span>New Community Education Program on <span class="hlt">Oceans</span> and <span class="hlt">Global</span> Climate Change: Results from Our Pilot Year</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bruno, B. C.; Wiener, C.</p> <p>2010-12-01</p> <p><span class="hlt">Ocean</span> FEST (Families Exploring Science Together) engages elementary school students and their parents and teachers in hands-on science. Through this evening program, we educate participants about <span class="hlt">ocean</span> and earth science issues that are relevant to their local communities. In the process, we hope to inspire more underrepresented students, including Native Hawaiians, Pacific Islanders and girls, to pursue careers in the <span class="hlt">ocean</span> and earth sciences. Hawaii and the Pacific Islands will be disproportionately affected by the impacts of <span class="hlt">global</span> climate change, including rising sea levels, coastal erosion, coral reef degradation and <span class="hlt">ocean</span> acidification. It is therefore critically important to train <span class="hlt">ocean</span> and earth scientists within these communities. This two-hour program explores <span class="hlt">ocean</span> properties and timely environmental topics through six hands-on science activities. Activities are designed so students can see how <span class="hlt">globally</span> important issues (e.g., climate change and <span class="hlt">ocean</span> acidification) have local effects (e.g., sea level rise, coastal erosion, coral bleaching) which are particularly relevant to island communities. The <span class="hlt">Ocean</span> FEST program ends with a career component, drawing parallel between the program activities and the activities done by "real scientists" in their jobs. The take-home message is that we are all scientists, we do science every day, and we can choose to do this as a career. <span class="hlt">Ocean</span> FEST just completed our pilot year. During the 2009-2010 academic year, we conducted 20 events, including 16 formal events held at elementary schools and 4 informal outreach events. Evaluation data were collected at all formal events. Formative feedback from adult participants (parents, teachers, administrators and volunteers) was solicited through written questionnaires. Students were invited to respond to a survey of five questions both before and after the program to see if there were any changes in content knowledge and career attitudes. In our presentation, we will present our</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170004578&hterms=PRIMARY+NON+FUNCTION&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPRIMARY%2BNON%2BFUNCTION','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170004578&hterms=PRIMARY+NON+FUNCTION&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPRIMARY%2BNON%2BFUNCTION"><span>Directional and Spectral Irradiance in <span class="hlt">Ocean</span> Models: Effects on Simulated <span class="hlt">Global</span> Phytoplankton, Nutrients, and Primary Production</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Watson W.; Rousseaux, Cecile S.</p> <p>2016-01-01</p> <p>The importance of including directional and spectral light in simulations of <span class="hlt">ocean</span> radiative transfer was investigated using a coupled biogeochemical-circulation-radiative model of the <span class="hlt">global</span> <span class="hlt">oceans</span>. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary production. The importance was approached by sequentially removing directional (i.e., direct vs. diffuse) and spectral irradiance and comparing results of the above variables to a fully directionally and spectrally-resolved model. In each case the total irradiance was kept constant; it was only the pathways and spectral nature that were changed. Assuming all irradiance was diffuse had negligible effect on <span class="hlt">global</span> <span class="hlt">ocean</span> primary production. <span class="hlt">Global</span> nitrate and total chlorophyll concentrations declined by about 20% each. The largest changes occurred in the tropics and sub-tropics rather than the high latitudes, where most of the irradiance is already diffuse. Disregarding spectral irradiance had effects that depended upon the choice of attenuation wavelength. The wavelength closest to the spectrally-resolved model, 500 nm, produced lower nitrate (19%) and chlorophyll (8%) and higher primary production (2%) than the spectral model. Phytoplankton relative abundances were very sensitive to the choice of non-spectral wavelength transmittance. The combined effects of neglecting both directional and spectral irradiance exacerbated the differences, despite using attenuation at 500 nm. <span class="hlt">Global</span> nitrate decreased 33% and chlorophyll decreased 24%. Changes in phytoplankton community structure were considerable, representing a change from chlorophytes to cyanobacteria and coccolithophores. This suggested a shift in community function, from light-limitation to nutrient limitation: lower demands for nutrients from cyanobacteria and coccolithophores favored them over the more nutrient-demanding chlorophytes. Although diatoms have the highest nutrient demands in the model, their</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1225146-understanding-el-nino-like-oceanic-response-tropical-pacific-global-warming','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1225146-understanding-el-nino-like-oceanic-response-tropical-pacific-global-warming"><span>Understanding the El Niño-like <span class="hlt">Oceanic</span> Response in the Tropical Pacific to <span class="hlt">Global</span> Warming</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Luo, Yiyong; Lu, Jian; Liu, Fukai</p> <p></p> <p>The enhanced central and eastern Pacific SST warming and the associated <span class="hlt">ocean</span> processes under <span class="hlt">global</span> warming are investigated using the <span class="hlt">ocean</span> component of the Community Earth System Model (CESM), Parallel <span class="hlt">Ocean</span> Program version 2 (POP2). The tropical SST warming pattern in the coupled CESM can be faithfully reproduced by the POP2 forced with surface fluxes computed using the aerodynamic bulk formula. By prescribing the wind stress and/or wind speed through the bulk formula, the effects of wind stress change and/or the wind-evaporation-SST (WES) feedback are isolated and their linearity is evaluated in this <span class="hlt">ocean</span>-alone setting. Result shows that, although themore » weakening of the equatorial easterlies contributes positively to the El Niño-like SST warming, 80% of which can be simulated by the POP2 without considering the effects of wind change in both mechanical and thermodynamic fluxes. This result points to the importance of the air-sea thermal interaction and the relative feebleness of the <span class="hlt">ocean</span> dynamical process in the El Niño-like equatorial Pacific SST response to <span class="hlt">global</span> warming. On the other hand, the wind stress change is found to play a dominant role in the <span class="hlt">oceanic</span> response in the tropical Pacific, accounting for most of the changes in the equatorial <span class="hlt">ocean</span> current system and thermal structures, including the weakening of the surface westward currents, the enhancement of the near-surface stratification and the shoaling of the equatorial thermocline. Interestingly, greenhouse gas warming in the absence of wind stress change and WES feedback also contributes substantially to the changes at the subsurface equatorial Pacific. Further, this warming impact can be largely replicated by an idealized <span class="hlt">ocean</span> experiment forced by a uniform surface heat flux, whereby, arguably, a purest form of <span class="hlt">oceanic</span> dynamical thermostat is revealed.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23599492','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23599492"><span><span class="hlt">Global</span> charcoal mobilization from soils via dissolution and riverine transport to the <span class="hlt">oceans</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaffé, Rudolf; Ding, Yan; Niggemann, Jutta; Vähätalo, Anssi V; Stubbins, Aron; Spencer, Robert G M; Campbell, John; Dittmar, Thorsten</p> <p>2013-04-19</p> <p><span class="hlt">Global</span> biomass burning generates 40 million to 250 million tons of charcoal every year, part of which is preserved for millennia in soils and sediments. We have quantified dissolution products of charcoal in a wide range of rivers worldwide and show that <span class="hlt">globally</span>, a major portion of the annual charcoal production is lost from soils via dissolution and subsequent transport to the <span class="hlt">ocean</span>. The <span class="hlt">global</span> flux of soluble charcoal accounts to 26.5 ± 1.8 million tons per year, which is ~10% of the <span class="hlt">global</span> riverine flux of dissolved organic carbon (DOC). We suggest that the mobilization of charcoal and DOC out of soils is mechanistically coupled. This study closes a major gap in the <span class="hlt">global</span> charcoal budget and provides critical information in the context of geoengineering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.482..126G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.482..126G"><span><span class="hlt">Global</span> assessment of benthic nepheloid layers and linkage with upper <span class="hlt">ocean</span> dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gardner, Wilford D.; Richardson, Mary Jo; Mishonov, Alexey V.</p> <p>2018-01-01</p> <p><span class="hlt">Global</span> maps of the maximum bottom concentration, thickness, and integrated particle mass in benthic nepheloid layers are published here to support collaborations to understand deep <span class="hlt">ocean</span> sediment dynamics, linkage with upper <span class="hlt">ocean</span> dynamics, and assessing the potential for scavenging of adsorption-prone elements near the deep <span class="hlt">ocean</span> seafloor. Mapping the intensity of benthic particle concentrations from natural <span class="hlt">oceanic</span> processes also provides a baseline that will aid in quantifying the industrial impact of current and future deep-sea mining. Benthic nepheloid layers have been mapped using 6,392 full-depth profiles made during 64 cruises using our transmissometers mounted on CTDs in multiple national/international programs including WOCE, SAVE, JGOFS, CLIVAR-Repeat Hydrography, and GO-SHIP during the last four decades. Intense benthic nepheloid layers are found in areas where eddy kinetic energy in overlying waters, mean kinetic energy 50 m above bottom (mab), and energy dissipation in the bottom boundary layer are near the highest values in the <span class="hlt">ocean</span>. Areas of intense benthic nepheloid layers include the Western North Atlantic, Argentine Basin in the South Atlantic, parts of the Southern <span class="hlt">Ocean</span> and areas around South Africa. Benthic nepheloid layers are weak or absent in most of the Pacific, Indian, and Atlantic basins away from continental margins. High surface eddy kinetic energy is associated with the Kuroshio Current east of Japan. Data south of the Kuroshio show weak nepheloid layers, but no transmissometer data exist beneath the Kuroshio, a deficiency that should be remedied to increase understanding of eddy dynamics in un-sampled and under-sampled <span class="hlt">oceanic</span> areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20224766','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20224766"><span>Modeling selective pressures on phytoplankton in the <span class="hlt">global</span> <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bragg, Jason G; Dutkiewicz, Stephanie; Jahn, Oliver; Follows, Michael J; Chisholm, Sallie W</p> <p>2010-03-10</p> <p>Our view of marine microbes is transforming, as culture-independent methods facilitate rapid characterization of microbial diversity. It is difficult to assimilate this information into our understanding of marine microbe ecology and evolution, because their distributions, traits, and genomes are shaped by forces that are complex and dynamic. Here we incorporate diverse forces--physical, biogeochemical, ecological, and mutational--into a <span class="hlt">global</span> <span class="hlt">ocean</span> model to study selective pressures on a simple trait in a widely distributed lineage of picophytoplankton: the nitrogen use abilities of Synechococcus and Prochlorococcus cyanobacteria. Some Prochlorococcus ecotypes have lost the ability to use nitrate, whereas their close relatives, marine Synechococcus, typically retain it. We impose mutations for the loss of nitrogen use abilities in modeled picophytoplankton, and ask: in which parts of the <span class="hlt">ocean</span> are mutants most disadvantaged by losing the ability to use nitrate, and in which parts are they least disadvantaged? Our model predicts that this selective disadvantage is smallest for picophytoplankton that live in tropical regions where Prochlorococcus are abundant in the real <span class="hlt">ocean</span>. Conversely, the selective disadvantage of losing the ability to use nitrate is larger for modeled picophytoplankton that live at higher latitudes, where Synechococcus are abundant. In regions where we expect Prochlorococcus and Synechococcus populations to cycle seasonally in the real <span class="hlt">ocean</span>, we find that model ecotypes with seasonal population dynamics similar to Prochlorococcus are less disadvantaged by losing the ability to use nitrate than model ecotypes with seasonal population dynamics similar to Synechococcus. The model predictions for the selective advantage associated with nitrate use are broadly consistent with the distribution of this ability among marine picocyanobacteria, and at finer scales, can provide insights into interactions between temporally varying <span class="hlt">ocean</span> processes and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOS.A14A2533M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOS.A14A2533M"><span>Design and analysis of a <span class="hlt">global</span> sub-mesoscale and tidal dynamics admitting virtual <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menemenlis, D.; Hill, C. N.</p> <p>2016-02-01</p> <p>We will describe the techniques used to realize a <span class="hlt">global</span> kilometerscale <span class="hlt">ocean</span> model configuration that includes representation of sea-ice and tidal excitation, and spans scales from planetary gyres to internal tides. A simulation using this model configuration provides a virtual <span class="hlt">ocean</span> that admits some sub-mesoscale dynamics and tidal energetics not normally represented in <span class="hlt">global</span> calculations. This extends simulated <span class="hlt">ocean</span> behavior beyond broadly quasi-geostrophic flows and provides a preliminary example of a next generation computational approach to explicitly probing the interactions between instabilities that are usually parameterized and dominant energetic scales in the <span class="hlt">ocean</span>. From previous process studies we have ascertained that this can lead to a qualitative improvement in the realism of many significant processes including geostrophic eddy dynamics, shelf-break exchange and topographic mixing. Computationally we exploit high-degrees of parallelism in both numerical evaluation and in recording model state to persistent disk storage. Together this allows us to compute and record a full three-dimensional model trajectory at hourly frequency for a timeperiod of 5 months with less than 9 million core hours of parallel computer time, using the present generation NASA Ames Research Center facilities. We have used this capability to create a 5 month trajectory archive, sampled at high spatial and temporal frequency for an <span class="hlt">ocean</span> configuration that is initialized from a realistic data-assimilated state and driven with reanalysis surface forcing from ECMWF. The resulting database of model state provides a novel virtual laboratory for exploring coupling across scales in the <span class="hlt">ocean</span>, and for testing ideas on the relationship between small scale fluxes and large scale state. The computation is complemented by counterpart computations that are coarsened two and four times respectively. In this presentation we will review the computational and numerical technologies employed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11473314','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11473314"><span>Warm tropical <span class="hlt">ocean</span> surface and <span class="hlt">global</span> anoxia during the mid-Cretaceous period.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilson, P A; Norris, R D</p> <p>2001-07-26</p> <p>The middle of the Cretaceous period (about 120 to 80 Myr ago) was a time of unusually warm polar temperatures, repeated reef-drowning in the tropics and a series of <span class="hlt">oceanic</span> anoxic events (OAEs) that promoted both the widespread deposition of organic-carbon-rich marine sediments and high biological turnover. The cause of the warm temperatures is unproven but widely attributed to high levels of atmospheric greenhouse gases such as carbon dioxide. In contrast, there is no consensus on the climatic causes and effects of the OAEs, with both high biological productivity and <span class="hlt">ocean</span> 'stagnation' being invoked as the cause of <span class="hlt">ocean</span> anoxia. Here we show, using stable isotope records from multiple species of well-preserved foraminifera, that the thermal structure of surface waters in the western tropical Atlantic <span class="hlt">Ocean</span> underwent pronounced variability about 100 Myr ago, with maximum sea surface temperatures 3-5 degrees C warmer than today. This variability culminated in a collapse of upper-<span class="hlt">ocean</span> stratification during OAE-1d (the 'Breistroffer' event), a <span class="hlt">globally</span> significant period of organic-carbon burial that we show to have fundamental, stratigraphically valuable, geochemical similarities to the main OAEs of the Mesozoic era. Our records are consistent with greenhouse forcing being responsible for the warm temperatures, but are inconsistent both with explanations for OAEs based on <span class="hlt">ocean</span> stagnation, and with the traditional view (reviewed in ref. 12) that past warm periods were more stable than today's climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20689845','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20689845"><span>Biodiversity's big wet secret: the <span class="hlt">global</span> distribution of marine biological records reveals chronic under-exploration of the deep pelagic <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Webb, Thomas J; Vanden Berghe, Edward; O'Dor, Ron</p> <p>2010-08-02</p> <p>Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a <span class="hlt">global</span> picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic <span class="hlt">ocean</span>--the largest biome on Earth--is chronically under-represented in <span class="hlt">global</span> databases of marine biodiversity. We use data from the <span class="hlt">Ocean</span> Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this <span class="hlt">global</span> picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the <span class="hlt">ocean</span> differing in depth reveals that regardless of <span class="hlt">ocean</span> depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. The deep pelagic <span class="hlt">ocean</span> is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in <span class="hlt">global</span> databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earth's largest ecosystem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2914017','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2914017"><span>Biodiversity's Big Wet Secret: The <span class="hlt">Global</span> Distribution of Marine Biological Records Reveals Chronic Under-Exploration of the Deep Pelagic <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Webb, Thomas J.; Vanden Berghe, Edward; O'Dor, Ron</p> <p>2010-01-01</p> <p>Background Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a <span class="hlt">global</span> picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic <span class="hlt">ocean</span> – the largest biome on Earth – is chronically under-represented in <span class="hlt">global</span> databases of marine biodiversity. Methodology/Principal Findings We use data from the <span class="hlt">Ocean</span> Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this <span class="hlt">global</span> picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the <span class="hlt">ocean</span> differing in depth reveals that regardless of <span class="hlt">ocean</span> depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. Conclusions/Significance The deep pelagic <span class="hlt">ocean</span> is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in <span class="hlt">global</span> databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earth's largest ecosystem. PMID:20689845</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.V13D0425S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V13D0425S"><span>A comparison of chemical compositions of reported altered <span class="hlt">oceanic</span> crusts and <span class="hlt">global</span> MORB data set: implication for isotopic heterogeneity of recycled materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shimoda, G.; Kogiso, T.</p> <p>2017-12-01</p> <p>Chemical composition of altered <span class="hlt">oceanic</span> crust is one of important constraints to delineate chemical heterogeneity of the mantle. Accordingly, many researchers have been studied to determine bulk chemical composition of altered <span class="hlt">oceanic</span> crust mainly based on chemical compositions of old <span class="hlt">oceanic</span> crusts at Site 801 and Site 417/418, and young crust at Site 504 (e.g., Staudigel et al., 1996; Bach et al. 2003; Kuo et al., 2016). Their careful estimation provided reliable bulk chemical compositions of these Sites and revealed common geochemical feature of alteration. To assess effect of recycling of altered <span class="hlt">oceanic</span> crust on chemical evolution of the mantle, it might be meaningful to discuss whether the reported chemical compositions of altered <span class="hlt">oceanic</span> crusts can represent chemical composition of <span class="hlt">globally</span> subducted <span class="hlt">oceanic</span> crusts. Reported chemical compositions of fresh glass or less altered samples from Site 801, 417/418 and 504 were highly depleted compared to that of <span class="hlt">global</span> MORB reported by Gale et al. (2013), suggesting that there might be sampling bias. Hence, it could be important to consider chemical difference between <span class="hlt">oceanic</span> crusts of these three Sites and <span class="hlt">global</span> MORB to discuss effect of recycling of <span class="hlt">oceanic</span> crust on isotopic heterogeneity of the mantle. It has been suggested that one of controlling factors of chemical variation of <span class="hlt">oceanic</span> crust is crustal spreading rate because different degree of partial melting affects chemical composition of magmas produced at a mid-<span class="hlt">ocean</span> ridge. Crustal spreading rate could also affect intensity of alteration. Namely, <span class="hlt">oceanic</span> crusts produced at slow-spreading ridges may prone to be altered due to existence of larger displacement faults compared to fast spreading ridges which have relatively smooth topography. Thus, it might be significant to evaluate isotopic evolution of <span class="hlt">oceanic</span> crusts those were produced at different spreading rates. In this presentation, we will provide a possible chemical variation of altered <span class="hlt">oceanic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70028074','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70028074"><span>Multidecadal climate variability of <span class="hlt">global</span> lands and <span class="hlt">oceans</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McCabe, G.J.; Palecki, M.A.</p> <p>2006-01-01</p> <p>Principal components analysis (PCA) and singular value decomposition (SVD) are used to identify the primary modes of decadal and multidecadal variability in annual <span class="hlt">global</span> Palmer Drought Severity Index (PDSI) values and sea-surface temperature (SSTs). The PDSI and SST data for 1925-2003 were detrended and smoothed (with a 10-year moving average) to isolate the decadal and multidecadal variability. The first two principal components (PCs) of the PDSI PCA explained almost 38% of the decadal and multidecadal variance in the detrended and smoothed <span class="hlt">global</span> annual PDSI data. The first two PCs of detrended and smoothed <span class="hlt">global</span> annual SSTs explained nearly 56% of the decadal variability in <span class="hlt">global</span> SSTs. The PDSI PCs and the SST PCs are directly correlated in a pairwise fashion. The first PDSI and SST PCs reflect variability of the detrended and smoothed annual Pacific Decadal Oscillation (PDO), as well as detrended and smoothed annual Indian <span class="hlt">Ocean</span> SSTs. The second set of PCs is strongly associated with the Atlantic Multidecadal Oscillation (AMO). The SVD analysis of the cross-covariance of the PDSI and SST data confirmed the close link between the PDSI and SST modes of decadal and multidecadal variation and provided a verification of the PCA results. These findings indicate that the major modes of multidecadal variations in SSTs and land-surface climate conditions are highly interrelated through a small number of spatially complex but slowly varying teleconnections. Therefore, these relations may be adaptable to providing improved baseline conditions for seasonal climate forecasting. Published in 2006 by John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRC..119.7725L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.7725L"><span>Exploiting satellite earth observation to quantify current <span class="hlt">global</span> <span class="hlt">oceanic</span> DMS flux and its future climate sensitivity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Land, P. E.; Shutler, J. D.; Bell, T. G.; Yang, M.</p> <p>2014-11-01</p> <p>We used coincident Envisat RA2 and AATSR temperature and wind speed data from 2008/2009 to calculate the <span class="hlt">global</span> net sea-air flux of dimethyl sulfide (DMS), which we estimate to be 19.6 Tg S a-1. Our monthly flux calculations are compared to open <span class="hlt">ocean</span> eddy correlation measurements of DMS flux from 10 recent cruises, with a root mean square difference of 3.1 μmol m-2 day-1. In a sensitivity analysis, we varied temperature, salinity, surface wind speed, and aqueous DMS concentration, using fixed <span class="hlt">global</span> changes as well as CMIP5 model output. The range of DMS flux in future climate scenarios is discussed. The CMIP5 model predicts a reduction in surface wind speed and we estimate that this will decrease the <span class="hlt">global</span> annual sea-air flux of DMS by 22% over 25 years. Concurrent changes in temperature, salinity, and DMS concentration increase the <span class="hlt">global</span> flux by much smaller amounts. The net effect of all CMIP5 modelled 25 year predictions was a 19% reduction in <span class="hlt">global</span> DMS flux. 25 year DMS concentration changes had significant regional effects, some positive (Southern <span class="hlt">Ocean</span>, North Atlantic, Northwest Pacific) and some negative (isolated regions along the Equator and in the Indian <span class="hlt">Ocean</span>). Using satellite-detected coverage of coccolithophore blooms, our estimate of their contribution to North Atlantic DMS emissions suggests that the coccolithophores contribute only a small percentage of the North Atlantic annual flux estimate, but may be more important in the summertime and in the northeast Atlantic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC23H..07D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC23H..07D"><span>Current State and Recent Changes in the Arctic <span class="hlt">Ocean</span> from the HYCOM-NCODA <span class="hlt">Global</span> <span class="hlt">Ocean</span> and Sea Ice Prediction System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dukhovskoy, D. S.; Chassignet, E. P.; Hogan, P. J.; Metzger, E. J.; Posey, P.; Smedstad, O. M.; Stefanova, L. B.; Wallcraft, A. J.</p> <p>2016-12-01</p> <p>The great potential of numerical models to provide a high-resolution continuous picture of the environmental characteristics of the Arctic system is related to the problem of reliability and accuracy of the simulations. Recent Arctic <span class="hlt">Ocean</span> model intercomparison projects have identified substantial disagreements in water mass distribution and circulation among the models over the last two decades. In situ and satellite observations cannot yield enough continuous in time and space information to interpret the observed changes in the Arctic system. Observations combined with Arctic <span class="hlt">Ocean</span> models via data assimilation provide perhaps the most complete knowledge about the state of the Arctic system. We use outputs from the US Navy <span class="hlt">Global</span> <span class="hlt">Ocean</span> Forecast System (20-year reanalysis + analysis) to investigate several hypotheses that have been put forward regarding the current state and recent changes in the Arctic <span class="hlt">Ocean</span>. The system is based on the 0.08-degree HYbrid Coordinate <span class="hlt">Ocean</span> Model (HYCOM) and can be run with two-way coupling to the Los Alamos Community Ice CodE (CICE) or with an energy-loan ice model. Observations are assimilated by the Navy Coupled <span class="hlt">Ocean</span> Data Assimilation (NCODA) algorithm. HYCOM temperature and salinity fields are shown to be in good agreement with observational data in the Arctic and North Atlantic. The model reproduces changes in the freshwater budget in the Arctic as reported in other studies. The modeled freshwater fluxes between the Arctic <span class="hlt">Ocean</span> and the North Atlantic are analyzed to document and discuss the interaction between the two regions over the last two decades.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRII.140...55D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRII.140...55D"><span><span class="hlt">Global</span> trophic ecology of yellowfin, bigeye, and albacore tunas: Understanding predation on micronekton communities at <span class="hlt">ocean</span>-basin scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duffy, Leanne M.; Kuhnert, Petra M.; Pethybridge, Heidi R.; Young, Jock W.; Olson, Robert J.; Logan, John M.; Goñi, Nicolas; Romanov, Evgeny; Allain, Valerie; Staudinger, Michelle D.; Abecassis, Melanie; Choy, C. Anela; Hobday, Alistair J.; Simier, Monique; Galván-Magaña, Felipe; Potier, Michel; Ménard, Frederic</p> <p>2017-06-01</p> <p>Predator-prey interactions for three commercially valuable tuna species: yellowfin (Thunnus albacares), bigeye (T. obesus), and albacore (T. alalunga), collected over a 40-year period from the Pacific, Indian, and Atlantic <span class="hlt">Oceans</span>, were used to quantitatively assess broad, macro-scale trophic patterns in pelagic ecosystems. Analysis of over 14,000 tuna stomachs, using a modified classification tree approach, revealed for the first time the <span class="hlt">global</span> expanse of pelagic predatory fish diet and <span class="hlt">global</span> patterns of micronekton diversity. Ommastrephid squids were consistently one of the top prey groups by weight across all tuna species and in most <span class="hlt">ocean</span> bodies. Interspecific differences in prey were apparent, with epipelagic scombrid and mesopelagic paralepidid fishes <span class="hlt">globally</span> important for yellowfin and bigeye tunas, respectively, while vertically-migrating euphausiid crustaceans were important for albacore tuna in the Atlantic and Pacific <span class="hlt">Oceans</span>. Diet diversity showed <span class="hlt">global</span> and regional patterns among tuna species. In the central and western Pacific <span class="hlt">Ocean</span>, characterized by low productivity, a high diversity of micronekton prey was detected while low prey diversity was evident in highly productive coastal waters where upwelling occurs. Spatial patterns of diet diversity were most variable in yellowfin and bigeye tunas while a latitudinal diversity gradient was observed with lower diversity in temperate regions for albacore tuna. Sea-surface temperature was a reasonable predictor of the diets of yellowfin and bigeye tunas, whereas chlorophyll-a was the best environmental predictor of albacore diet. These results suggest that the ongoing expansion of warmer, less productive waters in the world's <span class="hlt">oceans</span> may alter foraging opportunities for tunas due to regional changes in prey abundances and compositions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930051771&hterms=microwaves+water+structure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmicrowaves%2Bwater%2Bstructure','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930051771&hterms=microwaves+water+structure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmicrowaves%2Bwater%2Bstructure"><span>An analysis of errors in special sensor microwave imager evaporation estimates over the <span class="hlt">global</span> <span class="hlt">oceans</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esbensen, S. K.; Chelton, D. B.; Vickers, D.; Sun, J.</p> <p>1993-01-01</p> <p>The method proposed by Liu (1984) is used to estimate monthly averaged evaporation over the <span class="hlt">global</span> <span class="hlt">oceans</span> from 1 yr of special sensor microwave imager (SDSM/I) data. Intercomparisons involving SSM/I and in situ data are made over a wide range of <span class="hlt">oceanic</span> conditions during August 1987 and February 1988 to determine the source of errors in the evaporation estimates. The most significant spatially coherent evaporation errors are found to come from estimates of near-surface specific humidity, q. Systematic discrepancies of over 2 g/kg are found in the tropics, as well as in the middle and high latitudes. The q errors are partitioned into contributions from the parameterization of q in terms of the columnar water vapor, i.e., the Liu q/W relationship, and from the retrieval algorithm for W. The effects of W retrieval errors are found to be smaller over most of the <span class="hlt">global</span> <span class="hlt">oceans</span> and due primarily to the implicitly assumed vertical structures of temperature and specific humidity on which the physically based SSM/I retrievals of W are based.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910007221','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910007221"><span>Bio-optical profile data report: <span class="hlt">Joint</span> <span class="hlt">Global</span> <span class="hlt">Ocean</span> Flux Study, Hawaii <span class="hlt">Ocean</span> Time-Series, HOT-3, R/V Moana Wave, 6-10 January 1989</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Collins, Donald J.; Rhea, W. Joseph; Tran, An Van</p> <p>1990-01-01</p> <p>Time-series measurements of the incident surface downwelling irradiance and vertical profiles of the Bio-optical properties of the <span class="hlt">ocean</span> have been measured during the third cruise of the Hawaii <span class="hlt">Ocean</span> Time-Series to the ALOHA site, 22 degrees 56.4 minutes N, 157 degrees 54.6 minutes W, north of the island of Oahu, Hawaii, during the period January 6 to 10, 1989. A summary of these data is presented to permit investigators an overview of the data collected. The data are available in digital form for scientific investigators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JOL....36....4Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JOL....36....4Y"><span>The IOD-ENSO precursory teleconnection over the tropical Indo-Pacific <span class="hlt">Ocean</span>: dynamics and long-term trends under <span class="hlt">global</span> warming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Dongliang; Hu, Xiaoyue; Xu, Peng; Zhao, Xia; Masumoto, Yukio; Han, Weiqing</p> <p>2018-01-01</p> <p>The dynamics of the teleconnection between the Indian <span class="hlt">Ocean</span> Dipole (IOD) in the tropical Indian <span class="hlt">Ocean</span> and El Niño-Southern Oscillation (ENSO) in the tropical Pacific <span class="hlt">Ocean</span> at the time lag of one year are investigated using lag correlations between the <span class="hlt">oceanic</span> anomalies in the southeastern tropical Indian <span class="hlt">Ocean</span> in fall and those in the tropical Indo-Pacific <span class="hlt">Ocean</span> in the following winter-fall seasons in the observations and in high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> model simulations. The lag correlations suggest that the IOD-forced interannual transport anomalies of the Indonesian Throughflow generate thermocline anomalies in the western equatorial Pacific <span class="hlt">Ocean</span>, which propagate to the east to induce <span class="hlt">ocean</span>-atmosphere coupled evolution leading to ENSO. In comparison, lag correlations between the surface zonal wind anomalies over the western equatorial Pacific in fall and the Indo-Pacific <span class="hlt">oceanic</span> anomalies at time lags longer than a season are all insignificant, suggesting the short memory of the atmospheric bridge. A linear continuously stratified model is used to investigate the dynamics of the <span class="hlt">oceanic</span> connection between the tropical Indian and Pacific <span class="hlt">Oceans</span>. The experiments suggest that interannual equatorial Kelvin waves from the Indian <span class="hlt">Ocean</span> propagate into the equatorial Pacific <span class="hlt">Ocean</span> through the Makassar Strait and the eastern Indonesian seas with a penetration rate of about 10%-15% depending on the baroclinic modes. The IOD-ENSO teleconnection is found to get stronger in the past century or so. Diagnoses of the CMIP5 model simulations suggest that the increased teleconnection is associated with decreased Indonesian Throughflow transports in the recent century, which is found sensitive to the <span class="hlt">global</span> warming forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26515811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26515811"><span>Changes in <span class="hlt">Ocean</span> Heat, Carbon Content, and Ventilation: A Review of the First Decade of GO-SHIP <span class="hlt">Global</span> Repeat Hydrography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Talley, L D; Feely, R A; Sloyan, B M; Wanninkhof, R; Baringer, M O; Bullister, J L; Carlson, C A; Doney, S C; Fine, R A; Firing, E; Gruber, N; Hansell, D A; Ishii, M; Johnson, G C; Katsumata, K; Key, R M; Kramp, M; Langdon, C; Macdonald, A M; Mathis, J T; McDonagh, E L; Mecking, S; Millero, F J; Mordy, C W; Nakano, T; Sabine, C L; Smethie, W M; Swift, J H; Tanhua, T; Thurnherr, A M; Warner, M J; Zhang, J-Z</p> <p>2016-01-01</p> <p><span class="hlt">Global</span> ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting <span class="hlt">ocean</span> change. The <span class="hlt">ocean</span>, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19% of this excess in the abyssal <span class="hlt">ocean</span> beneath 2,000 m, dominated by Southern <span class="hlt">Ocean</span> warming. The <span class="hlt">ocean</span> also has taken up about 27% of anthropogenic carbon, resulting in acidification of the upper <span class="hlt">ocean</span>. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcing and ventilation. The most recent decade of <span class="hlt">global</span> hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (∼20%) and deep-<span class="hlt">ocean</span> oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the <span class="hlt">ocean</span>'s overturning circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.3841J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.3841J"><span><span class="hlt">Global</span> warming and <span class="hlt">ocean</span> stratification: A potential result of large extraterrestrial impacts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, Manoj; von Glasow, Roland; Smith, Robin S.; Paxton, Charles G. M.; Maycock, Amanda C.; Lunt, Daniel J.; Loptson, Claire; Markwick, Paul</p> <p>2017-04-01</p> <p>The prevailing paradigm for the climatic effects of large asteroid or comet impacts is a reduction in sunlight and significant short-term cooling caused by atmospheric aerosol loading. Here we show, using <span class="hlt">global</span> climate model experiments, that the large increases in stratospheric water vapor that can occur upon impact with the <span class="hlt">ocean</span> cause radiative forcings of over +20 W m-2 in the case of 10 km sized bolides. The result of such a positive forcing is rapid climatic warming, increased upper <span class="hlt">ocean</span> stratification, and potentially disruption of upper <span class="hlt">ocean</span> ecosystems. Since two thirds of the world's surface is <span class="hlt">ocean</span>, we suggest that some bolide impacts may actually warm climate overall. For impacts producing both stratospheric water vapor and aerosol loading, radiative forcing by water vapor can reduce or even cancel out aerosol-induced cooling, potentially causing 1-2 decades of increased temperatures in both the upper <span class="hlt">ocean</span> and on the land surface. Such a response, which depends on the ratio of aerosol to water vapor radiative forcing, is distinct from many previous scenarios for the climatic effects of large bolide impacts, which mostly account for cooling from aerosol loading. Finally, we discuss how water vapor forcing from bolide impacts may have contributed to two well-known phenomena: extinction across the Cretaceous/Paleogene boundary and the deglaciation of the Neoproterozoic snowball Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA526502','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA526502"><span>Near-Inertial and Thermal Upper <span class="hlt">Ocean</span> Response to Atmospheric Forcing in the North Atlantic <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-06-01</p> <p>meridional transport of heat (Hoskins and Valdes, 1990). Formation of North Atlantic Subtropical Mode Water is thought to take place during the...North Atlantic <span class="hlt">Ocean</span> MIT/WHOI <span class="hlt">Joint</span> Program in Oceanography/ Applied <span class="hlt">Ocean</span> Science and Engineering Massachusetts Institute of Technology Woods Hole...Oceanographic Institution MITIWHOI 2010-16 Near-inertial and Thermal Upper <span class="hlt">Ocean</span> Response to Atmospheric Forcing in the North Atlantic <span class="hlt">Ocean</span> by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V11E..06W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V11E..06W"><span>Crustal accretion along the <span class="hlt">global</span> mid-<span class="hlt">ocean</span> ridge system based on basaltic glass and olivine-hosted melt inclusion compositions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wanless, V. D.; Behn, M. D.</p> <p>2015-12-01</p> <p>The depth and distribution of crystallization at mid-<span class="hlt">ocean</span> ridges controls the overall architecture of the <span class="hlt">oceanic</span> crust, influences hydrothermal circulation, and determines geothermal gradients in the crust and uppermost mantle. Despite this, there is no overall consensus on how crystallization is distributed within the crust/upper mantle or how this varies with spreading rate. Here, we examine crustal accretion at mid-<span class="hlt">ocean</span> ridges by combining crystallization pressures calculated from major element barometers on mid-<span class="hlt">ocean</span> ridge basalt (MORB) glasses with vapor-saturation pressures from melt inclusions to produce a detailed map of crystallization depths and distributions along the <span class="hlt">global</span> ridge system. We calculate pressures of crystallization from >11,500 MORB glasses from the <span class="hlt">global</span> ridge system using two established major element barometers (1,2). Additionally, we use vapor-saturation pressures from >400 olivine-hosted melt inclusions from five ridges with variable spreading rates to constrain pressures and distributions of crystallization along the <span class="hlt">global</span> ridge system. We show that (i) crystallization depths from MORB glasses increase and become less focused with decreasing spreading rate, (ii) maximum glass pressures are greater than the maximum melt inclusion pressure, which indicates that the melt inclusions do not record the deepest crystallization at mid-<span class="hlt">ocean</span> ridges, and (iii) crystallization occurs in the lower crust/upper mantle at all ridges, indicating accretion is distributed throughout the crust at all spreading rates, including those with a steady-state magma lens. Finally, we suggest that the remarkably similar maximum vapor-saturation pressures (~ 3000 bars) in melt inclusion from all spreading rates reflects the CO2 content of the depleted upper mantle feeding the <span class="hlt">global</span> mid-<span class="hlt">ocean</span> ridge system. (1) Michael, P. & W. Cornell (1998), Journal of Geophysical Research, 103(B8), 18325-18356; (2) Herzberg, C. (2004), Journal of Petrology, 45(12), 2389.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMIN21D1721S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMIN21D1721S"><span><span class="hlt">Ocean</span> Data Interoperability Platform (ODIP): developing a common framework for marine data management on a <span class="hlt">global</span> scale</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaap, D.</p> <p>2015-12-01</p> <p>Europe, the USA, and Australia are making significant progress in facilitating the discovery, access and long term stewardship of <span class="hlt">ocean</span> and marine data through the development, implementation, population and operation of national, regional or international distributed <span class="hlt">ocean</span> and marine observing and data management infrastructures such as SeaDataNet, EMODnet, IOOS, R2R, and IMOS. All of these developments are resulting in the development of standards and services implemented and used by their regional communities. The <span class="hlt">Ocean</span> Data Interoperability Platform (ODIP) project is supported by the EU FP7 Research Infrastructures programme, National Science Foundation (USA) and Australian government and has been initiated 1st October 2012. Recently the project has been continued as ODIP 2 for another 3 years with EU HORIZON 2020 funding. ODIP includes all the major organisations engaged in <span class="hlt">ocean</span> data management in EU, US, and Australia. ODIP is also supported by the IOC-IODE, closely linking this activity with its <span class="hlt">Ocean</span> Data Portal (ODP) and <span class="hlt">Ocean</span> Data Standards Best Practices (ODSBP) projects. The ODIP platform aims to ease interoperability between the regional marine data management infrastructures. Therefore it facilitates an organised dialogue between the key infrastructure representatives by means of publishing best practice, organising a series of international workshops and fostering the development of common standards and interoperability solutions. These are evaluated and tested by means of prototype projects. The presentation will give further background on the ODIP projects and the latest information on the progress of three prototype projects addressing: establishing interoperability between the regional EU, USA and Australia data discovery and access services (SeaDataNet CDI, US NODC, and IMOS MCP) and contributing to the <span class="hlt">global</span> GEOSS and IODE-ODP portals; establishing interoperability between cruise summary reporting systems in Europe, the USA and Australia for</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3048S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3048S"><span><span class="hlt">Ocean</span> Data Interoperability Platform (ODIP): developing a common framework for marine data management on a <span class="hlt">global</span> scale</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaap, Dick M. A.; Glaves, Helen</p> <p>2016-04-01</p> <p>Europe, the USA, and Australia are making significant progress in facilitating the discovery, access and long term stewardship of <span class="hlt">ocean</span> and marine data through the development, implementation, population and operation of national, regional or international distributed <span class="hlt">ocean</span> and marine observing and data management infrastructures such as SeaDataNet, EMODnet, IOOS, R2R, and IMOS. All of these developments are resulting in the development of standards and services implemented and used by their regional communities. The <span class="hlt">Ocean</span> Data Interoperability Platform (ODIP) project is supported by the EU FP7 Research Infrastructures programme, National Science Foundation (USA) and Australian government and has been initiated 1st October 2012. Recently the project has been continued as ODIP II for another 3 years with EU HORIZON 2020 funding. ODIP includes all the major organisations engaged in <span class="hlt">ocean</span> data management in EU, US, and Australia. ODIP is also supported by the IOC-IODE, closely linking this activity with its <span class="hlt">Ocean</span> Data Portal (ODP) and <span class="hlt">Ocean</span> Data Standards Best Practices (ODSBP) projects. The ODIP platform aims to ease interoperability between the regional marine data management infrastructures. Therefore it facilitates an organised dialogue between the key infrastructure representatives by means of publishing best practice, organising a series of international workshops and fostering the development of common standards and interoperability solutions. These are evaluated and tested by means of prototype projects. The presentation will give further background on the ODIP projects and the latest information on the progress of three prototype projects addressing: 1. establishing interoperability between the regional EU, USA and Australia data discovery and access services (SeaDataNet CDI, US NODC, and IMOS MCP) and contributing to the <span class="hlt">global</span> GEOSS and IODE-ODP portals; 2. establishing interoperability between cruise summary reporting systems in Europe, the USA and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA569864','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA569864"><span>Inferring Dynamics from the Wavenumber Spectra of an Eddying <span class="hlt">Global</span> <span class="hlt">Ocean</span> Model with Embedded Tides</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-12-12</p> <p>MODEL WAVENUMBER SPECTRA (12(112 <span class="hlt">Ocean</span> Model (HYCOM) [Chassignet et al., 2007 ; Metzger et al., 2010] with 1/12.5° (approximately 9 km) equatorial...Chassignet, E. P., H. E. Ilurlburt. O. M. Smedstad, G. R. Halliwcll, P. J. Hogan, A. J. Wallcraft, R. Baraille. and R. Bleck ( 2007 ), The HYCOM (HYbrid...tide models, J. Geophys. Res., 102, 25,173 25,194, doi:10.1029/97JC00445. Stammer , D. (1997), <span class="hlt">Global</span> characteristics of <span class="hlt">ocean</span> variability estimated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRC..123..358J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRC..123..358J"><span>Effects of Model Resolution and <span class="hlt">Ocean</span> Mixing on Forced Ice-<span class="hlt">Ocean</span> Physical and Biogeochemical Simulations Using <span class="hlt">Global</span> and Regional System Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Meibing; Deal, Clara; Maslowski, Wieslaw; Matrai, Patricia; Roberts, Andrew; Osinski, Robert; Lee, Younjoo J.; Frants, Marina; Elliott, Scott; Jeffery, Nicole; Hunke, Elizabeth; Wang, Shanlin</p> <p>2018-01-01</p> <p>The current coarse-resolution <span class="hlt">global</span> Community Earth System Model (CESM) can reproduce major and large-scale patterns but is still missing some key biogeochemical features in the Arctic <span class="hlt">Ocean</span>, e.g., low surface nutrients in the Canada Basin. We incorporated the CESM Version 1 <span class="hlt">ocean</span> biogeochemical code into the Regional Arctic System Model (RASM) and coupled it with a sea-ice algal module to investigate model limitations. Four ice-<span class="hlt">ocean</span> hindcast cases are compared with various observations: two in a <span class="hlt">global</span> 1° (40˜60 km in the Arctic) grid: G1deg and G1deg-OLD with/without new sea-ice processes incorporated; two on RASM's 1/12° (˜9 km) grid R9km and R9km-NB with/without a subgrid scale brine rejection parameterization which improves <span class="hlt">ocean</span> vertical mixing under sea ice. Higher-resolution and new sea-ice processes contributed to lower model errors in sea-ice extent, ice thickness, and ice algae. In the Bering Sea shelf, only higher resolution contributed to lower model errors in salinity, nitrate (NO3), and chlorophyll-a (Chl-a). In the Arctic Basin, model errors in mixed layer depth (MLD) were reduced 36% by brine rejection parameterization, 20% by new sea-ice processes, and 6% by higher resolution. The NO3 concentration biases were caused by both MLD bias and coarse resolution, because of excessive horizontal mixing of high NO3 from the Chukchi Sea into the Canada Basin in coarse resolution models. R9km showed improvements over G1deg on NO3, but not on Chl-a, likely due to light limitation under snow and ice cover in the Arctic Basin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMOS41A1989L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMOS41A1989L"><span>Interhemispheric Changes in Atlantic <span class="hlt">Ocean</span> Heat Content and Their Link to <span class="hlt">Global</span> Monsoons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopez, H.; Lee, S. K.; Dong, S.; Goni, G. J.</p> <p>2015-12-01</p> <p>This study tested the hypothesis whether low frequency decadal variability of the South Atlantic meridional heat transport (SAMHT) influences decadal variability of the <span class="hlt">global</span> monsoons. A multi-century run from a state-of-the-art coupled general circulation model is used as basis for the analysis. Our findings indicate that multi-decadal variability of the South Atlantic <span class="hlt">Ocean</span> plays a key role in modulating atmospheric circulation via interhemispheric changes in Atlantic <span class="hlt">Ocean</span> heat content. Weaker SAMHT produces anomalous <span class="hlt">ocean</span> heat divergence over the South Atlantic resulting in negative <span class="hlt">ocean</span> heat content anomaly about 15 years later. This, in turn, forces a thermally direct anomalous interhemispheric Hadley circulation in the atmosphere, transporting heat from the northern hemisphere (NH) to the southern hemisphere (SH) and moisture from the SH to the NH, thereby intensify (weaken) summer (winter) monsoon in the NH and winter (summer) monsoon in the SH. Results also show that anomalous atmospheric eddies, both transient and stationary, transport heat northward in both hemispheres producing eddy heat flux convergence (divergence) in the NH (SH) around 15-30°, reinforcing the anomalous Hadley circulation. The effect of eddies on the NH (SH) poleward of 30° is opposite with heat flux divergence (convergence), which must be balanced by sinking (rising) motion, consistent with a poleward (equatorward) displacement of the jet stream and mean storm track. The mechanism described here could easily be interpreted for the case of strong SAMHT, with the reverse influence on the interhemispheric atmospheric circulation and monsoons. Overall, SAMHT decadal variability leads its atmospheric response by about 15 years, suggesting that the South Atlantic is a potential predictor of <span class="hlt">global</span> climate variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4331586','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4331586"><span><span class="hlt">Global</span> abundance of planktonic heterotrophic protists in the deep <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pernice, Massimo C; Forn, Irene; Gomes, Ana; Lara, Elena; Alonso-Sáez, Laura; Arrieta, Jesus M; del Carmen Garcia, Francisca; Hernando-Morales, Victor; MacKenzie, Roy; Mestre, Mireia; Sintes, Eva; Teira, Eva; Valencia, Joaquin; Varela, Marta M; Vaqué, Dolors; Duarte, Carlos M; Gasol, Josep M; Massana, Ramon</p> <p>2015-01-01</p> <p>The dark <span class="hlt">ocean</span> is one of the largest biomes on Earth, with critical roles in organic matter remineralization and <span class="hlt">global</span> carbon sequestration. Despite its recognized importance, little is known about some key microbial players, such as the community of heterotrophic protists (HP), which are likely the main consumers of prokaryotic biomass. To investigate this microbial component at a <span class="hlt">global</span> scale, we determined their abundance and biomass in deepwater column samples from the Malaspina 2010 circumnavigation using a combination of epifluorescence microscopy and flow cytometry. HP were ubiquitously found at all depths investigated down to 4000 m. HP abundances decreased with depth, from an average of 72±19 cells ml−1 in mesopelagic waters down to 11±1 cells ml−1 in bathypelagic waters, whereas their total biomass decreased from 280±46 to 50±14 pg C ml−1. The parameters that better explained the variance of HP abundance were depth and prokaryote abundance, and to lesser extent oxygen concentration. The generally good correlation with prokaryotic abundance suggested active grazing of HP on prokaryotes. On a finer scale, the prokaryote:HP abundance ratio varied at a regional scale, and sites with the highest ratios exhibited a larger contribution of fungi molecular signal. Our study is a step forward towards determining the relationship between HP and their environment, unveiling their importance as players in the dark <span class="hlt">ocean</span>'s microbial food web. PMID:25290506</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25290506','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25290506"><span><span class="hlt">Global</span> abundance of planktonic heterotrophic protists in the deep <span class="hlt">ocean</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pernice, Massimo C; Forn, Irene; Gomes, Ana; Lara, Elena; Alonso-Sáez, Laura; Arrieta, Jesus M; del Carmen Garcia, Francisca; Hernando-Morales, Victor; MacKenzie, Roy; Mestre, Mireia; Sintes, Eva; Teira, Eva; Valencia, Joaquin; Varela, Marta M; Vaqué, Dolors; Duarte, Carlos M; Gasol, Josep M; Massana, Ramon</p> <p>2015-03-01</p> <p>The dark <span class="hlt">ocean</span> is one of the largest biomes on Earth, with critical roles in organic matter remineralization and <span class="hlt">global</span> carbon sequestration. Despite its recognized importance, little is known about some key microbial players, such as the community of heterotrophic protists (HP), which are likely the main consumers of prokaryotic biomass. To investigate this microbial component at a <span class="hlt">global</span> scale, we determined their abundance and biomass in deepwater column samples from the Malaspina 2010 circumnavigation using a combination of epifluorescence microscopy and flow cytometry. HP were ubiquitously found at all depths investigated down to 4000 m. HP abundances decreased with depth, from an average of 72±19 cells ml(-1) in mesopelagic waters down to 11±1 cells ml(-1) in bathypelagic waters, whereas their total biomass decreased from 280±46 to 50±14 pg C ml(-1). The parameters that better explained the variance of HP abundance were depth and prokaryote abundance, and to lesser extent oxygen concentration. The generally good correlation with prokaryotic abundance suggested active grazing of HP on prokaryotes. On a finer scale, the prokaryote:HP abundance ratio varied at a regional scale, and sites with the highest ratios exhibited a larger contribution of fungi molecular signal. Our study is a step forward towards determining the relationship between HP and their environment, unveiling their importance as players in the dark <span class="hlt">ocean</span>'s microbial food web.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940030837','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940030837"><span>Mission to Planet Earth. The living <span class="hlt">ocean</span>: Observing <span class="hlt">ocean</span> color from space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1994-01-01</p> <p>Measurements of <span class="hlt">ocean</span> color are part of NASA's Mission to Planet Earth, which will assess how the <span class="hlt">global</span> environment is changing. Using the unique perspective available from space, NASA will observe, monitor, and study large-scale environmental processes, focusing on quantifying climate change. NASA will distribute the results of these studies to researchers worldwide to furnish a basis for informed decisions on environmental protection and economic policy. This information packet includes discussion on the reasons for measuring <span class="hlt">ocean</span> color, the carbon cycle and <span class="hlt">ocean</span> color, priorities for <span class="hlt">global</span> climate research, and SeWiFS (sea-viewing wide field-of-view sensor) <span class="hlt">global</span> <span class="hlt">ocean</span> color measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NatCC...3..254C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NatCC...3..254C"><span>Shrinking of fishes exacerbates impacts of <span class="hlt">global</span> <span class="hlt">ocean</span> changes on marine ecosystems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheung, William W. L.; Sarmiento, Jorge L.; Dunne, John; Frölicher, Thomas L.; Lam, Vicky W. Y.; Deng Palomares, M. L.; Watson, Reg; Pauly, Daniel</p> <p>2013-03-01</p> <p>Changes in temperature, oxygen content and other <span class="hlt">ocean</span> biogeochemical properties directly affect the ecophysiology of marine water-breathing organisms. Previous studies suggest that the most prominent biological responses are changes in distribution, phenology and productivity. Both theory and empirical observations also support the hypothesis that warming and reduced oxygen will reduce body size of marine fishes. However, the extent to which such changes would exacerbate the impacts of climate and <span class="hlt">ocean</span> changes on <span class="hlt">global</span> marine ecosystems remains unexplored. Here, we employ a model to examine the integrated biological responses of over 600 species of marine fishes due to changes in distribution, abundance and body size. The model has an explicit representation of ecophysiology, dispersal, distribution, and population dynamics. We show that assemblage-averaged maximum body weight is expected to shrink by 14-24% <span class="hlt">globally</span> from 2000 to 2050 under a high-emission scenario. About half of this shrinkage is due to change in distribution and abundance, the remainder to changes in physiology. The tropical and intermediate latitudinal areas will be heavily impacted, with an average reduction of more than 20%. Our results provide a new dimension to understanding the integrated impacts of climate change on marine ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMOS21A1571K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMOS21A1571K"><span>Are Salps A Silver Bullet Against <span class="hlt">Global</span> Warming And <span class="hlt">Ocean</span> Acidification?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kithil, P. W.</p> <p>2006-12-01</p> <p> solar panel to power communications & provide remote control. Adjacent pumps are connected at the bottom to maintain relative position. If required, periodic seafloor anchoring can maintain absolute position within an <span class="hlt">ocean</span> basin. Deployment is low cost as the pumps self-deploy when dropped into the <span class="hlt">ocean</span> from barges. Pumps would not be deployed in <span class="hlt">ocean</span> shipping channels, regions used by recreational boaters, nor where excessive tides or currents exist. In a <span class="hlt">global</span> application, 1,340 arrays each 100,000 km2 are needed to cover the 134 million km2 calculated above. Assuming one pump per square km costing 2,000, an investment of 268 billion is needed. Using a five year payback, this investment is recouped if the carbon credit price is 26.80 per ton applied to sequestering 1.96 billion tons per year of carbon. This is not dramatically different from today's carbon credit price of about 15 per ton. Assuming a governmental mandate of carbon sequestration, today's price could easily increase many-fold, making <span class="hlt">ocean</span> sequestration using forced upwelling economically attractive. Additional benefits of widespread forced upwelling include: 1 Buffering of <span class="hlt">ocean</span> pH by removing CO2 during photosynthesis; 2 Possible cooling the upper mixed layer upstream from coral reefs to reduce bleaching from <span class="hlt">ocean</span> hotspots; 3 Possible mitigation of rapid climate change by enhancing the mixing of arctic/Greenland meltwater; 4 Enhancement of wild fish populations; and, 5 Reduced hurricane intensity, achieved by cooling the upper mixed layer upon approach of a tropical storm in high risk regions such as the Gulf of Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC41F..07T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC41F..07T"><span>Transforming <span class="hlt">Ocean</span> Observations of the Carbon Budget, Acidification, Hypoxia, Nutrients, and Biological Productivity: a <span class="hlt">Global</span> Array of Biogeochemical Argo Floats</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Talley, L. D.; Johnson, K. S.; Claustre, H.; Boss, E.; Emerson, S. R.; Westberry, T. K.; Sarmiento, J. L.; Mazloff, M. R.; Riser, S.; Russell, J. L.</p> <p>2017-12-01</p> <p>Our ability to detect changes in biogeochemical (BGC) processes in the <span class="hlt">ocean</span> that may be driven by increasing atmospheric CO2, as well as by natural climate variability, is greatly hindered by undersampling in vast areas of the open <span class="hlt">ocean</span>. Argo is a major international program that measures <span class="hlt">ocean</span> heat content and salinity with about 4000 floats distributed throughout the <span class="hlt">ocean</span>, profiling to 2000 m every 10 days. Extending this approach to a <span class="hlt">global</span> BGC-Argo float array, using recent, proven sensor technology, and in close synergy with satellite systems, will drive a transformative shift in observing and predicting the effects of climate change on <span class="hlt">ocean</span> metabolism, carbon uptake, acidification, deoxygenation, and living marine resource management. BGC-Argo will add sensors for pH, oxygen, nitrate, chlorophyll, suspended particles, and downwelling irradiance, with sufficient accuracy for climate studies. Observing System Simulation Experiments (OSSEs) using BGC models indicate that 1000 BGC floats would provide sufficient coverage, hence equipping 1/4 of the Argo array. BGC-Argo (http://biogeochemical-argo.org) will enhance current sustained observational programs such as Argo, GO-SHIP, and long-term <span class="hlt">ocean</span> time series. BGC-Argo will benefit from deployments on GO-SHIP vessels, which provide sensor verification. Empirically derived algorithms that relate the observed BGC float parameters to the carbon system parameters will provide <span class="hlt">global</span> information on seasonal <span class="hlt">ocean</span>-atmosphere carbon exchange. BGC Argo measurements could be paired with other emerging technology, such as pCO2 measurements from ships of opportunity and wave gliders, to extend and validate exchange estimates. BGC-Argo prototype programs already show the potential of a <span class="hlt">global</span> observing system that can measure seasonal to decadal variability. Various countries have developed regional BGC arrays: Southern <span class="hlt">Ocean</span> (SOCCOM), North Atlantic Subpolar Gyre (rem<span class="hlt">Ocean</span>), Mediterranean (NAOS), the Kuroshio (INBOX</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMED11C3430P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMED11C3430P"><span>Local Observations, <span class="hlt">Global</span> Connections: An Educational Program Using <span class="hlt">Ocean</span> Networks Canada's Community-Based Observatories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pelz, M.; Hoeberechts, M.; Ewing, N.; Davidson, E.; Riddell, D. J.</p> <p>2014-12-01</p> <p>Schools on Canada's west coast and in the Canadian Arctic are participating in the pilot year of a novel educational program based on analyzing, understanding and sharing <span class="hlt">ocean</span> data collected by cabled observatories. The core of the program is "local observations, <span class="hlt">global</span> connections." First, students develop an understanding of <span class="hlt">ocean</span> conditions at their doorstep through the analysis of community-based observatory data. Then, they connect that knowledge with the health of the <span class="hlt">global</span> <span class="hlt">ocean</span> by engaging with students at other schools participating in the educational program and through supplemental educational resources. <span class="hlt">Ocean</span> Networks Canada (ONC), an initiative of the University of Victoria, operates cabled <span class="hlt">ocean</span> observatories which supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea. This Internet connectivity permits researchers, students and members of the public to download freely available data on their computers anywhere around the globe, in near real-time. In addition to the large NEPTUNE and VENUS cabled observatories off the coast of Vancouver Island, British Columbia, ONC has been installing smaller, community-based cabled observatories. Currently two are installed: one in Cambridge Bay, Nunavut and one at Brentwood College School, on Mill Bay in Saanich Inlet, BC. Several more community-based observatories are scheduled for installation within the next year. The observatories support a variety of subsea instruments, such as a video camera, hydrophone and water quality monitor and shore-based equipment including a weather station and a video camera. Schools in communities hosting an observatory are invited to participate in the program, alongside schools located in other coastal and inland communities. Students and teachers access educational material and data through a web portal, and use video conferencing and social media tools to communicate their findings. A series of lesson plans</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSMM41A..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSMM41A..05L"><span>Shedding light on the <span class="hlt">Global</span> <span class="hlt">Ocean</span> microbiome with algorithms and data collection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauro, F.; Ostrowski, M.; Chénard, C.; Acerbi, E.; Paulsen, I.; Jensen, R.</p> <p>2016-02-01</p> <p>In the <span class="hlt">Global</span> <span class="hlt">Oceans</span>, the marine microbiome plays a critical role in biogeochemical cycling of nutrients, but surveying marine microbial communities requires ship time for sample collection, economically constraining the number of samples collected. An integrative understanding of the microbiome's activity and performance requires the collection of high-density data, both temporally and spatially in a cost-effective way. We have overcome this bottleneck by crowdsourcing the data collection to vessels of opportunity, including bluewater sailing yachts. Sailors know the <span class="hlt">oceans</span>, and experience first-hand the declines in <span class="hlt">ocean</span> productivity and the effects of pollution and climate change. Moreover, simply the ability to sample a microbial community during anomalous or inclement weather conditions is a major advance in sampling strategy. Our approach inherently incorporates the benefit of outreach and participation of people in scientific research, gaining positive media attention for sailors, scientists and concerned citizens alike. We have tested the basic methods during a 2013 Indian <span class="hlt">Ocean</span> Concept Cruise, from Cape Town to Singapore, performing experimental work and reaching sampling locations inaccessible to traditional Oceanographic Vessels. At the same time we developed a small, yacht-adapted automated sampling device that takes a variety of biological and chemical measurements. In 2015 our first beta-cruisers sampled the Pacific <span class="hlt">Ocean</span> in the first ever citizen-oceanography transect at high and low latitudes in both hemispheres. The collected samples were characterized with next-gen sequencing technology and analysed with a combination of novel algorithmic approaches. With big data management, machine learning algorithms and agent-based models we show that it is possible to deconvolute the complexity of the <span class="hlt">Ocean</span> Microbiome for the scientific management of fisheries, marine protected areas and preservation of the <span class="hlt">oceans</span> and seas for generations to come.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OcDyn..68..347S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OcDyn..68..347S"><span>High-frequency and meso-scale winter sea-ice variability in the Southern <span class="hlt">Ocean</span> in a high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stössel, Achim; von Storch, Jin-Song; Notz, Dirk; Haak, Helmuth; Gerdes, Rüdiger</p> <p>2018-03-01</p> <p>This study is on high-frequency temporal variability (HFV) and meso-scale spatial variability (MSV) of winter sea-ice drift in the Southern <span class="hlt">Ocean</span> simulated with a <span class="hlt">global</span> high-resolution (0.1°) sea ice-<span class="hlt">ocean</span> model. Hourly model output is used to distinguish MSV characteristics via patterns of mean kinetic energy (MKE) and turbulent kinetic energy (TKE) of ice drift, surface currents, and wind stress, and HFV characteristics via time series of raw variables and correlations. We find that (1) along the ice edge, the MSV of ice drift coincides with that of surface currents, in particular such due to <span class="hlt">ocean</span> eddies; (2) along the coast, the MKE of ice drift is substantially larger than its TKE and coincides with the MKE of wind stress; (3) in the interior of the ice pack, the TKE of ice drift is larger than its MKE, mostly following the TKE pattern of wind stress; (4) the HFV of ice drift is dominated by weather events, and, in the absence of tidal currents, locally and to a much smaller degree by inertial oscillations; (5) along the ice edge, the curl of the ice drift is highly correlated with that of surface currents, mostly reflecting the impact of <span class="hlt">ocean</span> eddies. Where <span class="hlt">ocean</span> eddies occur and the ice is relatively thin, ice velocity is characterized by enhanced relative vorticity, largely matching that of surface currents. Along the ice edge, <span class="hlt">ocean</span> eddies produce distinct ice filaments, the realism of which is largely confirmed by high-resolution satellite passive-microwave data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8377G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8377G"><span>Did hydrographic sampling capture <span class="hlt">global</span> and regional deep <span class="hlt">ocean</span> heat content trends accurately between 1990-2010?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garry, Freya; McDonagh, Elaine; Blaker, Adam; Roberts, Chris; Desbruyères, Damien; King, Brian</p> <p>2017-04-01</p> <p>Estimates of heat content change in the deep <span class="hlt">oceans</span> (below 2000 m) over the last thirty years are obtained from temperature measurements made by hydrographic survey ships. Cruises occupy the same tracks across an <span class="hlt">ocean</span> basin approximately every 5+ years. Measurements may not be sufficiently frequent in time or space to allow accurate evaluation of total <span class="hlt">ocean</span> heat content (OHC) and its rate of change. It is widely thought that additional deep <span class="hlt">ocean</span> sampling will also aid understanding of the mechanisms for OHC change on annual to decadal timescales, including how OHC varies regionally under natural and anthropogenically forced climate change. Here a 0.25˚ <span class="hlt">ocean</span> model is used to investigate the magnitude of uncertainties and biases that exist in estimates of deep <span class="hlt">ocean</span> temperature change from hydrographic sections due to their infrequent timing and sparse spatial distribution during 1990 - 2010. Biases in the observational data may be due to lack of spatial coverage (not enough sections covering the basin), lack of data between occupations (typically 5-10 years apart) and due to occupations not closely spanning the time period of interest. Between 1990 - 2010, the modelled biases <span class="hlt">globally</span> are comparatively small in the abyssal <span class="hlt">ocean</span> below 3500 m although regionally certain biases in heat flux into the 4000 - 6000 m layer can be up to 0.05 Wm-2. Biases in the heat flux into the deep 2000 - 4000 m layer due to either temporal or spatial sampling uncertainties are typically much larger and can be over 0.1 Wm-2 across an <span class="hlt">ocean</span>. Overall, 82% of the warming trend below 2000 m is captured by observational-style sampling in the model. However, at 2500 m (too deep for additional temperature information to be inferred from upper <span class="hlt">ocean</span> Argo) less than two thirds of the magnitude of the <span class="hlt">global</span> warming trend is obtained, and regionally large biases exist in the Atlantic, Southern and Indian <span class="hlt">Oceans</span>, highlighting the need for widespread improved deep <span class="hlt">ocean</span> temperature sampling</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29476630','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29476630"><span>Experimental strategies to assess the biological ramifications of multiple drivers of <span class="hlt">global</span> <span class="hlt">ocean</span> change-A review.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boyd, Philip W; Collins, Sinead; Dupont, Sam; Fabricius, Katharina; Gattuso, Jean-Pierre; Havenhand, Jonathan; Hutchins, David A; Riebesell, Ulf; Rintoul, Max S; Vichi, Marcello; Biswas, Haimanti; Ciotti, Aurea; Gao, Kunshan; Gehlen, Marion; Hurd, Catriona L; Kurihara, Haruko; McGraw, Christina M; Navarro, Jorge M; Nilsson, Göran E; Passow, Uta; Pörtner, Hans-Otto</p> <p>2018-06-01</p> <p>Marine life is controlled by multiple physical and chemical drivers and by diverse ecological processes. Many of these <span class="hlt">oceanic</span> properties are being altered by climate change and other anthropogenic pressures. Hence, identifying the influences of multifaceted <span class="hlt">ocean</span> change, from local to <span class="hlt">global</span> scales, is a complex task. To guide policy-making and make projections of the future of the marine biosphere, it is essential to understand biological responses at physiological, evolutionary and ecological levels. Here, we contrast and compare different approaches to multiple driver experiments that aim to elucidate biological responses to a complex matrix of <span class="hlt">ocean</span> <span class="hlt">global</span> change. We present the benefits and the challenges of each approach with a focus on marine research, and guidelines to navigate through these different categories to help identify strategies that might best address research questions in fundamental physiology, experimental evolutionary biology and community ecology. Our review reveals that the field of multiple driver research is being pulled in complementary directions: the need for reductionist approaches to obtain process-oriented, mechanistic understanding and a requirement to quantify responses to projected future scenarios of <span class="hlt">ocean</span> change. We conclude the review with recommendations on how best to align different experimental approaches to contribute fundamental information needed for science-based policy formulation. © 2018 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA619524','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA619524"><span>Deep Water <span class="hlt">Ocean</span> Acoustics</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-07-17</p> <p>under- ice scattering, bathymetric diffraction and the application of the <span class="hlt">ocean</span> acoustic Parabolic Equation to infrasound. 2. Tasks a. Task 1...and Climate of the <span class="hlt">Ocean</span>, Phase II (ECCO2): High-Resolution <span class="hlt">Global-Ocean</span> and Sea- Ice Data Synthesis) model re- analysis for the years 1992 and 1993...The ECCO2 model is a state estimation based upon data syntheses obtained by least squares fitting of the <span class="hlt">global</span> <span class="hlt">ocean</span> and sea- ice configuration of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA579660','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA579660"><span>Variational Data Assimilation for the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-01-01</p> <p><span class="hlt">ocean</span> includes the Geoid (a fixed gravity equipotential surface ) as well as the MDT, which is not known accurately enough relative to the centimeter...scales, including processes that control the surface mixed layer, the formation of <span class="hlt">ocean</span> eddies, meandering <span class="hlt">ocean</span> J.A. Cummings (E3) nography Division...variables. Examples of this in the <span class="hlt">ocean</span> are integral quantities, such as acous^B travel time and altimeter measures of sea surface height, and direct</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9447F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9447F"><span>A 15-year <span class="hlt">global</span> biogeochemical reanalysis with <span class="hlt">ocean</span> colour data assimilation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ford, David; Barciela, Rosa</p> <p>2013-04-01</p> <p>A continuous <span class="hlt">global</span> time-series of remotely sensed <span class="hlt">ocean</span> colour observations is available from 1997 to the present day. However coverage is incomplete, and limited to the sea surface. Models are therefore required to provide full spatial coverage, and to investigate the relationships between physical and biological variables and the carbon cycle. Data assimilation can then be used to constrain models to fit the observations, thereby combining the advantages of both sources of information. As part of the European Space Agency's Climate Change Initiative (ESA-CCI), we assimilate chlorophyll concentration derived from <span class="hlt">ocean</span> colour observations into a coupled physical-biogeochemical model. The data assimilation scheme (Hemmings et al., 2008, J. Mar. Res.; Ford et al., 2012, <span class="hlt">Ocean</span> Sci.) uses the information from the observations to update all biological and carbon cycle state variables within the model. <span class="hlt">Global</span> daily reanalyses have been produced, with and without assimilation of merged <span class="hlt">ocean</span> colour data provided by GlobColour, for the period September 1997 to August 2012. The assimilation has been shown to significantly improve the model's representation of chlorophyll concentration, at the surface and at depth. Furthermore, there is evidence of improvement to the representation of pCO2, nutrients and zooplankton concentration compared to in situ observations. We use the results to quantify recent seasonal and inter-annual variability in variables including chlorophyll concentration, air-sea CO2 flux and alkalinity. In particular, we explore the impact of physical drivers such as the El Niño Southern Oscillation (ENSO) on the model's representation of chlorophyll and the carbon cycle, and the pros and cons of the model reanalyses compared to observation-based climatologies. Furthermore, we perform a comparison between the GlobColour product and an initial version of a new merged product being developed as part of the ESA-CCI. Equivalent year-long hindcasts are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1818308T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1818308T"><span>RTopo-2: A <span class="hlt">global</span> high-resolution dataset of ice sheet topography, ice shelf cavity geometry and <span class="hlt">ocean</span> bathymetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timmermann, Ralph; Schaffer, Janin</p> <p>2016-04-01</p> <p>The RTopo-1 data set of Antarctic ice sheet/shelf geometry and <span class="hlt">global</span> <span class="hlt">ocean</span> bathymetry has proven useful not only for modelling studies of ice-<span class="hlt">ocean</span> interaction in the southern hemisphere. Following the spirit of this data set, we introduce a new product (RTopo-2) that contains consistent maps of <span class="hlt">global</span> <span class="hlt">ocean</span> bathymetry, upper and lower ice surface topographies for Greenland and Antarctica, and <span class="hlt">global</span> surface height on a spherical grid with now 30 arc seconds resolution. We used the General Bathymetric Chart of the <span class="hlt">Oceans</span> (GEBCO_2014) as the backbone and added the International Bathymetric Chart of the Arctic <span class="hlt">Ocean</span> version 3 (IBCAOv3) and the International Bathymetric Chart of the Southern <span class="hlt">Ocean</span> (IBCSO) version 1. To achieve a good representation of the fjord and shelf bathymetry around the Greenland continent, we corrected data from earlier gridded products in the areas of Petermann Glacier, Hagen Bræ and Helheim Glacier assuming that sub-ice and fjord bathymetries roughly follow plausible Last Glacial Maximum ice flow patterns. For the continental shelf off northeast Greenland and the floating ice tongue of Nioghalvfjerdsfjorden Glacier at about 79°N, we incorporated a high-resolution digital bathymetry model including all available multibeam survey data for the region. Radar data for ice surface and ice base topographies of the floating ice tongues of Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm have been obtained from the data centers of Technical University of Denmark (DTU), Operation Icebridge (NASA/NSF) and Alfred Wegener Institute (AWI). For the Antarctic ice sheet/ice shelves, RTopo-2 largely relies on the Bedmap-2 product but applies corrections for the geometry of Getz, Abbot and Fimbul ice shelf cavities. The data set is available in full and in regional subsets in NetCDF format from the PANGAEA database.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4028991','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4028991"><span>Future habitat suitability for coral reef ecosystems under <span class="hlt">global</span> warming and <span class="hlt">ocean</span> acidification</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Couce, Elena; Ridgwell, Andy; Hendy, Erica J</p> <p>2013-01-01</p> <p>Rising atmospheric CO2 concentrations are placing spatially divergent stresses on the world's tropical coral reefs through increasing <span class="hlt">ocean</span> surface temperatures and <span class="hlt">ocean</span> acidification. We show how these two stressors combine to alter the <span class="hlt">global</span> habitat suitability for shallow coral reef ecosystems, using statistical Bioclimatic Envelope Models rather than basing projections on any a priori assumptions of physiological tolerances or fixed thresholds. We apply two different modeling approaches (Maximum Entropy and Boosted Regression Trees) with two levels of complexity (one a simplified and reduced environmental variable version of the other). Our models project a marked temperature-driven decline in habitat suitability for many of the most significant and bio-diverse tropical coral regions, particularly in the central Indo-Pacific. This is accompanied by a temperature-driven poleward range expansion of favorable conditions accelerating up to 40–70 km per decade by 2070. We find that <span class="hlt">ocean</span> acidification is less influential for determining future habitat suitability than warming, and its deleterious effects are centered evenly in both hemispheres between 5° and 20° latitude. Contrary to expectations, the combined impact of <span class="hlt">ocean</span> surface temperature rise and acidification leads to little, if any, degradation in future habitat suitability across much of the Atlantic and areas currently considered ‘marginal’ for tropical corals, such as the eastern Equatorial Pacific. These results are consistent with fossil evidence of range expansions during past warm periods. In addition, the simplified models are particularly sensitive to short-term temperature variations and their projections correlate well with reported locations of bleaching events. Our approach offers new insights into the relative impact of two <span class="hlt">global</span> environmental pressures associated with rising atmospheric CO2 on potential future habitats, but greater understanding of past and current controls on</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23893550','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23893550"><span>Future habitat suitability for coral reef ecosystems under <span class="hlt">global</span> warming and <span class="hlt">ocean</span> acidification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Couce, Elena; Ridgwell, Andy; Hendy, Erica J</p> <p>2013-12-01</p> <p>Rising atmospheric CO2 concentrations are placing spatially divergent stresses on the world's tropical coral reefs through increasing <span class="hlt">ocean</span> surface temperatures and <span class="hlt">ocean</span> acidification. We show how these two stressors combine to alter the <span class="hlt">global</span> habitat suitability for shallow coral reef ecosystems, using statistical Bioclimatic Envelope Models rather than basing projections on any a priori assumptions of physiological tolerances or fixed thresholds. We apply two different modeling approaches (Maximum Entropy and Boosted Regression Trees) with two levels of complexity (one a simplified and reduced environmental variable version of the other). Our models project a marked temperature-driven decline in habitat suitability for many of the most significant and bio-diverse tropical coral regions, particularly in the central Indo-Pacific. This is accompanied by a temperature-driven poleward range expansion of favorable conditions accelerating up to 40-70 km per decade by 2070. We find that <span class="hlt">ocean</span> acidification is less influential for determining future habitat suitability than warming, and its deleterious effects are centered evenly in both hemispheres between 5° and 20° latitude. Contrary to expectations, the combined impact of <span class="hlt">ocean</span> surface temperature rise and acidification leads to little, if any, degradation in future habitat suitability across much of the Atlantic and areas currently considered 'marginal' for tropical corals, such as the eastern Equatorial Pacific. These results are consistent with fossil evidence of range expansions during past warm periods. In addition, the simplified models are particularly sensitive to short-term temperature variations and their projections correlate well with reported locations of bleaching events. Our approach offers new insights into the relative impact of two <span class="hlt">global</span> environmental pressures associated with rising atmospheric CO2 on potential future habitats, but greater understanding of past and current controls on coral</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.7106E..03N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.7106E..03N"><span>The <span class="hlt">Ocean</span> Surface Topography Mission (OSTM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neeck, Steven P.; Vaze, Parag V.</p> <p>2008-10-01</p> <p>The <span class="hlt">Ocean</span> Surface Topography Mission (OSTM), also known as Jason-2, will extend into the next decade the continuous climate data record of sea surface height measurements begun in 1992 by the <span class="hlt">joint</span> NASA/Centre National d'Etudes Spatiales (CNES) TOPEX/Poseidon mission and continued by the NASA/CNES Jason-1 mission in 2001. This multi-decadal record has already helped scientists study the issue of <span class="hlt">global</span> sea level rise and better understand how <span class="hlt">ocean</span> circulation and climate change are related. With OSTM, high-precision <span class="hlt">ocean</span> altimetry has come of age. The mission will serve as a bridge to transition the collection of these measurements to the world's weather and climate forecasting agencies. The agencies will use them for short- and seasonal-to-long-range weather and climate forecasting. OSTM is designed to last at least three years. It will be placed in the same orbit (1,336 kilometers) as Jason-1 and will move along the same ground track at an inclination of 66 degrees to the equator. It will repeat its ground track every 10 days, covering 95 percent of the world's ice-free <span class="hlt">oceans</span>. A tandem mission between Jason-1 and OSTM will be conducted to further improve tide models in coastal and shallow seas, and to better understand the dynamics of <span class="hlt">ocean</span> currents and eddies. OSTM is an international and interagency mission developed and operated as a four-party collaboration among NASA, the National <span class="hlt">Oceanic</span> and Atmospheric Administration (NOAA), CNES, and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). CNES is providing the spacecraft, NASA and CNES are <span class="hlt">jointly</span> providing the payload instruments and NASA is providing the launch vehicle. After completing the onorbit commissioning of the spacecraft, CNES will hand over operation and control of the spacecraft to NOAA. NOAA and EUMETSAT will generate the near-real-time products and distribute them to users. OSTM was launched from Vandenberg Air Force Base, California on June 20, 2008</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMIN53A1832N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMIN53A1832N"><span>3D Visualization of <span class="hlt">Global</span> <span class="hlt">Ocean</span> Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelson, V. G.; Sharma, R.; Zhang, E.; Schmittner, A.; Jenny, B.</p> <p>2015-12-01</p> <p>Advanced 3D visualization techniques are seldom used to explore the dynamic behavior of <span class="hlt">ocean</span> circulation. Streamlines are an effective method for visualization of flow, and they can be designed to clearly show the dynamic behavior of a fluidic system. We employ vector field editing and extraction software to examine the topology of velocity vector fields generated by a 3D <span class="hlt">global</span> circulation model coupled to a one-layer atmosphere model simulating preindustrial and last glacial maximum (LGM) conditions. This results in a streamline-based visualization along multiple density isosurfaces on which we visualize points of vertical exchange and the distribution of properties such as temperature and biogeochemical tracers. Previous work involving this model examined the change in the energetics driving overturning circulation and mixing between simulations of LGM and preindustrial conditions. This visualization elucidates the relationship between locations of vertical exchange and mixing, as well as demonstrates the effects of circulation and mixing on the distribution of tracers such as carbon isotopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ESSD....8..543S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ESSD....8..543S"><span>A <span class="hlt">global</span>, high-resolution data set of ice sheet topography, cavity geometry, and <span class="hlt">ocean</span> bathymetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaffer, Janin; Timmermann, Ralph; Arndt, Jan Erik; Savstrup Kristensen, Steen; Mayer, Christoph; Morlighem, Mathieu; Steinhage, Daniel</p> <p>2016-10-01</p> <p>The <span class="hlt">ocean</span> plays an important role in modulating the mass balance of the polar ice sheets by interacting with the ice shelves in Antarctica and with the marine-terminating outlet glaciers in Greenland. Given that the flux of warm water onto the continental shelf and into the sub-ice cavities is steered by complex bathymetry, a detailed topography data set is an essential ingredient for models that address ice-<span class="hlt">ocean</span> interaction. We followed the spirit of the <span class="hlt">global</span> RTopo-1 data set and compiled consistent maps of <span class="hlt">global</span> <span class="hlt">ocean</span> bathymetry, upper and lower ice surface topographies, and <span class="hlt">global</span> surface height on a spherical grid with now 30 arcsec grid spacing. For this new data set, called RTopo-2, we used the General Bathymetric Chart of the <span class="hlt">Oceans</span> (GEBCO_2014) as the backbone and added the International Bathymetric Chart of the Arctic <span class="hlt">Ocean</span> version 3 (IBCAOv3) and the International Bathymetric Chart of the Southern <span class="hlt">Ocean</span> (IBCSO) version 1. While RTopo-1 primarily aimed at a good and consistent representation of the Antarctic ice sheet, ice shelves, and sub-ice cavities, RTopo-2 now also contains ice topographies of the Greenland ice sheet and outlet glaciers. In particular, we aimed at a good representation of the fjord and shelf bathymetry surrounding the Greenland continent. We modified data from earlier gridded products in the areas of Petermann Glacier, Hagen Bræ, and Sermilik Fjord, assuming that sub-ice and fjord bathymetries roughly follow plausible Last Glacial Maximum ice flow patterns. For the continental shelf off Northeast Greenland and the floating ice tongue of Nioghalvfjerdsfjorden Glacier at about 79° N, we incorporated a high-resolution digital bathymetry model considering original multibeam survey data for the region. Radar data for surface topographies of the floating ice tongues of Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm have been obtained from the data centres of Technical University of Denmark (DTU), Operation Icebridge (NASA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.8070W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.8070W"><span>On the sensitivity of the <span class="hlt">global</span> <span class="hlt">ocean</span> circulation to reconstructions of paleo-bathymetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weber, Tobias; Thomas, Maik</p> <p>2013-04-01</p> <p>The ability to model the long-term evolution of the climate does considerably depend on the accuracy of <span class="hlt">ocean</span> models and their interaction with the atmosphere. Thereby, the <span class="hlt">ocean</span> model's behavior with respect to uncertain and changing boundary conditions is of crucial importance. One of the remaining questions is, how different reconstructions of the <span class="hlt">ocean</span> floor influence the model. Although of general interest, this effect has mostly been neglected, so far. We modeled Pliocene and pre-industrial <span class="hlt">ocean</span> currents with the Max-Planck-Institute <span class="hlt">Ocean</span> Model (MPIOM), forced by climatologies derived from an atmospheric and vegetational <span class="hlt">Global</span> Circulation Model (GCM). We equipped it with different reconstructions of the bathymetry, what allowed us to study the model's sensitivity regarding changes in bathymetry. On the one hand we examined the influence of reconstructions with different locations of major ridges, but the same treatment of the shelf. On the other hand, reconstruction techniques that treated the shelf areas differently were taken into consideration. This leads to different <span class="hlt">oceanic</span> circulation realizations, which induce changes in deep <span class="hlt">ocean</span> temperature and salinity. Some of the simulations result in unrealistic behavior, such as an increase in surface temperature by several degrees. Most important, small bathymetric changes in the areas of deep water formation near Greenland and the Antarctic alter the thermohaline circulation strongly. This leads to its complete cessation in some of the simulations and therefore to stationary deep laying <span class="hlt">ocean</span> masses. This shows that not all bathymetric reconstruction sequences are applicable for the generation of boundary conditions for GCMs. In order to obtain reliable and physically realistic data from the models, the reconstruction method to be used for the paleo-bathymetry also needs to be applied to the present day bathymetry. This reconstruction can then be used in a control simulation which can be validated against</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAMES...9..438P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAMES...9..438P"><span>Incorporating a prognostic representation of marine nitrogen fixers into the <span class="hlt">global</span> <span class="hlt">ocean</span> biogeochemical model HAMOCC</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paulsen, Hanna; Ilyina, Tatiana; Six, Katharina D.; Stemmler, Irene</p> <p>2017-03-01</p> <p>Nitrogen (N2) fixation is a major source of bioavailable nitrogen to the euphotic zone, thereby exerting an important control on <span class="hlt">ocean</span> biogeochemical cycling. This paper presents the incorporation of prognostic N2 fixers into the HAMburg <span class="hlt">Ocean</span> Carbon Cycle model (HAMOCC), a component of the Max Planck Institute Earth System Model (MPI-ESM). Growth dynamics of N2 fixers in the model are based on physiological characteristics of the cyanobacterium Trichodesmium. The applied temperature dependency confines diazotrophic growth and N2 fixation to the tropical and subtropical <span class="hlt">ocean</span> roughly between 40°S and 40°N. Simulated large-scale spatial patterns compare well with observations, and the <span class="hlt">global</span> N2 fixation rate of 135.6 Tg N yr-1 is within the range of current estimates. The vertical distribution of N2 fixation also matches well the observations, with a major fraction of about 85% occurring in the upper 20 m. The observed seasonal variability at the stations BATS and ALOHA is reasonably reproduced, with highest fixation rates in northern summer/fall. Iron limitation was found to be an important factor in controlling the simulated distribution of N2 fixation, especially in the Pacific <span class="hlt">Ocean</span>. The new model component considerably improves the representation of present-day N2 fixation in HAMOCC. It provides the basis for further studies on the role of diazotrophs in <span class="hlt">global</span> biogeochemical cycles, as well as on the response of N2 fixation to changing environmental conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.U41A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.U41A..02B"><span>Capturing the <span class="hlt">global</span> signature of surface <span class="hlt">ocean</span> acidification during the PETM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Babila, T. L.; Penman, D. E.; Hoenisch, B.; Kelly, D. C.; Bralower, T. J.; Rosenthal, Y.; Zachos, J. C.</p> <p>2016-12-01</p> <p>Anthropogenic greenhouse gas emissions over the last century have elevated atmospheric carbon dioxide concentrations while concomitantly acidifying the <span class="hlt">oceans</span>. Instrumental records are sparse and limited in duration, making it difficult to separate regional from <span class="hlt">global</span> trends of <span class="hlt">ocean</span> acidification. Geologically rapid carbon perturbations such as the Paleocene-Eocene Thermal Maximum (PETM, 56 Ma) are arguably the closest paleo analogue to present climate change. Marine ecosystems experienced dynamic changes during the event, and parallel environmental changes, including acidification and warming. Here we present a synthesis of new and published geochemical reconstructions from various oceanographic settings to determine the magnitude and spatial extent of surface <span class="hlt">ocean</span> acidification. In the deep <span class="hlt">ocean</span>, acidification is inferred from widespread dissolution of seafloor carbonates, whereas evidence for surface <span class="hlt">ocean</span> acidification has emerged from planktonic foraminifera boron proxy records (B/Ca and δ11B) (Penman et al. 2014; Babila et al. 2016). B/Ca and δ11B in surface and thermocline planktonic foraminifera suggest a simultaneous decrease at the PETM onset in all pelagic and shelf sites. Salinity, diagenesis and foraminiferal symbiont loss can complicate the interpretation of boron proxy records. Local salinity changes (based on paired Mg/Ca and δ18O) account for a relatively small component of total B/Ca change. The large range in environmental conditions between sites could explain the subtle differences in absolute values exhibited by the records. Shelf sites (ODP 174AX Bass River and Ancora, NJ) reveal similar absolute values and trends compared to pelagic sites (ODP 1209, N. Pacific), precluding a significant preservation bias on the geochemical records. Southern <span class="hlt">Ocean</span> sites (ODP 689 and 690) are located in colder surface waters and exhibit a similar decrease in B/Ca, suggesting that temperature and symbiont loss are likely not major factors. We conclude</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy...50.1581M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy...50.1581M"><span>Simulating the characteristics of tropical cyclones over the South West Indian <span class="hlt">Ocean</span> using a Stretched-Grid <span class="hlt">Global</span> Climate Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maoyi, Molulaqhooa L.; Abiodun, Babatunde J.; Prusa, Joseph M.; Veitch, Jennifer J.</p> <p>2018-03-01</p> <p>Tropical cyclones (TCs) are one of the most devastating natural phenomena. This study examines the capability of a <span class="hlt">global</span> climate model with grid stretching (CAM-EULAG, hereafter CEU) in simulating the characteristics of TCs over the South West Indian <span class="hlt">Ocean</span> (SWIO). In the study, CEU is applied with a variable increment <span class="hlt">global</span> grid that has a fine horizontal grid resolution (0.5° × 0.5°) over the SWIO and coarser resolution (1° × 1°—2° × 2.25°) over the rest of the globe. The simulation is performed for the 11 years (1999-2010) and validated against the <span class="hlt">Joint</span> Typhoon Warning Center (JTWC) best track data, <span class="hlt">global</span> precipitation climatology project (GPCP) satellite data, and ERA-Interim (ERAINT) reanalysis. CEU gives a realistic simulation of the SWIO climate and shows some skill in simulating the spatial distribution of TC genesis locations and tracks over the basin. However, there are some discrepancies between the observed and simulated climatic features over the Mozambique channel (MC). Over MC, CEU simulates a substantial cyclonic feature that produces a higher number of TC than observed. The dynamical structure and intensities of the CEU TCs compare well with observation, though the model struggles to produce TCs with a deep pressure centre as low as the observed. The reanalysis has the same problem. The model captures the monthly variation of TC occurrence well but struggles to reproduce the interannual variation. The results of this study have application in improving and adopting CEU for seasonal forecasting over the SWIO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10568275','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10568275"><span>Anthropogenic radioactivity in the Arctic <span class="hlt">Ocean</span>--review of the results from the <span class="hlt">joint</span> German project.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nies, H; Harms, I H; Karcher, M J; Dethleff, D; Bahe, C</p> <p>1999-09-30</p> <p>The paper presents the results of the <span class="hlt">joint</span> project carried out in Germany in order to assess the consequences in the marine environment from the dumping of nuclear wastes in the Kara and Barents Seas. The project consisted of experimental work on measurements of radionuclides in samples from the Arctic marine environment and numerical modelling of the potential pathways and dispersion of contaminants in the Arctic <span class="hlt">Ocean</span>. Water and sediment samples were collected for determination of radionuclide such as 137Cs, 90Sr, 239 + 240Pu, 238Pu, and 241Am and various organic micropollutants. In addition, a few water and numerous surface sediment samples collected in the Kara Sea and from the Kola peninsula were taken by Russian colleagues and analysed for artificial radionuclide by the BSH laboratory. The role of transport by sea ice from the Kara Sea into the Arctic <span class="hlt">Ocean</span> was assessed by a small subgroup at GEOMAR. This transport process might be considered as a rapid contribution due to entrainment of contaminated sediments into sea ice, following export from the Kara Sea into the transpolar ice drift and subsequent release in the Atlantic <span class="hlt">Ocean</span> in the area of the East Greenland Current. Numerical modelling of dispersion of pollutants from the Kara and Barents Seas was carried out both on a local scale for the Barents and Kara Seas and for long range dispersion into the Arctic and Atlantic <span class="hlt">Oceans</span>. Three-dimensional baroclinic circulation models were applied to trace the transport of pollutants. Experimental results were used to validate the model results such as the discharges from the nuclear reprocessing plant at Sellafield and subsequent contamination of the North Sea up the Arctic Seas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..4312543B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..4312543B"><span>Spread in the magnitude of climate model interdecadal <span class="hlt">global</span> temperature variability traced to disagreements over high-latitude <span class="hlt">oceans</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brown, Patrick T.; Li, Wenhong; Jiang, Jonathan H.; Su, Hui</p> <p>2016-12-01</p> <p>Unforced variability in <span class="hlt">global</span> mean surface air temperature can obscure or exaggerate <span class="hlt">global</span> warming on interdecadal time scales; thus, understanding both the magnitude and generating mechanisms of such variability is of critical importance for both attribution studies as well as decadal climate prediction. Coupled atmosphere-<span class="hlt">ocean</span> general circulation models (climate models) simulate a wide range of magnitudes of unforced interdecadal variability in <span class="hlt">global</span> mean surface air temperature (UITglobal), hampering efforts to quantify the influence of UITglobal on contemporary <span class="hlt">global</span> temperature trends. Recently, a preliminary consensus has emerged that unforced interdecadal variability in local surface temperatures (UITlocal) over the tropical Pacific <span class="hlt">Ocean</span> is particularly influential on UITglobal. Therefore, a reasonable hypothesis might be that the large spread in the magnitude of UITglobal across climate models can be explained by the spread in the magnitude of simulated tropical Pacific UITlocal. Here we show that this hypothesis is mostly false. Instead, the spread in the magnitude of UITglobal is linked much more strongly to the spread in the magnitude of UITlocal over high-latitude regions characterized by significant variability in <span class="hlt">oceanic</span> convection, sea ice concentration, and energy flux at both the surface and the top of the atmosphere. Thus, efforts to constrain the climate model produced range of UITglobal magnitude would be best served by focusing on the simulation of air-sea interaction at high latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950053167&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dworlds%2Boceans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950053167&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dworlds%2Boceans"><span>Development of improved space sampling strategies for <span class="hlt">ocean</span> chemical properties: Total carbon dioxide and dissolved nitrate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goyet, Catherine; Davis, Daniel; Peltzer, Edward T.; Brewer, Peter G.</p> <p>1995-01-01</p> <p>Large-scale <span class="hlt">ocean</span> observing programs such as the <span class="hlt">Joint</span> <span class="hlt">Global</span> <span class="hlt">Ocean</span> Flux Study (JGOFS) and the World <span class="hlt">Ocean</span> Circulation Experiment (WOCE) today, must face the problem of designing an adequate sampling strategy. For <span class="hlt">ocean</span> chemical variables, the goals and observing technologies are quite different from <span class="hlt">ocean</span> physical variables (temperature, salinity, pressure). We have recently acquired data on the <span class="hlt">ocean</span> CO2 properties on WOCE cruises P16c and P17c that are sufficiently dense to test for sampling redundancy. We use linear and quadratic interpolation methods on the sampled field to investigate what is the minimum number of samples required to define the deep <span class="hlt">ocean</span> total inorganic carbon (TCO2) field within the limits of experimental accuracy (+/- 4 micromol/kg). Within the limits of current measurements, these lines were oversampled in the deep <span class="hlt">ocean</span>. Should the precision of the measurement be improved, then a denser sampling pattern may be desirable in the future. This approach rationalizes the efficient use of resources for field work and for estimating gridded (TCO2) fields needed to constrain geochemical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GMD....10..499H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GMD....10..499H"><span>Prospects for improving the representation of coastal and shelf seas in <span class="hlt">global</span> <span class="hlt">ocean</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holt, Jason; Hyder, Patrick; Ashworth, Mike; Harle, James; Hewitt, Helene T.; Liu, Hedong; New, Adrian L.; Pickles, Stephen; Porter, Andrew; Popova, Ekaterina; Icarus Allen, J.; Siddorn, John; Wood, Richard</p> <p>2017-02-01</p> <p>Accurately representing coastal and shelf seas in <span class="hlt">global</span> <span class="hlt">ocean</span> models represents one of the grand challenges of Earth system science. They are regions of immense societal importance through the goods and services they provide, hazards they pose and their role in <span class="hlt">global</span>-scale processes and cycles, e.g. carbon fluxes and dense water formation. However, they are poorly represented in the current generation of <span class="hlt">global</span> <span class="hlt">ocean</span> models. In this contribution, we aim to briefly characterise the problem, and then to identify the important physical processes, and their scales, needed to address this issue in the context of the options available to resolve these scales <span class="hlt">globally</span> and the evolving computational landscape.We find barotropic and topographic scales are well resolved by the current state-of-the-art model resolutions, e.g. nominal 1/12°, and still reasonably well resolved at 1/4°; here, the focus is on process representation. We identify tides, vertical coordinates, river inflows and mixing schemes as four areas where modelling approaches can readily be transferred from regional to <span class="hlt">global</span> modelling with substantial benefit. In terms of finer-scale processes, we find that a 1/12° <span class="hlt">global</span> model resolves the first baroclinic Rossby radius for only ˜ 8 % of regions < 500 m deep, but this increases to ˜ 70 % for a 1/72° model, so resolving scales <span class="hlt">globally</span> requires substantially finer resolution than the current state of the art.We quantify the benefit of improved resolution and process representation using 1/12° <span class="hlt">global</span>- and basin-scale northern North Atlantic nucleus for a European model of the <span class="hlt">ocean</span> (NEMO) simulations; the latter includes tides and a k-ɛ vertical mixing scheme. These are compared with <span class="hlt">global</span> stratification observations and 19 models from CMIP5. In terms of correlation and basin-wide rms error, the high-resolution models outperform all these CMIP5 models. The model with tides shows improved seasonal cycles compared to the high-resolution model without</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950047289&hterms=temperature+variability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtemperature%2Bvariability','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950047289&hterms=temperature+variability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtemperature%2Bvariability"><span>Decadal variability of the Tropical Atlantic <span class="hlt">Ocean</span> Surface Temperature in shipboard measurements and in a <span class="hlt">Global</span> <span class="hlt">Ocean</span>-Atmosphere model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mehta, Vikram M.; Delworth, Thomas</p> <p>1995-01-01</p> <p>Sea surface temperature (SST) variability was investigated in a 200-yr integration of a <span class="hlt">global</span> model of the coupled <span class="hlt">oceanic</span> and atmospheric general circulations developed at the Geophysical Fluid Dynamics Laboratory (GFDL). The second 100 yr of SST in the coupled model's tropical Atlantic region were analyzed with a variety of techniques. Analyses of SST time series, averaged over approximately the same subregions as the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Surface Temperature Atlas (GOSTA) time series, showed that the GFDL SST anomalies also undergo pronounced quasi-oscillatory decadal and multidecadal variability but at somewhat shorter timescales than the GOSTA SST anomalies. Further analyses of the horizontal structures of the decadal timescale variability in the GFDL coupled model showed the existence of two types of variability in general agreement with results of the GOSTA SST time series analyses. One type, characterized by timescales between 8 and 11 yr, has high spatial coherence within each hemisphere but not between the two hemispheres of the tropical Atlantic. A second type, characterized by timescales between 12 and 20 yr, has high spatial coherence between the two hemispheres. The second type of variability is considerably weaker than the first. As in the GOSTA time series, the multidecadal variability in the GFDL SST time series has approximately opposite phases between the tropical North and South Atlantic <span class="hlt">Oceans</span>. Empirical orthogonal function analyses of the tropical Atlantic SST anomalies revealed a north-south bipolar pattern as the dominant pattern of decadal variability. It is suggested that the bipolar pattern can be interpreted as decadal variability of the interhemispheric gradient of SST anomalies. The decadal and multidecadal timescale variability of the tropical Atlantic SST, both in the actual and in the GFDL model, stands out significantly above the background 'red noise' and is coherent within each of the time series, suggesting that specific sets of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26081243','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26081243"><span>Disciplinary reporting affects the interpretation of climate change impacts in <span class="hlt">global</span> <span class="hlt">oceans</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hauser, Donna D W; Tobin, Elizabeth D; Feifel, Kirsten M; Shah, Vega; Pietri, Diana M</p> <p>2016-01-01</p> <p>Climate change is affecting marine ecosystems, but different investigative approaches in physical, chemical, and biological disciplines may influence interpretations of climate-driven changes in the <span class="hlt">ocean</span>. Here, we review the <span class="hlt">ocean</span> change literature from 2007 to 2012 based on 461 of the most highly cited studies in physical and chemical oceanography and three biological subdisciplines. Using highly cited studies, we focus on research that has shaped recent discourse on climate-driven <span class="hlt">ocean</span> change. Our review identified significant differences in spatial and temporal scales of investigation among disciplines. Physical/chemical studies had a median duration of 29 years (n = 150) and covered the greatest study areas (median 1.41 × 10(7) km(2) , n = 148). Few biological studies were conducted over similar spatial and temporal scales (median 8 years, n = 215; median 302 km(2) , n = 196), suggesting a more limited ability to separate climate-related responses from natural variability. We linked physical/chemical and biological disciplines by tracking studies examining biological responses to changing <span class="hlt">ocean</span> conditions. Of the 545 biological responses recorded, a single physical or chemical stressor was usually implicated as the cause (59%), with temperature as the most common primary stressor (44%). The most frequently studied biological responses were changes in physiology (31%) and population abundance (30%). Differences in disciplinary studies, as identified in this review, can ultimately influence how researchers interpret climate-related impacts in marine systems. We identified research gaps and the need for more discourse in (1) the Indian and other Southern Hemisphere <span class="hlt">ocean</span> basins; (2) research themes such as archaea, bacteria, viruses, mangroves, turtles, and <span class="hlt">ocean</span> acidification; (3) physical and chemical stressors such as dissolved oxygen, salinity, and upwelling; and (4) adaptive responses of marine organisms to climate-driven <span class="hlt">ocean</span> change. Our findings reveal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OcMod.120..120H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OcMod.120..120H"><span>Will high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> models benefit coupled predictions on short-range to climate timescales?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hewitt, Helene T.; Bell, Michael J.; Chassignet, Eric P.; Czaja, Arnaud; Ferreira, David; Griffies, Stephen M.; Hyder, Pat; McClean, Julie L.; New, Adrian L.; Roberts, Malcolm J.</p> <p>2017-12-01</p> <p>As the importance of the <span class="hlt">ocean</span> in the weather and climate system is increasingly recognised, operational systems are now moving towards coupled prediction not only for seasonal to climate timescales but also for short-range forecasts. A three-way tension exists between the allocation of computing resources to refine model resolution, the expansion of model complexity/capability, and the increase of ensemble size. Here we review evidence for the benefits of increased <span class="hlt">ocean</span> resolution in <span class="hlt">global</span> coupled models, where the <span class="hlt">ocean</span> component explicitly represents transient mesoscale eddies and narrow boundary currents. We consider lessons learned from forced <span class="hlt">ocean</span>/sea-ice simulations; from studies concerning the SST resolution required to impact atmospheric simulations; and from coupled predictions. Impacts of the mesoscale <span class="hlt">ocean</span> in western boundary current regions on the large-scale atmospheric state have been identified. Understanding of air-sea feedback in western boundary currents is modifying our view of the dynamics in these key regions. It remains unclear whether variability associated with open <span class="hlt">ocean</span> mesoscale eddies is equally important to the large-scale atmospheric state. We include a discussion of what processes can presently be parameterised in coupled models with coarse resolution non-eddying <span class="hlt">ocean</span> models, and where parameterizations may fall short. We discuss the benefits of resolution and identify gaps in the current literature that leave important questions unanswered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15.2161B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15.2161B"><span>Constraints on <span class="hlt">global</span> <span class="hlt">oceanic</span> emissions of N2O from observations and models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buitenhuis, Erik T.; Suntharalingam, Parvadha; Le Quéré, Corinne</p> <p>2018-04-01</p> <p>We estimate the <span class="hlt">global</span> <span class="hlt">ocean</span> N2O flux to the atmosphere and its confidence interval using a statistical method based on model perturbation simulations and their fit to a database of ΔpN2O (n = 6136). We evaluate two submodels of N2O production. The first submodel splits N2O production into oxic and hypoxic pathways following previous publications. The second submodel explicitly represents the redox transformations of N that lead to N2O production (nitrification and hypoxic denitrification) and N2O consumption (suboxic denitrification), and is presented here for the first time. We perturb both submodels by modifying the key parameters of the N2O cycling pathways (nitrification rates; NH4+ uptake; N2O yields under oxic, hypoxic and suboxic conditions) and determine a set of optimal model parameters by minimisation of a cost function against four databases of N cycle observations. Our estimate of the <span class="hlt">global</span> <span class="hlt">oceanic</span> N2O flux resulting from this cost function minimisation derived from observed and model ΔpN2O concentrations is 2.4 ± 0.8 and 2.5 ± 0.8 Tg N yr-1 for the two N2O submodels. These estimates suggest that the currently available observational data of surface ΔpN2O constrain the <span class="hlt">global</span> N2O flux to a narrower range relative to the large range of results presented in the latest IPCC report.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915843E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915843E"><span><span class="hlt">Global</span> <span class="hlt">ocean</span> climatology of the 13C Suess effect and preindustrial δ13C</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eide, Marie; Olsen, Are; Ninnemann, Ulysses; Eldevik, Tor; Johannessen, Truls</p> <p>2017-04-01</p> <p>We present the first observationally based estimate of the full <span class="hlt">global</span> <span class="hlt">ocean</span> 13C Suess effect since preindustrial times. This was constructed by using Olsen and Ninnemann's [2010] back-calculation method to calculate the 13C Suess effect with data from 29 cruises spanning the world <span class="hlt">ocean</span>. We find a strong 13C Suess effect in the upper 1000 m of all basins, with strongest decrease in the Subtropical Gyres of the Northern Hemisphere, where δ13C has decreased by more than 0.8‰ since the industrial revolution. At greater depths, a significant 13C Suess effect can only be detected in the northern parts of the North Atlantic <span class="hlt">Ocean</span>. The magnitude of the 13C Suess effect is correlated with the concentration of anthropogenic carbon, but their relationship varying strongly between water masses, reflecting the degree to which source waters are equilibrated with the atmospheric 13C Suess effect before sinking. From the 13C Suess effect estimates, we have estimated the preindustrial δ13C (δ13CPI) along the 29 sections. Further, we developed regional multilinear regression equations, which were applied on the World <span class="hlt">Ocean</span> Atlas data to construct the δ13CPI climatology, which reveals the natural δ13C distribution in the <span class="hlt">global</span> <span class="hlt">ocean</span>. Compared to the modern distribution, the preindustrial δ13C spans a larger range of values, and we find that in some regions in the high northern latitudes, the gradient in modern <span class="hlt">ocean</span> δ13C is completely reversed compared to the preindustrial. Maximum δ13CPI, of up to 1.8‰, are found in the subtropical gyres of all basins, in the upper and intermediate waters of the North Atlantic, as well as in mode waters with a Southern <span class="hlt">Ocean</span> origin. Particularly strong gradients occur at intermediate depths, revealing a strong potential for using δ13C as a tracer for changes in water mass geometry at these levels. Further, we identify a much tighter relationship between δ13C and Apparent Oxygen Utilization (AOU) than between δ13C and phosphate that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915171N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915171N"><span>Southern <span class="hlt">Ocean</span> coccolithophore biogeography - controlling factors and implications for <span class="hlt">global</span> biogeochemical cycles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nissen, Cara; Vogt, Meike; Münnich, Matthias; Gruber, Nicolas</p> <p>2017-04-01</p> <p>Southern <span class="hlt">Ocean</span> phytoplankton biogeography is important for the biogeochemical cycling of carbon, silicate, and the transport of macronutrients to lower latitudes. With the discovery of the "Great Calcite Belt" (GBC), revealing an unexpectedly high prevalence of calcifying phytoplankton in the subtropical frontal region between 40-55°S, the relative importance of Southern <span class="hlt">Ocean</span> coccolithophores for phytoplankton biomass, net primary productivity and the carbon cycle need to be revisited. Using a regional high-resolution model with an embedded ecosystem module (ROMS-BEC) for the Southern <span class="hlt">Ocean</span> (24-78°S) that has been extended to include an explicit representation of coccolithophores, we assess the environmental drivers of Southern <span class="hlt">Ocean</span> coccolithophore biogeography over the course of the growing season. We thereby focus on biotic interactions and the relative importance of top-down (grazing) versus bottom-up factors (light, nutrient, temperature) controlling growth and abundance. In our simulation, coccolithophores are an important member of the Southern <span class="hlt">Ocean</span> phytoplankton community, contributing 13% to annually integrated net primary productivity south of 30°S. We estimate the integrated annual calcification rate to account for 40% of the satellite derived <span class="hlt">global</span> estimate. Modeled coccolithophore biomass is highest in February and March in a latitudinal band between 40-55°S, when diatoms become heavily silicate limited. This region is characterized by a number of divergent fronts with a low Si:Fe ratio of waters supplied to the mixed layer, supporting an increased growth of coccolithophores at the expense of diatoms. We find top down controls to be the major control on the relative abundance of diatoms and coccolithophores in the Southern <span class="hlt">Ocean</span>. We perform iron and silicate fertilization experiments to assess the effects of changed nutrient availability on coccolithophore abundance in the GCB. We find that changes in nutrient stoichiometry significantly alter</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030151','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030151"><span>Lithium contents and isotopic compositions of ferromanganese deposits from the <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chan, L.-H.; Hein, J.R.</p> <p>2007-01-01</p> <p>To test the feasibility of using lithium isotopes in marine ferromanganese deposits as an indicator of paleoceanographic conditions and seawater composition, we analyzed samples from a variety of tectonic environments in the <span class="hlt">global</span> <span class="hlt">ocean</span>. Hydrogenetic, hydrothermal, mixed hydrogenetic–hydrothermal, and hydrogenetic–diagenetic samples were subjected to a two-step leaching and dissolution procedure to extract first the loosely bound Li and then the more tightly bound Li in the Mn oxide and Fe oxyhydroxide. Total leachable Li contents vary from 2 by coulombic force. Hence, the abundant Li in hydrothermal deposits is mainly associated with the dominant phase, MnO2. The surface of amorphous FeOOH holds a slightly positive charge and attracts little Li, as demonstrated by data for hydrothermal Fe oxyhydroxide. Loosely sorbed Li in both hydrogenetic crusts and hydrothermal deposits exhibit Li isotopic compositions that resemble that of modern seawater. We infer that the hydrothermally derived Li scavenged onto the surface of MnO2 freely exchanged with ambient seawater, thereby losing its original isotopic signature. Li in the tightly bound sites is always isotopically lighter than that in the loosely bound fraction, suggesting that the isotopic fractionation occurred during formation of chemical bonds in the oxide and oxyhydroxide structures. Sr isotopes also show evidence of re-equilibration with seawater after deposition. Because of their mobility, Li and Sr in the ferromanganese crusts do not faithfully record secular variations in the isotopic compositions of seawater. However, Li content can be a useful proxy for the hydrothermal history of <span class="hlt">ocean</span> basins. Based on the Li concentrations of the <span class="hlt">globally</span> distributed hydrogenetic and hydrothermal samples, we estimate a scavenging flux of Li that is insignificant compared to the hydrothermal flux and river input to the <span class="hlt">ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRII.136....1R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRII.136....1R"><span>Pelagic ecology of the South West Indian <span class="hlt">Ocean</span> Ridge seamounts: Introduction and overview</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rogers, A. D.</p> <p>2017-02-01</p> <p>The Indian <span class="hlt">Ocean</span> was described by Behrman (1981) as the "Forlorn <span class="hlt">Ocean</span>", a region neglected by science up to the late-1950s. For example, the Challenger Expedition from 1872 to 1876 largely avoided the Indian <span class="hlt">Ocean</span>, sailing from Cape Town into Antarctic waters sampling around the Prince Edward Islands, Kerguelen Island and Crozet Islands before heading to Melbourne. From 1876 to the 1950s there were expeditions on several vessels including the Valdivia, Gauss and Planet (Germany), the Snellius (Netherlands), Discovery II, MahaBiss (United Kingdom), Albatross (Sweden), Dana and Galathea (Denmark; Behrman, 1981). There was no coordination between these efforts and overall the Indian <span class="hlt">Ocean</span>, especially the deep sea remained perhaps the most poorly explored of the world's <span class="hlt">oceans</span>. This situation was largely behind the multilateral effort represented by the International Indian <span class="hlt">Ocean</span> Expedition (IIEO), which was coordinated by the Scientific Committee for <span class="hlt">Ocean</span> Research (SCOR), and which ran from 1959-1965. Work during this expedition focused on the Arabian Sea, the area to the northwest of Australia and the waters over the continental shelves and slopes of coastal states in the region. Subsequently several large-scale international oceanographic programmes have included significant components in the Indian <span class="hlt">Ocean</span>, including the <span class="hlt">Joint</span> <span class="hlt">Global</span> <span class="hlt">Ocean</span> Flux Study (JGOFS) and the World <span class="hlt">Ocean</span> Circulation Experiment (WOCE). These studies were focused on physical oceanographic measurements and biogeochemistry and whilst the Indian <span class="hlt">Ocean</span> is still less understood than other large <span class="hlt">oceans</span> it is now integrated into the major <span class="hlt">ocean</span> observation systems (Talley et al., 2011). This cannot be said for many aspects of the biology of the region, despite the fact that the Indian <span class="hlt">Ocean</span> is one of the places where exploitation of marine living resources is still growing (FAO, 2016). The biology of the deep Indian <span class="hlt">Ocean</span> outside of the Arabian Sea is particularly poorly understood given the presence</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA482695','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA482695"><span>The ARGO Project: <span class="hlt">Global</span> <span class="hlt">Ocean</span> Observations for Understanding and Prediction of Climate Variability. Report for Calendar Year 2004</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2004-01-01</p> <p>international Argo practices. Data appropriate for research applications and for comparison with climate change models are not available for several...<span class="hlt">global</span> <span class="hlt">ocean</span> heat and fresh water storage and the detection and attribution of climate change . These presentations can be accessed at http...stresses on <span class="hlt">ocean</span> ecosystems have serious consequences, and sometimes dramatic ones, such as coral reef bleaching . In the future, the impacts of a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760013479&hterms=oceans+tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Doceans%2Btide','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760013479&hterms=oceans+tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Doceans%2Btide"><span><span class="hlt">Ocean</span> tides</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hendershott, M. C.</p> <p>1975-01-01</p> <p>A review of recent developments in the study of <span class="hlt">ocean</span> tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the <span class="hlt">ocean</span>; the resonant frequencies and Q factors of <span class="hlt">oceanic</span> normal modes; the relationship of earth tides and <span class="hlt">ocean</span> tides; and numerical <span class="hlt">global</span> tidal models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020028892&hterms=Kaufman+martin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DKaufman%2Bmartin','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020028892&hterms=Kaufman+martin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DKaufman%2Bmartin"><span>The New MODIS-Terra, and the Proposed COBRA Mission: First <span class="hlt">Global</span> Aerosol Distribution and Properties Over Land and <span class="hlt">Ocean</span>, and Plans to Measure <span class="hlt">Global</span> Black Carbon Absorption Over the <span class="hlt">Ocean</span> Glint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kaufman, Yoram J.; Tanre, Didier; Remer, Lorraine; Martins, Vanderlei; Schoeberl, Mark; Lau, William K. M. (Technical Monitor)</p> <p>2001-01-01</p> <p>The MODIS instrument was launched on the NASA Terra satellite in Dec. 1999. Since last Oct, the sensor and the aerosol algorithm reached maturity and provide <span class="hlt">global</span> daily retrievals of aerosol optical thickness and properties. MODIS has 36 spectral channels in the visible to IR with resolution down to 250 m. This allows accurate cloud screening and multi-spectral aerosol retrievals. We derive the aerosol optical thickness over the <span class="hlt">ocean</span> and most of the land areas, distinguishing between fine (mainly man-made aerosol) and coarse (mainly natural) aerosol particles. New methods to derive the aerosol absorption of sunlight are also being developed. These measurements are use to track different aerosol sources, transport and the radiative forcing at the top and bottom of the atmosphere. However MODIS or any present satellite sensor cannot measure absorption by Black Carbon over the <span class="hlt">oceans</span>, a critical component in studying climate change and human health. For this purpose we propose the COBRA mission that observes the <span class="hlt">ocean</span> at glint and off glint simultaneously measuring the spectral polarized light and deriving precisely the aerosol absorption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp.2383S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp.2383S"><span>Atmosphere surface storm track response to resolved <span class="hlt">ocean</span> mesoscale in two sets of <span class="hlt">global</span> climate model experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Small, R. Justin; Msadek, Rym; Kwon, Young-Oh; Booth, James F.; Zarzycki, Colin</p> <p>2018-05-01</p> <p>It has been hypothesized that the <span class="hlt">ocean</span> mesoscale (particularly <span class="hlt">ocean</span> fronts) can affect the strength and location of the overlying extratropical atmospheric storm track. In this paper, we examine whether resolving <span class="hlt">ocean</span> fronts in <span class="hlt">global</span> climate models indeed leads to significant improvement in the simulated storm track, defined using low level meridional wind. Two main sets of experiments are used: (i) <span class="hlt">global</span> climate model Community Earth System Model version 1 with non-eddy-resolving standard resolution or with <span class="hlt">ocean</span> eddy-resolving resolution, and (ii) the same but with the GFDL Climate Model version 2. In case (i), it is found that higher <span class="hlt">ocean</span> resolution leads to a reduction of a very warm sea surface temperature (SST) bias at the east coasts of the U.S. and Japan seen in standard resolution models. This in turn leads to a reduction of storm track strength near the coastlines, by up to 20%, and a better location of the storm track maxima, over the western boundary currents as observed. In case (ii), the change in absolute SST bias in these regions is less notable, and there are modest (10% or less) increases in surface storm track, and smaller changes in the free troposphere. In contrast, in the southern Indian <span class="hlt">Ocean</span>, case (ii) shows most sensitivity to <span class="hlt">ocean</span> resolution, and this coincides with a larger change in mean SST as <span class="hlt">ocean</span> resolution is changed. Where the <span class="hlt">ocean</span> resolution does make a difference, it consistently brings the storm track closer in appearance to that seen in ERA-Interim Reanalysis data. Overall, for the range of <span class="hlt">ocean</span> model resolutions used here (1° versus 0.1°) we find that the differences in SST gradient have a small effect on the storm track strength whilst changes in absolute SST between experiments can have a larger effect. The latter affects the land-sea contrast, air-sea stability, surface latent heat flux, and the boundary layer baroclinicity in such a way as to reduce storm track activity adjacent to the western boundary in the N</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS52A..01W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS52A..01W"><span>Detecting anthropogenic climate forcing in the <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wijffels, S. A.</p> <p>2016-12-01</p> <p>Owing to its immense heat capacity, the <span class="hlt">global</span> <span class="hlt">ocean</span> is the fly-wheel of the climate system, absorbing, redistributing and storing heat on long timescales and over great distances. Of the extra heat trapped in the Earth System due to rising greenhouse gases, over 90% is being stored in the <span class="hlt">global</span> <span class="hlt">oceans</span>. Tracking this warming has been challenging due to past changes in the coverage and technology used in past <span class="hlt">ocean</span> observations. Here, I'll review progress in estimating past warming rates and patterns. The warming of Earth's surface is also driving changes in the <span class="hlt">global</span> hydrological cycle, which also intimately involves the <span class="hlt">oceans</span>. <span class="hlt">Global</span> <span class="hlt">ocean</span> salinity changes reveal another footprint of a warming Earth. Some simple model runs that give insight into observed subsurface changes will also be described, along with an update on current warming rates and patterns as tracked by the <span class="hlt">global</span> Argo programme. The prospects for the next advances in broadscale <span class="hlt">ocean</span> monitoring will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930015733','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930015733"><span>World <span class="hlt">Ocean</span> Circulation Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clarke, R. Allyn</p> <p>1992-01-01</p> <p>The <span class="hlt">oceans</span> are an equal partner with the atmosphere in the <span class="hlt">global</span> climate system. The World <span class="hlt">Ocean</span> Circulation Experiment is presently being implemented to improve <span class="hlt">ocean</span> models that are useful for climate prediction both by encouraging more model development but more importantly by providing quality data sets that can be used to force or to validate such models. WOCE is the first oceanographic experiment that plans to generate and to use multiparameter <span class="hlt">global</span> <span class="hlt">ocean</span> data sets. In order for WOCE to succeed, oceanographers must establish and learn to use more effective methods of assembling, quality controlling, manipulating and distributing oceanographic data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP31B2250H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP31B2250H"><span>Uranium isotopes as a potential <span class="hlt">global-ocean</span> redox proxy: a test from the Upper Pennsylvanian Hushpuckney Shale (Kansas, U.S.A.)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herrmann, A. D.; Algeo, T. J.; Gordon, G. W.; Anbar, A. D.</p> <p>2015-12-01</p> <p>Uranium (U) isotope variation in marine sediments has been proposed as a proxy for changes in average <span class="hlt">global-ocean</span> redox conditions. Here, we investigate U isotope variation in the black shale (BS) member of the Hushpuckney Shale (Swope Formation) at two sites ~400 km apart within the Late Paleozoic Midcontinent Sea (LPMS) of North America, with the goal of testing whether sediment δ238U records a <span class="hlt">global-ocean</span> redox signal or local environmental influences. Our results document a spatial gradient of at least 0.25‰ in δ238U within the LPMS, demonstrating that local (probably redox) controls have overprinted any <span class="hlt">global</span> U-isotope signal. Furthermore, the pattern of stratigraphic variation in δ238U in both study cores, with low values (‒0.4 to ‒0.2‰) at the base and top and peak values (+0.4 to +0.65‰) in the middle of the BS, is inconsistent with dominance of a <span class="hlt">global-ocean</span> redox signal because (1) the middle of the BS was deposited at maximum eustatic highstand when euxinic conditions existed most widely within the LPMS and coeval epicontinental seas, and (2) more extensive euxinia should have shifted <span class="hlt">global-ocean</span> seawater δ238U to lower values based on mass-balance principles. On the other hand, the observed δ238U pattern is consistent with a dominant local redox control, with larger U-isotope fractionations associated with more reducing bottom waters. We therefore conclude that U was not removed quantitatively to euxinic facies of the LPMS, and that sediment U-isotope compositions were controlled mainly by local redox and hydrographic factors. Our results imply that U-isotope signals from epicontinental-sea sections must be vetted carefully through analysis of high-resolution datasets at multiple sites in order to validate their potential use as a <span class="hlt">global</span>-seawater redox proxy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRB..123.1736E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRB..123.1736E"><span>The Role of <span class="hlt">Oceanic</span> Transform Faults in Seafloor Spreading: A <span class="hlt">Global</span> Perspective From Seismic Anisotropy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eakin, Caroline M.; Rychert, Catherine A.; Harmon, Nicholas</p> <p>2018-02-01</p> <p>Mantle anisotropy beneath mid-<span class="hlt">ocean</span> ridges and <span class="hlt">oceanic</span> transforms is key to our understanding of seafloor spreading and underlying dynamics of divergent plate boundaries. Observations are sparse, however, given the remoteness of the <span class="hlt">oceans</span> and the difficulties of seismic instrumentation. To overcome this, we utilize the <span class="hlt">global</span> distribution of seismicity along transform faults to measure shear wave splitting of over 550 direct S phases recorded at 56 carefully selected seismic stations worldwide. Applying this source-side splitting technique allows for characterization of the upper mantle seismic anisotropy, and therefore the pattern of mantle flow, directly beneath seismically active transform faults. The majority of the results (60%) return nulls (no splitting), while the non-null measurements display clear azimuthal dependency. This is best simply explained by anisotropy with a near vertical symmetry axis, consistent with mantle upwelling beneath <span class="hlt">oceanic</span> transforms as suggested by numerical models. It appears therefore that the long-term stability of seafloor spreading may be associated with widespread mantle upwelling beneath the transforms creating warm and weak faults that localize strain to the plate boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS53E1087Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS53E1087Z"><span><span class="hlt">Global</span> 3-D model of <span class="hlt">oceanic</span> mercury coupled to carbon biogeochemistry and particle dynamics: application to the transport and fate or riverine mercury</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Y.; Jacob, D. J.; Dutkiewicz, S.; Amos, H. M.; Long, M. S.; Sunderland, E. M.</p> <p>2014-12-01</p> <p>Rivers are estimated to deliver 27 Mmol a-1 of mercury (Hg) to <span class="hlt">ocean</span> margins, which is comparable to the <span class="hlt">global</span> atmospheric deposition flux of Hg to the <span class="hlt">ocean</span>. Previous studies presumed that most of this riverine Hg is sequestered by settling to the coastal regions. However, there has been little investigation of the mechanism and efficiency with which this sequestration takes place, and the implications for riverine influence in different <span class="hlt">ocean</span> regions. Here we develop a <span class="hlt">global</span> 3-D chemical transport model for Hg in the <span class="hlt">ocean</span> (MITgcm-Hg) with ecology (DARWIN model). We track offshore export of the discharged Hg from heterogeneous river systems over different <span class="hlt">ocean</span> regions, and how it is influenced by the interaction of Hg in a variety of geochemical forms with carbon and suspended particles. We constrain our model assumptions with available offshore observations that bear strong riverine signals. Modeling results suggest that some of the riverine Hg is highly refractory, sorbs strongly to particles and does not follow equilibrium partitioning with the dissolved phase. Simulated <span class="hlt">global</span> Hg evasion from riverine sources is 50 times larger without this refractory particulate pool, which results in a total evasion flux two times larger than our current best estimate. Based on a typology system of <span class="hlt">global</span> rivers, we calculate that 10% to 60% of the particulate Hg from different rivers settles in <span class="hlt">ocean</span> margin sediments because of subgrid sedimentation processes. The remaining 7.5 Mmol a-1 (28% of total river discharge) is available for offshore transport, where it undergoes further sedimentation to the shelf (5.3 Mmol a-1) as well as evasion to the atmosphere (0.44 Mmol a-1). Only 1.7 Mmol a-1 (6.4% of the <span class="hlt">global</span> riverine Hg) reaches the open <span class="hlt">ocean</span>, although that fraction varies from 2.6% in East Asia because of the blockage of Korean Peninsula to 25% in east North America facilitated by the Gulf Stream. We find large riverine influences over coastal <span class="hlt">oceans</span> off East Asia</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMDD....8.1337X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMDD....8.1337X"><span>On the use of Schwarz-Christoffel conformal mappings to the grid generation for <span class="hlt">global</span> <span class="hlt">ocean</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, S.; Wang, B.; Liu, J.</p> <p>2015-02-01</p> <p>In this article we propose two conformal mapping based grid generation algorithms for <span class="hlt">global</span> <span class="hlt">ocean</span> general circulation models (OGCMs). Contrary to conventional, analytical forms based dipolar or tripolar grids, the new algorithms are based on Schwarz-Christoffel (SC) conformal mapping with prescribed boundary information. While dealing with the basic grid design problem of pole relocation, these new algorithms also address more advanced issues such as smoothed scaling factor, or the new requirements on OGCM grids arisen from the recent trend of high-resolution and multi-scale modeling. The proposed grid generation algorithm could potentially achieve the alignment of grid lines to coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the generated grids are still orthogonal curvilinear, they can be readily utilized in existing Bryan-Cox-Semtner type <span class="hlt">ocean</span> models. The proposed methodology can also be applied to the grid generation task for regional <span class="hlt">ocean</span> modeling where complex land-<span class="hlt">ocean</span> distribution is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS31A1385K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS31A1385K"><span>The Occurrence of Tidal Hybrid Kelvin-Edge Waves in the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaur, H.; Buijsman, M. C.; Yankovsky, A. E.; Zhang, T.; Jeon, C. H.</p> <p>2017-12-01</p> <p>This study presents the analysis of hybrid Kelvin-edge waves on the continental shelves in a <span class="hlt">global</span> <span class="hlt">ocean</span> model. Our objective is to find areas where the transition occurs from Kelvin waves to hybrid Kelvin-edge waves. The change in continental shelf width may convert a Kelvin wave into a hybrid Kelvin-edge wave. In this process the group velocity reaches a minimum and tidal energy is radiated on and/or offshore [Zhang 2016]. We extract M2 SSH (Sea Surface Height) and velocity from the Hybrid Coordinate <span class="hlt">Ocean</span> Model (HYCOM) and calculate barotropic energy fluxes. We analyze these three areas: the Bay of Biscay, the Amazon Shelf and North West Africa. In these three regions, the continental shelf widens in the propagation direction and the alongshore flux changes its direction towards the coast. A transect is taken at different points in these areas to compute the dispersion relations of the waves on the continental shelf. In model simulations, we change the bathymetry of the Bay of Biscay to study the behavior of the hybrid Kelvin-edge waves. BibliographyZhang, T., and A. E Yankovsky. (2016), On the nature of cross-isobath energy fluxes in topographically modified barotropic semidiurnal Kelvin waves, J. Geophys. Res. <span class="hlt">Oceans</span>, 121, 3058-3074, doi:10.1002/2015JC011617.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMOS41A0568G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMOS41A0568G"><span>Simulation of <span class="hlt">global</span> <span class="hlt">oceanic</span> upper layers forced at the surface by an optimal bulk formulation derived from multi-campaign measurements.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garric, G.; Pirani, A.; Belamari, S.; Caniaux, G.</p> <p>2006-12-01</p> <p>order to improve the air/sea interface for the future MERCATOR <span class="hlt">global</span> <span class="hlt">ocean</span> operational system, we have implemented the new bulk formulation developed by METEO-FRANCE (French Meteo office) in the MERCATOR 2 degree <span class="hlt">global</span> <span class="hlt">ocean</span>-ice coupled model (ORCA2/LIM). A single bulk formulation for the drag, temperature and moisture exchange coefficients is derived from an extended consistent database gathering 10 years of measurements issued from five experiments dedicated to air-sea fluxes estimates (SEMAPHORE, CATCH, FETCH, EQUALANT99 and POMME) in various <span class="hlt">oceanic</span> basins (from Northern to equatorial Atlantic). The available database (ALBATROS) cover the widest range of atmospheric and <span class="hlt">oceanic</span> conditions, from very light (0.3 m/s) to very strong (up to 29 m/s) wind speeds, and from unstable to extremely stable atmospheric boundary layer stratification. We have defined a work strategy to test this new formulation in a <span class="hlt">global</span> <span class="hlt">oceanic</span> context, by using this multi- campaign bulk formulation to derive air-sea fluxes from base meteorological variables produces by the ECMWF (European Centre for Medium Range and Weather Forecast) atmospheric forecast model, in order to get surface boundary conditions for ORCA2/LIM. The simulated <span class="hlt">oceanic</span> upper layers forced at the surface by the previous air/sea interface are compared to those forced by the optimal bulk formulation. Consecutively with generally weaker transfer coefficient, the latter formulation reduces the cold bias in the equatorial Pacific and increases the too weak summer sea ice extent in Antarctica. Compared to a recent mixed layer depth (MLD) climatology, the optimal bulk formulation reduces also the too deep simulated MLDs. Comparison with in situ temperature and salinity profiles in different areas allowed us to evaluate the impact of changing the air/sea interface in the vertical structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6303M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6303M"><span>Baroclinic stabilization effect of the Atlantic-Arctic water exchange simulated by the eddy-permitting <span class="hlt">ocean</span> model and <span class="hlt">global</span> atmosphere-<span class="hlt">ocean</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moshonkin, Sergey; Bagno, Alexey; Gritsun, Andrey; Gusev, Anatoly</p> <p>2017-04-01</p> <p>Numerical experiments were performed with the <span class="hlt">global</span> atmosphere-<span class="hlt">ocean</span> model INMCM5 (for version of the international project CMIP6, resolution for atmosphere is 2°x1.5°, 21 level) and with the three-dimensional, free surface, sigma coordinate eddy-permitting <span class="hlt">ocean</span> circulation model for Atlantic (from 30°S) - Arctic and Bering sea domain (0.25 degrees resolution, Institute of Numerical Mathematics <span class="hlt">Ocean</span> Model or INMOM). Spatial resolution of the INMCM5 <span class="hlt">oceanic</span> component is 0.5°x0.25°. Both models have 40 s-levels in <span class="hlt">ocean</span>. Previously, the simulations were carried out for INMCM5 to generate climatic system stable state. Then model was run for 180 years. In the experiment with INMOM, CORE-II data for 1948-2009 were used. As the goal for comparing results of two these numerical models, we selected evolution of the density and velocity anomalies in the 0-300m active <span class="hlt">ocean</span> layer near Fram Strait in the Greenland Sea, where <span class="hlt">oceanic</span> cyclonic circulation influences Atlantic-Arctic water exchange. Anomalies were count without climatic seasonal cycle for time scales smaller than 30 years. We use Singular Value Decomposition analysis (SVD) for density-velocity anomalies with time lag from minus one to six months. Both models perform identical stable physical result. They reveal that changes of heat and salt transports by West Spitsbergen and East Greenland currents, caused by atmospheric forcing, produce the baroclinic modes of velocity anomalies in 0-300m layer, thereby stabilizing <span class="hlt">ocean</span> response on the atmospheric forcing, which stimulates keeping water exchange between the North Atlantic and Arctic <span class="hlt">Ocean</span> at the certain climatological level. The first SVD-mode of density-velocity anomalies is responsible for the cyclonic circulation variability. The second and third SVD-modes stabilize existing <span class="hlt">ocean</span> circulation by the anticyclonic vorticity generation. The second and third SVD-modes give 35% of the input to the total dispersion of density anomalies and 16-18% of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.2120A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.2120A"><span>Development of an eddy-resolving reanalysis using the 1/12° <span class="hlt">global</span> HYbrid Coordinate <span class="hlt">Ocean</span> Model and the Navy Coupled <span class="hlt">Ocean</span> Data Assimilation Scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allard, Richard; Metzger, E. Joseph; Broome, Robert; Franklin, Deborah; Smedstad, Ole Martin; Wallcraft, Alan</p> <p>2013-04-01</p> <p>Multiple international agencies have performed atmospheric reanalyses using static dynamical models and assimilation schemes while ingesting all available quality controlled observational data. Some are clearly aimed at climate time scales while others focus on the more recent time period in which assimilated satellite data are used to constrain the system. Typically these are performed at horizontal and vertical resolutions that are coarser than the existing operational atmospheric prediction system. Multiple agencies have also performed <span class="hlt">ocean</span> reanalyses using some of the atmospheric forcing products described above. However, only a few are eddy-permitting and none are capable of resolving <span class="hlt">oceanic</span> mesoscale features (eddies and current meanders) across the entire globe. To fill this void, the Naval Research Laboratory is performing an eddy-resolving 1993-2010 <span class="hlt">ocean</span> reanalysis using the 1/12° <span class="hlt">global</span> HYbrid Coordinate <span class="hlt">Ocean</span> Model (HYCOM) that employs the Navy Coupled <span class="hlt">Ocean</span> Data Assimilation (NCODA) scheme. A 1/12° <span class="hlt">global</span> HYCOM/NCODA prediction system has been running in real-time at the Naval Oceanographic Office (NAVOCEANO) since 22 December 2006. It has undergone operational testing and will become an operational product by early 2013. It is capable of nowcasting and forecasting the <span class="hlt">oceanic</span> "weather" which includes the 3D <span class="hlt">ocean</span> temperature, salinity and current structure, the surface mixed layer, and the location of mesoscale features such as eddies, meandering currents and fronts. The system has a mid-latitude resolution of ~7 km and employs 32 hybrid vertical coordinate surfaces. Compared to traditional isopycnal coordinate models, the hybrid vertical coordinate extends the geographic range of applicability toward shallow coastal seas and the unstratified parts of the world <span class="hlt">ocean</span>. HYCOM contains a built-in thermodynamic ice model, where ice grows and melts due to heat flux and sea surface temperature (SST) changes, but it does not contain advanced rheological</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMED11D..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMED11D..03S"><span><span class="hlt">Global</span> Climate Change and <span class="hlt">Ocean</span> Education</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spitzer, W.; Anderson, J.</p> <p>2011-12-01</p> <p>The New England Aquarium, collaborating with other aquariums across the country, is leading a national effort to enable aquariums and related informal science education institutions to effectively communicate the impacts of climate change and <span class="hlt">ocean</span> acidification on marine animals, habitats and ecosystems. Our goal is to build on visitors' emotional connection with <span class="hlt">ocean</span> animals, connect to their deeply held values, help them understand causes and effects of climate change and motivate them to embrace effective solutions. Our objectives are to: (1) Build a national coalition of aquariums and related informal education institutions collaborating on climate change education; (2) Develop an interpretive framework for climate change and the <span class="hlt">ocean</span> that is scientifically sound, research-based, field tested and evaluated; and (3) Build capacity of aquariums to interpret climate change via training for interpreters, interactive exhibits and activities and communities of practice for ongoing support. Centers of informal learning have the potential to bring important environmental issues to the public by presenting the facts, explaining the science, connecting with existing values and interests, and motivating concern and action. Centers that work with live animals (including aquariums, zoos, nature centers, national parks, national marine sanctuaries, etc.) are unique in that they attract large numbers of people of all ages (over 140 million in the US), have strong connections to the natural, and engage many visitors who may not come with a primary interest in science. Recent research indicates that that the public expects and trusts aquariums, zoos, and museums to communicate solutions to environmental and <span class="hlt">ocean</span> issues, and to advance <span class="hlt">ocean</span> conservation, and that climate change is the environmental issue of most concern to the public; Ironically, however, most people do not associate climate change with <span class="hlt">ocean</span> health, or understand the critical role that the <span class="hlt">ocean</span> plays in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=strategic+AND+business+AND+leader&pg=7&id=ED523165','ERIC'); return false;" href="https://eric.ed.gov/?q=strategic+AND+business+AND+leader&pg=7&id=ED523165"><span>One Mission-Centered, Market-Smart <span class="hlt">Globalization</span> Response: A Case Study of the Georgia Tech-Emory University Biomedical Engineering Curricular <span class="hlt">Joint</span> Venture</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Burriss, Annie Hunt</p> <p>2010-01-01</p> <p>One innovative, higher-education response to <span class="hlt">globalization</span> and changing fiscal realities is the curricular <span class="hlt">joint</span> venture (CJV), a formal collaboration between academic institutions that leverages missions through new <span class="hlt">joint</span> degrees and research not previously offered by collaborating institutions (Eckel, 2003). In 1997, a pioneering biomedical…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050160213','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050160213"><span>Role of the Polar <span class="hlt">Oceans</span> in <span class="hlt">Global</span> Climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rothrock, D. A.</p> <p>2003-01-01</p> <p>The project focused on ice-<span class="hlt">ocean</span> model development and in particular on the assimilation of ice motion data and ice concentration data into both regional and <span class="hlt">global</span> models. Many of the resulting publications below deal with improvements made in the physics treated by the model and the procedures for assimilating data. Several papers examine how the ability of the model to simulate the past behavior of the ice cover, especially to represent the ice thickness and ice deformation, is improved by data assimilation. A second aspect of the work involved interpretation of modeled behavior. Resulting papers treat the decline of arctic ice thickness over the last thirty years, and how that decline was caused by a slight warming of the near-surface atmosphere, and also how large variation in ice thickness are due to changes in wind patterns associated with a well- known oscillation of the atmospheric circulation. The research resulted in over 20 published papers on these topics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008jsrs.meet..188K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008jsrs.meet..188K"><span>Geophysical excitation of LOD/UT1 estimated from the output of the <span class="hlt">global</span> circulation models of the atmosphere - ERA-40 reanalysis and of the <span class="hlt">ocean</span> - OMCT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korbacz, A.; Brzeziński, A.; Thomas, M.</p> <p>2008-04-01</p> <p>We use new estimates of the <span class="hlt">global</span> atmospheric and <span class="hlt">oceanic</span> angular momenta (AAM, OAM) to study the influence on LOD/UT1. The AAM series was calculated from the output fields of the atmospheric general circulation model ERA-40 reanalysis. The OAM series is an outcome of <span class="hlt">global</span> <span class="hlt">ocean</span> model OMCT simulation driven by <span class="hlt">global</span> fields of the atmospheric parameters from the ERA- 40 reanalysis. The excitation data cover the period between 1963 and 2001. Our calculations concern atmospheric and <span class="hlt">oceanic</span> effects in LOD/UT1 over the periods between 20 days and decades. Results are compared to those derived from the alternative AAM/OAM data sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AdAtS..33..208Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AdAtS..33..208Z"><span>Evaluation of the tropical variability from the Beijing Climate Center's real-time operational <span class="hlt">global</span> <span class="hlt">Ocean</span> Data Assimilation System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Wei; Chen, Mengyan; Zhuang, Wei; Xu, Fanghua; Zheng, Fei; Wu, Tongwen; Wang, Xin</p> <p>2016-02-01</p> <p>The second-generation <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Assimilation System of the Beijing Climate Center (BCC GODAS2.0) has been run daily in a pre-operational mode. It spans the period 1990 to the present day. The goal of this paper is to introduce the main components and to evaluate BCC GODAS2.0 for the user community. BCC GODAS2.0 consists of an observational data preprocess, <span class="hlt">ocean</span> data quality control system, a three-dimensional variational (3DVAR) data assimilation, and <span class="hlt">global</span> <span class="hlt">ocean</span> circulation model [Modular <span class="hlt">Ocean</span> Model 4 (MOM4)]. MOM4 is driven by six-hourly fluxes from the National Centers for Environmental Prediction. Satellite altimetry data, SST, and in-situ temperature and salinity data are assimilated in real time. The monthly results from the BCC GODAS2.0 reanalysis are compared and assessed with observations for 1990-2011. The climatology of the mixed layer depth of BCC GODAS2.0 is generally in agreement with that ofWorld <span class="hlt">Ocean</span> Atlas 2001. The modeled sea level variations in the tropical Pacific are consistent with observations from satellite altimetry on interannual to decadal time scales. Performances in predicting variations in the SST using BCC GODAS2.0 are evaluated. The standard deviation of the SST in BCC GODAS2.0 agrees well with observations in the tropical Pacific. BCC GODAS2.0 is able to capture the main features of El Ni˜no Modoki I and Modoki II, which have different impacts on rainfall in southern China. In addition, the relationships between the Indian <span class="hlt">Ocean</span> and the two types of El Ni˜no Modoki are also reproduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JGR...10321355W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JGR...10321355W"><span><span class="hlt">Global</span> upper <span class="hlt">ocean</span> heat storage response to radiative forcing from changing solar irradiance and increasing greenhouse gas/aerosol concentrations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>White, Warren B.; Cayan, Daniel R.; Lean, Judith</p> <p>1998-09-01</p> <p>We constructed gridded fields of diabatic heat storage changes in the upper <span class="hlt">ocean</span> from 20°S to 60°N from historical temperature profiles collected from 1955 to 1996. We filtered these 42 year records for periods of 8 to 15 years and 15 to 30 years, producing depth-weighted vertical average temperature (DVT) changes from the sea surface to the top of the main pycnocline. Basin and <span class="hlt">global</span> averages of these DVT changes reveal decadal and interdecadal variability in phase across the Indian, Pacific, Atlantic, and <span class="hlt">Global</span> <span class="hlt">Oceans</span>, each significantly correlated with changing surface solar radiative forcing at a lag of 0+/-2 years. Decadal and interdecadal changes in <span class="hlt">global</span> average DVT are 0.06°+/-0.01°K and 0.04°K+/-0.01°K, respectively, the same as those expected from consideration of the Stefan-Boltzmann radiation balance (i.e., 0.3°K per Wm-2) in response to 0.1% changes in surface solar radiative forcing of 0.2 Wm-2 and 0.15 Wm-2, respectively. <span class="hlt">Global</span> spatial patterns of DVT changes are similar to temperature changes simulated in coupled <span class="hlt">ocean</span>-atmosphere models, suggesting that natural modes of Earth's variability are phase-locked to the solar irradiance cycle. A trend in <span class="hlt">global</span> average DVT of 0.15°K over this 42 year record cannot be explained by changing surface solar radiative forcing. But when we consider the 0.5 Wm-2 increase in surface radiative forcing estimated from the increase in atmospheric greenhouse gas and aerosol (GGA) concentrations over this period [Intergovernmental Panel on Climate Change, 1995], the Stefan-Boltzmann radiation balance yields this observed change. Moreover, the sum of solar and GGA surface radiative forcing can explain the relatively sharp increase in <span class="hlt">global</span> and basin average DVT in the late 1970's.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT........43G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT........43G"><span>Classification and <span class="hlt">global</span> distribution of <span class="hlt">ocean</span> precipitation types based on satellite passive microwave signatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gautam, Nitin</p> <p></p> <p>The main objectives of this thesis are to develop a robust statistical method for the classification of <span class="hlt">ocean</span> precipitation based on physical properties to which the SSM/I is sensitive and to examine how these properties vary <span class="hlt">globally</span> and seasonally. A two step approach is adopted for the classification of <span class="hlt">oceanic</span> precipitation classes from multispectral SSM/I data: (1)we subjectively define precipitation classes using a priori information about the precipitating system and its possible distinct signature on SSM/I data such as scattering by ice particles aloft in the precipitating cloud, emission by liquid rain water below freezing level, the difference of polarization at 19 GHz-an indirect measure of optical depth, etc.; (2)we then develop an objective classification scheme which is found to reproduce the subjective classification with high accuracy. This hybrid strategy allows us to use the characteristics of the data to define and encode classes and helps retain the physical interpretation of classes. The classification methods based on k-nearest neighbor and neural network are developed to objectively classify six precipitation classes. It is found that the classification method based neural network yields high accuracy for all precipitation classes. An inversion method based on minimum variance approach was used to retrieve gross microphysical properties of these precipitation classes such as column integrated liquid water path, column integrated ice water path, and column integrated min water path. This classification method is then applied to 2 years (1991-92) of SSM/I data to examine and document the seasonal and <span class="hlt">global</span> distribution of precipitation frequency corresponding to each of these objectively defined six classes. The characteristics of the distribution are found to be consistent with assumptions used in defining these six precipitation classes and also with well known climatological patterns of precipitation regions. The seasonal and <span class="hlt">global</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033839','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033839"><span>Pliocene three-dimensional <span class="hlt">global</span> <span class="hlt">ocean</span> temperature reconstruction</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dowsett, H.J.; Robinson, M.M.; Foley, K.M.</p> <p>2009-01-01</p> <p>A snapshot of the thermal structure of the mid-Piacenzian <span class="hlt">ocean</span> is obtained by combining the Pliocene Research, Interpretation and Synoptic Mapping Project (PRISM3) multiproxy sea-surface temperature (SST) reconstruction with bottom water tempera-5 ture estimates produced using Mg/Ca paleothermometry. This reconstruction assumes a Pliocene water mass framework similar to that which exists today, with several important modifications. The area of formation of present day North Atlantic Deep Water (NADW) was expanded and extended further north toward the Arctic <span class="hlt">Ocean</span> during the mid-Piacenzian relative to today. This, combined with a deeper Greenland-Scotland Ridge, allowed a greater volume of warmer NADW to enter the Atlantic <span class="hlt">Ocean</span>. In the Southern <span class="hlt">Ocean</span>, the Polar Front Zone was expanded relative to present day, but shifted closer to the Antarctic continent. This, combined with at least seasonal reduction in sea ice extent, resulted in decreased Antarctic BottomWater (AABW) production (relative to present day) as well as possible changes in the depth of intermediate wa15 ters. The reconstructed mid-Piacenzian three-dimensional <span class="hlt">ocean</span> was warmer overall than today, and the hypothesized aerial extent of water masses appears to fit the limited stable isotopic data available for this time period. ?? Author(s) 2009.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy...50.2471W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy...50.2471W"><span>Consensuses and discrepancies of basin-scale <span class="hlt">ocean</span> heat content changes in different <span class="hlt">ocean</span> analyses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Gongjie; Cheng, Lijing; Abraham, John; Li, Chongyin</p> <p>2018-04-01</p> <p>Inconsistent <span class="hlt">global</span>/basin <span class="hlt">ocean</span> heat content (OHC) changes were found in different <span class="hlt">ocean</span> subsurface temperature analyses, especially in recent studies related to the slowdown in <span class="hlt">global</span> surface temperature rise. This finding challenges the reliability of the <span class="hlt">ocean</span> subsurface temperature analyses and motivates a more comprehensive inter-comparison between the analyses. Here we compare the OHC changes in three <span class="hlt">ocean</span> analyses (Ishii, EN4 and IAP) to investigate the uncertainty in OHC in four major <span class="hlt">ocean</span> basins from decadal to multi-decadal scales. First, all products show an increase of OHC since 1970 in each <span class="hlt">ocean</span> basin revealing a robust warming, although the warming rates are not identical. The geographical patterns, the key modes and the vertical structure of OHC changes are consistent among the three datasets, implying that the main OHC variabilities can be robustly represented. However, large discrepancies are found in the percentage of basinal <span class="hlt">ocean</span> heating related to the <span class="hlt">global</span> <span class="hlt">ocean</span>, with the largest differences in the Pacific and Southern <span class="hlt">Ocean</span>. Meanwhile, we find a large discrepancy of <span class="hlt">ocean</span> heat storage in different layers, especially within 300-700 m in the Pacific and Southern <span class="hlt">Oceans</span>. Furthermore, the near surface analysis of Ishii and IAP are consistent with sea surface temperature (SST) products, but EN4 is found to underestimate the long-term trend. Compared with <span class="hlt">ocean</span> heat storage derived from the atmospheric budget equation, all products show consistent seasonal cycles of OHC in the upper 1500 m especially during 2008 to 2012. Overall, our analyses further the understanding of the observed OHC variations, and we recommend a careful quantification of errors in the <span class="hlt">ocean</span> analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PrOce.161...19H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PrOce.161...19H"><span>A window on the deep <span class="hlt">ocean</span>: The special value of <span class="hlt">ocean</span> bottom pressure for monitoring the large-scale, deep-<span class="hlt">ocean</span> circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, Chris W.; Williams, Joanne; Blaker, Adam; Coward, Andrew; Stepanov, Vladimir</p> <p>2018-02-01</p> <p>We show how, by focusing on bottom pressure measurements particularly on the <span class="hlt">global</span> continental slope, it is possible to avoid the "fog" of mesoscale variability which dominates most observables in the deep <span class="hlt">ocean</span>. This makes it possible to monitor those aspects of the <span class="hlt">ocean</span> circulation which are most important for <span class="hlt">global</span> scale <span class="hlt">ocean</span> variability and climate. We therefore argue that such measurements should be considered an important future component of the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Observing System, to complement the present open-<span class="hlt">ocean</span> and coastal elements. Our conclusions are founded on both theoretical arguments, and diagnostics from a fine-resolution <span class="hlt">ocean</span> model that has realistic amplitudes and spectra of mesoscale variability. These show that boundary pressure variations are coherent over along-slope distances of tens of thousands of kilometres, for several vertical modes. We illustrate the value of this in the model Atlantic, by determining the time for boundary and equatorial waves to complete a circuit of the northern basin (115 and 205 days for the first and second vertical modes), showing how the boundary features compare with basin-scale theoretical models, and demonstrating the ability to monitor the meridional overturning circulation using these boundary measurements. Finally, we discuss applicability to the real <span class="hlt">ocean</span> and make recommendations on how to make such measurements without contamination from instrumental drift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1344036-response-tropical-pacific-ocean-el-nino-versus-global-warming','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1344036-response-tropical-pacific-ocean-el-nino-versus-global-warming"><span>Response of the tropical Pacific <span class="hlt">Ocean</span> to El Niño versus <span class="hlt">global</span> warming</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Liu, Fukai; Luo, Yiyong; Lu, Jian</p> <p></p> <p>Climate models project an El Niño-like SST response in the tropical Pacific <span class="hlt">Ocean</span> to <span class="hlt">global</span> warming (GW). By employing the Community Earth System Model (CESM) and applying an overriding technique to its <span class="hlt">ocean</span> component, Parallel <span class="hlt">Ocean</span> Program version 2 (POP2), this study investigates the similarity and difference of formation mechanism for the changes in the tropical Pacific <span class="hlt">Ocean</span> under El Niño and GW. Results show that, despite sharing some similarities between the two scenarios, there are many significant distinctions between GW and El Niño: 1) the phase locking of the seasonal cycle reduction is more notable under GW compared withmore » El Niño, implying more extreme El Niño events in the future; 2) in contrast to the penetration of the equatorial subsurface temperature anomaly that appears to propagate in the form of an <span class="hlt">oceanic</span> equatorial upwelling Kelvin wave during El Niño, the GW-induced subsurface temperature anomaly manifest in the form of off-equatorial upwelling Rossby waves; 3) while significant across-equator northward heat transport (NHT) is induced by the wind stress anomalies associated with El Niño, little NHT is found at the equator due to a symmetric change in the shallow meridional overturning circulation that appears to be weakened in both North and South Pacific under GW; and 4) the maintaining mechanisms for the eastern equatorial Pacific warming are also substantially different.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9971E..1JP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9971E..1JP"><span>Scene-aware <span class="hlt">joint</span> <span class="hlt">global</span> and local homographic video coding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peng, Xiulian; Xu, Jizheng; Sullivan, Gary J.</p> <p>2016-09-01</p> <p>Perspective motion is commonly represented in video content that is captured and compressed for various applications including cloud gaming, vehicle and aerial monitoring, etc. Existing approaches based on an eight-parameter homography motion model cannot deal with this efficiently, either due to low prediction accuracy or excessive bit rate overhead. In this paper, we consider the camera motion model and scene structure in such video content and propose a <span class="hlt">joint</span> <span class="hlt">global</span> and local homography motion coding approach for video with perspective motion. The camera motion is estimated by a computer vision approach, and camera intrinsic and extrinsic parameters are <span class="hlt">globally</span> coded at the frame level. The scene is modeled as piece-wise planes, and three plane parameters are coded at the block level. Fast gradient-based approaches are employed to search for the plane parameters for each block region. In this way, improved prediction accuracy and low bit costs are achieved. Experimental results based on the HEVC test model show that up to 9.1% bit rate savings can be achieved (with equal PSNR quality) on test video content with perspective motion. Test sequences for the example applications showed a bit rate savings ranging from 3.7 to 9.1%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45..267P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45..267P"><span>The <span class="hlt">Global</span> Signature of <span class="hlt">Ocean</span> Wave Spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Portilla-Yandún, Jesús</p> <p>2018-01-01</p> <p>A <span class="hlt">global</span> atlas of <span class="hlt">ocean</span> wave spectra is developed and presented. The development is based on a new technique for deriving wave spectral statistics, which is applied to the extensive ERA-Interim database from European Centre of Medium-Range Weather Forecasts. Spectral statistics is based on the idea of long-term wave systems, which are unique and distinct at every geographical point. The identification of those wave systems allows their separation from the overall spectrum using the partition technique. Their further characterization is made using standard integrated parameters, which turn out much more meaningful when applied to the individual components than to the total spectrum. The parameters developed include the density distribution of spectral partitions, which is the main descriptor; the identified wave systems; the individual distribution of the characteristic frequencies, directions, wave height, wave age, seasonal variability of wind and waves; return periods derived from extreme value analysis; and crossing-sea probabilities. This information is made available in web format for public use at http://www.modemat.epn.edu.ec/#/nereo. It is found that wave spectral statistics offers the possibility to synthesize data while providing a direct and comprehensive view of the local and regional wave conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040182378&hterms=ocean+climate+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Docean%2Bclimate%2Bchanges','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040182378&hterms=ocean+climate+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Docean%2Bclimate%2Bchanges"><span>The Application of Jason-1 Measurements to Estimate the <span class="hlt">Global</span> Near Surface <span class="hlt">Ocean</span> Circulation for Climate Research</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Niiler, Peran P.</p> <p>2004-01-01</p> <p>The scientific objective of this research program was to utilize drifter, Jason-1 altimeter data and a variety of wind data for the determination of time mean and time variable wind driven surface currents of the <span class="hlt">global</span> <span class="hlt">ocean</span>. To accomplish this task has required the interpolation of 6-hourly winds on drifter tracks and the computation of the wind coherent motions of the drifters. These calculations showed that the Ekman current model proposed by Ralph and Niiler for the tropical Pacific was valid for all the <span class="hlt">oceans</span> south of 40N latitude. Improvements to RN99 model were computed and poster presentations of the results were given in several <span class="hlt">ocean</span> science venues, including the November 2004 GODAY meeting in St. Petersburg, FL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMOS33B1647R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMOS33B1647R"><span>IMBER (Integrated Marine Biogeochemistry and Ecosystem Research: Support of <span class="hlt">Ocean</span> Carbon Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rimetz-Planchon, J.; Gattuso, J.; Maddison, L.; Bakker, D. C.; Gruber, N.</p> <p>2011-12-01</p> <p>IMBER (Integrated Marine Biogeochemistry and Ecosystem Research), co-sponsored by SCOR (Scientific Committee on <span class="hlt">Oceanic</span> Research) and IGBP (International Geosphere-Biosphere Programme), coordinates research that focuses on understanding and predicting changes in <span class="hlt">oceanic</span> food webs and biogeochemical cycles that arise from <span class="hlt">global</span> change. An integral part of this overall goal is to understand the marine carbon cycle, with emphasis on changes that may occur as a result of a changing climate, increased atmospheric CO2 levels and/or reduced <span class="hlt">oceanic</span> pH. To address these key <span class="hlt">ocean</span> carbon issues, IMBER and SOLAS (Surface <span class="hlt">Ocean</span> Lower Atmosphere Study), formed the <span class="hlt">joint</span> SOLAS-IMBER Carbon, or SIC Working Group. The SIC Working Group activities are organised into three sub-groups. Sub-group 1 (Surface <span class="hlt">Ocean</span> Systems) focuses on synthesis, instrumentation and technology development, VOS (Voluntary Observing Ships) and mixed layer sampling strategies. The group contributed to the development of SOCAT (Surface <span class="hlt">Ocean</span> CO2 Atlas, www.socat.info), a <span class="hlt">global</span> compilation of underway surface water fCO2 (fugacity of CO2) data in common format. It includes 6.3 million measurements from 1767 cruises from 1968 and 2008 by more than 10 countries. SOCAT will be publically available and will serve a wide range of user communities. Its public release is planned for September 2011. SOCAT is strongly supported by IOCCP and CARBOOCEAN. Sub-group 2 (Interior <span class="hlt">Ocean</span> Carbon Storage) covers inventory and observations, natural variability, transformation and interaction with modelling. It coordinated a review of vulnerabilities of the decadal variations of the interior <span class="hlt">ocean</span> carbon and oxygen cycle. It has also developed a plan to add dissolved oxygen sensors to the ARGO float program in order to address the expected loss of oxygen as a result of <span class="hlt">ocean</span> warming. The group also focuses on the <span class="hlt">global</span> synthesis of <span class="hlt">ocean</span> interior carbon observations to determine the <span class="hlt">oceanic</span> uptake of anthropogenic CO2 since</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5623C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5623C"><span>Structure of analysis-minus-observation misfits within a <span class="hlt">global</span> <span class="hlt">ocean</span> reanalysis system: implications for atmospheric reanalyses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carton, James; Chepurin, Gennady</p> <p>2017-04-01</p> <p>While atmospheric reanalyses do not ingest data from the subsurface <span class="hlt">ocean</span> they must produce fluxes consistent with, for example, <span class="hlt">ocean</span> storage and divergence of heat transport. Here we present a test of the consistency of two different atmospheric reanalyses with 2.5 million <span class="hlt">global</span> <span class="hlt">ocean</span> temperature observations during the data-rich eight year period 2007-2014. The examination is carried out by using atmospheric reanalysis variables to drive the SODA3 <span class="hlt">ocean</span> reanalysis system, and then collecting and analyzing the temperature analysis increments (observation misfits). For the widely used MERRA2 and ERA-Int atmospheric reanalyses the temperature analysis increments reveal inconsistencies between those atmospheric fluxes and the <span class="hlt">ocean</span> observations in the range of 10-30 W/m2. In the interior basins excess heat during a single assimilation cycle is stored primarily locally within the mixed layer, a simplification of the heat budget that allows us to identify the source of the error as the specified net surface heat flux. Along the equator the increments are primarily confined to thermocline depths indicating the primary source of the error is dominated by heat transport divergence. The error in equatorial heat transport divergence, in turn, can be traced to errors in the strength of the equatorial trade winds. We test our conclusions by introducing modifications of the atmospheric reanalyses based on analysis of <span class="hlt">ocean</span> temperature analysis increments and repeating the <span class="hlt">ocean</span> reanalysis experiments using the modified surface fluxes. Comparison of the experiments reveals that the modified fluxes reduce the misfit to <span class="hlt">ocean</span> observations as well as the differences between the different atmospheric reanalyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3617727','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3617727"><span>Bomb fall-out 236U as a <span class="hlt">global</span> <span class="hlt">oceanic</span> tracer using an annually resolved coral core</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Winkler, Stephan R.; Steier, Peter; Carilli, Jessica</p> <p>2012-01-01</p> <p>Anthropogenic 236U (t½=23.4 My) is an emerging isotopic <span class="hlt">ocean</span> tracer with interesting oceanographic properties, but only with recent advances in accelerator mass spectrometry techniques is it now possible to detect the levels from <span class="hlt">global</span> fall-out of nuclear weapons testing across the water column. To make full use of this tracer, an assessment of its input into the <span class="hlt">ocean</span> over the past decades is required. We captured the bomb-pulse of 236U in an annually resolved coral core record from the Caribbean Sea. We thereby establish a concept which gives 236U great advantage – the presence of reliable, well-resolved chronological archives. This allows studies of not only the present distribution pattern, but gives access to the temporal evolution of 236U in <span class="hlt">ocean</span> waters over the past decades. PMID:23564966</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006EOSTr..87S.582Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006EOSTr..87S.582Z"><span><span class="hlt">Ocean</span> research plan reviewed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zielinski, Sarah</p> <p></p> <p>A draft plan setting out priorities for U.S. <span class="hlt">ocean</span> research generally was lauded for its clear and well-articulated view in a recent report from a committee of the U.S. National Research Council (NRC) of the US. National Academies. However, the committee advised that the plan would benefit from a bold vision for the future of <span class="hlt">ocean</span> science research, additional details, and a reorganization to include cross-cutting research.The draft "Charting the Course for <span class="hlt">Ocean</span> Science in the United States: Research Priorities for the Next Decade" was made available for public comment in September 2006 by the U.S. National Science and Technology Council's <span class="hlt">Joint</span> Subcommittee on <span class="hlt">Ocean</span> Science and Technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMIN34A..08G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMIN34A..08G"><span>A Time Series of Sea Surface Nitrate and Nitrate based New Production in the <span class="hlt">Global</span> <span class="hlt">Oceans</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goes, J. I.; Fargion, G. S.; Gomes, H. R.; Franz, B. A.</p> <p>2014-12-01</p> <p>With support from NASA's MEaSUREs program, we are developing algorithms for two innovative satellite-based Earth Science Data Records (ESDRs), one Sea Surface Nitrate (SSN) and the other, Nitrate based new Production (NnP). Newly developed algorithms will be applied to mature ESDRs of Chlorophyll a and SST available from NASA, to generate maps of SSN and NnP. Our proposed ESDRs offer the potential of greatly improving our understanding of the role of the <span class="hlt">oceans</span> in <span class="hlt">global</span> carbon cycling, earth system processes and climate change, especially for regions and seasons which are inaccessible to traditional shipboard studies. They also provide an innovative means for validating and improving coupled ecosystem models that currently rely on <span class="hlt">global</span> maps of nitrate generated from multi-year data sets. To aid in our algorithm development efforts and to ensure that our ESDRs are truly <span class="hlt">global</span> in nature, we are currently in the process of assembling a large database of nutrients from oceanographic institutions all over the world. Once our products are developed and our algorithms are fine-tuned, large-scale data production will be undertaken in collaboration with NASA's <span class="hlt">Ocean</span> Biology Processing Group (OPBG), who will make the data publicly available first as evaluation products and then as mature ESDRs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B23G0682R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B23G0682R"><span>Revisiting <span class="hlt">ocean</span> carbon sequestration by direct injection: A <span class="hlt">global</span> carbon budget perspective Fabian Reith, David P. Keller & Andreas Oschlies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reith, F.; Keller, D. P.; Martin, T.; Oschlies, A.</p> <p>2015-12-01</p> <p>Marchetti [1977] proposed that CO2 could be directly injected into the deep <span class="hlt">ocean</span> to mitigate its rapid build-up in the atmosphere. Although previous studies have investigated biogeochemical and climatic effects of injecting CO2 into the <span class="hlt">ocean</span>, they have not looked at <span class="hlt">global</span> carbon cycle feedbacks and backfluxes that are important for accounting. Using an Earth System Model of intermediate complexity we simulated the injection of CO2 into the deep <span class="hlt">ocean</span> during a high CO2 emissions scenario. At seven sites 0.1 GtC yr-1 was injected at three different depths (3 separate experiments) between the years 2020 and 2120. After the 100-year injection period, our simulations continued until the year 3020 to assess the long-term dynamics. In addition, we investigated the effects of marine sediment feedbacks during the experiments by running the model with and without a sediment sub-model. Our results, in regards to efficiency (the residence time of injected CO2) and seawater chemistry changes, are similar to previous studies. However, from a carbon budget perspective the targeted cumulative atmospheric CO2 reduction of 70 GtC was never reached. This was caused by the atmosphere-to-terrestrial and/or atmosphere-to-<span class="hlt">ocean</span> carbon fluxes (relative to the control run), which were effected by the reduction in atmospheric carbon. With respect to <span class="hlt">global</span> <span class="hlt">oceanic</span> carbon, the respective carbon cycle-climate feedbacks led to an even smaller efficiency than indicated by tracing the injected CO2. The <span class="hlt">ocean</span> also unexpectedly took up carbon after the injection at 1500 m was stopped because of a deep convection event in the Southern <span class="hlt">Ocean</span>. These findings highlighted that the accounting of CO2 injection would be challenging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ESASP.710E..51P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ESASP.710E..51P"><span><span class="hlt">Global</span> Eddy-Permitting <span class="hlt">Ocean</span> Reanalyses and Simulations of the Period 1992 to Present</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parent, L.; Ferry, N.; Barnier, B.; Garric, G.; Bricaud, C.; Testut, C.-E.; Le Galloudec, O.; Lellouche, J.-M.; Greiner, E.; Drevillon, M.; Remy, E.; Moulines, J.-M.; Guinehut, S.; Cabanes, C.</p> <p>2013-09-01</p> <p>We present GLORYS2V1 <span class="hlt">global</span> <span class="hlt">ocean</span> and sea-ice eddy permitting reanalysis over the altimetric era (1993- 2009). This reanalysis is based on an <span class="hlt">ocean</span> and sea-ice general circulation model at 1⁄4° horizontal resolution assimilating sea surface temperature, in situ profiles of temperature and salinity and along-track sea level anomaly observations. The reanalysis has been produced along with a reference simulation called MJM95 which allows evaluating the benefits of the data assimilation. In the introduction, we briefly describe the GLORYS2V1 reanalysis system. In sections 2, 3 and 4, the reanalysis skill is presented. Data assimilation diagnostics reveal that the reanalysis is stable all along the time period, with however an improved skill when Argo observation network establishes. GLORYS2V1 captures well climate signals and trends and describes meso-scale variability in a realistic manner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912473S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912473S"><span>Adjustments of a <span class="hlt">global</span> Finite-Element Sea Ice <span class="hlt">Ocean</span> Model configuration to improve the general <span class="hlt">ocean</span> circulation in the North Pacific and its marginal seas.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scholz, Patrick; Lohmann, Gerrit</p> <p>2017-04-01</p> <p>The sub-Arctic <span class="hlt">oceans</span> like the Sea of Okhotsk, the Bering Sea, the Labrador Sea or the Greenland- Irminger-Norwegian (GIN) Sea react particularly sensitive to <span class="hlt">global</span> climate changes and have the potential to reversely regulate climate change by CO2 uptake in the other areas of the world. So far, the natural processes in the Arctic and Subarctic system, especially over the Pacific realm, remain poorly understood in terms of numerical modeling. As such, in this study we focus on the North Pacific and its adjacent marginal seas (e.g. the Sea of Okhotsk, the Bering Sea and the Sea of Japan), which have nowadays a significant role in the climate system of the Northwest Pacific by influencing the atmospheric and <span class="hlt">oceanic</span> circulation as well as the hydrology of the Pacific water masses. The Sea of Okhotsk, in particular, is characterized by a highly dynamical sea-ice coverage, where, in autumn and winter, due to massive sea ice formation and brine rejection, the Sea of Okhotsk Intermediate Water (SOIW) is formed which contributes to the mid-depth (500-1000m) water layer of the North Pacific known as newly formed North Pacific Intermediate Water (NPIW). By employing a Finite-Element Sea-Ice <span class="hlt">Ocean</span> Model (FESOM), in a <span class="hlt">global</span> configuration, but with high resolution over the marginal seas of the Northwest Pacific <span class="hlt">Ocean</span> ( 7 km), we tested different meshes and forcing improvements to correct the general <span class="hlt">ocean</span> circulation in the North Pacific realm towards a more realistic pattern. By using different forcing data (e.g. CORE2, ERA-40/interim, CCMP-correction), adapting the mesh resolutions in the tropical and subtropical North Pacific and changing the bathymetry over important inflow straits (e.g. Amukta Passage, Kruzenstern Strait), we show that the better results are obtained (when compared with observational data) via a combination of CCMP corrected COREv2 forcing with increased resolution in the pathway of the Kuroshio Extension Current and Northern Equatorial Current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP21A1241L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP21A1241L"><span>Evolution of organic carbon burial in the <span class="hlt">Global</span> <span class="hlt">Ocean</span> during the Neogene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>LI, Z.; Zhang, Y.</p> <p>2017-12-01</p> <p>Although only a small fraction of the organic carbon (OC) that rains from surface waters is eventually buried in the sediments, it is a process that controls the organic sub-cycle of the long-term carbon cycle, and the key for atmospheric O2, CO2 and nutrient cycling. Here we constrain the spatiotemporal variability of OC burial by quantifying the total organic carbon (TOC) mass accumulation rate (MAR) over the Neogene (23.0-2.6 Ma) by compiling the TOC, age model and sediment density data from sites retrieved by the Deep Sea Drilling Program, <span class="hlt">Ocean</span> Drilling Program, and Integrated <span class="hlt">Ocean</span> Drilling Program. We screened all available sites which yielded 80 sites with adequate data quality, covering all major <span class="hlt">ocean</span> basins and sedimentary depositional environments. All age models are updated to the GTS 2012 timescale so the TOC MAR records from different sites are comparable. Preliminary results show a clear early Miocene peak of OC burial in many sites related to high sediment flux which might reflect the orogenic uplift and/or glacier erosion. Places that receive high influx of terrigenous inputs become "hotspots" for Neogene burial of OC. At "open <span class="hlt">ocean</span>" sites, OC burial seems to be more impacted by marine productivity changes, with a pronounced increase during the middle Miocene "Monterey Formation" and late Miocene - early Pliocene "Biogenic Bloom". Upon the completion of the data collection, we will further explore the regional and <span class="hlt">global</span> OC burial in the context of tectonic uplift, climate change and the evolution of primary producers and consumers during the last 23 million years of Earth history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.5822D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.5822D"><span>Iron Resources and <span class="hlt">Oceanic</span> Nutrients - Advancement of <span class="hlt">Global</span> Environment Simulations (ironages)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Baar, H. J. W.; Ironages Team</p> <p></p> <p>Iron limits productivity in 40 percent of the <span class="hlt">oceans</span>, and is a co-limitation in the re- maining 60 percent of surface waters. Moreover the paradigm of a single factor limit- ing plankton blooms, is presently giving way to co-limitation by light, and the nutri- ents N, P, Si, and Fe. Primary production, export into the deep sea, and CO2 uptake from the atmosphere together form the 'biological pump' in <span class="hlt">Ocean</span> Biogeochemi- cal Climate Models (OBCM's). Thus far OBCM's assume just one limiting nutrient (P) and one universal phytoplankton species, for deriving C budgets and CO2 ex- change with the atmosphere. New realistic OBCM's are being developed in IRON- AGES for budgeting and air/sea exchanges of both CO2 and DMS, implementing (1) co-limitation by 4 nutrients of 5 major taxonomic classes of phytoplankton in a nested plankton ecosystem model, (ii) DMS(P) pathways, (iii) <span class="hlt">global</span> iron cycling, (iv) chem- ical forms of iron and (v) iron supply in surface waters from above by aerosols and from below out of reducing margin sediments. IRONAGES is a consortium of 12 Eu- ropean institutes coordinated by the Royal NIOZ.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770016765','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770016765"><span>A computer software system for the generation of <span class="hlt">global</span> <span class="hlt">ocean</span> tides including self-gravitation and crustal loading effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Estes, R. H.</p> <p>1977-01-01</p> <p>A computer software system is described which computes <span class="hlt">global</span> numerical solutions of the integro-differential Laplace tidal equations, including dissipation terms and <span class="hlt">ocean</span> loading and self-gravitation effects, for arbitrary diurnal and semidiurnal tidal constituents. The integration algorithm features a successive approximation scheme for the integro-differential system, with time stepping forward differences in the time variable and central differences in spatial variables. Solutions for M2, S2, N2, K2, K1, O1, P1 tidal constituents neglecting the effects of <span class="hlt">ocean</span> loading and self-gravitation and a converged M2, solution including <span class="hlt">ocean</span> loading and self-gravitation effects are presented in the form of cotidal and corange maps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChJOL..34..847R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChJOL..34..847R"><span>A <span class="hlt">joint</span> method to retrieve directional <span class="hlt">ocean</span> wave spectra from SAR and wave spectrometer data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Lin; Yang, Jingsong; Zheng, Gang; Wang, Juan</p> <p>2016-07-01</p> <p>This paper proposes a <span class="hlt">joint</span> method to simultaneously retrieve wave spectra at different scales from spaceborne Synthetic Aperture Radar (SAR) and wave spectrometer data. The method combines the output from the two different sensors to overcome retrieval limitations that occur in some sea states. The wave spectrometer sensitivity coefficient is estimated using an effective significant wave height (SWH), which is an average of SAR-derived and wave spectrometer-derived SWH. This averaging extends the area of the sea surface sampled by the nadir beam of the wave spectrometer to improve the accuracy of the estimated sensitivity coefficient in inhomogeneous sea states. Wave spectra are then retrieved from SAR data using wave spectrometer-derived spectra as first guess spectra to complement the short waves lost in SAR data retrieval. In addition, the problem of 180° ambiguity in retrieved spectra is overcome using SAR imaginary cross spectra. Simulated data were used to validate the <span class="hlt">joint</span> method. The simulations demonstrated that retrieved wave parameters, including SWH, peak wave length (PWL), and peak wave direction (PWD), agree well with reference parameters. Collocated data from ENVISAT advanced SAR (ASAR), the airborne wave spectrometer STORM, the PHAROS buoy, and the European Centre for Medium-Range Weather Forecasting (ECMWF) were then used to verify the proposed method. Wave parameters retrieved from STORM and two ASAR images were compared to buoy and ECMWF wave data. Most of the retrieved parameters were comparable to reference parameters. The results of this study show that the proposed <span class="hlt">joint</span> retrieval method could be a valuable complement to traditional methods used to retrieve directional <span class="hlt">ocean</span> wave spectra, particularly in inhomogeneous sea states.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP31B2236T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP31B2236T"><span>A Stable U Isotopic Perspective on the U Budget and <span class="hlt">Global</span> Extent of Modern Anoxia in the <span class="hlt">Ocean</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tissot, F.; Dauphas, N.</p> <p>2015-12-01</p> <p>Isotopic fractionation between U4+ and U6+makes U stable isotopes potential tracers of <span class="hlt">global</span> paleoredox conditions. In this work [1], we put the U-proxy up to a test against a highly constrained system: the modern <span class="hlt">ocean</span>. We measured a large number of seawater samples from geographically diverse locations and found that the open <span class="hlt">ocean</span> has a homogenous isotopic composition at δ238USW= -0.392 ± 0.005 ‰ (rel. to CRM-112a). From our measurement of rock samples (n=64) and compilations of literature data (n=380), we then estimated the U isotopic compositions of the various reservoirs involved in the modern <span class="hlt">oceanic</span> U budget, as well as the fractionation factors associated with U incorporation into those reservoirs. Using a steady-state model, we compared the isotopic composition of the seawater predicted by the four most recent U <span class="hlt">oceanic</span> budgets [2-5] to the modern seawater value we measured. Three of these budgets [2-4] predict a seawater isotopic composition in very good agreement with the observed δ238USW, which strengthens our confidence in the isotopic fractionation factors associated with each deposition environment and the fact that U is at steady-state in the modern <span class="hlt">ocean</span>. The U <span class="hlt">oceanic</span> budget of Henderson and Anderson (2003) does not reproduce the observed seawater composition because the U flux to anoxic/euxinic sediments relative to the total U flux out of the <span class="hlt">ocean</span> is high in their model, which our analysis shows cannot be correct. The U isotopic composition of seawater is used to constrain the extent of anoxia in the modern <span class="hlt">ocean</span> (% of seafloor covered by anoxic/euxinic sediments), which is 0.21 ± 0.09 %. This work demonstrates that stable isotopes of U can indeed trace the extent of anoxia in the modern <span class="hlt">global</span> <span class="hlt">ocean</span>, thereby validating the application of U isotope measurements to paleoredox reconstructions. Based on the above work, we will present the best estimate of the modern <span class="hlt">oceanic</span> U budget. [1] Tissot F.L.H., Dauphas N. (2015) Geochim Cosmochim</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSIS12A..04O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSIS12A..04O"><span>Radiometry from Bio-Argo Floats: a New Strategy to Validate <span class="hlt">Ocean</span> Color Products at the <span class="hlt">Global</span> Scale.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Organelli, E.; Claustre, H.; Serra, R.; Bricaud, A.; Schmechtig, C.; D'Ortenzio, F.; Poteau, A.; Mangin, A.; Leymarie, E.; Obolensky, G.; Prieur, L. M.; Dall'Olmo, G.; Xing, X.</p> <p>2016-02-01</p> <p>Thanks to a new generation of Bio-Argo floats equipped with sensors for PAR (Photosynthetically Available Irradiance) and downward irradiance measurements at selected wavelengths (i.e., 380, 412 and 490 nm), the number of radiometric measurements has been dramatically increasing and data are available for diverse open <span class="hlt">ocean</span> systems, including winter periods with harsh seas when ships can hardly sample. More than 6500 radiometric profiles have so far been acquired around solar noon in the upper 250 m of the <span class="hlt">ocean</span>. These radiometric profiles, acquired simultaneously to other key biogeochemical and bio-optical variables (chlorophyll a, CDOM, light backscattering), represent a fruitful data source for validation of <span class="hlt">Ocean</span> Color (OC) products. Two different strategies can be implemented: direct validation of satellite OC products and identification of regions characterized by bio-optical anomalies. Diffuse attenuation coefficients (Kd) derived from these profiles, after a specifically developed quality control, are used for these purposes.A good agreement is observed between satellite-derived Kd values at 490 nm and their Bio-Argo counterparts. However, satellite overestimates low in situ Kd values found in very clear waters (e.g., Atlantic and Pacific Sub-Tropical Gyres). The analysis of the spectral Kd variability in the surface <span class="hlt">ocean</span> shows the potential of Bio-Argo floats in identifying those regions with optical properties departing from <span class="hlt">global</span> bio-optical relationships. Divergences of the ratio between Kd values at 380 nm and those at 490 nm from <span class="hlt">global</span> bio-optical models are observed in areas such as the Mediterranean Sea and the North Atlantic in winter. This might cause difficulties in retrieving biogeochemical parameters from satellite data. Hence, delineation of "anomalous" regions by Bio-Argo floats represents a useful strategy for planning dedicated cruises, setting mooring buoys or using CAL/VAL floats in order to improve <span class="hlt">Ocean</span> Color applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130014466','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130014466"><span>Atmospheric Dissolved Iron Depostiion to the <span class="hlt">Global</span> <span class="hlt">Oceans</span>: Effects of Oxalate-Promoted Fe Dissolution, Photochemical Redox Cycling, and Dust Mineralogy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, M. S.; Meskhidze, N.</p> <p>2013-01-01</p> <p>Mineral dust deposition is suggested to be a significant atmospheric supply pathway of bioavailable iron (Fe) to Fe-depleted surface <span class="hlt">oceans</span>. In this study, mineral dust and dissolved Fe (Fed) deposition rates are predicted for March 2009 to February 2010 using the 3-D chemical transport model GEOS-Chem implemented with a comprehensive dust-Fe dissolution scheme. The model simulates Fed production during the atmospheric transport of mineral dust taking into account inorganic and organic (oxalate)-promoted Fe dissolution processes, photochemical redox cycling between ferric (Fe(III)) and ferrous (Fe(II)) forms of Fe, dissolution of three different Fe-containing minerals (hematite, goethite, and aluminosilicates), and detailed mineralogy of windblown dust from the major desert regions. Our calculations suggest that during the yearlong simulation is approximately 0.26 Tg (1 Tg = 1012 g) of Fed was deposited to <span class="hlt">global</span> <span class="hlt">oceanic</span> regions. Compared to simulations only taking into account proton-promoted Fe dissolution, the addition of oxalate to the dust-Fe mobilization scheme increased total annual model-predicted Fed deposition to <span class="hlt">global</span> <span class="hlt">oceanic</span> regions by approximately 75%. The implementation of Fe(II)/Fe(III) photochemical redox cycling in the model allows for the distinction between different oxidation states of deposited Fed. Our calculations suggest that during the daytime, large fractions of Fed deposited to the <span class="hlt">global</span> <span class="hlt">oceans</span> is likely to be in Fe(II) form, while nocturnal fluxes of Fed are largely in Fe(III) form. Model simulations also show that atmospheric fluxes of Fed can be strongly influenced by the mineralogy of Fe-containing compounds. This study shows that Fed deposition to the <span class="hlt">oceans</span> is controlled by total dust-Fe mass concentrations, mineralogy, the surface area of dust particles, atmospheric chemical composition, cloud processing, and meteorological parameters and exhibits complex and spatiotemporally variable patterns. Our study suggests that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035221','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035221"><span>Pliocene three-dimensional <span class="hlt">global</span> <span class="hlt">ocean</span> temperature reconstruction</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dowsett, H.J.; Robinson, M.M.; Foley, K.M.</p> <p>2009-01-01</p> <p>The thermal structure of the mid-Piacenzian <span class="hlt">ocean</span> is obtained by combining the Pliocene Research, Interpretation and Synoptic Mapping Project (PRISM3) multiproxy sea-surface temperature (SST) reconstruction with bottom water temperature estimates from 27 locations produced using Mg/Ca paleothermometry based upon the ostracod genus Krithe. Deep water temperature estimates are skewed toward the Atlantic Basin (63% of the locations) and represent depths from 1000m to 4500 m. This reconstruction, meant to serve as a validation data set as well as an initialization for coupled numerical climate models, assumes a Pliocene water mass framework similar to that which exists today, with several important modifications. The area of formation of present day North Atlantic Deep Water (NADW) was expanded and extended further north toward the Arctic <span class="hlt">Ocean</span> during the mid-Piacenzian relative to today. This, combined with a deeper Greenland-Scotland Ridge, allowed a greater volume of warmer NADW to enter the Atlantic <span class="hlt">Ocean</span>. In the Southern <span class="hlt">Ocean</span>, the Polar Front Zone was expanded relative to present day, but shifted closer to the Antarctic continent. This, combined with at least seasonal reduction in sea ice extent, resulted in decreased Antarctic Bottom Water (AABW) production (relative to present day) as well as possible changes in the depth of intermediate waters. The reconstructed mid-Piacenzian three-dimensional <span class="hlt">ocean</span> was warmer overall than today, and the hypothesized aerial extent of water masses appears to fit the limited stable isotopic data available for this time period. ?? Author(s) 2009.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME54C0935G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME54C0935G"><span>Neural Network Technique for <span class="hlt">Global</span> <span class="hlt">Ocean</span> Color (Chl-a) Estimates Bridging Multiple Satellite Missions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garraffo, Z. D.; Nadiga, S.; Krasnopolsky, V.; Mehra, A.; Bayler, E. J.; Kim, H. C.; Behringer, D.</p> <p>2016-02-01</p> <p>A Neural Network (NN) technique is used to produce consistent <span class="hlt">global</span> <span class="hlt">ocean</span> color estimates, bridging multiple satellite <span class="hlt">ocean</span> color missions by linking <span class="hlt">ocean</span> color variability - primarily driven by biological processes - with the physical processes of the upper <span class="hlt">ocean</span>. Satellite-derived surface variables - sea-surface temperature (SST) and sea-surface height (SSH) fields - are used as signatures of upper-<span class="hlt">ocean</span> dynamics. The NN technique employs adaptive weights that are tuned by applying statistical learning (training) algorithms to past data sets, providing robustness with respect to random noise, accuracy, fast emulations, and fault-tolerance. This study employs Sea-viewing Wide Field-of-View Sensor (SeaWiFS) chlorophyll-a data for 1998-2010 in conjunction with satellite SSH and SST fields. After interpolating all data sets to the same two-degree latitude-longitude grid, the annual mean was removed and monthly anomalies extracted . The NN technique wass trained for even years of that period and tested for errors and bias for the odd years. The NN output are assessed for: (i) bias, (ii) variability, (iii) root-mean-square error (RMSE), and (iv) cross-correlation. A Jacobian is evaluated to estimate the impact of each input (SSH, SST) on the NN chlorophyll-a estimates. The differences between an ensemble of NNs vs a single NN are examined. After the NN is trained for the SeaWiFS period, the NN is then applied and validated for 2005-2015, a period covered by other satellite missions — the Moderate Resolution Imaging Spectroradiometer (MODIS AQUA) and the Visible Imaging Infrared Radiometer Suite (VIIRS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JGR...10517161P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JGR...10517161P"><span><span class="hlt">Global</span> and regional axial <span class="hlt">ocean</span> angular momentum signals and length-of-day variations (1985-1996)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ponte, Rui M.; Stammer, Detlef</p> <p>2000-07-01</p> <p>Changes in <span class="hlt">ocean</span> angular momentum M about the polar axis are related to fluctuations in zonal currents (relative component Mr) and latitudinal shifts in mass (planetary component MΩ). Output from a 1° <span class="hlt">ocean</span> model is used to calculate <span class="hlt">global</span> Mr, MΩ, and M time series at 5 day intervals for the period January 1985 to April 1996. The annual cycle in Mr, MΩ, and M is larger than the semiannual cycle, and MΩ amplitudes are nearly twice those of Mr. Year-to-year modulation of the seasonal cycle is present, but interannual variability is weak. The spectrum of M is red (background slope between ω-1 and ω-2) at subseasonal periods, implying a white or blue spectrum for the external torque on the <span class="hlt">ocean</span>. Comparisons with previous studies indicate the importance of direct atmospheric forcing in inducing subseasonal M signals, relative to instabilities and other internal sources of rapid <span class="hlt">oceanic</span> signals. Regional angular momentum estimates show that seasonal variability tends to be larger at low latitudes, but many local maxima exist because of the spatial structure of zonal current and mass variability. At seasonal timescales, latitudes ~20°S-10°N contribute substantial variability to MΩ, while signals in Mr can be traced to Antarctic Circumpolar Current transports and associated circulation. Variability in M is found to be small when compared with similar time series for the atmosphere and the solid Earth, but <span class="hlt">ocean</span> signals are significantly coherent with atmosphere-solid Earth residuals, implying a measurable <span class="hlt">oceanic</span> impact on length-of-day variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025186','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025186"><span><span class="hlt">Ocean</span> observer study: A proposed national asset to augment the future U.S. operational satellite system</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cunningham, J.D.; Chambers, D.; Davis, C.O.; Gerber, A.; Helz, R.; McGuire, J.P.; Pichel, W.</p> <p>2003-01-01</p> <p>The next generation of U.S. polar orbiting environmental satellites, are now under development. These satellites, <span class="hlt">jointly</span> developed by the Department of Defense (DoD), the Department of Commerce (DOC), and the National Aeronautics and Space Administration (NASA), will be known as the National Polar-orbiting Operational Environmental Satellite System (NPOESS). It is expected that the first of these satellites will be launched in 2010. NPOESS has been designed to meet the operational needs of the U.S. civilian meteorological, environmental, climatic, and space environmental remote sensing programs, and the <span class="hlt">Global</span> Military Space and Geophysical Environmental remote sewing programs. This system, however, did not meet all the needs of the user community interested in operational oceanography (particularly in coastal regions). Beginning in the fall of 2000, the Integrated Program Office (IPO), a <span class="hlt">joint</span> DoD, DOC, and NASA office responsible for the NPOESS development, initiated the <span class="hlt">Ocean</span> Observer Study (OOS). The purpose of this study was to assess and recommend how best to measure the missing or inadequately sampled <span class="hlt">ocean</span> parameters. This paper summarizes the <span class="hlt">ocean</span> measurement requirements documented in the OOS, describes the national need to measure these parameters, and describes the satellite instrumentation required to make those measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V31D2552D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V31D2552D"><span><span class="hlt">Oceanic</span> mantle rocks reveal evidence for an ancient, 1.2-1.3 Ga <span class="hlt">global</span> melting event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dijkstra, A. H.; Sergeev, D.; McTaminey, L.; Dale, C. W.; Meisel, T. C.</p> <p>2011-12-01</p> <p>It is now increasingly being recognized that many <span class="hlt">oceanic</span> peridotites are refertilized harzburgites, and that the refertilization often masks an extremely refractory character of the original mantle rock 'protolith'. <span class="hlt">Oceanic</span> peridotites are, when the effects of melt refertilization are undone, often too refractory to be simple mantle melting residues after the extraction of mid-<span class="hlt">ocean</span> ridge basalts at a spreading center. Rhenium-osmium isotope analysis is a powerful method to look through the effects of refertilization and to obtain constraints on the age of the melting that produced the refractory mantle protolith. Rhenium-depletion model ages of such anomalously refractory <span class="hlt">oceanic</span> mantle rocks - found as abyssal peridotites or as mantle xenoliths on <span class="hlt">ocean</span> islands - are typically >1 Ga, i.e., much older than the ridge system at which they were emplaced. In my contribution I will show results from two case studies of refertilized anciently depleted mantle rocks (Macquarie Island 'abyssal' peridotites and Lanzarote mantle xenoliths). Interestingly, very refractory <span class="hlt">oceanic</span> mantle rocks from sites all around the world show recurring evidence for a Mesoproterozoic (~1.2-1.3 Ga) melting event [1]. Therefore, <span class="hlt">oceanic</span> mantle rocks seem to preserve evidence for ancient melting events of <span class="hlt">global</span> significance. Alternatively, such mantle rocks may be samples of rafts of ancient continental lithospheric mantle. Laser-ablation osmium isotope 'dating' of large populations of individual osmium-bearing alloys from mantle rocks is the key to better constrain the nature and significance of these ancient depletion events. Osmium-bearing alloys form when mantle rocks are melted to high-degrees. We have now extracted over >250 detrital osmium alloys from placer gold occurrences in the river Rhine. These alloys are derived from outcrops of ophiolitic mantle rocks in the Alps, which include blocks of mantle rocks emplaced within the Tethys <span class="hlt">Ocean</span>, and ultramafic lenses of unknown</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMPP31A1297D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMPP31A1297D"><span>Seawater Os heterogeneity during the OAE 2 and across the Cenomanian-Turonian Boundary: Implications for <span class="hlt">global</span> <span class="hlt">ocean</span> paleocirculation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du Vivier, A.</p> <p>2009-12-01</p> <p>Alice D.C. Du Vivier1, David Selby1, Darren R. Gröcke1, Bradley B. Sageman2, Silke Voigt3 1Department of Earth Sciences, Durham University, Durham, DH1 3LE, UK 2Department of Geological Sciences, Northwestern University, Evanston, Illinois 60208, USA 3Leibniz Institute of Marine Sciences (IFM-Geomar), Wischhofstrasse 1-3, 24184 Kiel, Germany Organic-rich sediments (ORS) from two OAE 2 sites (ODP Site 1260B and Furlo) show significant enrichment in Os (>1 ppb) and possess mantle-like initial 187Os/188Os (IOs, ~0.13) prior to the onset and during the lower part of the OAE 2 [1]. However, these sites show significantly different IOs profiles for the upper part of the OAE 2, suggesting Os heterogeneity within the <span class="hlt">global</span> <span class="hlt">ocean</span>. We use new IOs data from correlative sections based on chemostratigraphy and biostratigraphy (Rock Canyon, Pueblo USA and Wunstorf, Germany) to evaluate the evolution of <span class="hlt">global</span> seawater IOs during OAE 2. Wunstorf and Rock Canyon OAE 2 sections are the European type and CTB GSSP sections, respectively. These sections have average Os abundances that are an order of magnitude lower than that from Furlo and Site 1260B (410 and 245 pg/g vs. 3630 and 2575 pg/g, respectively). Redox is important for Os capture in ORS, but not a controlling factor for Os uptake. The significant enrichment in Os in ORS from Furlo and Site 1260B may relate to the slow sedimentation rate of the ORS (~ 0.2 cm/kyrs vs ~ 1.8 cm/kyrs and ~ 0.5cm/kyrs at Wunstorf and Pueblo), thus permitting a greater contact time for Os uptake. Spikes in the ORS Os abundance coincide with unradiogenic IOs (0.13 to 0.30). Our high-resolution IOs coupled with that of site 1260B and Furlo [1] show distinct variations in IOs throughout the OAE 2. This suggests that the 187Os/188Os ratio in the <span class="hlt">global</span> <span class="hlt">ocean</span> was not homogeneous. During the peak of OAE 2 the IOs at Furlo and Site 1260B are more unradiogenic (0.13 and 0.15) than that recorded at Wunstorf, 0.18 and Pueblo, ~ 0.2. The IOs profile from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS31B1398L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS31B1398L"><span>Vertical Redistribution of <span class="hlt">Ocean</span> Salt Content</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, X.; Liu, C.; Ponte, R. M.; Piecuch, C. G.</p> <p>2017-12-01</p> <p><span class="hlt">Ocean</span> salinity is an important proxy for change and variability in the <span class="hlt">global</span> water cycle. Multi-decadal trends have been observed in both surface and subsurface salinity in the past decades, and are usually attributed to the change in air-sea freshwater flux. Although air-sea freshwater flux, a major component of the <span class="hlt">global</span> water cycle, certainly contributes to the change in surface and upper <span class="hlt">ocean</span> salinity, the salt redistribution inside the <span class="hlt">ocean</span> can affect the surface and upper <span class="hlt">ocean</span> salinity as well. Also, the mechanisms controlling the surface and upper <span class="hlt">ocean</span> salinity changes likely depend on timescales. Here we examined the <span class="hlt">ocean</span> salinity changes as well as the contribution of the vertical redistribution of salt with a 20-year dynamically consistent and data-constrained <span class="hlt">ocean</span> state estimate (ECCO: Estimating Circulation and Climate of the <span class="hlt">Ocean</span>). A decrease in the spatial mean upper <span class="hlt">ocean</span> salinity and an upward salt flux inside the <span class="hlt">ocean</span> were observed. These findings indicate that over 1992-2011, surface freshwater fluxes contribute to the decrease in spatial mean upper <span class="hlt">ocean</span> salinity and are partly compensated by the vertical redistribution of salt inside the <span class="hlt">ocean</span>. Between advection and diffusion, the two major processes determining the vertical exchange of salt, the advective term at different depths shows a downward transport, while the diffusive term is the dominant upward transport contributor. These results suggest that the salt transport in the <span class="hlt">ocean</span> interior should be considered in interpreting the observed surface and upper <span class="hlt">ocean</span> salinity changes, as well as inferring information about the changes in the <span class="hlt">global</span> water cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170003469','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170003469"><span>On the Land-<span class="hlt">Ocean</span> Contrast of Tropical Convection and Microphysics Statistics Derived from TRMM Satellite Signals and <span class="hlt">Global</span> Storm-Resolving Models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matsui, Toshihisa; Chern, Jiun-Dar; Tao, Wei-Kuo; Lang, Stephen E.; Satoh, Masaki; Hashino, Tempei; Kubota, Takuji</p> <p>2016-01-01</p> <p>A 14-year climatology of Tropical Rainfall Measuring Mission (TRMM) collocated multi-sensor signal statistics reveal a distinct land-<span class="hlt">ocean</span> contrast as well as geographical variability of precipitation type, intensity, and microphysics. Microphysics information inferred from the TRMM precipitation radar and Microwave Imager (TMI) show a large land-<span class="hlt">ocean</span> contrast for the deep category, suggesting continental convective vigor. Over land, TRMM shows higher echo-top heights and larger maximum echoes, suggesting taller storms and more intense precipitation, as well as larger microwave scattering, suggesting the presence of morelarger frozen convective hydrometeors. This strong land-<span class="hlt">ocean</span> contrast in deep convection is invariant over seasonal and multi-year time-scales. Consequently, relatively short-term simulations from two <span class="hlt">global</span> storm-resolving models can be evaluated in terms of their land-<span class="hlt">ocean</span> statistics using the TRMM Triple-sensor Three-step Evaluation via a satellite simulator. The models evaluated are the NASA Multi-scale Modeling Framework (MMF) and the Non-hydrostatic Icosahedral Cloud Atmospheric Model (NICAM). While both simulations can represent convective land-<span class="hlt">ocean</span> contrasts in warm precipitation to some extent, near-surface conditions over land are relatively moisture in NICAM than MMF, which appears to be the key driver in the divergent warm precipitation results between the two models. Both the MMF and NICAM produced similar frequencies of large CAPE between land and <span class="hlt">ocean</span>. The dry MMF boundary layer enhanced microwave scattering signals over land, but only NICAM had an enhanced deep convection frequency over land. Neither model could reproduce a realistic land-<span class="hlt">ocean</span> contrast in in deep convective precipitation microphysics. A realistic contrast between land and <span class="hlt">ocean</span> remains an issue in <span class="hlt">global</span> storm-resolving modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000120582&hterms=coastal+zone&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcoastal%2Bzone','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000120582&hterms=coastal+zone&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcoastal%2Bzone"><span><span class="hlt">Global</span> Distribution of Aerosols Over the Open <span class="hlt">Ocean</span> as Derived from the Coastal Zone Color Scanner</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stegmann, P. M.; Tindale, N. W.</p> <p>1999-01-01</p> <p>Climatological maps of monthly mean aerosol radiance levels derived from the coastal zone color scanner (CZCS) were constructed for the world's <span class="hlt">ocean</span> basins. This is the first study to use the 7.5.-year CZCS data set to examine the distribution and seasonality of aerosols over the open <span class="hlt">ocean</span> on a <span class="hlt">global</span> scale. Examination of our satellite images found the most prominent large-scale patch of elevated aerosol radiances in each month off the coast of northwest Africa. The well-known, large-scale plumes of elevated aerosol levels in the Arabian Sea, the northwest Pacific, and off the east coast of North America were also successfully captured. Radiance data were extracted from 13 major open-<span class="hlt">ocean</span> zones, ranging from the subpolar to equatorial regions. Results from these extractions revealed the aerosol load in both subpolar and subtropical zones to be higher in the Northern Hemisphere than in the Southern Hemisphere. Aerosol radiances in the subtropics of both hemispheres were about 2 times higher in summer than in winter. In subpolar regions, aerosol radiances in late spring/early summer were almost 3 times that observed in winter. In general, the aerosol signal was higher during the warmer months and lower during the cooler months, irrespective of location. A comparison between our mean monthly aerosol radiance maps with mean monthly chlorophyll maps (also from CZCS) showed similar seasonality between aerosol and chlorophyll levels in the subpolar zones of both hemispheres, i.e., high levels in summer, low levels in winter. In the subtropics of both hemispheres, however, chlorophyll levels were higher in winter months which coincided with a depressed aerosol signal. Our results indicate that the near-IR channel on <span class="hlt">ocean</span> color sensors can be used to successfully capture well-known, large-scale aerosol plumes on a <span class="hlt">global</span> scale and that future <span class="hlt">ocean</span> color sensors may provide a platform for long-term synoptic studies of combined aerosol-phytoplankton productivity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160013557&hterms=climate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dclimate','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160013557&hterms=climate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dclimate"><span><span class="hlt">Ocean</span>-Atmosphere Interactions Modulate Irrigation's Climate Impacts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krakauer, Nir Y.; Puma, Michael J.; Cook, Benjamin I.; Gentine, Pierre; Nazarenko, Larissa</p> <p>2016-01-01</p> <p>Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of <span class="hlt">ocean</span>- atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity. We find that <span class="hlt">ocean</span>-atmosphere interaction does impact the magnitude of <span class="hlt">global</span>-mean and spatially varying climate impacts, greatly increasing their <span class="hlt">global</span> reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, particularly over the <span class="hlt">oceans</span>, tend to be larger. The interaction amplifies irrigation-driven standing wave patterns in the tropics and mid-latitudes in our simulations, approximately doubling the <span class="hlt">global</span>-mean amplitude of surface temperature changes due to irrigation. The fractions of <span class="hlt">global</span> area experiencing significant annual-mean surface air temperature and precipitation change also approximately double with <span class="hlt">ocean</span>-atmosphere interaction. Subject to confirmation with other models, these findings imply that LCLUC is an important contributor to climate change even in remote areas such as the Southern <span class="hlt">Ocean</span>, and that attribution studies should include interactive <span class="hlt">oceans</span> and need to consider LCLUC, including irrigation, as a truly <span class="hlt">global</span> forcing that affects climate and the water cycle over <span class="hlt">ocean</span> as well as land areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA511328','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA511328"><span><span class="hlt">Ocean</span> Data Assimilation Systems for GODAE</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-09-01</p> <p>we describe some of the <span class="hlt">ocean</span> data assimilation systems that have been developed within the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Assimilation Experiment (GODAE...assimilation systems in the post-GODAF. time period beyond 2008. 15. SUBJECT TERMS <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Assimilation Experiment, ARGO, subsurface...E. R. Franchi , 7000 Public Affairs (Unclassified/ Unlimited Only), Code 703o 4 yj ?>-* i o’ 1. Release of this paper is approved. 2. To the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28738200','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28738200"><span><span class="hlt">Global</span> distribution of dissolved organic matter along the aquatic continuum: Across rivers, lakes and <span class="hlt">oceans</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Massicotte, Philippe; Asmala, Eero; Stedmon, Colin; Markager, Stiig</p> <p>2017-12-31</p> <p>Based on an extensive literature survey containing more than 12,000 paired measurements of dissolved organic carbon (DOC) concentrations and absorption of chromophoric dissolved organic matter (CDOM) distributed over four continents and seven <span class="hlt">oceans</span>, we described the <span class="hlt">global</span> distribution and transformation of dissolved organic matter (DOM) along the aquatic continuum across rivers and lakes to <span class="hlt">oceans</span>. A strong log-linear relationship (R 2 =0.92) between DOC concentration and CDOM absorption at 350nm was observed at a <span class="hlt">global</span> scale, but was found to be ecosystem-dependent at local and regional scales. Our results reveal that as DOM is transported towards the <span class="hlt">oceans</span>, the robustness of the observed relation decreases rapidly (R 2 from 0.94 to 0.44) indicating a gradual decoupling between DOC and CDOM. This likely reflects the decreased connectivity between the landscape and DOM along the aquatic continuum. To support this hypothesis, we used the DOC-specific UV absorbance (SUVA) to characterize the reactivity of the DOM pool which decreased from 4.9 to 1.7m 2 × gC -1 along the aquatic continuum. Across the continuum, a piecewise linear regression showed that the observed decrease of SUVA occurred more rapidly in freshwater ecosystems compared to marine water ecosystems, suggesting that the different degradation processes act preferentially on CDOM rather than carbon content. The observed change in the DOM characteristics along the aquatic continuum also suggests that the terrestrial DOM pool is gradually becoming less reactive, which has profound consequences on cycling of organic carbon in aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4537J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4537J"><span>Using a <span class="hlt">global</span> <span class="hlt">ocean</span> circulation model to conduct a preliminary risk assessment of oil spills in the Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobs, Zoe; Popova, Katya; Hirschi, Joel; Coward, Andrew; Yool, Andrew; van Gennip, Simon; Anifowose, Babtunde; Harrington-Missin, Liam</p> <p>2017-04-01</p> <p>Although oil blowouts from deep-water drilling happen very rarely, they can cause catastrophic damage to the environment. Despite such potentially high impacts, relatively little research effort has gone into understanding subsurface oil plumes in the deep <span class="hlt">ocean</span>. In this study, we demonstrate the significance of this problem and offer potential solutions using a novel approach based on a leading-edge, high-resolution <span class="hlt">global</span> <span class="hlt">ocean</span> circulation model. We present examples demonstrating: (a) the importance of <span class="hlt">ocean</span> circulation in the propagation of oil spills; and (b) likely circulation footprints for oil spills at four key locations in the Atlantic <span class="hlt">Ocean</span> that exist in different circulation regimes - the shelves of Brazil, the Gulf of Guinea, the Gulf of Mexico and the Faroe-Shetland Channel. In order to quantify the variability at each site on seasonal timescales, interannual timescales and at different depths, we utilize the Modified Hausdorff Distance (MHD), which is a shape-distance metric that measures the similarity between two shapes. The scale of the footprints across the four focus locations varies considerably and is determined by the main circulation features in their vicinity. For example, the hypothetical oil plume can be affected by variations in the speed and location of a particular current (e.g. Brazil Current at the Brazilian shelf site) or be influenced by different currents entirely depending on the release depth, month and year (e.g. Angola Current or Southern Equatorial Current at the Gulf of Guinea site). Overall, our results demonstrate the need to use state of the art <span class="hlt">global</span>, or basin-scale, <span class="hlt">ocean</span> circulation models when assessing the environmental impacts of proposed oil drilling activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2010/1227/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2010/1227/"><span>Monitoring and assessment of <span class="hlt">ocean</span> acidification in the Arctic <span class="hlt">Ocean</span>-A scoping paper</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Robbins, Lisa L.; Yates, Kimberly K.; Feely, Richard; Fabry, Victoria</p> <p>2010-01-01</p> <p>Carbon dioxide (CO2) in the atmosphere is absorbed at the <span class="hlt">ocean</span> surface by reacting with seawater to form a weak, naturally occurring acid called carbonic acid. As atmospheric carbon dioxide increases, the concentration of carbonic acid in seawater also increases, causing a decrease in <span class="hlt">ocean</span> pH and carbonate mineral saturation states, a process known as <span class="hlt">ocean</span> acidification. The <span class="hlt">oceans</span> have absorbed approximately 525 billion tons of carbon dioxide from the atmosphere, or about one-quarter to one-third of the anthropogenic carbon emissions released since the beginning of the Industrial Revolution. <span class="hlt">Global</span> surveys of <span class="hlt">ocean</span> chemistry have revealed that seawater pH has decreased by about 0.1 units (from a pH of 8.2 to 8.1) since the 1700s due to absorption of carbon dioxide (Raven and others, 2005). Modeling studies, based on Intergovernmental Panel on Climate Change (IPCC) CO2 emission scenarios, predict that atmospheric carbon dioxide levels could reach more than 500 parts per million (ppm) by the middle of this century and 800 ppm by the year 2100, causing an additional decrease in surface water pH of 0.3 pH units. <span class="hlt">Ocean</span> acidification is a <span class="hlt">global</span> threat and is already having profound and deleterious effects on the geology, biology, chemistry, and socioeconomic resources of coastal and marine habitats. The polar and sub-polar seas have been identified as the bellwethers for <span class="hlt">global</span> <span class="hlt">ocean</span> acidification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29623683','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29623683"><span>Essential <span class="hlt">ocean</span> variables for <span class="hlt">global</span> sustained observations of biodiversity and ecosystem changes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miloslavich, Patricia; Bax, Nicholas J; Simmons, Samantha E; Klein, Eduardo; Appeltans, Ward; Aburto-Oropeza, Octavio; Andersen Garcia, Melissa; Batten, Sonia D; Benedetti-Cecchi, Lisandro; Checkley, David M; Chiba, Sanae; Duffy, J Emmett; Dunn, Daniel C; Fischer, Albert; Gunn, John; Kudela, Raphael; Marsac, Francis; Muller-Karger, Frank E; Obura, David; Shin, Yunne-Jai</p> <p>2018-04-05</p> <p>Sustained observations of marine biodiversity and ecosystems focused on specific conservation and management problems are needed around the world to effectively mitigate or manage changes resulting from anthropogenic pressures. These observations, while complex and expensive, are required by the international scientific, governance and policy communities to provide baselines against which the effects of human pressures and climate change may be measured and reported, and resources allocated to implement solutions. To identify biological and ecological essential <span class="hlt">ocean</span> variables (EOVs) for implementation within a <span class="hlt">global</span> <span class="hlt">ocean</span> observing system that is relevant for science, informs society, and technologically feasible, we used a driver-pressure-state-impact-response (DPSIR) model. We (1) examined relevant international agreements to identify societal drivers and pressures on marine resources and ecosystems, (2) evaluated the temporal and spatial scales of variables measured by 100+ observing programs, and (3) analysed the impact and scalability of these variables and how they contribute to address societal and scientific issues. EOVs were related to the status of ecosystem components (phytoplankton and zooplankton biomass and diversity, and abundance and distribution of fish, marine turtles, birds and mammals), and to the extent and health of ecosystems (cover and composition of hard coral, seagrass, mangrove and macroalgal canopy). Benthic invertebrate abundance and distribution and microbe diversity and biomass were identified as emerging EOVs to be developed based on emerging requirements and new technologies. The temporal scale at which any shifts in biological systems will be detected will vary across the EOVs, the properties being monitored and the length of the existing time-series. <span class="hlt">Global</span> implementation to deliver useful products will require collaboration of the scientific and policy sectors and a significant commitment to improve human and infrastructure</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OcMod.123...66C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OcMod.123...66C"><span>CMIP5-based <span class="hlt">global</span> wave climate projections including the entire Arctic <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Casas-Prat, M.; Wang, X. L.; Swart, N.</p> <p>2018-03-01</p> <p>This study presents simulations of the <span class="hlt">global</span> <span class="hlt">ocean</span> wave climate corresponding to the surface winds and sea ice concentrations as simulated by five CMIP5 (Coupled Model Intercomparison Project Phase 5) climate models for the historical (1979-2005) and RCP8.5 scenario future (2081-2100) periods. To tackle the numerical complexities associated with the inclusion of the North Pole, the WAVEWATCH III (WW3) wave model was used with a customized unstructured Spherical Multi-Cell grid of ∼100 km offshore and ∼50 km along coastlines. The climate model simulated wind and sea ice data, and the corresponding WW3 simulated wave data, were evaluated against reanalysis and hindcast data. The results show that all the five sets of wave simulations projected lower waves in the North Atlantic, corresponding to decreased surface wind speeds there in the warmer climate. The selected CMIP5 models also consistently projected an increase in the surface wind speed in the Southern Hemisphere (SH) mid-high latitudes, which translates in an increase in the WW3 simulated significant wave height (Hs) there. The higher waves are accompanied with increased peak wave period and increased wave age in the East Pacific and Indian <span class="hlt">Oceans</span>, and a significant counterclockwise rotation in the mean wave direction in the Southern <span class="hlt">Oceans</span>. The latter is caused by more intense waves from the SH traveling equatorward and developing into swells. Future wave climate in the Arctic <span class="hlt">Ocean</span> in summer is projected to be predominantly of mixed sea states, with the climatological mean of September maximum Hs ranging mostly 3-4 m. The new waves approaching Arctic coasts will be less fetch-limited as ice retreats since a predominantly southwards mean wave direction is projected in the surrounding seas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030249','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030249"><span>Shelf and open-<span class="hlt">ocean</span> calcareous phytoplankton assemblages across the Paleocene-Eocene thermal maximum: Implications for <span class="hlt">global</span> productivity gradients</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gibbs, S.J.; Bralower, T.J.; Bown, Paul R.; Zachos, J.C.; Bybell, L.M.</p> <p>2006-01-01</p> <p>Abrupt <span class="hlt">global</span> warming and profound perturbation of the carbon cycle during the Paleocene-Eocene Thermal Maximum (PETM, ca. 55 Ma) have been linked to a massive release of carbon into the <span class="hlt">ocean</span>-atmosphere system. Increased phytoplankton productivity has been invoked to cause subsequent CO2 drawdown, cooling, and environmental recovery. However, interpretations of geochemical and biotic data differ on when and where this increased productivity occurred. Here we present high-resolution nannofossil assemblage data from a shelf section (the U.S. Geological Survey [USGS] drill hole at Wilson Lake, New Jersey) and an open-<span class="hlt">ocean</span> location (<span class="hlt">Ocean</span> Drilling Program [ODP] Site 1209, paleoequatorial Pacific). These data combined with published biotic records indicate a transient steepening of shelf-offshelf trophic gradients across the PETM onset and peak, with a decrease in open-<span class="hlt">ocean</span> productivity coeval with increased nutrient availability in shelf areas. Productivity levels recovered in the open <span class="hlt">ocean</span> during the later stages of the event, which, coupled with intensified continental weathering rates, may have played an important role in carbon sequestration and CO2 drawdown. ?? 2006 Geological Society of America.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21141663','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21141663"><span><span class="hlt">Ocean</span> deoxygenation in a warming world.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keeling, Ralph E; Körtzinger, Arne; Gruber, Nicolas</p> <p>2010-01-01</p> <p><span class="hlt">Ocean</span> warming and increased stratification of the upper <span class="hlt">ocean</span> caused by <span class="hlt">global</span> climate change will likely lead to declines in dissolved O2 in the <span class="hlt">ocean</span> interior (<span class="hlt">ocean</span> deoxygenation) with implications for <span class="hlt">ocean</span> productivity, nutrient cycling, carbon cycling, and marine habitat. <span class="hlt">Ocean</span> models predict declines of 1 to 7% in the <span class="hlt">global</span> <span class="hlt">ocean</span> O2 inventory over the next century, with declines continuing for a thousand years or more into the future. An important consequence may be an expansion in the area and volume of so-called oxygen minimum zones, where O2 levels are too low to support many macrofauna and profound changes in biogeochemical cycling occur. Significant deoxygenation has occurred over the past 50 years in the North Pacific and tropical <span class="hlt">oceans</span>, suggesting larger changes are looming. The potential for larger O2 declines in the future suggests the need for an improved observing system for tracking <span class="hlt">ocean</span> 02 changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990009283','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990009283"><span>A Preliminary Model Study of the Large-Scale Seasonal Cycle in Bottom Pressure Over the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ponte, Rui M.</p> <p>1998-01-01</p> <p>Output from the primitive equation model of Semtner and Chervin is used to examine the seasonal cycle in bottom pressure (Pb) over the <span class="hlt">global</span> <span class="hlt">ocean</span>. Effects of the volume-conserving formulation of the model on the calculation Of Pb are considered. The estimated seasonal, large-scale Pb signals have amplitudes ranging from less than 1 cm over most of the deep <span class="hlt">ocean</span> to several centimeters over shallow, boundary regions. Variability generally increases toward the western sides of the basins, and is also larger in some Southern <span class="hlt">Ocean</span> regions. An oscillation between subtropical and higher latitudes in the North Pacific is clear. Comparison with barotropic simulations indicates that, on basin scales, seasonal Pb variability is related to barotropic dynamics and the seasonal cycle in Ekman pumping, and results from a small, net residual in mass divergence from the balance between Ekman and Sverdrup flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013esm..book..439D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013esm..book..439D"><span>Remote Sensing of <span class="hlt">Ocean</span> Color</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dierssen, Heidi M.; Randolph, Kaylan</p> <p></p> <p>The <span class="hlt">oceans</span> cover over 70% of the earth's surface and the life inhabiting the <span class="hlt">oceans</span> play an important role in shaping the earth's climate. Phytoplankton, the microscopic organisms in the surface <span class="hlt">ocean</span>, are responsible for half of the photosynthesis on the planet. These organisms at the base of the food web take up light and carbon dioxide and fix carbon into biological structures releasing oxygen. Estimating the amount of microscopic phytoplankton and their associated primary productivity over the vast expanses of the <span class="hlt">ocean</span> is extremely challenging from ships. However, as phytoplankton take up light for photosynthesis, they change the color of the surface <span class="hlt">ocean</span> from blue to green. Such shifts in <span class="hlt">ocean</span> color can be measured from sensors placed high above the sea on satellites or aircraft and is called "<span class="hlt">ocean</span> color remote sensing." In open <span class="hlt">ocean</span> waters, the <span class="hlt">ocean</span> color is predominantly driven by the phytoplankton concentration and <span class="hlt">ocean</span> color remote sensing has been used to estimate the amount of chlorophyll a, the primary light-absorbing pigment in all phytoplankton. For the last few decades, satellite data have been used to estimate large-scale patterns of chlorophyll and to model primary productivity across the <span class="hlt">global</span> <span class="hlt">ocean</span> from daily to interannual timescales. Such <span class="hlt">global</span> estimates of chlorophyll and primary productivity have been integrated into climate models and illustrate the important feedbacks between <span class="hlt">ocean</span> life and <span class="hlt">global</span> climate processes. In coastal and estuarine systems, <span class="hlt">ocean</span> color is significantly influenced by other light-absorbing and light-scattering components besides phytoplankton. New approaches have been developed to evaluate the <span class="hlt">ocean</span> color in relationship to colored dissolved organic matter, suspended sediments, and even to characterize the bathymetry and composition of the seafloor in optically shallow waters. <span class="hlt">Ocean</span> color measurements are increasingly being used for environmental monitoring of harmful algal blooms, critical coastal habitats</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070023935&hterms=ocean+climate+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Docean%2Bclimate%2Bchanges','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070023935&hterms=ocean+climate+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Docean%2Bclimate%2Bchanges"><span>NASA Supercomputer Improves Prospects for <span class="hlt">Ocean</span> Climate Research</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Menemenlis, D.; Hill, C.; Adcroft, A.; Campin, J. -M.; Cheng, B.; Ciotti, B.; Fukumori, I.; Heimbach, P.; Henze, C.; Kohl, A.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20070023935'); toggleEditAbsImage('author_20070023935_show'); toggleEditAbsImage('author_20070023935_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20070023935_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20070023935_hide"></p> <p>2005-01-01</p> <p>Estimates of <span class="hlt">ocean</span> circulation constrained by in situ and remotely sensed observations have become routinely available during the past five years, and they are being applied to myriad scientific and operational problems [Stammer et al.,2002]. Under the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Data Assimilation Experiment (GODAE), several regional and <span class="hlt">global</span> estimates have evolved for applications in climate research, seasonal forecasting, naval operations, marine safety, fisheries,the offshore oil industry, coastal management, and other areas. This article reports on recent progress by one effort, the consortium for Estimating the Circulation and Climate of the <span class="hlt">Ocean</span> (ECCO), toward a next-generation synthesis of <span class="hlt">ocean</span> and sea-ice data that is <span class="hlt">global</span>, that covers the full <span class="hlt">ocean</span> depth, and that permits eddies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMD.....8.3471X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMD.....8.3471X"><span>On the use of Schwarz-Christoffel conformal mappings to the grid generation for <span class="hlt">global</span> <span class="hlt">ocean</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, S.; Wang, B.; Liu, J.</p> <p>2015-10-01</p> <p>In this article we propose two grid generation methods for <span class="hlt">global</span> <span class="hlt">ocean</span> general circulation models. Contrary to conventional dipolar or tripolar grids, the proposed methods are based on Schwarz-Christoffel conformal mappings that map areas with user-prescribed, irregular boundaries to those with regular boundaries (i.e., disks, slits, etc.). The first method aims at improving existing dipolar grids. Compared with existing grids, the sample grid achieves a better trade-off between the enlargement of the latitudinal-longitudinal portion and the overall smooth grid cell size transition. The second method addresses more modern and advanced grid design requirements arising from high-resolution and multi-scale <span class="hlt">ocean</span> modeling. The generated grids could potentially achieve the alignment of grid lines to the large-scale coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the grids are orthogonal curvilinear, they can be easily utilized by the majority of <span class="hlt">ocean</span> general circulation models that are based on finite difference and require grid orthogonality. The proposed grid generation algorithms can also be applied to the grid generation for regional <span class="hlt">ocean</span> modeling where complex land-sea distribution is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000032787','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000032787"><span><span class="hlt">Global</span> and Regional Axial <span class="hlt">Ocean</span> Angular Momentum Signals and Length-of-Day Variations (1985-1996)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ponte, Rui M.; Stammer, Detlef</p> <p>1999-01-01</p> <p>Changes in <span class="hlt">ocean</span> angular momentum about the polar axis (M) are related to fluctuations in zonal currents (relative component M(sub r)) and latitudinal shifts in mass (planetary component M(sub Omega)). Output from a 1 deg <span class="hlt">ocean</span> model is used to calculate <span class="hlt">global</span> M(sub r), M(sub Omega), and M time series at 5-day intervals for the period January 1985-April 1996. The annual cycle in M(sub r), M(sub Omega), and M is larger than the semiannual cycle, and M(sub Omega) amplitudes are nearly twice those of M(sub r). Year-to-year modulation of the seasonal cycle is present, but interannual variability is weak. The spectrum of M is red (background slope between omega(sup (-1) and omega(sup -2)) at subseasonal periods, implying a white or blue spectrum for the external torque on the <span class="hlt">ocean</span>. Comparisons with previous studies indicate the importance of direct atmospheric forcing in inducing subseasonal M signals, relative to instabilities and other internal sources of rapid <span class="hlt">oceanic</span> signals. Regional angular momentum estimates show that seasonal variability tends to be larger at low latitudes but there are many local maxima due to the spatial structure of zonal current and mass variability. At seasonal timescales, latitudes approximately 20 S - 10 N contribute substantial variability to M(sub Omega), while signals in M(sub r) can be traced to Antarctic Circumpolar Current transports and associated circulation. Variability in M is found to be small when compared with similar time series for the atmosphere and the solid Earth, but <span class="hlt">ocean</span> signals are significantly coherent with atmosphere-solid Earth residuals, implying a measurable <span class="hlt">oceanic</span> impact on length-of-day variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25103900','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25103900"><span>The effect of <span class="hlt">ocean</span> acidification on carbon storage and sequestration in seagrass beds; a <span class="hlt">global</span> and UK context.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garrard, Samantha L; Beaumont, Nicola J</p> <p>2014-09-15</p> <p><span class="hlt">Ocean</span> acidification will have many negative consequences for marine organisms and ecosystems, leading to a decline in many ecosystem services provided by the marine environment. This study reviews the effect of <span class="hlt">ocean</span> acidification (OA) on seagrasses, assessing how this may affect their capacity to sequester carbon in the future and providing an economic valuation of these changes. If <span class="hlt">ocean</span> acidification leads to a significant increase in above- and below-ground biomass, the capacity of seagrass to sequester carbon will be significantly increased. The associated value of this increase in sequestration capacity is approximately £500 and 600 billion <span class="hlt">globally</span> between 2010 and 2100. A proportionally similar increase in carbon sequestration value was found for the UK. This study highlights one of the few positive stories for <span class="hlt">ocean</span> acidification and underlines that sustainable management of seagrasses is critical to avoid their continued degradation and loss of carbon sequestration capacity. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ESD.....7..797R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ESD.....7..797R"><span>Revisiting <span class="hlt">ocean</span> carbon sequestration by direct injection: a <span class="hlt">global</span> carbon budget perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reith, Fabian; Keller, David P.; Oschlies, Andreas</p> <p>2016-11-01</p> <p>In this study we look beyond the previously studied effects of <span class="hlt">oceanic</span> CO2 injections on atmospheric and <span class="hlt">oceanic</span> reservoirs and also account for carbon cycle and climate feedbacks between the atmosphere and the terrestrial biosphere. Considering these additional feedbacks is important since backfluxes from the terrestrial biosphere to the atmosphere in response to reducing atmospheric CO2 can further offset the targeted reduction. To quantify these dynamics we use an Earth system model of intermediate complexity to simulate direct injection of CO2 into the deep <span class="hlt">ocean</span> as a means of emissions mitigation during a high CO2 emission scenario. In three sets of experiments with different injection depths, we simulate a 100-year injection period of a total of 70 Gt<mspace linebreak="nobreak" width="0.125em"/>C and follow <span class="hlt">global</span> carbon cycle dynamics over another 900 years. In additional parameter perturbation runs, we varied the default terrestrial photosynthesis CO2 fertilization parameterization by ±50 % in order to test the sensitivity of this uncertain carbon cycle feedback to the targeted atmospheric carbon reduction through direct CO2 injections. Simulated seawater chemistry changes and marine carbon storage effectiveness are similar to previous studies. As expected, by the end of the injection period avoided emissions fall short of the targeted 70 Gt<mspace linebreak="nobreak" width="0.125em"/>C by 16-30 % as a result of carbon cycle feedbacks and backfluxes in both land and <span class="hlt">ocean</span> reservoirs. The target emissions reduction in the parameter perturbation simulations is about 0.2 and 2 % more at the end of the injection period and about 9 % less to 1 % more at the end of the simulations when compared to the unperturbed injection runs. An unexpected feature is the effect of the model's internal variability of deep-water formation in the Southern <span class="hlt">Ocean</span>, which, in some model runs, causes additional <span class="hlt">oceanic</span> carbon uptake after injection</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.8310M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.8310M"><span>The anthropogenic influence on Iron deposition over the <span class="hlt">oceans</span>: a 3-D <span class="hlt">global</span> modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Myriokefalitakis, Stelios; Mihalopoulos, Nikos; Baker, Alex; Kanakidou, Maria</p> <p>2014-05-01</p> <p>Iron (Fe) deposition over <span class="hlt">oceans</span> is directly linked to the marine biological productivity and consequently to atmospheric CO2 concentrations. Experimental and modeling results support that both inorganic (sulphate, ammonium and nitrate) and organic (e.g. oxalate) ligands can increase the Fe mobilization. Mineral dust deposition is considered as the most important supply of bioavailable Fe in the <span class="hlt">oceans</span>. Although, due to the low soil soluble iron fractions, atmospheric processes which are also related to anthropogenic emissions, can convert iron to more soluble forms in the atmosphere. Recent studies also support that anthropogenic emissions of Fe from combustion sources also significantly contribute to the dissolved Fe atmospheric pool. The evaluation of the impact of humans on atmospheric soluble or bioavailable Fe deposition remains challenging, since Fe mobilization due to changes in anthropogenic emissions is largely uncertain. In the present study, the <span class="hlt">global</span> atmospheric Fe cycle is parameterized in the 3-D chemical transport <span class="hlt">global</span> model TM4-ECPL and the model is used to calculate the Fe deposition over the <span class="hlt">oceans</span>. The model considers explicitly organic, sulfur and nitrogen gas-phase chemistry, aqueous-phase organic chemistry, including oxalate and all major aerosol constituents. TM4-ECPL simulates the organic and inorganic ligand-promoted mineral Fe dissolution and also aqueous-phase photochemical reactions between different forms of Fe (III/II). Primary emissions of Fe associated with dust and soluble Fe from combustion processes as well as atmospheric processing of the emitted Fe is taken into account in the model Sensitivity simulations are performed to study the impact of anthropogenic emissions on Fe deposition. For this preindustrial, present and future emission scenarios are used in the model in order to examine the response of chemical composition of iron-containing aerosols to environmental changes. The release of soluble iron associated with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED404119.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED404119.pdf"><span>The Living <span class="hlt">Ocean</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>National Aeronautics and Space Administration, Washington, DC.</p> <p></p> <p>This teaching guide contains information, activities, and discussion questions and answers about <span class="hlt">oceans</span> for grades nine and ten. The information section covers the following topics: studying <span class="hlt">global</span> <span class="hlt">ocean</span> color from space, what can be seen from space, phytoplankton, carbon dioxide, and the greenhouse effect of the earth. (MKR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000092882','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000092882"><span>Projected Impact of Climate Change on the Water and Salt Budgets of the Arctic <span class="hlt">Ocean</span> by a <span class="hlt">Global</span> Climate Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, James R.; Russell, Gary L.</p> <p>1996-01-01</p> <p>The annual flux of freshwater into the Arctic <span class="hlt">Ocean</span> by the atmosphere and rivers is balanced by the export of sea ice and <span class="hlt">oceanic</span> freshwater. Two 150-year simulations of a <span class="hlt">global</span> climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. Relative to the control, the last 50-year period of the GHG experiment indicates that the total inflow of water from the atmosphere and rivers increases by 10% primarily due to an increase in river discharge, the annual sea-ice export decreases by about half, the <span class="hlt">oceanic</span> liquid water export increases, salinity decreases, sea-ice cover decreases, and the total mass and sea-surface height of the Arctic <span class="hlt">Ocean</span> increase. The closed, compact, and multi-phased nature of the hydrologic cycle in the Arctic <span class="hlt">Ocean</span> makes it an ideal test of water budgets that could be included in model intercomparisons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GBioC..32..516K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GBioC..32..516K"><span>The Impact of Variable Phytoplankton Stoichiometry on Projections of Primary Production, Food Quality, and Carbon Uptake in the <span class="hlt">Global</span> <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwiatkowski, Lester; Aumont, Olivier; Bopp, Laurent; Ciais, Philippe</p> <p>2018-04-01</p> <p><span class="hlt">Ocean</span> biogeochemical models are integral components of Earth system models used to project the evolution of the <span class="hlt">ocean</span> carbon sink, as well as potential changes in the physical and chemical environment of marine ecosystems. In such models the stoichiometry of phytoplankton C:N:P is typically fixed at the Redfield ratio. The observed stoichiometry of phytoplankton, however, has been shown to considerably vary from Redfield values due to plasticity in the expression of phytoplankton cell structures with different elemental compositions. The intrinsic structure of fixed C:N:P models therefore has the potential to bias projections of the marine response to climate change. We assess the importance of variable stoichiometry on 21st century projections of net primary production, food quality, and <span class="hlt">ocean</span> carbon uptake using the recently developed Pelagic Interactions Scheme for Carbon and Ecosystem Studies Quota (PISCES-QUOTA) <span class="hlt">ocean</span> biogeochemistry model. The model simulates variable phytoplankton C:N:P stoichiometry and was run under historical and business-as-usual scenario forcing from 1850 to 2100. PISCES-QUOTA projects similar 21st century <span class="hlt">global</span> net primary production decline (7.7%) to current generation fixed stoichiometry models. <span class="hlt">Global</span> phytoplankton N and P content or food quality is projected to decline by 1.2% and 6.4% over the 21st century, respectively. The largest reductions in food quality are in the oligotrophic subtropical gyres and Arctic <span class="hlt">Ocean</span> where declines by the end of the century can exceed 20%. Using the change in the carbon export efficiency in PISCES-QUOTA, we estimate that fixed stoichiometry models may be underestimating 21st century cumulative <span class="hlt">ocean</span> carbon uptake by 0.5-3.5% (2.0-15.1 PgC).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EOSTr..95..241S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EOSTr..95..241S"><span>Highlights of the 2014 <span class="hlt">Ocean</span> Sciences Meeting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharp, Jonathan; Briscoe, Melbourne; Itsweire, Eric</p> <p>2014-07-01</p> <p>The 2014 <span class="hlt">Ocean</span> Sciences Meeting was the 17th biennial gathering since the inception of <span class="hlt">ocean</span> sciences meetings in 1982. A <span class="hlt">joint</span> venture of the Association for the Sciences of Limnology and Oceanography (ASLO), The Oceanography Society (TOS), and the <span class="hlt">Ocean</span> Sciences section of AGU, the meeting was by far the largest ever: More than 5600 attendees made this meeting more than 30% larger than any previous one. Forty percent of attendees live outside the United States, hailing from 55 countries, showing the importance of this meeting as an international gathering of <span class="hlt">ocean</span> scientists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160014672','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160014672"><span><span class="hlt">Global</span> <span class="hlt">Ocean</span> Evaporation Increases Since 1960 in Climate Reanalyses: How Accurate Are They?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Franklin R.; Roberts, Jason B.; Bosilovich, Michael G.</p> <p>2016-01-01</p> <p>AGCMs w/ Specified SSTs (AMIPs) GEOS-5, ERA-20CM Ensembles Incorporate best historical estimates of SST, sea ice, radiative forcing Atmospheric "weather noise" is inconsistent with specified SST. Instantaneous Sfc fluxes can be wrong sign (e.g. Indian <span class="hlt">Ocean</span> Monsoon, high latitude <span class="hlt">oceans</span>). Averaging over ensemble members helps isolate SST-forced signal. Reduced Observational Reanalyses: NOAA 20CR V2C, ERA-20C, JRA-55C Incorporate observed Sfc Press (20CR), Marine Winds (ERA-20C) and rawinsondes (JRA-55C) to recover much of true synoptic or weather w/o shock of new sat obs. Comprehensive Reanalyses (MERRA-2) Full suite of observational constraints- both conventional and remote sensing. But... substantial uncertainties owing to evolving satellite observing system. Multi-source Statistically Blended OAFlux, LargeYeager Blend reanalysis, satellite, and <span class="hlt">ocean</span> buoy information. While climatological biases are removed, non-physical trends or variations in components remain. Satellite Retrievals GSSTF3, SeaFlux, HOAPS3... <span class="hlt">Global</span> coverage. Retrieved near sfc wind speed, & humidity used with SST to drive accurate bulk aerodynamic flux estimates. Satellite inter-calibration, spacecraft pointing variations crucial. Short record ( late 1987-present). In situ Measurements ICOADS, IVAD, Res Cruises VOS and buoys offer direct measurements. Sparse data coverage (esp south of 30S. Changes in measurement techniques (e.g. shipboard anemometer height).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.4214I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.4214I"><span>Upper <span class="hlt">ocean</span> O2 trends: 1958-2015</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ito, Takamitsu; Minobe, Shoshiro; Long, Matthew C.; Deutsch, Curtis</p> <p>2017-05-01</p> <p>Historic observations of dissolved oxygen (O2) in the <span class="hlt">ocean</span> are analyzed to quantify multidecadal trends and variability from 1958 to 2015. Additional quality control is applied, and the resultant oxygen anomaly field is used to quantify upper <span class="hlt">ocean</span> O2 trends at <span class="hlt">global</span> and hemispheric scales. A widespread negative O2 trend is beginning to emerge from the envelope of interannual variability. <span class="hlt">Ocean</span> reanalysis data are used to evaluate relationships with changes in <span class="hlt">ocean</span> heat content (OHC) and oxygen solubility (O2,sat). <span class="hlt">Global</span> O2 decline is evident after the 1980s, accompanied by an increase in <span class="hlt">global</span> OHC. The <span class="hlt">global</span> upper <span class="hlt">ocean</span> O2 inventory (0-1000 m) changed at the rate of -243 ± 124 T mol O2 per decade. Further, the O2 inventory is negatively correlated with the OHC (r = -0.86; 0-1000 m) and the regression coefficient of O2 to OHC is approximately -8.2 ± 0.66 nmol O2 J-1, on the same order of magnitude as the simulated O2-heat relationship typically found in <span class="hlt">ocean</span> climate models. Variability and trends in the observed upper <span class="hlt">ocean</span> O2 concentration are dominated by the apparent oxygen utilization component with relatively small contributions from O2,sat. This indicates that changing <span class="hlt">ocean</span> circulation, mixing, and/or biochemical processes, rather than the direct thermally induced solubility effects, are the primary drivers for the observed O2 changes. The spatial patterns of the multidecadal trend include regions of enhanced <span class="hlt">ocean</span> deoxygenation including the subpolar North Pacific, eastern boundary upwelling systems, and tropical oxygen minimum zones. Further studies are warranted to understand and attribute the <span class="hlt">global</span> O2 trends and their regional expressions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ClDy...37.1929V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ClDy...37.1929V"><span><span class="hlt">Global</span> and regional <span class="hlt">ocean</span> carbon uptake and climate change: sensitivity to a substantial mitigation scenario</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vichi, Marcello; Manzini, Elisa; Fogli, Pier Giuseppe; Alessandri, Andrea; Patara, Lavinia; Scoccimarro, Enrico; Masina, Simona; Navarra, Antonio</p> <p>2011-11-01</p> <p>Under future scenarios of business-as-usual emissions, the <span class="hlt">ocean</span> storage of anthropogenic carbon is anticipated to decrease because of <span class="hlt">ocean</span> chemistry constraints and positive feedbacks in the carbon-climate dynamics, whereas it is still unknown how the <span class="hlt">oceanic</span> carbon cycle will respond to more substantial mitigation scenarios. To evaluate the natural system response to prescribed atmospheric "target" concentrations and assess the response of the <span class="hlt">ocean</span> carbon pool to these values, 2 centennial projection simulations have been performed with an Earth System Model that includes a fully coupled carbon cycle, forced in one case with a mitigation scenario and the other with the SRES A1B scenario. End of century <span class="hlt">ocean</span> uptake with the mitigation scenario is projected to return to the same magnitude of carbon fluxes as simulated in 1960 in the Pacific <span class="hlt">Ocean</span> and to lower values in the Atlantic. With A1B, the major <span class="hlt">ocean</span> basins are instead projected to decrease the capacity for carbon uptake <span class="hlt">globally</span> as found with simpler carbon cycle models, while at the regional level the response is contrasting. The model indicates that the equatorial Pacific may increase the carbon uptake rates in both scenarios, owing to enhancement of the biological carbon pump evidenced by an increase in Net Community Production (NCP) following changes in the subsurface equatorial circulation and enhanced iron availability from extratropical regions. NCP is a proxy of the bulk organic carbon made available to the higher trophic levels and potentially exportable from the surface layers. The model results indicate that, besides the localized increase in the equatorial Pacific, the NCP of lower trophic levels in the northern Pacific and Atlantic <span class="hlt">oceans</span> is projected to be halved with respect to the current climate under a substantial mitigation scenario at the end of the twenty-first century. It is thus suggested that changes due to cumulative carbon emissions up to present and the projected concentration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23968992','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23968992"><span><span class="hlt">Ocean</span> in peril: reforming the management of <span class="hlt">global</span> <span class="hlt">ocean</span> living resources in areas beyond national jurisdiction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gjerde, Kristina M; Currie, Duncan; Wowk, Kateryna; Sack, Karen</p> <p>2013-09-30</p> <p>This article presents the outcome of research aimed at assisting governments in meeting their commitments and legal obligations for sustainable fisheries, based on increasing evidence that <span class="hlt">global</span> fisheries are in crisis. The article assesses the effectiveness of the existing legal and institutional framework for high seas living resources. It focuses on: (1) the role of regional fisheries management organizations (RFMOs); (2) tools for compliance and enforcement to stem illegal fishing; and (3) mechanisms for habitat protection. The article further highlights a variety of options for addressing key weaknesses and gaps in current <span class="hlt">ocean</span> governance, including United Nations General Assembly (UNGA) resolutions, reforms at the regional level, as well as a possible new legal instrument, with a view to informing international discussions on ways to ensure the sustainable use of high seas resources without compromising the health of the marine environment. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PalOc..31..564V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PalOc..31..564V"><span>Effects of Drake Passage on a strongly eddying <span class="hlt">global</span> <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viebahn, Jan P.; von der Heydt, Anna S.; Le Bars, Dewi; Dijkstra, Henk A.</p> <p>2016-05-01</p> <p>The climate impact of <span class="hlt">ocean</span> gateway openings during the Eocene-Oligocene transition is still under debate. Previous model studies employed grid resolutions at which the impact of mesoscale eddies has to be parameterized. We present results of a state-of-the-art eddy-resolving <span class="hlt">global</span> <span class="hlt">ocean</span> model with a closed Drake Passage and compare with results of the same model at noneddying resolution. An analysis of the pathways of heat by decomposing the meridional heat transport into eddy, horizontal, and overturning circulation components indicates that the model behavior on the large scale is qualitatively similar at both resolutions. Closing Drake Passage induces (i) sea surface warming around Antarctica due to equatorward expansion of the subpolar gyres, (ii) the collapse of the overturning circulation related to North Atlantic Deep Water formation leading to surface cooling in the North Atlantic, and (iii) significant equatorward eddy heat transport near Antarctica. However, quantitative details significantly depend on the chosen resolution. The warming around Antarctica is substantially larger for the noneddying configuration (˜5.5°C) than for the eddying configuration (˜2.5°C). This is a consequence of the subpolar mean flow which partitions differently into gyres and circumpolar current at different resolutions. We conclude that for a deciphering of the different mechanisms active in Eocene-Oligocene climate change detailed analyses of the pathways of heat in the different climate subsystems are crucial in order to clearly identify the physical processes actually at work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1438736','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1438736"><span><span class="hlt">Global</span> Climate Impacts of Fixing the Southern <span class="hlt">Ocean</span> Shortwave Radiation Bias in the Community Earth System Model (CESM)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kay, Jennifer E.; Wall, Casey; Yettella, Vineel</p> <p></p> <p>Here, a large, long-standing, and pervasive climate model bias is excessive absorbed shortwave radiation (ASR) over the midlatitude <span class="hlt">oceans</span>, especially the Southern <span class="hlt">Ocean</span>. This study investigates both the underlying mechanisms for and climate impacts of this bias within the Community Earth System Model, version 1, with the Community Atmosphere Model, version 5 [CESM1(CAM5)]. Excessive Southern <span class="hlt">Ocean</span> ASR in CESM1(CAM5) results in part because low-level clouds contain insufficient amounts of supercooled liquid. In a present-day atmosphere-only run, an observationally motivated modification to the shallow convection detrainment increases supercooled cloud liquid, brightens low-level clouds, and substantially reduces the Southern <span class="hlt">Ocean</span> ASR bias.more » Tuning to maintain <span class="hlt">global</span> energy balance enables reduction of a compensating tropical ASR bias. In the resulting preindustrial fully coupled run with a brighter Southern <span class="hlt">Ocean</span> and dimmer tropics, the Southern <span class="hlt">Ocean</span> cools and the tropics warm. As a result of the enhanced meridional temperature gradient, poleward heat transport increases in both hemispheres (especially the Southern Hemisphere), and the Southern Hemisphere atmospheric jet strengthens. Because northward cross-equatorial heat transport reductions occur primarily in the <span class="hlt">ocean</span> (80%), not the atmosphere (20%), a proposed atmospheric teleconnection linking Southern <span class="hlt">Ocean</span> ASR bias reduction and cooling with northward shifts in tropical precipitation has little impact. In summary, observationally motivated supercooled liquid water increases in shallow convective clouds enable large reductions in long-standing climate model shortwave radiation biases. Of relevance to both model bias reduction and climate dynamics, quantifying the influence of Southern <span class="hlt">Ocean</span> cooling on tropical precipitation requires a model with dynamic <span class="hlt">ocean</span> heat transport.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1438736-global-climate-impacts-fixing-southern-ocean-shortwave-radiation-bias-community-earth-system-model-cesm','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1438736-global-climate-impacts-fixing-southern-ocean-shortwave-radiation-bias-community-earth-system-model-cesm"><span><span class="hlt">Global</span> Climate Impacts of Fixing the Southern <span class="hlt">Ocean</span> Shortwave Radiation Bias in the Community Earth System Model (CESM)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Kay, Jennifer E.; Wall, Casey; Yettella, Vineel; ...</p> <p>2016-06-10</p> <p>Here, a large, long-standing, and pervasive climate model bias is excessive absorbed shortwave radiation (ASR) over the midlatitude <span class="hlt">oceans</span>, especially the Southern <span class="hlt">Ocean</span>. This study investigates both the underlying mechanisms for and climate impacts of this bias within the Community Earth System Model, version 1, with the Community Atmosphere Model, version 5 [CESM1(CAM5)]. Excessive Southern <span class="hlt">Ocean</span> ASR in CESM1(CAM5) results in part because low-level clouds contain insufficient amounts of supercooled liquid. In a present-day atmosphere-only run, an observationally motivated modification to the shallow convection detrainment increases supercooled cloud liquid, brightens low-level clouds, and substantially reduces the Southern <span class="hlt">Ocean</span> ASR bias.more » Tuning to maintain <span class="hlt">global</span> energy balance enables reduction of a compensating tropical ASR bias. In the resulting preindustrial fully coupled run with a brighter Southern <span class="hlt">Ocean</span> and dimmer tropics, the Southern <span class="hlt">Ocean</span> cools and the tropics warm. As a result of the enhanced meridional temperature gradient, poleward heat transport increases in both hemispheres (especially the Southern Hemisphere), and the Southern Hemisphere atmospheric jet strengthens. Because northward cross-equatorial heat transport reductions occur primarily in the <span class="hlt">ocean</span> (80%), not the atmosphere (20%), a proposed atmospheric teleconnection linking Southern <span class="hlt">Ocean</span> ASR bias reduction and cooling with northward shifts in tropical precipitation has little impact. In summary, observationally motivated supercooled liquid water increases in shallow convective clouds enable large reductions in long-standing climate model shortwave radiation biases. Of relevance to both model bias reduction and climate dynamics, quantifying the influence of Southern <span class="hlt">Ocean</span> cooling on tropical precipitation requires a model with dynamic <span class="hlt">ocean</span> heat transport.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AREPS..44..107M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AREPS..44..107M"><span><span class="hlt">Ocean</span> Basin Evolution and <span class="hlt">Global</span>-Scale Plate Reorganization Events Since Pangea Breakup</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller, R. Dietmar; Seton, Maria; Zahirovic, Sabin; Williams, Simon E.; Matthews, Kara J.; Wright, Nicky M.; Shephard, Grace E.; Maloney, Kayla T.; Barnett-Moore, Nicholas; Hosseinpour, Maral; Bower, Dan J.; Cannon, John</p> <p>2016-06-01</p> <p>We present a revised <span class="hlt">global</span> plate motion model with continuously closing plate boundaries ranging from the Triassic at 230 Ma to the present day, assess differences among alternative absolute plate motion models, and review <span class="hlt">global</span> tectonic events. Relatively high mean absolute plate motion rates of approximately 9-10 cm yr-1 between 140 and 120 Ma may be related to transient plate motion accelerations driven by the successive emplacement of a sequence of large igneous provinces during that time. An event at ˜100 Ma is most clearly expressed in the Indian <span class="hlt">Ocean</span> and may reflect the initiation of Andean-style subduction along southern continental Eurasia, whereas an acceleration at ˜80 Ma of mean rates from 6 to 8 cm yr-1 reflects the initial northward acceleration of India and simultaneous speedups of plates in the Pacific. An event at ˜50 Ma expressed in relative, and some absolute, plate motion changes around the globe and in a reduction of <span class="hlt">global</span> mean plate speeds from about 6 to 4-5 cm yr-1 indicates that an increase in collisional forces (such as the India-Eurasia collision) and ridge subduction events in the Pacific (such as the Izanagi-Pacific Ridge) play a significant role in modulating plate velocities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS51C1265C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS51C1265C"><span><span class="hlt">Ocean</span> products delivered by the Mercator <span class="hlt">Ocean</span> Service Department</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crosnier, L.; Durand, E.; Soulat, F.; Messal, F.; Buarque, S.; Toumazou, V.; Landes, V.; Drevillon, M.; Lellouche, J.</p> <p>2008-12-01</p> <p>The newly created Service Department at Mercator <span class="hlt">Ocean</span> is now offering various services for academic and private <span class="hlt">ocean</span> applications. Mercator <span class="hlt">Ocean</span> runs operationally <span class="hlt">ocean</span> forecast systems for the <span class="hlt">Global</span> and North Atlantic <span class="hlt">Ocean</span>. These systems are based on an <span class="hlt">ocean</span> general circulation model NEMO as well as on data assimilation of sea level anomalies, sea surface temperature and temperature and salinity vertical profiles. Three dimensional <span class="hlt">ocean</span> fields of temperature, salinity and currents are updated and available weekly, including analysis and 2 weeks forecast fields. The Mercator <span class="hlt">Ocean</span> service department is now offering a wide range of <span class="hlt">ocean</span> derived products. This presentation will display some of the various products delivered in the framework of academic and private <span class="hlt">ocean</span> applications: " Monitoring of the <span class="hlt">ocean</span> current at the surface and at depth in several geographical areas for offshore oil platform, for offshore satellite launch platform, for transatlantic sailing or rowing boat races. " Monitoring of <span class="hlt">ocean</span> climate indicators (Coral bleaching...) for marine reserve survey; " Monitoring of upwelling systems for fisheries; " Monitoring of the <span class="hlt">ocean</span> heat content for tropical cyclone monitoring. " Monitoring of the <span class="hlt">ocean</span> temperature/salinity and currents to guide research vessels during scientific cruises. The Mercator <span class="hlt">Ocean</span> products catalogue will grow wider in the coming years, especially in the framework of the European GMES My<span class="hlt">Ocean</span> project (FP7).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JMS....65....3S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JMS....65....3S"><span>1/32° real-time <span class="hlt">global</span> <span class="hlt">ocean</span> prediction and value-added over 1/16° resolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shriver, J. F.; Hurlburt, H. E.; Smedstad, O. M.; Wallcraft, A. J.; Rhodes, R. C.</p> <p>2007-03-01</p> <p>A 1/32° <span class="hlt">global</span> <span class="hlt">ocean</span> nowcast/forecast system has been developed by the Naval Research Laboratory at the Stennis Space Center. It started running at the Naval Oceanographic Office in near real-time on 1 Nov. 2003 and has been running daily in real-time since 1 Mar. 2005. It became an operational system on 6 March 2006, replacing the existing 1/16° system which ceased operation on 12 March 2006. Both systems use the NRL Layered <span class="hlt">Ocean</span> Model (NLOM) with assimilation of sea surface height from satellite altimeters and sea surface temperature from multi-channel satellite infrared radiometers. Real-time and archived results are available online at http://www.<span class="hlt">ocean.nrlssc.navy.mil/global</span>_nlom. The 1/32° system has improvements over the earlier system that can be grouped into two categories: (1) better resolution and representation of dynamical processes and (2) design modifications. The design modifications are the result of accrued knowledge since the development of the earlier 1/16° system. The improved horizontal resolution of the 1/32° system has significant dynamical benefits which increase the ability of the model to accurately nowcast and skillfully forecast. At the finer resolution, current pathways and their transports become more accurate, the sea surface height (SSH) variability increases and becomes more realistic and even the <span class="hlt">global</span> <span class="hlt">ocean</span> circulation experiences some changes (including inter-basin exchange). These improvements make the 1/32° system a better dynamical interpolator of assimilated satellite altimeter track data, using a one-day model forecast as the first guess. The result is quantitatively more accurate nowcasts, as is illustrated by several model-data comparisons. Based on comparisons with <span class="hlt">ocean</span> color imagery in the northwestern Arabian Sea and the Gulf of Oman, the 1/32° system has even demonstrated the ability to map small eddies, 25-75 km in diameter, with 70% reliability and a median eddy center location error of 22.5 km, a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MAP...130...23K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MAP...130...23K"><span>Tropical cyclones over the North Indian <span class="hlt">Ocean</span>: experiments with the high-resolution <span class="hlt">global</span> icosahedral grid point model GME</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumkar, Yogesh V.; Sen, P. N.; Chaudhari, Hemankumar S.; Oh, Jai-Ho</p> <p>2018-02-01</p> <p>In this paper, an attempt has been made to conduct a numerical experiment with the high-resolution <span class="hlt">global</span> model GME to predict the tropical storms in the North Indian <span class="hlt">Ocean</span> during the year 2007. Numerical integrations using the icosahedral hexagonal grid point <span class="hlt">global</span> model GME were performed to study the evolution of tropical cyclones, viz., Akash, Gonu, Yemyin and Sidr over North Indian <span class="hlt">Ocean</span> during 2007. It has been seen that the GME model forecast underestimates cyclone's intensity, but the model can capture the evolution of cyclone's intensity especially its weakening during landfall, which is primarily due to the cutoff of the water vapor supply in the boundary layer as cyclones approach the coastal region. A series of numerical simulation of tropical cyclones have been performed with GME to examine model capability in prediction of intensity and track of the cyclones. The model performance is evaluated by calculating the root mean square errors as cyclone track errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.G21C..04J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.G21C..04J"><span><span class="hlt">Ocean</span> Bottom Pressure Seasonal Cycles and Decadal Trends from GRACE Release-05: <span class="hlt">Ocean</span> Circulation Implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, G. C.; Chambers, D. P.</p> <p>2013-12-01</p> <p><span class="hlt">Ocean</span> mass variations are important for diagnosing sea level budgets, the hydrological cycle and <span class="hlt">global</span> energy budget, as well as <span class="hlt">ocean</span> circulation variability. Here seasonal cycles and decadal trends of <span class="hlt">ocean</span> mass from January 2003 to December 2012, both <span class="hlt">global</span> and regional, are analyzed using GRACE Release 05 data. The trend of <span class="hlt">global</span> flux of mass into the <span class="hlt">ocean</span> approaches 2 cm decade-1 in equivalent sea level rise. Regional trends are of similar magnitude, with the North Pacific, South Atlantic, and South Indian <span class="hlt">oceans</span> generally gaining mass and other regions losing mass. These trends suggest a spin-down of the North Pacific western boundary current extension and the Antarctic Circumpolar Current in the South Atlantic and South Indian <span class="hlt">oceans</span>. The <span class="hlt">global</span> average seasonal cycle of <span class="hlt">ocean</span> mass is about 1 cm in amplitude, with a maximum in early October and volume fluxes in and out of the <span class="hlt">ocean</span> reaching 0.5 Sv (1 Sv = 1 × 106 m3 s-1) when integrated over the area analyzed here. Regional patterns of seasonal <span class="hlt">ocean</span> mass change have typical amplitudes of 1-4 cm, and include maxima in the subtropics and minima in the subpolar regions in hemispheric winters. The subtropical mass gains and subpolar mass losses in the winter spin up both subtropical and subpolar gyres, hence the western boundary current extensions. Seasonal variations in these currents are order 10 Sv, but since the associated depth-averaged current variations are only order 0.1 cm s-1, they would be difficult to detect using in situ oceanographic instruments. a) Amplitude (colors, in cm) and b) phase (colors, in months of the year) of an annual harmonic fit to monthly GRACE Release 05 CSR 500 km smoothed maps (concurrently with a trend and the semiannual harmonic). The 97.5% confidence interval for difference from zero is also indicated (solid black line). Data within 300 km of coastlines are not considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.1041G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.1041G"><span>The new version of the Institute of Numerical Mathematics Sigma <span class="hlt">Ocean</span> Model (INMSOM) for simulation of <span class="hlt">Global</span> <span class="hlt">Ocean</span> circulation and its variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gusev, Anatoly; Fomin, Vladimir; Diansky, Nikolay; Korshenko, Evgeniya</p> <p>2017-04-01</p> <p>) Improvement river runoff algorithm accounting the total amount of discharged water. 6) Using explicit leapfrog time scheme for all lateral operators and implicit Euler scheme for vertical diffusion and viscosity. The INMSOM is tested by reproducing World <span class="hlt">Ocean</span> circulation and thermohaline characteristics using the well-proved CORE dataset. The presentation is devoted to the analysis of new INMSOM simulation results, estimation of their quality and comparison to the ones previously obtained with the INMOM. The main aim of the INMSOM development is using it as the <span class="hlt">oceanic</span> component of the next version of INMCM. The work was supported by the Russian Foundation for Basic Research (grants № 16-05-00534 and № 15-05-07539) References 1. Danabasoglu, G., Yeager S.G., Bailey D., et al., 2014: North Atlantic simulations in Coordinated <span class="hlt">Ocean</span>-ice Reference Experiments phase II (CORE-II). Part I: Mean states. <span class="hlt">Ocean</span> Modelling, 73, 76-107. 2. Danabasoglu, G., Yeager S.G., Kim W.M. et al., 2016: North Atlantic simulations in Coordinated <span class="hlt">Ocean</span>-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to decadal variability. <span class="hlt">Ocean</span> Modelling, 97, 65-90. 3. Downes S.M., Farneti R., Uotila P. et al. An assessment of Southern <span class="hlt">Ocean</span> water masses and sea ice during 1988-2007 in a suite of interannual CORE-II simulations. <span class="hlt">Ocean</span> Modelling (2015), 94, 67-94. 4. Farneti R., Downes S.M., Griffies S.M. et al. An assessment of Antarctic Circumpolar Current and Southern <span class="hlt">Ocean</span> Meridional Overturning Circulation during 1958-2007 in a suite of interannual CORE-II simulations, <span class="hlt">Ocean</span> Modelling (2015), 93, 84-120. 5. Gusev A.V. and Diansky N.A. Numerical simulation of the World <span class="hlt">ocean</span> circulation and its climatic variability for 1948-2007 using the INMOM. Izvestiya, Atmospheric and <span class="hlt">Oceanic</span> Physics, 2014, V. 50, N. 1, P. 1-12 6. Large, W., Yeager, S., 2009. The <span class="hlt">global</span> climatology of an interannually varying air-sea flux data set. Clim Dyn, V. 33, P. 341-364. 7. Ushakov K.V., Grankina T.B., Ibraev R</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EOSTr..83R.289S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EOSTr..83R.289S"><span>State estimation improves prospects for <span class="hlt">ocean</span> research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stammer, Detlef; Wunsch, C.; Fukumori, I.; Marshall, J.</p> <p></p> <p>Rigorous <span class="hlt">global</span> <span class="hlt">ocean</span> state estimation methods can now be used to produce dynamically consistent time-varying model/data syntheses, the results of which are being used to study a variety of important scientific problems. Figure 1 shows a schematic of a complete <span class="hlt">ocean</span> observing and synthesis system that includes <span class="hlt">global</span> observations and state-of-the-art <span class="hlt">ocean</span> general circulation models (OGCM) run on modern computer platforms. A <span class="hlt">global</span> observing system is described in detail in Smith and Koblinsky [2001],and the present status of <span class="hlt">ocean</span> modeling and anticipated improvements are addressed by Griffies et al. [2001]. Here, the focus is on the third component of state estimation: the synthesis of the observations and a model into a unified, dynamically consistent estimate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....5938M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5938M"><span>Indian-Southern <span class="hlt">Ocean</span> Latitudinal Transect (ISOLAT): A proposal for the recovery of high-resolution sedimentary records in the western Indian <span class="hlt">Ocean</span> sector of the Southern <span class="hlt">Ocean</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mackensen, A.; Zahn, R.; Hall, I.; Kuhn, G.; Koc, N.; Francois, R.; Hemming, S.; Goldstein, S.; Rogers, J.; Ehrmann, W.</p> <p>2003-04-01</p> <p>Quantifying <span class="hlt">oceanic</span> variability at timescales of <span class="hlt">oceanic</span>, atmospheric, and cryospheric processes are the fundamental objectives of the international IMAGES program. In this context the Southern <span class="hlt">Ocean</span> plays a leading role in that it is involved, through its influence on <span class="hlt">global</span> <span class="hlt">ocean</span> circulation and carbon budget, with the development and maintenance of the Earth's climate system. The seas surrounding Antarctica contain the world's only zonal circum-<span class="hlt">global</span> current system that entrains water masses from the three main <span class="hlt">ocean</span> basins, and maintains the thermal isolation of Antarctica from warmer surface waters to the north. Furthermore, the Southern <span class="hlt">Ocean</span> is a major site of bottom and intermediate water formation and thus actively impacts the <span class="hlt">global</span> thermohaline circulation (THC). This proposal is an outcome of the IMAGES Southern <span class="hlt">Ocean</span> Working Group and constitutes one component of a suite of new IMAGES/IODP initiatives that aim at resolving past variability of the Antarctic Circumpolar Current (ACC) on orbital and sub-orbital timescales and its involvement with rapid <span class="hlt">global</span> <span class="hlt">ocean</span> variability and climate instability. The primary aim of this proposal is to determine millennial- to sub-centennial scale variability of the ACC and the ensuing Atlantic-Indian water transports, including surface transports and deep-water flow. We will focus on periods of rapid <span class="hlt">ocean</span> and climate change and assess the role of the Southern <span class="hlt">Ocean</span> in these changes, both in terms of its thermohaline circulation and biogeochemical inventories. We propose a suite of 11 sites that form a latitudinal transect across the ACC in the westernmost Indian <span class="hlt">Ocean</span> sector of the Southern <span class="hlt">Ocean</span>. The transect is designed to allow the reconstruction of ACC variability across a range of latitudes in conjunction with meridional shifts of the surface <span class="hlt">ocean</span> fronts. The northernmost reaches of the transect extend into the Agulhas Current and its retroflection system which is a key component of the THC warm water return</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25083749','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25083749"><span>Background concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in the <span class="hlt">global</span> <span class="hlt">oceanic</span> atmosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morales, Laura; Dachs, Jordi; González-Gaya, Belén; Hernán, Gema; Abalos, Manuela; Abad, Esteban</p> <p>2014-09-02</p> <p>The remote <span class="hlt">oceans</span> are among the most pristine environments in the world, away from sources of anthropogenic persistent organic pollutants (POP), but nevertheless recipients of atmospheric deposition of POPs that have undergone long-range atmospheric transport (LRAT). In this work, the background occurrence of gas and aerosol phase polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCB) is evaluated for the first time in the atmosphere of the tropical and subtropical Atlantic, Pacific, and Indian <span class="hlt">oceans</span>. Thirty-nine air samples were collected during the eight-month Malaspina circumnavigation cruise onboard the R/V Hespérides. The background levels of dioxins and dl-PCBs remained very low and in many cases very close to or below the limit of detection. Expectedly, the levels of PCBs were higher than dioxins, PCB#118 being the most abundant compound. In the particular case of dioxins, octachlorodibenzo-p-dioxin (OCDD) was the most abundant PCDD/F congener. Distribution of dl-PCB is dominated by the gas phase, while for PCDD/F the aerosol phase concentrations were higher, particularly for the more hydrophobic congeners. The Atlantic <span class="hlt">Ocean</span> presented on average the highest PCDD/F and dl-PCB concentrations, being lower in the southern hemisphere. The assessment of air mass back trajectories show a clear influence of continental source regions, and lower concentrations when the air mass has an <span class="hlt">oceanic</span> origin. In addition, the samples affected by an <span class="hlt">oceanic</span> air mass are characterized by a lower contribution of the less chlorinated dioxins in comparison with the furans, consistent with the reported higher reaction rate constants of dibenzo-p-dioxins with OH radicals than those of dibenzofurans. The total dry atmospheric deposition of aerosol-bound ∑PCDD/F and ∑dl-PCB to the <span class="hlt">global</span> <span class="hlt">oceans</span> was estimated to be 354 and 896 kg/year, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010033255&hterms=Weak+signals&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DWeak%2Bsignals','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010033255&hterms=Weak+signals&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DWeak%2Bsignals"><span><span class="hlt">Global</span> and Regional Axial <span class="hlt">Ocean</span> Angular Momentum Signals and Length-of-day Variations (1985-1996)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ponte, Rui M.; Stammer, Detlef</p> <p>2000-01-01</p> <p>Changes in <span class="hlt">ocean</span> angular momentum M about the polar axis are related to fluctuations in zonal currents (relative component M(sub tau) and latitudinal shifts in mass (planetary component M(sub Omega). Output from a 1 deg. <span class="hlt">ocean</span> model is used to calculate <span class="hlt">global</span> M(sub tau), (sub Omega), and M time series at 5 day intervals for the period January 1985 to April 1996. The annual cycle in M(sub tau), M(sub Omega), and M is larger than the semiannual cycle, and M(sub Omega) amplitudes are nearly twice those of M(sub tau). Year-to-year modulation of the seasonal cycle is present, but interannual variability is weak. The spectrum of M is red (background slope between omega(sup -1) and omega(sup -2) at sub-seasonal periods, implying a white or blue spectrum for the external torque on the <span class="hlt">ocean</span>. Comparisons with previous studies indicate the importance of direct atmospheric forcing in inducing sub-seasonal M signals, relative to instabilities and other internal sources of rapid <span class="hlt">oceanic</span> signals. Regional angular momentum estimates show that seasonal variability tends to be larger at low latitudes, but many local maxima exist because of the spatial structure of zonal current and mass variability. At seasonal timescales, latitudes approx. 20 deg. S - 10 deg. N contribute substantial variability to M(sub Omega), while signals in M(sub tau) can be traced to Antarctic Circumpolar Current transports and associated circulation. Variability in M is found to be small when compared with similar time series for the atmosphere and the solid Earth, but <span class="hlt">ocean</span> signals are significantly coherent with atmosphere-solid Earth residuals, implying a measurable <span class="hlt">oceanic</span> impact on length-of-day variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060035633&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dworlds%2Boceans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060035633&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dworlds%2Boceans"><span>Spacebased Observation of <span class="hlt">Global</span> <span class="hlt">Ocean</span> Surface Wind Fields</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Polito, P. S.; Liu, W. T.</p> <p>1997-01-01</p> <p>The <span class="hlt">ocean</span> and the atmosphere are dynamically coupled by the transport of momentum which is driven by the wind shear at the sea surface. However, in situ wind measurements are relatively sparse over most of the world's <span class="hlt">ocean</span> and are largely limited to the locations of shipping routes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.7992R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.7992R"><span>The 2004 Sumatra tsunami in the Southeastern Pacific <span class="hlt">Ocean</span>: New <span class="hlt">Global</span> Insight from Observations and Modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rabinovich, A. B.; Titov, V. V.; Moore, C. W.; Eblé, M. C.</p> <p>2017-10-01</p> <p>The 2004 Sumatra tsunami was an unprecedented <span class="hlt">global</span> disaster measured throughout the world <span class="hlt">oceans</span>. The present study focused on a region of the southeastern Pacific <span class="hlt">Ocean</span> where the "westward" circumferentially propagating tsunami branch converged with the "eastward" branch, based on data from fortuitously placed Chilean DART 32401 and tide gauges along the coast of South America. By comparison of the tsunami and background spectra, we suppressed the influence of topography and reconstructed coastal "spectral ratios" that were in close agreement with a ratio at DART 32401 and spectral ratios in other <span class="hlt">oceans</span>. Findings indicate that even remote tsunami records carry spectral source signatures ("birth-marks"). The 2004 tsunami waves were found to occupy the broad frequency band of 0.25-10 cph with the prominent ratio peak at period of 40 min related to the southern fast-slip source domain. This rupture "hot-spot" of ˜350 km was responsible for the <span class="hlt">global</span> impact of the 2004 tsunami. Data from DART 32401 provided validation of model results: the simulated maximum tsunami wave height of 2.25 cm was a conservative approximation to the measured height of 2.05 cm; the computed tsunami travel time of 25 h 35 min to DART 32401, although 20 min earlier than the actual travel time, provided a favorable result in comparison with 24 h 25 min estimated from classical kinematic theory. The numerical simulations consistently reproduced the wave height changes observed along the coast of South America, including local amplification of tsunami waves at the northern stations of Arica (72 cm) and Callao (67 cm).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ESSD....8..325L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ESSD....8..325L"><span>A new <span class="hlt">global</span> interior <span class="hlt">ocean</span> mapped climatology: the 1° × 1° GLODAP version 2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauvset, Siv K.; Key, Robert M.; Olsen, Are; van Heuven, Steven; Velo, Anton; Lin, Xiaohua; Schirnick, Carsten; Kozyr, Alex; Tanhua, Toste; Hoppema, Mario; Jutterström, Sara; Steinfeldt, Reiner; Jeansson, Emil; Ishii, Masao; Perez, Fiz F.; Suzuki, Toru; Watelet, Sylvain</p> <p>2016-08-01</p> <p>We present a mapped climatology (GLODAPv2.2016b) of <span class="hlt">ocean</span> biogeochemical variables based on the new GLODAP version 2 data product (Olsen et al., 2016; Key et al., 2015), which covers all <span class="hlt">ocean</span> basins over the years 1972 to 2013. The quality-controlled and internally consistent GLODAPv2 was used to create <span class="hlt">global</span> 1° × 1° mapped climatologies of salinity, temperature, oxygen, nitrate, phosphate, silicate, total dissolved inorganic carbon (TCO2), total alkalinity (TAlk), pH, and CaCO3 saturation states using the Data-Interpolating Variational Analysis (DIVA) mapping method. Improving on maps based on an earlier but similar dataset, GLODAPv1.1, this climatology also covers the Arctic <span class="hlt">Ocean</span>. Climatologies were created for 33 standard depth surfaces. The conceivably confounding temporal trends in TCO2 and pH due to anthropogenic influence were removed prior to mapping by normalizing these data to the year 2002 using first-order calculations of anthropogenic carbon accumulation rates. We additionally provide maps of accumulated anthropogenic carbon in the year 2002 and of preindustrial TCO2. For all parameters, all data from the full 1972-2013 period were used, including data that did not receive full secondary quality control. The GLODAPv2.2016b <span class="hlt">global</span> 1° × 1° mapped climatologies, including error fields and ancillary information, are available at the GLODAPv2 web page at the Carbon Dioxide Information Analysis Center (CDIAC; <a href="http://dx.doi.org/10.3334/CDIAC/OTG.NDP093_GLODAPv2" target="_blank">doi:10.3334/CDIAC/OTG.NDP093_GLODAPv2</a>).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9810A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9810A"><span>Using an atmospheric boundary layer model to force <span class="hlt">global</span> <span class="hlt">ocean</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abel, Rafael; Böning, Claus</p> <p>2014-05-01</p> <p>Current practices in the atmospheric forcing of <span class="hlt">ocean</span> model simulations can lead to unphysical behaviours. The problem lies in the bulk formulation of the turbulent air-sea fluxes in the conjunction with a prescribed, and unresponsive, atmospheric state (as given by reanalysis products). This can have impacts both on mesoscale processes as well as on the dynamics of the large-scale circulation. First, a possible local mismatch between the given atmospheric state and evolving sea surface temperature (SST) signatures can occur, especially for mesoscale features such as frontal areas, eddies, or near the sea ice edge. Any <span class="hlt">ocean</span> front shift or evolution of mesoscale anomalies results in excessive, unrealistic surface fluxes due to the lack of atmospheric adaptation. Second, a subtle distortion in the sensitive balance of feedback processes being critical for the thermohaline circulation. Since the bulk formulations assume an infinite atmospheric heat capacity, resulting SST anomalies are strongly damped even on basin-scales (e.g. from trends in the Atlantic meridional overturning circulation). In consequence, an important negative feedback is eliminated, rendering the system excessively susceptible to small anomalies (or errors) in the freshwater fluxes. Previous studies (Seager et al., 1995, J. Clim.) have suggested a partial forcing issue remedy that aimed for a physically more realistic determination of air-sea fluxes by allowing some (thermodynamic) adaptation of the atmospheric boundary layer to SST changes. In this study a modernized formulation of this approach (Deremble et al., 2013, Mon. Weather Rev.; 'CheapAML') is implemented in a <span class="hlt">global</span> <span class="hlt">ocean</span>-ice model with moderate resolution (0.5°; ORCA05). In a set of experiments we explore the solution behaviour of this forcing approach (where only the winds are prescribed, while atmospheric temperature and humidity are computed), contrasting it with the solution obtained from the classical bulk formulation with a non</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA322259','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA322259"><span>The 1994 Arctic <span class="hlt">Ocean</span> Section. The First Major Scientific Crossing of the Arctic <span class="hlt">Ocean</span>,</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1996-09-01</p> <p>contribute to the international effort to better understand the role of the Arctic <span class="hlt">Ocean</span> in the <span class="hlt">global</span> carbon cycle and climate change. Summar...Barium Distributions in the Arctic <span class="hlt">Ocean</span> ? ........................ 32 Biology and the Carbon Cycle Cycling of Organic Carbon in the Central Arctic...of Heterotrophic Bacteria and Protists in the Arctic <span class="hlt">Ocean</span> Carbon Cycle............. 40</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16791191','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16791191"><span>The Southern <span class="hlt">Ocean</span> biogeochemical divide.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marinov, I; Gnanadesikan, A; Toggweiler, J R; Sarmiento, J L</p> <p>2006-06-22</p> <p>Modelling studies have demonstrated that the nutrient and carbon cycles in the Southern <span class="hlt">Ocean</span> play a central role in setting the air-sea balance of CO(2) and <span class="hlt">global</span> biological production. Box model studies first pointed out that an increase in nutrient utilization in the high latitudes results in a strong decrease in the atmospheric carbon dioxide partial pressure (pCO2). This early research led to two important ideas: high latitude regions are more important in determining atmospheric pCO2 than low latitudes, despite their much smaller area, and nutrient utilization and atmospheric pCO2 are tightly linked. Subsequent general circulation model simulations show that the Southern <span class="hlt">Ocean</span> is the most important high latitude region in controlling pre-industrial atmospheric CO(2) because it serves as a lid to a larger volume of the deep <span class="hlt">ocean</span>. Other studies point out the crucial role of the Southern <span class="hlt">Ocean</span> in the uptake and storage of anthropogenic carbon dioxide and in controlling <span class="hlt">global</span> biological production. Here we probe the system to determine whether certain regions of the Southern <span class="hlt">Ocean</span> are more critical than others for air-sea CO(2) balance and the biological export production, by increasing surface nutrient drawdown in an <span class="hlt">ocean</span> general circulation model. We demonstrate that atmospheric CO(2) and <span class="hlt">global</span> biological export production are controlled by different regions of the Southern <span class="hlt">Ocean</span>. The air-sea balance of carbon dioxide is controlled mainly by the biological pump and circulation in the Antarctic deep-water formation region, whereas <span class="hlt">global</span> export production is controlled mainly by the biological pump and circulation in the Subantarctic intermediate and mode water formation region. The existence of this biogeochemical divide separating the Antarctic from the Subantarctic suggests that it may be possible for climate change or human intervention to modify one of these without greatly altering the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910032731&hterms=color+memory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcolor%2Bmemory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910032731&hterms=color+memory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcolor%2Bmemory"><span><span class="hlt">Ocean</span> color - Availability of the <span class="hlt">global</span> data set</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feldman, Gene; Kuring, Norman; Ng, Carolyn; Esaias, Wayne; Mcclain, Chuck; Elrod, Jane; Maynard, Nancy; Endres, Dan</p> <p>1989-01-01</p> <p>The use of satellite observations of <span class="hlt">ocean</span> color to provide reliable estimates of marine phytoplankton biomass on synoptic scales is examined. An overview is given of the Coastal Zone Color Scanner data processing system. The archiving and distribution of <span class="hlt">ocean</span> color data are discussed, and NASA-sponsored archive sites are listed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030015860','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030015860"><span>Technical Report Series on <span class="hlt">Global</span> Modeling and Data Assimilation. Volume 22; A Coupled <span class="hlt">Ocean</span>-Atmosphere Radiative Model for <span class="hlt">Global</span> <span class="hlt">Ocean</span> Biogeochemical Models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Watson W.; Suarez, Max J. (Editor)</p> <p>2002-01-01</p> <p>An <span class="hlt">ocean</span>-atmosphere radiative model (OARM) evaluates irradiance availability and quality in the water column to support phytoplankton growth and drive <span class="hlt">ocean</span> thermodynamics. An atmospheric component incorporates spectral and directional effects of clear and cloudy skies as a function of atmospheric optical constituents, and spectral reflectance across the air-sea interface. An <span class="hlt">oceanic</span> component evaluates the propagation of spectral and directional irradiance through the water column as a function of water, five phytoplankton groups, and chromophoric dissolved organic matter. It tracks the direct and diffuse streams from the atmospheric component, and a third stream, upwelling diffuse irradiance. The atmospheric component of OARM was compared to data sources at the <span class="hlt">ocean</span> surface with a coefficient of determination (r2) of 0.97 and a root mean square of 12.1%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170005496&hterms=BIO&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBIO','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170005496&hterms=BIO&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBIO"><span>A Compilation of <span class="hlt">Global</span> Bio-Optical in Situ Data for <span class="hlt">Ocean</span>-Colour Satellite Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Valente, Andre; Sathyendranath, Shubha; Brotus, Vanda; Groom, Steve; Grant, Michael; Taberner, Malcolm; Antoine, David; Arnone, Robert; Balch, William M.; Barker, Kathryn; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170005496'); toggleEditAbsImage('author_20170005496_show'); toggleEditAbsImage('author_20170005496_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170005496_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170005496_hide"></p> <p>2016-01-01</p> <p>A compiled set of in situ data is important to evaluate the quality of <span class="hlt">ocean</span>-colour satellite-data records. Here we describe the data compiled for the validation of the <span class="hlt">ocean</span>-colour products from the ESA <span class="hlt">Ocean</span> Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GePCO), span between 1997 and 2012, and have a <span class="hlt">global</span> distribution. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll a, spectral inherent optical properties and spectral diffuse attenuation coefficients. The data were from multi-project archives acquired via the open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived <span class="hlt">ocean</span>-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were preserved throughout the work and made available in the final table. Using all the data in a validation exercise increases the number of matchups and enhances the representativeness of different marine regimes. By making available the metadata, it is also possible to analyse each set of data separately. The compiled data are available at doi:10.1594PANGAEA.854832 (Valente et al., 2015).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16731624','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16731624"><span>Scaling the metabolic balance of the <span class="hlt">oceans</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>López-Urrutia, Angel; San Martin, Elena; Harris, Roger P; Irigoien, Xabier</p> <p>2006-06-06</p> <p><span class="hlt">Oceanic</span> communities are sources or sinks of CO2, depending on the balance between primary production and community respiration. The prediction of how <span class="hlt">global</span> climate change will modify this metabolic balance of the <span class="hlt">oceans</span> is limited by the lack of a comprehensive underlying theory. Here, we show that the balance between production and respiration is profoundly affected by environmental temperature. We extend the general metabolic theory of ecology to the production and respiration of <span class="hlt">oceanic</span> communities and show that ecosystem rates can be reliably scaled from theoretical knowledge of organism physiology and measurement of population abundance. Our theory predicts that the differential temperature-dependence of respiration and photosynthesis at the organism level determines the response of the metabolic balance of the epipelagic <span class="hlt">ocean</span> to changes in ambient temperature, a prediction that we support with empirical data over the <span class="hlt">global</span> <span class="hlt">ocean</span>. Furthermore, our model predicts that there will be a negative feedback of <span class="hlt">ocean</span> communities to climate warming because they will capture less CO2 with a future increase in <span class="hlt">ocean</span> temperature. This feedback of marine biota will further aggravate the anthropogenic effects on <span class="hlt">global</span> warming.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020016079&hterms=overfishing+fisheries+communities&qs=Ntx%3Dmode%2Bmatchany%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Doverfishing%2Bfisheries%2Bcommunities','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020016079&hterms=overfishing+fisheries+communities&qs=Ntx%3Dmode%2Bmatchany%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Doverfishing%2Bfisheries%2Bcommunities"><span>Merging <span class="hlt">Ocean</span> Color Data from Multiple Missions. Chapter 12</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregg, Watson W.</p> <p>2001-01-01</p> <p><span class="hlt">Oceanic</span> phytoplankton may play an important role in the cycling of carbon on the Earth, through the uptake of carbon dioxide in the process of photosynthesis. Although they are ubiquitous in the <span class="hlt">global</span> <span class="hlt">oceans</span>, their abundances and dynamics are difficult to estimate, primarily due to the vast spatial extent of the <span class="hlt">oceans</span> and the short time scales over which their abundances can change. Consequently, the effects of <span class="hlt">oceanic</span> phytoplankton on biogeochemical cycling, climate change, and fisheries are not well known. In response to the potential importance of phytoplankton in the <span class="hlt">global</span> carbon cycle and the lack of comprehensive data, the National Aeronautics and Space Administration (NASA) and the international community have established high priority satellite missions designed to acquire and produce high quality <span class="hlt">ocean</span> color data. Seven of the missions are routine <span class="hlt">global</span> observational missions: the <span class="hlt">Ocean</span> Color and Temperature Sensor (OCTS), the Polarization and Directionality of the Earth's Reflectances sensor (POLDER), Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Moderate Resolution Imaging Spectrometer-AM (MODIS-AM), Medium Resolution Imaging Spectrometer (MERIS), <span class="hlt">Global</span> Imager (GLI), and MODIS-PM. In addition, there are several other missions capable of providing <span class="hlt">ocean</span> color data on smaller scales. Most of these missions contain the spectral band complement considered necessary to derive <span class="hlt">oceanic</span> pigment concentrations (i.e., phytoplankton abundance) and other related parameters. Many contain additional bands that can provide important ancillary information about the optical and biological state of the <span class="hlt">oceans</span>. Any individual <span class="hlt">ocean</span> color mission is limited in <span class="hlt">ocean</span> coverage due to sun glint and clouds. For example, one of the first proposed missions, the SeaWiFS, can provide about 45% coverage of the <span class="hlt">global</span> <span class="hlt">ocean</span> in four days and only about 15% in one day.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS23A1177J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS23A1177J"><span>Clio: An Autonomous Vertical Sampling Vehicle for <span class="hlt">Global</span> <span class="hlt">Ocean</span> Biogeochemical Mapping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jakuba, M.; Gomez-Ibanez, D.; Saito, M. A.; Dick, G.; Breier, J. A., Jr.</p> <p>2014-12-01</p> <p>We report the preliminary design of a fast vertical profiling autonomous underwater vehicle, called Clio, designed to cost-effectively improve the understanding of marine microorganism ecosystem dynamics on a <span class="hlt">global</span> scale. The insights into biogeochemical cycles to be gained from illuminating the relationships between <span class="hlt">ocean</span> life and chemistry have led to establishment of the GEOTRACES program. The nutrient and trace element profiles generated by GEOTRACES will provide insight into what is happening biogeochemically, but not how it is happening, i.e., what biochemical pathways are active? Advances in sequencing technology and in situ preservation have made it possible to study the genomics (DNA), transcriptomics (RNA), proteomics (proteins and enzymes), metabolomics (lipids and other metabolites), and metallomics (metals), associated with marine microorganisms; however, these techniques require sample collection. To this end, Clio will carry two to four SUspended Particle Rosette (SUPR) multi-samplers to depths of 6000 m. Clio is being designed specifically to complement the GEOTRACES program—to operate simultaneously and independently of the wire-based sampling protocols developed for GEOTRACES. At each GEOTRACES <span class="hlt">ocean</span> transect sampling station, Clio will be deployed from the ship, transit vertically to the seafloor, and then ascend to, and stop at up to 32 sampling depths, where it will filter up to 150 l of seawater per sample. Filtered samples for RNA will be administered a dose of preservative (RNALater) in situ. Clio must efficiently hold station at multiple depths between the surface and 6000 m, but also move rapidly between sampling depths. It must be chemically clean and avoid disturbing the water column while sampling. Clio must be operationally friendly, requiring few personnel to operate, and have minimal impact on shipboard operations. We have selected a positively-buoyant thruster-driven design with a quasi-isopycnal construction. Our simulations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JGR...10425647F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JGR...10425647F"><span>Assimilation of TOPEX/Poseidon altimeter data into a <span class="hlt">global</span> <span class="hlt">ocean</span> circulation model: How good are the results?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukumori, Ichiro; Raghunath, Ramanujam; Fu, Lee-Lueng; Chao, Yi</p> <p>1999-11-01</p> <p>The feasibility of assimilating satellite altimetry data into a <span class="hlt">global</span> <span class="hlt">ocean</span> general circulation model is studied. Three years of TOPEX/Poseidon data are analyzed using a <span class="hlt">global</span>, three-dimensional, nonlinear primitive equation model. The assimilation's success is examined by analyzing its consistency and reliability measured by formal error estimates with respect to independent measurements. Improvements in model solution are demonstrated, in particular, properties not directly measured. Comparisons are performed with sea level measured by tide gauges, subsurface temperatures and currents from moorings, and bottom pressure measurements. Model representation errors dictate what can and cannot be resolved by assimilation, and its identification is emphasized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ChOE...27..111Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ChOE...27..111Z"><span>Design and research on the two-<span class="hlt">joint</span> mating system of underwater vehicle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Zhong-lin; Wang, Li-quan</p> <p>2013-03-01</p> <p>In the 21st century, people have come to the era of <span class="hlt">ocean</span> science and <span class="hlt">ocean</span> economy. With the development of <span class="hlt">ocean</span> science and technology and the thorough research on the <span class="hlt">ocean</span>, underwater mating technique has been widely used in such fields as sunk ship salvage, deep <span class="hlt">ocean</span> workstation, submarine lifesaving aid and military affairs. In this paper, researches are made home and abroad on mating technology. Two-<span class="hlt">joint</span> mating system of underwater vehicle is designed including plane system, three-dimensional assembly system and control system in order to increase the capacity of adapting platform obliquity and adopting rotational skirt scheme. It is clear that the system fits the working space of underwater vehicle passageway and there is no interference phenomenon in assembly design. The finite element model of the system shell and the pressurization of the <span class="hlt">joint</span> are established. The results of the finite element computing and the pressing test are accordant, and thus it can testify that the shell material meet the need of intension and <span class="hlt">joint</span> pressurization is reliable. Modeling of the control system is accomplished, and simulation and analysis are made, which can provide directions for the controller design of mating system of underwater vehicles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14999278','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14999278"><span>Polar <span class="hlt">ocean</span> stratification in a cold climate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sigman, Daniel M; Jaccard, Samuel L; Haug, Gerald H</p> <p>2004-03-04</p> <p>The low-latitude <span class="hlt">ocean</span> is strongly stratified by the warmth of its surface water. As a result, the great volume of the deep <span class="hlt">ocean</span> has easiest access to the atmosphere through the polar surface <span class="hlt">ocean</span>. In the modern polar <span class="hlt">ocean</span> during the winter, the vertical distribution of temperature promotes overturning, with colder water over warmer, while the salinity distribution typically promotes stratification, with fresher water over saltier. However, the sensitivity of seawater density to temperature is reduced as temperature approaches the freezing point, with potential consequences for <span class="hlt">global</span> <span class="hlt">ocean</span> circulation under cold climates. Here we present deep-sea records of biogenic opal accumulation and sedimentary nitrogen isotopic composition from the Subarctic North Pacific <span class="hlt">Ocean</span> and the Southern <span class="hlt">Ocean</span>. These records indicate that vertical stratification increased in both northern and southern high latitudes 2.7 million years ago, when Northern Hemisphere glaciation intensified in association with <span class="hlt">global</span> cooling during the late Pliocene epoch. We propose that the cooling caused this increased stratification by weakening the role of temperature in polar <span class="hlt">ocean</span> density structure so as to reduce its opposition to the stratifying effect of the vertical salinity distribution. The shift towards stratification in the polar <span class="hlt">ocean</span> 2.7 million years ago may have increased the quantity of carbon dioxide trapped in the abyss, amplifying the <span class="hlt">global</span> cooling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ACP....17.3749L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ACP....17.3749L"><span>An improved parameterisation of ozone dry deposition to the <span class="hlt">ocean</span> and its impact in a <span class="hlt">global</span> climate-chemistry model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luhar, Ashok K.; Galbally, Ian E.; Woodhouse, Matthew T.; Thatcher, Marcus</p> <p>2017-03-01</p> <p>Schemes used to parameterise ozone dry deposition velocity at the <span class="hlt">oceanic</span> surface mainly differ in terms of how the dominant term of surface resistance is parameterised. We examine three such schemes and test them in a <span class="hlt">global</span> climate-chemistry model that incorporates meteorological nudging and monthly-varying reactive-gas emissions. The default scheme invokes the commonly used assumption that the water surface resistance is constant. The other two schemes, named the one-layer and two-layer reactivity schemes, include the simultaneous influence on the water surface resistance of ozone solubility in water, waterside molecular diffusion and turbulent transfer, and a first-order chemical reaction of ozone with dissolved iodide. Unlike the one-layer scheme, the two-layer scheme can indirectly control the degree of interaction between chemical reaction and turbulent transfer through the specification of a surface reactive layer thickness. A comparison is made of the modelled deposition velocity dependencies on sea surface temperature (SST) and wind speed with recently reported cruise-based observations. The default scheme overestimates the observed deposition velocities by a factor of 2-4 when the chemical reaction is slow (e.g. under colder SSTs in the Southern <span class="hlt">Ocean</span>). The default scheme has almost no temperature, wind speed, or latitudinal variations in contrast with the observations. The one-layer scheme provides noticeably better variations, but it overestimates deposition velocity by a factor of 2-3 due to an enhancement of the interaction between chemical reaction and turbulent transfer. The two-layer scheme with a surface reactive layer thickness specification of 2.5 µm, which is approximately equal to the reaction-diffusive length scale of the ozone-iodide reaction, is able to simulate the field measurements most closely with respect to absolute values as well as SST and wind-speed dependence. The annual <span class="hlt">global</span> <span class="hlt">oceanic</span> deposition of ozone determined using this</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE14A1382W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE14A1382W"><span>Pathways of Atlantic Waters in the Nordic seas: locally eddy-permitting <span class="hlt">ocean</span> simulation in a <span class="hlt">global</span> setup</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wekerle, C.; Wang, Q.; Danilov, S.; Jung, T.; Schourup-Kristensen, V.</p> <p>2016-02-01</p> <p>Atlantic Water (AW) passes through the Nordic Seas and enters the Arctic <span class="hlt">Ocean</span> through the shallow Barents Sea and the deep Fram Strait. Since the 1990's, observations indicate a series of anomalously warm pulses of Atlantic Water that entered the Arctic <span class="hlt">Ocean</span>. In fact, poleward <span class="hlt">oceanic</span> heat transport may even increase in the future, which might have implications for the heat uptake in the Arctic <span class="hlt">Ocean</span> as well as for the sea ice cover. The ability of models to faithfully simulate the pathway of the AW and accompanying dynamics is thus of high climate relevance. In this study, we explore the potential of a <span class="hlt">global</span> multi-resolution sea ice-<span class="hlt">ocean</span> model with a locally eddy-permitting resolution (around 4.5 km) in the Nordic seas region and Arctic <span class="hlt">Ocean</span> in improving the representation of Atlantic Water inflow, and more broadly, the dynamics of the circulation in the Northern North Atlantic and Arctic. The simulation covers the time period 1969-2009. We find that locally increased resolution improves the localization and thickness of the Atlantic Water layer in the Nordic seas, compared with a 20 km resolution reference simulation. In particular, the inflow of Atlantic Waters through the Greenland Scotland Ridge and the narrow branches of the Norwegian Atlantic Current can be realistically represented. Lateral spreading due to simulated eddies essentially reduces the bias in the surface temperature. In addition, a qualitatively good agreement of the simulated eddy kinetic energy field with observations can be achieved. This study indicates that a substantial improvement in representing local <span class="hlt">ocean</span> dynamics can be reached through the local refinement, which requires a rather moderate computational effort. The successful model assessment allows us to further investigate the variability and mechanisms behind Atlantic Water transport into the Arctic <span class="hlt">Ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19901326','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19901326"><span>Climate, carbon cycling, and deep-<span class="hlt">ocean</span> ecosystems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smith, K L; Ruhl, H A; Bett, B J; Billett, D S M; Lampitt, R S; Kaufmann, R S</p> <p>2009-11-17</p> <p>Climate variation affects surface <span class="hlt">ocean</span> processes and the production of organic carbon, which ultimately comprises the primary food supply to the deep-sea ecosystems that occupy approximately 60% of the Earth's surface. Warming trends in atmospheric and upper <span class="hlt">ocean</span> temperatures, attributed to anthropogenic influence, have occurred over the past four decades. Changes in upper <span class="hlt">ocean</span> temperature influence stratification and can affect the availability of nutrients for phytoplankton production. <span class="hlt">Global</span> warming has been predicted to intensify stratification and reduce vertical mixing. Research also suggests that such reduced mixing will enhance variability in primary production and carbon export flux to the deep sea. The dependence of deep-sea communities on surface water production has raised important questions about how climate change will affect carbon cycling and deep-<span class="hlt">ocean</span> ecosystem function. Recently, unprecedented time-series studies conducted over the past two decades in the North Pacific and the North Atlantic at >4,000-m depth have revealed unexpectedly large changes in deep-<span class="hlt">ocean</span> ecosystems significantly correlated to climate-driven changes in the surface <span class="hlt">ocean</span> that can impact the <span class="hlt">global</span> carbon cycle. Climate-driven variation affects <span class="hlt">oceanic</span> communities from surface waters to the much-overlooked deep sea and will have impacts on the <span class="hlt">global</span> carbon cycle. Data from these two widely separated areas of the deep <span class="hlt">ocean</span> provide compelling evidence that changes in climate can readily influence deep-sea processes. However, the limited geographic coverage of these existing time-series studies stresses the importance of developing a more <span class="hlt">global</span> effort to monitor deep-sea ecosystems under modern conditions of rapidly changing climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49..753T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49..753T"><span>Intercomparison and validation of the mixed layer depth fields of <span class="hlt">global</span> <span class="hlt">ocean</span> syntheses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Toyoda, Takahiro; Fujii, Yosuke; Kuragano, Tsurane; Kamachi, Masafumi; Ishikawa, Yoichi; Masuda, Shuhei; Sato, Kanako; Awaji, Toshiyuki; Hernandez, Fabrice; Ferry, Nicolas; Guinehut, Stéphanie; Martin, Matthew J.; Peterson, K. Andrew; Good, Simon A.; Valdivieso, Maria; Haines, Keith; Storto, Andrea; Masina, Simona; Köhl, Armin; Zuo, Hao; Balmaseda, Magdalena; Yin, Yonghong; Shi, Li; Alves, Oscar; Smith, Gregory; Chang, You-Soon; Vernieres, Guillaume; Wang, Xiaochun; Forget, Gael; Heimbach, Patrick; Wang, Ou; Fukumori, Ichiro; Lee, Tong</p> <p>2017-08-01</p> <p>Intercomparison and evaluation of the <span class="hlt">global</span> <span class="hlt">ocean</span> surface mixed layer depth (MLD) fields estimated from a suite of major <span class="hlt">ocean</span> syntheses are conducted. Compared with the reference MLDs calculated from individual profiles, MLDs calculated from monthly mean and gridded profiles show negative biases of 10-20 m in early spring related to the re-stratification process of relatively deep mixed layers. Vertical resolution of profiles also influences the MLD estimation. MLDs are underestimated by approximately 5-7 (14-16) m with the vertical resolution of 25 (50) m when the criterion of potential density exceeding the 10-m value by 0.03 kg m-3 is used for the MLD estimation. Using the larger criterion (0.125 kg m-3) generally reduces the underestimations. In addition, positive biases greater than 100 m are found in wintertime subpolar regions when MLD criteria based on temperature are used. Biases of the reanalyses are due to both model errors and errors related to differences between the assimilation methods. The result shows that these errors are partially cancelled out through the ensemble averaging. Moreover, the bias in the ensemble mean field of the reanalyses is smaller than in the observation-only analyses. This is largely attributed to comparably higher resolutions of the reanalyses. The robust reproduction of both the seasonal cycle and interannual variability by the ensemble mean of the reanalyses indicates a great potential of the ensemble mean MLD field for investigating and monitoring upper <span class="hlt">ocean</span> processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1279014-ocean-acidification-over-next-three-centuries-using-simple-global-climate-carbon-cycle-model-projections-sensitivities','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1279014-ocean-acidification-over-next-three-centuries-using-simple-global-climate-carbon-cycle-model-projections-sensitivities"><span><span class="hlt">Ocean</span> acidification over the next three centuries using a simple <span class="hlt">global</span> climate carbon-cycle model: projections and sensitivities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Hartin, Corinne A.; Bond-Lamberty, Benjamin; Patel, Pralit; ...</p> <p>2016-08-01</p> <p>Continued <span class="hlt">oceanic</span> uptake of anthropogenic CO 2 is projected to significantly alter the chemistry of the upper <span class="hlt">oceans</span> over the next three centuries, with potentially serious consequences for marine ecosystems. Relatively few models have the capability to make projections of <span class="hlt">ocean</span> acidification, limiting our ability to assess the impacts and probabilities of <span class="hlt">ocean</span> changes. In this study we examine the ability of Hector v1.1, a reduced-form <span class="hlt">global</span> model, to project changes in the upper <span class="hlt">ocean</span> carbonate system over the next three centuries, and quantify the model's sensitivity to parametric inputs. Hector is run under prescribed emission pathways from the Representativemore » Concentration Pathways (RCPs) and compared to both observations and a suite of Coupled Model Intercomparison (CMIP5) model outputs. Current observations confirm that <span class="hlt">ocean</span> acidification is already taking place, and CMIP5 models project significant changes occurring to 2300. Hector is consistent with the observational record within both the high- (> 55°) and low-latitude <span class="hlt">oceans</span> (< 55°). The model projects low-latitude surface <span class="hlt">ocean</span> pH to decrease from preindustrial levels of 8.17 to 7.77 in 2100, and to 7.50 in 2300; aragonite saturation levels (Ω Ar) decrease from 4.1 units to 2.2 in 2100 and 1.4 in 2300 under RCP 8.5. These magnitudes and trends of <span class="hlt">ocean</span> acidification within Hector are largely consistent with the CMIP5 model outputs, although we identify some small biases within Hector's carbonate system. Of the parameters tested, changes in [H +] are most sensitive to parameters that directly affect atmospheric CO 2 concentrations – Q 10 (terrestrial respiration temperature response) as well as changes in <span class="hlt">ocean</span> circulation, while changes in Ω Ar saturation levels are sensitive to changes in <span class="hlt">ocean</span> salinity and Q 10. We conclude that Hector is a robust tool well suited for rapid <span class="hlt">ocean</span> acidification projections and sensitivity analyses, and it is capable of emulating both current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1279014-ocean-acidification-over-next-three-centuries-using-simple-global-climate-carbon-cycle-model-projections-sensitivities','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1279014-ocean-acidification-over-next-three-centuries-using-simple-global-climate-carbon-cycle-model-projections-sensitivities"><span><span class="hlt">Ocean</span> acidification over the next three centuries using a simple <span class="hlt">global</span> climate carbon-cycle model: projections and sensitivities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hartin, Corinne A.; Bond-Lamberty, Benjamin; Patel, Pralit</p> <p></p> <p>Continued <span class="hlt">oceanic</span> uptake of anthropogenic CO 2 is projected to significantly alter the chemistry of the upper <span class="hlt">oceans</span> over the next three centuries, with potentially serious consequences for marine ecosystems. Relatively few models have the capability to make projections of <span class="hlt">ocean</span> acidification, limiting our ability to assess the impacts and probabilities of <span class="hlt">ocean</span> changes. In this study we examine the ability of Hector v1.1, a reduced-form <span class="hlt">global</span> model, to project changes in the upper <span class="hlt">ocean</span> carbonate system over the next three centuries, and quantify the model's sensitivity to parametric inputs. Hector is run under prescribed emission pathways from the Representativemore » Concentration Pathways (RCPs) and compared to both observations and a suite of Coupled Model Intercomparison (CMIP5) model outputs. Current observations confirm that <span class="hlt">ocean</span> acidification is already taking place, and CMIP5 models project significant changes occurring to 2300. Hector is consistent with the observational record within both the high- (> 55°) and low-latitude <span class="hlt">oceans</span> (< 55°). The model projects low-latitude surface <span class="hlt">ocean</span> pH to decrease from preindustrial levels of 8.17 to 7.77 in 2100, and to 7.50 in 2300; aragonite saturation levels (Ω Ar) decrease from 4.1 units to 2.2 in 2100 and 1.4 in 2300 under RCP 8.5. These magnitudes and trends of <span class="hlt">ocean</span> acidification within Hector are largely consistent with the CMIP5 model outputs, although we identify some small biases within Hector's carbonate system. Of the parameters tested, changes in [H +] are most sensitive to parameters that directly affect atmospheric CO 2 concentrations – Q 10 (terrestrial respiration temperature response) as well as changes in <span class="hlt">ocean</span> circulation, while changes in Ω Ar saturation levels are sensitive to changes in <span class="hlt">ocean</span> salinity and Q 10. We conclude that Hector is a robust tool well suited for rapid <span class="hlt">ocean</span> acidification projections and sensitivity analyses, and it is capable of emulating both current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1340795-ocean-acidification-over-next-three-centuries-using-simple-global-climate-carbon-cycle-model-projections-sensitivities','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1340795-ocean-acidification-over-next-three-centuries-using-simple-global-climate-carbon-cycle-model-projections-sensitivities"><span><span class="hlt">Ocean</span> acidification over the next three centuries using a simple <span class="hlt">global</span> climate carbon-cycle model: projections and sensitivities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hartin, Corinne A.; Bond-Lamberty, Benjamin; Patel, Pralit</p> <p></p> <p>Continued <span class="hlt">oceanic</span> uptake of anthropogenic CO 2 is projected to significantly alter the chemistry of the upper <span class="hlt">oceans</span> over the next three centuries, with potentially serious consequences for marine ecosystems. Relatively few models have the capability to make projections of <span class="hlt">ocean</span> acidification, limiting our ability to assess the impacts and probabilities of <span class="hlt">ocean</span> changes. In this study we examine the ability of Hector v1.1, a reduced-form <span class="hlt">global</span> model, to project changes in the upper <span class="hlt">ocean</span> carbonate system over the next three centuries, and quantify the model's sensitivity to parametric inputs. Hector is run under prescribed emission pathways from the Representativemore » Concentration Pathways (RCPs) and compared to both observations and a suite of Coupled Model Intercomparison (CMIP5) model outputs. Current observations confirm that <span class="hlt">ocean</span> acidification is already taking place, and CMIP5 models project significant changes occurring to 2300. Hector is consistent with the observational record within both the high- (> 55°) and low-latitude <span class="hlt">oceans</span> (< 55°). The model projects low-latitude surface <span class="hlt">ocean</span> pH to decrease from preindustrial levels of 8.17 to 7.77 in 2100, and to 7.50 in 2300; aragonite saturation levels (Ω Ar) decrease from 4.1 units to 2.2 in 2100 and 1.4 in 2300 under RCP 8.5. These magnitudes and trends of <span class="hlt">ocean</span> acidification within Hector are largely consistent with the CMIP5 model outputs, although we identify some small biases within Hector's carbonate system. Of the parameters tested, changes in [H +] are most sensitive to parameters that directly affect atmospheric CO 2 concentrations – Q 10 (terrestrial respiration temperature response) as well as changes in <span class="hlt">ocean</span> circulation, while changes in Ω Ar saturation levels are sensitive to changes in <span class="hlt">ocean</span> salinity and Q 10. We conclude that Hector is a robust tool well suited for rapid <span class="hlt">ocean</span> acidification projections and sensitivity analyses, and it is capable of emulating both current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGeo...12.3301R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGeo...12.3301R"><span>Emergence of multiple <span class="hlt">ocean</span> ecosystem drivers in a large ensemble suite with an Earth system model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodgers, K. B.; Lin, J.; Frölicher, T. L.</p> <p>2015-06-01</p> <p>Marine ecosystems are increasingly stressed by human-induced changes. Marine ecosystem drivers that contribute to stressing ecosystems - including warming, acidification, deoxygenation and perturbations to biological productivity - can co-occur in space and time, but detecting their trends is complicated by the presence of noise associated with natural variability in the climate system. Here we use large initial-condition ensemble simulations with an Earth system model under a historical/RCP8.5 (representative concentration pathway 8.5) scenario over 1950-2100 to consider emergence characteristics for the four individual and combined drivers. Using a 1-standard-deviation (67% confidence) threshold of signal to noise to define emergence with a 30-year trend window, we show that <span class="hlt">ocean</span> acidification emerges much earlier than other drivers, namely during the 20th century over most of the <span class="hlt">global</span> <span class="hlt">ocean</span>. For biological productivity, the anthropogenic signal does not emerge from the noise over most of the <span class="hlt">global</span> <span class="hlt">ocean</span> before the end of the 21st century. The early emergence pattern for sea surface temperature in low latitudes is reversed from that of subsurface oxygen inventories, where emergence occurs earlier in the Southern <span class="hlt">Ocean</span>. For the combined multiple-driver field, 41% of the <span class="hlt">global</span> <span class="hlt">ocean</span> exhibits emergence for the 2005-2014 period, and 63% for the 2075-2084 period. The combined multiple-driver field reveals emergence patterns by the end of this century that are relatively high over much of the Southern <span class="hlt">Ocean</span>, North Pacific, and Atlantic, but relatively low over the tropics and the South Pacific. For the case of two drivers, the tropics including habitats of coral reefs emerges earliest, with this driven by the <span class="hlt">joint</span> effects of acidification and warming. It is precisely in the regions with pronounced emergence characteristics where marine ecosystems may be expected to be pushed outside of their comfort zone determined by the degree of natural background variability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15.1701R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15.1701R"><span>Uncertainty in the <span class="hlt">global</span> <span class="hlt">oceanic</span> CO2 uptake induced by wind forcing: quantification and spatial analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roobaert, Alizée; Laruelle, Goulven G.; Landschützer, Peter; Regnier, Pierre</p> <p>2018-03-01</p> <p>The calculation of the air-water CO2 exchange (FCO2) in the <span class="hlt">ocean</span> not only depends on the gradient in CO2 partial pressure at the air-water interface but also on the parameterization of the gas exchange transfer velocity (k) and the choice of wind product. Here, we present regional and <span class="hlt">global</span>-scale quantifications of the uncertainty in FCO2 induced by several widely used k formulations and four wind speed data products (CCMP, ERA, NCEP1 and NCEP2). The analysis is performed at a 1° × 1° resolution using the sea surface pCO2 climatology generated by Landschützer et al. (2015a) for the 1991-2011 period, while the regional assessment relies on the segmentation proposed by the Regional Carbon Cycle Assessment and Processes (RECCAP) project. First, we use k formulations derived from the <span class="hlt">global</span> 14C inventory relying on a quadratic relationship between k and wind speed (k = c ṡ U102; Sweeney et al., 2007; Takahashi et al., 2009; Wanninkhof, 2014), where c is a calibration coefficient and U10 is the wind speed measured 10 m above the surface. Our results show that the range of <span class="hlt">global</span> FCO2, calculated with these k relationships, diverge by 12 % when using CCMP, ERA or NCEP1. Due to differences in the regional wind patterns, regional discrepancies in FCO2 are more pronounced than <span class="hlt">global</span>. These <span class="hlt">global</span> and regional differences significantly increase when using NCEP2 or other k formulations which include earlier relationships (i.e., Wanninkhof, 1992; Wanninkhof et al., 2009) as well as numerous local and regional parameterizations derived experimentally. To minimize uncertainties associated with the choice of wind product, it is possible to recalculate the coefficient c <span class="hlt">globally</span> (hereafter called c∗) for a given wind product and its spatio-temporal resolution, in order to match the last evaluation of the <span class="hlt">global</span> k value. We thus performed these recalculations for each wind product at the resolution and time period of our study but the resulting <span class="hlt">global</span> FCO2 estimates</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GBioC..32..594T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GBioC..32..594T"><span>The Role of External Inputs and Internal Cycling in Shaping the <span class="hlt">Global</span> <span class="hlt">Ocean</span> Cobalt Distribution: Insights From the First Cobalt Biogeochemical Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tagliabue, Alessandro; Hawco, Nicholas J.; Bundy, Randelle M.; Landing, William M.; Milne, Angela; Morton, Peter L.; Saito, Mak A.</p> <p>2018-04-01</p> <p>Cobalt is an important micronutrient for <span class="hlt">ocean</span> microbes as it is present in vitamin B12 and is a co-factor in various metalloenzymes that catalyze cellular processes. Moreover, when seawater availability of cobalt is compared to biological demands, cobalt emerges as being depleted in seawater, pointing to a potentially important limiting role. To properly account for the potential biological role for cobalt, there is therefore a need to understand the processes driving the biogeochemical cycling of cobalt and, in particular, the balance between external inputs and internal cycling. To do so, we developed the first cobalt model within a state-of-the-art three-dimensional <span class="hlt">global</span> <span class="hlt">ocean</span> biogeochemical model. Overall, our model does a good job in reproducing measurements with a correlation coefficient of >0.7 in the surface and >0.5 at depth. We find that continental margins are the dominant source of cobalt, with a crucial role played by supply under low bottom-water oxygen conditions. The basin-scale distribution of cobalt supplied from margins is facilitated by the activity of manganese-oxidizing bacteria being suppressed under low oxygen and low temperatures, which extends the residence time of cobalt. Overall, we find a residence time of 7 and 250 years in the upper 250 m and <span class="hlt">global</span> <span class="hlt">ocean</span>, respectively. Importantly, we find that the dominant internal resupply process switches from regeneration and recycling of particulate cobalt to dissolution of scavenged cobalt between the upper <span class="hlt">ocean</span> and the <span class="hlt">ocean</span> interior. Our model highlights key regions of the <span class="hlt">ocean</span> where biological activity may be most sensitive to cobalt availability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS41B1201E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS41B1201E"><span>The DEBOT Model, a New <span class="hlt">Global</span> Barotropic <span class="hlt">Ocean</span> Tidal Model: Test Computations and an Application in Related Geophysical Disciplines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Einspigel, D.; Sachl, L.; Martinec, Z.</p> <p>2014-12-01</p> <p>We present the DEBOT model, which is a new <span class="hlt">global</span> barotropic <span class="hlt">ocean</span> model. The DEBOT model is primarily designed for modelling of <span class="hlt">ocean</span> flow generated by the tidal attraction of the Moon and the Sun, however it can be used for other <span class="hlt">ocean</span> applications where the barotropic model is sufficient, for instance, a tsunami wave propagation. The model has been thoroughly tested by several different methods: 1) synthetic example which involves a tsunami-like wave propagation of an initial Gaussian depression and testing of the conservation of integral invariants, 2) a benchmark study with another barotropic model, the LSGbt model, has been performed and 3) results of realistic simulations have been compared with data from tide gauge measurements around the world. The test computations prove the validity of the numerical code and demonstrate the ability of the DEBOT model to simulate the realistic <span class="hlt">ocean</span> tides. The DEBOT model will be principaly applied in related geophysical disciplines, for instance, in an investigation of an influence of the <span class="hlt">ocean</span> tides on the geomagnetic field or the Earth's rotation. A module for modelling of the secondary poloidal magnetic field generated by an <span class="hlt">ocean</span> flow is already implemented in the DEBOT model and preliminary results will be presented. The future aim is to assimilate magnetic data provided by the Swarm satellite mission into the <span class="hlt">ocean</span> flow model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA502848','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA502848"><span>Eddy-Resolving <span class="hlt">Global</span> <span class="hlt">Ocean</span> Prediction</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-07-01</p> <p>Smed - stad et al, 2003; Shriver et al., 2007]. NLOM assimilates along-track satellite altimeter data using the model as a first guess for the...diverse research, commercial, military, and recreational ap- plications have been reported [Hurlburt el al., 2002; Smed - stad et al., 2003; Johannessen...Smedstad. J. M. Dastugue. and (). M. Smed - stad (2007). Evaluation of <span class="hlt">ocean</span> models using observed and simulated drifter trajectories: Impact of sea</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919614K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919614K"><span>New developments in the <span class="hlt">global</span> <span class="hlt">ocean</span> observing system Argo and its European component EuroArgo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klein, Birgit</p> <p>2017-04-01</p> <p>Since about 2005 Argo is the largest source of in situ <span class="hlt">ocean</span> data, with the number of Argo-profiles exceeding that of all ship-born profiles ever made. Having a dense and near-homogeneous <span class="hlt">global</span> and temporal coverage, Argo data are essential to derive <span class="hlt">ocean</span>-state estimates to initialize seasonal and decadal climate model forecasts and to validate climate model output. For instance, Argo data made it possible to accurately determine <span class="hlt">ocean</span> heat content and show that it kept increasing during the so-called hiatus period (2000-2014), during which atmospheric near-surface temperature stayed almost constant. Climate models ought to be able to reproduce such events. Currently Argo is entering new realms. New floats types are capable of measuring down to 4 km (instead of 2 km until now), and new sensors have been developed that can measure a variety of biogeochemical variables like oxygen, nitrate, or chlorophyll. These new data will be very important to validate and improve Earth System Models. First, about 40% of the <span class="hlt">ocean</span> volume is in the depth-range 2-4 km, but observations are currently limited to a few sections in space and time. Deep Argo data will make a thorough validation of <span class="hlt">ocean</span> models in this depth range possible for the first time. Secondly, the large amount of new biogeochemical data becoming available will allow process studies that will lead to improved parameterizations of biogenic and chemical processes in the <span class="hlt">ocean</span>, improvements that can be implemented in the models to increase their realism. Third, the data form the first-ever set of biogeochemical data that is consistent and homogeneous over a large spatial and temporal extent will make it possible to validate the models to a degree that was hitherto impossible, simply because of the lack of data. The Argo data system is composed of national Data Assembly Centers (DAC) that supply data to two mirrored <span class="hlt">Global</span> Data Assembly Centers (GDAC). GDAC data exchanges are based on File Transfer Protocol (FTP</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950019921','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950019921"><span>Intercomparison of hydrologic processes in <span class="hlt">global</span> climate models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lau, W. K.-M.; Sud, Y. C.; Kim, J.-H.</p> <p>1995-01-01</p> <p>In this report, we address the intercomparison of precipitation (P), evaporation (E), and surface hydrologic forcing (P-E) for 23 Atmospheric Model Intercomparison Project (AMIP) general circulation models (GCM's) including relevant observations, over a variety of spatial and temporal scales. The intercomparison includes <span class="hlt">global</span> and hemispheric means, latitudinal profiles, selected area means for the tropics and extratropics, <span class="hlt">ocean</span> and land, respectively. In addition, we have computed anomaly pattern correlations among models and observations for different seasons, harmonic analysis for annual and semiannual cycles, and rain-rate frequency distribution. We also compare the <span class="hlt">joint</span> influence of temperature and precipitation on local climate using the Koeppen climate classification scheme.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030005005','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030005005"><span>Sub-<span class="hlt">Ocean</span> Drilling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1981-01-01</p> <p>The National Science Foundation (NSF) initialized a new phase of exploration last year, a 10 year effort <span class="hlt">jointly</span> funded by NSF and several major oil companies, known as the <span class="hlt">Ocean</span> Margin Drilling Program (OMDP). The OMDP requires a ship with capabilities beyond existing drill ships; it must drill in 13,000 feet of water to a depth 20,000 feet below the <span class="hlt">ocean</span> floor. To meet requirements, NSF is considering the conversion of the government-owned mining ship Glomar Explorer to a deep <span class="hlt">ocean</span> drilling and coring vessel. Feasibility study performed by Donhaiser Marine, Inc. analyzed the ship's characteristics for suitability and evaluated conversion requirement. DMI utilized COSMIC's Ship Motion and Sea Load Computer program to perform analysis which could not be accomplished by other means. If approved for conversion, Glomar Explorer is expected to begin operations as a drillship in 1984.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. Their policies may differ from this site.</div> </div><!-- container --> <footer><a id="backToTop" href="#top"> </a><nav><a id="backToTop" href="#top"> </a><ul class="links"><a id="backToTop" href="#top"> </a><li><a id="backToTop" href="#top"></a><a href="/sitemap.html">Site Map</a></li> <li><a href="/members/index.html">Members Only</a></li> <li><a href="/website-policies.html">Website Policies</a></li> <li><a href="https://doe.responsibledisclosure.com/hc/en-us" target="_blank">Vulnerability Disclosure Program</a></li> <li><a href="/contact.html">Contact Us</a></li> </ul> <div class="small">Science.gov is maintained by the U.S. Department of Energy's <a href="https://www.osti.gov/" target="_blank">Office of Scientific and Technical Information</a>, in partnership with <a href="https://www.cendi.gov/" target="_blank">CENDI</a>.</div> </nav> </footer> <script type="text/javascript"><!-- // var lastDiv = ""; function showDiv(divName) { // hide last div if (lastDiv) { document.getElementById(lastDiv).className = "hiddenDiv"; } //if value of the box is not nothing and an object with that name exists, then change the class if (divName && document.getElementById(divName)) { document.getElementById(divName).className = "visibleDiv"; lastDiv = divName; } } //--> </script> <script> /** * Function that tracks a click on an outbound link in Google Analytics. * This function takes a valid URL string as an argument, and uses that URL string * as the event label. */ var trackOutboundLink = function(url,collectionCode) { try { h = window.open(url); setTimeout(function() { ga('send', 'event', 'topic-page-click-through', collectionCode, url); }, 1000); } catch(err){} }; </script> <!-- Google Analytics --> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-1122789-34', 'auto'); ga('send', 'pageview'); </script> <!-- End Google Analytics --> <script> showDiv('page_1') </script> </body> </html>