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Sample records for early productive ocean

  1. Production and recycling of oceanic crust in the early Earth

    NASA Astrophysics Data System (ADS)

    van Thienen, P.; van den Berg, A. P.; Vlaar, N. J.

    2004-08-01

    Because of the strongly different conditions in the mantle of the early Earth regarding temperature and viscosity, present-day geodynamics cannot simply be extrapolated back to the early history of the Earth. We use numerical thermochemical convection models including partial melting and a simple mechanism for melt segregation and oceanic crust production to investigate an alternative suite of dynamics which may have been in operation in the early Earth. Our modelling results show three processes that may have played an important role in the production and recycling of oceanic crust: (1) Small-scale ( x×100 km) convection involving the lower crust and shallow upper mantle. Partial melting and thus crustal production takes place in the upwelling limb and delamination of the eclogitic lower crust in the downwelling limb. (2) Large-scale resurfacing events in which (nearly) the complete crust sinks into the (eventually lower) mantle, thereby forming a stable reservoir enriched in incompatible elements in the deep mantle. New crust is simultaneously formed at the surface from segregating melt. (3) Intrusion of lower mantle diapirs with a high excess temperature (about 250 K) into the upper mantle, causing massive melting and crustal growth. This allows for plumes in the Archean upper mantle with a much higher excess temperature than previously expected from theoretical considerations.

  2. Suomi NPP VIIRS Ocean Color Data Product Early Mission Assessment

    NASA Technical Reports Server (NTRS)

    Turpie, Kevin R.; Robinson, Wayne D.; Franz, Bryan A.; Eplee, Robert E., Jr.; Meister, Gerhard; Fireman, Gwyn F.; Patt, Frederick S.; Barnes, Robert A.; McClain, Charles R.

    2013-01-01

    Following the launch of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polarorbiting Partnership (NPP) spacecraft, the NASA NPP VIIRS Ocean Science Team (VOST) began an evaluation of ocean color data products to determine whether they could continue the existing NASA ocean color climate data record (CDR). The VOST developed an independent evaluation product based on NASA algorithms with a reprocessing capability. Here we present a preliminary assessment of both the operational ocean color data products and the NASA evaluation data products regarding their applicability to NASA science objectives.

  3. Automation of Ocean Product Metrics

    DTIC Science & Technology

    2008-09-30

    Presented in: Ocean Sciences 2008 Conf., 5 Mar 2008. Shriver, J., J. D. Dykes, and J. Fabre: Automation of Operational Ocean Product Metrics. Presented in 2008 EGU General Assembly , 14 April 2008. 9 ...processing (multiple data cuts per day) and multiple-nested models. Routines for generating automated evaluations of model forecast statistics will be...developed and pre-existing tools will be collected to create a generalized tool set, which will include user-interface tools to the metrics data

  4. Ocean products delivered by the Mercator Ocean Service Department

    NASA Astrophysics Data System (ADS)

    Crosnier, L.; Durand, E.; Soulat, F.; Messal, F.; Buarque, S.; Toumazou, V.; Landes, V.; Drevillon, M.; Lellouche, J.

    2008-12-01

    The newly created Service Department at Mercator Ocean is now offering various services for academic and private ocean applications. Mercator Ocean runs operationally ocean forecast systems for the Global and North Atlantic Ocean. These systems are based on an ocean 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 ocean fields of temperature, salinity and currents are updated and available weekly, including analysis and 2 weeks forecast fields. The Mercator Ocean service department is now offering a wide range of ocean derived products. This presentation will display some of the various products delivered in the framework of academic and private ocean applications: " Monitoring of the ocean 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 ocean climate indicators (Coral bleaching...) for marine reserve survey; " Monitoring of upwelling systems for fisheries; " Monitoring of the ocean heat content for tropical cyclone monitoring. " Monitoring of the ocean temperature/salinity and currents to guide research vessels during scientific cruises. The Mercator Ocean products catalogue will grow wider in the coming years, especially in the framework of the European GMES MyOcean project (FP7).

  5. Amino Acid Stability in the Early Oceans

    NASA Technical Reports Server (NTRS)

    Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J. L.

    2015-01-01

    It is likely that a variety of amino acids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" amino acids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein amino acids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these amino acids could have persisted before their destruction by abiotic and biotic processes. Prior to life, amino acid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine amino acid life-time would have been shorter. After life, amino acids in the oceans could have been assimilated by primitive organisms.

  6. Early detection of ocean acidification effects on marine calcification

    SciT

    Ilyina, T.; Zeebe, R. E.; E. Maier-Reimer

    Ocean acidification is likely to impact calcification rates in many pelagic organisms, which may in turn cause significant changes in marine ecosystem structure. We examine effects of changes in marine CaCO3 production on total alkalinity (TA) in the ocean using the global biogeochemical ocean model HAMOCC. We test a variety of future calcification scenarios because experimental studies with different organisms have revealed a wide range of calcification sensitivities to CaCO3 saturation state. The model integrations start at a preindustrial steady state in the year 1800 and run until the year 2300 forced with anthropogenic CO2 emissions. Calculated trends in TAmore » are evaluated taking into account the natural variability in ocean carbonate chemistry, as derived from repeat hydrographic transects. We conclude that the data currently available does not allow discerning significant trends in TA due to changes in pelagic calcification caused by ocean acidification. Given different calcification scenarios, our model calculations indicate that the TA increase over time will start being detectable by the year 2040, increasing by 5–30 umol/kg compared to the present-day values. In a scenario of extreme reductions in calcification, large TA changes relative to preindustrial conditions would have occurred at present, which we consider very unlikely. However, the time interval of reliable TA observations is too short to disregard this scenario. The largest increase in surface ocean TA is predicted for the tropical and subtropical regions. In order to monitor and quantify possible early signs of acidification effects, we suggest to specifically target those regions during future ocean chemistry surveys.« less

  7. Early concepts and charts of ocean circulation

    NASA Astrophysics Data System (ADS)

    Peterson, R. G.; Stramma, L.; Kortum, G.

    little about them was reported in the Classical works. Following the dark and Middle Ages, when little progress was made, the voyages of discovery brought startling observations of many of Earth's most important ocean currents, such as the North and South Equatorial currents, the Gulf Stream, the Agulhas, Kuroshio, Peru, and Guinea currents, and others. The Gulf Stream appears to have been mapped as early as 1525 (Ribeiro) on the basis of Spanish pilot charts. Some currents were found to be westward, in the direction of the primum mobile as expected by theologians and philosophers, while others were not. The fifteenth through seventeenth centuries were marked by attainments of knowledge that increasingly taxed the abilities of science writers to reconcile new information with accepted doctrine. Consequences of this were descriptions of ocean circulation that questioned doctrine, yet were limited by it (Martyr; Gilbert; Bourne; Varen), while other descriptions disdainfully violated observation (Kircher; Happel). The expectation of a continuous westward oceanic flow around Earth in the direction of the primum mobile was so pervasive that it became central to arguments about a need for a passage through or around the Canadian north, and thus weighed significantly on the exploration and mapping of North America. Religious influences and the conceptual importance of the primum mobile waned by the close of the Renaissance and wind came to be seen as the primary cause of ocean currents (Dampier). The Gulf Stream (Franklin) and other North Atlantic flow patterns (de Brahm), as well as the southern Agulhas Current (Rennell), were mapped in the mid-to-late eighteenth century. Significant advances beyond these in determining the global ocean circulation came only after the routine determination of longitude at sea was instituted. The introduction of the marine chronometer in the late eighteenth century (Harrison) made this possible. By the end of the eighteenth century it was

  8. Early Humour Production

    ERIC Educational Resources Information Center

    Hoicka, Elena; Akhtar, Nameera

    2012-01-01

    The current studies explored early humour as a complex socio-cognitive phenomenon by examining 2- and 3-year-olds' humour production with their parents. We examined whether children produced novel humour, whether they cued their humour, and the types of humour produced. Forty-seven parents were interviewed, and videotaped joking with their…

  9. The rise of oxygen in Earth's early ocean and atmosphere.

    PubMed

    Lyons, Timothy W; Reinhard, Christopher T; Planavsky, Noah J

    2014-02-20

    The rapid increase of carbon dioxide concentration in Earth's modern atmosphere is a matter of major concern. But for the atmosphere of roughly two-and-half billion years ago, interest centres on a different gas: free oxygen (O2) spawned by early biological production. The initial increase of O2 in the atmosphere, its delayed build-up in the ocean, its increase to near-modern levels in the sea and air two billion years later, and its cause-and-effect relationship with life are among the most compelling stories in Earth's history.

  10. Evolving Oxygen Landscape of the Early Atmosphere and Oceans

    NASA Astrophysics Data System (ADS)

    Lyons, T. W.; Reinhard, C. T.; Planavsky, N. J.

    2013-12-01

    The past decade has witnessed remarkable advances in our understanding of oxygen on the early Earth, and a new framework, the topic of this presentation, is now in place to address the controls on spatiotemporal distributions of oxygen and their potential relationships to deep-Earth processes. Recent challenges to the Archean biomarker record have put an added burden on inorganic geochemistry to fingerprint and quantify the early production, accumulation, and variation of biospheric oxygen. Fortunately, a wide variety of techniques now point convincingly to photosynthetic oxygen production and dynamic accumulation well before the canonical Great Oxidation Event (GOE). Recent modeling of sulfur recycling over this interval allows for transient oxygen accumulation in the atmosphere without the disappearance of non-mass-dependent (NMD) sulfur isotope anomalies from the stratigraphic record and further allows for persistent accumulation in the atmosphere well before the permanent disappearance of NMD signals. This recent work suggests that the initial rise of oxygen may have occurred in fits and starts rather than a single step, and that once permanently present in the atmosphere, oxygen likely rose to high levels and then plummeted, in phase with the Paleoproterozoic Lomagundi positive carbon isotope excursion. More than a billion years of oxygen-free conditions in the deep ocean followed and set a challenging course for life, including limited abundances and diversity of eukaryotic organisms. Despite this widespread anoxia, sulfidic (euxinic) conditions were likely limited to productive ocean margins. Nevertheless, euxinia was sufficiently widespread to impact redox-dependent nutrient relationships, particularly the availability of bioessential trace metals critical in the nitrogen cycle, which spawned feedbacks that likely maintained oxygen at very low levels in the ocean and atmosphere and delayed the arrival of animals. Then, in the mid, pre-glacial Neoproterozoic

  11. Possible role of oceanic heat transport in early Eocene climate

    NASA Technical Reports Server (NTRS)

    Sloan, L. C.; Walker, J. C.; Moore, T. C. Jr

    1995-01-01

    Increased oceanic heat transport has often been cited as a means of maintaining warm high-latitude surface temperatures in many intervals of the geologic past, including the early Eocene. Although the excess amount of oceanic heat transport required by warm high latitude sea surface temperatures can be calculated empirically, determining how additional oceanic heat transport would take place has yet to be accomplished. That the mechanisms of enhanced poleward oceanic heat transport remain undefined in paleoclimate reconstructions is an important point that is often overlooked. Using early Eocene climate as an example, we consider various ways to produce enhanced poleward heat transport and latitudinal energy redistribution of the sign and magnitude required by interpreted early Eocene conditions. Our interpolation of early Eocene paleotemperature data indicate that an approximately 30% increase in poleward heat transport would be required to maintain Eocene high-latitude temperatures. This increased heat transport appears difficult to accomplish by any means of ocean circulation if we use present ocean circulation characteristics to evaluate early Eocene rates. Either oceanic processes were very different from those of the present to produce the early Eocene climate conditions or oceanic heat transport was not the primary cause of that climate. We believe that atmospheric processes, with contributions from other factors, such as clouds, were the most likely primary cause of early Eocene climate.

  12. Observations of Ocean Primary Productivity Using MODIS

    NASA Technical Reports Server (NTRS)

    Esaias, Wayne E.; Abbott, Mark R.; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Measuring the magnitude and variability of oceanic net primary productivity (NPP) represents a key advancement toward our understanding of the dynamics of marine ecosystems and the role of the ocean in the global carbon cycle. MODIS observations make two new contributions in addition to continuing the bio-optical time series begun with Orbview-2's SeaWiFS sensor. First, MODIS provides weekly estimates of global ocean net primary productivity on weekly and annual time periods, and annual empirical estimates of carbon export production. Second, MODIS provides additional insight into the spatial and temporal variations in photosynthetic efficiency through the direct measurements of solar-stimulated chlorophyll fluorescence. The two different weekly productivity indexes (first developed by Behrenfeld & Falkowski and by Yoder, Ryan and Howard) are used to derive daily productivity as a function of chlorophyll biomass, incident daily surface irradiance, temperature, euphotic depth, and mixed layer depth. Comparisons between these two estimates using both SeaWiFS and MODIS data show significant model differences in spatial distribution after allowance for the different integration depths. Both estimates are strongly dependence on the accuracy of the chlorophyll determination. In addition, an empirical approach is taken on annual scales to estimate global NPP and export production. Estimates of solar stimulated fluorescence efficiency from chlorophyll have been shown to be inversely related to photosynthetic efficiency by Abbott and co-workers. MODIS provides the first global estimates of oceanic chlorophyll fluorescence, providing an important proof of concept. MODIS observations are revealing spatial patterns of fluorescence efficiency which show expected variations with phytoplankton photo-physiological parameters as measured during in-situ surveys. This has opened the way for research into utilizing this information to improve our understanding of oceanic NPP

  13. Statistical Evaluation of VIIRS Ocean Color Products

    NASA Astrophysics Data System (ADS)

    Mikelsons, K.; Wang, M.; Jiang, L.

    2016-02-01

    Evaluation and validation of satellite-derived ocean color products is a complicated task, which often relies on precise in-situ measurements for satellite data quality assessment. However, in-situ measurements are only available in comparatively few locations, expensive, and not for all times. In the open ocean, the variability in spatial and temporal scales is longer, and the water conditions are generally more stable. We use this fact to perform extensive statistical evaluations of consistency for ocean color retrievals based on comparison of retrieved data at different times, and corresponding to various retrieval parameters. We have used the NOAA Multi-Sensor Level-1 to Level-2 (MSL12) ocean color data processing system for ocean color product data derived from the Visible Infrared Imaging Radiometer Suite (VIIRS). We show the results for statistical dependence of normalized water-leaving radiance spectra with respect to various parameters of retrieval geometry, such as solar- and sensor-zenith angles, as well as physical variables, such as wind speed, air pressure, ozone amount, water vapor, etc. In most cases, the results show consistent retrievals within the relevant range of retrieval parameters, showing a good performance with the MSL12 in the open ocean. The results also yield the upper bounds of solar- and sensor-zenith angles for reliable ocean color retrievals, and also show a slight increase of VIIRS-derived normalized water-leaving radiances with wind speed and water vapor concentration.

  14. VIIRS Product Evaluation at the Ocean PEATE

    NASA Technical Reports Server (NTRS)

    Patt, Frederick S.; Feldman, Gene C.

    2010-01-01

    The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) mission will support the continuation of climate records generated from NASA missions. The NASA Science Data Segment (SDS) relies upon discipline-specific centers of expertise to evaluate the NPP data products for suitability as climate data records, The Ocean Product Evaluation and Analysis Tool Element (PEATE) will build upon Well established NASA capabilities within the Ocean Color program in order to evaluate the NPP Visible and Infrared Imager/Radiometer Suite (VIIRS) Ocean Color and Chlorophyll data products. The specific evaluation methods will support not only the evaluation of product quality but also the sources of differences with existing data records.

  15. A review of ocean chlorophyll algorithms and primary production models

    NASA Astrophysics Data System (ADS)

    Li, Jingwen; Zhou, Song; Lv, Nan

    2015-12-01

    This paper mainly introduces the five ocean chlorophyll concentration inversion algorithm and 3 main models for computing ocean primary production based on ocean chlorophyll concentration. Through the comparison of five ocean chlorophyll inversion algorithm, sums up the advantages and disadvantages of these algorithm,and briefly analyzes the trend of ocean primary production model.

  16. Evaluation of VIIRS ocean color products

    NASA Astrophysics Data System (ADS)

    Wang, Menghua; Liu, Xiaoming; Jiang, Lide; Son, SeungHyun; Sun, Junqiang; Shi, Wei; Tan, Liqin; Naik, Puneeta; Mikelsons, Karlis; Wang, Xiaolong; Lance, Veronica

    2014-11-01

    The Suomi National Polar-orbiting Partnership (SNPP) was successfully launched on October 28, 2011. The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi NPP, which has 22 spectral bands (from visible to infrared) similar to the NASA's Moderate Resolution Imaging Spectroradiometer (MODIS), is a multi-disciplinary sensor providing observations for the Earth's atmosphere, land, and ocean properties. In this paper, we provide some evaluations and assessments of VIIRS ocean color data products, or ocean color Environmental Data Records (EDR), including normalized water-leaving radiance spectra nLw(λ) at VIIRS five spectral bands, chlorophyll-a (Chl-a) concentration, and water diffuse attenuation coefficient at the wavelength of 490 nm Kd(490). Specifically, VIIRS ocean color products derived from the NOAA Multi-Sensor Level-1 to Level-2 (NOAA-MSL12) ocean color data processing system are evaluated and compared with MODIS ocean color products and in situ measurements. MSL12 is now NOAA's official ocean color data processing system for VIIRS. In addition, VIIRS Sensor Data Records (SDR or Level- 1B data) have been evaluated. In particular, VIIRS SDR and ocean color EDR have been compared with a series of in situ data from the Marine Optical Buoy (MOBY) in the waters off Hawaii. A notable discrepancy of global deep water Chl-a derived from MODIS and VIIRS between 2012 and 2013 is observed. This discrepancy is attributed to the SDR (or Level-1B data) calibration issue and particularly related to VIIRS green band at 551 nm. To resolve this calibration issue, we have worked on our own sensor calibration by combining the lunar calibration effect into the current calibration method. The ocean color products derived from our new calibrated SDR in the South Pacific Gyre show that the Chl-a differences between 2012 and 2013 are significantly reduced. Although there are still some issues, our results show that VIIRS is capable of providing high-quality global

  17. LIDAR and acoustics applications to ocean productivity

    NASA Technical Reports Server (NTRS)

    Collins, D. J.

    1982-01-01

    The requirements for the submersible, the instrumentation necessary to perform these measurements, and the optical and acoustical technology required to develop the ocean color scanner instrumentation are described. The development of a second generation ocean color scanner produced the need for coincident in situ scientific measurements which examine the primary productivity of the upper ocean on time and space scales which are large compared to the environmental scales. The vertical and horizontal variability of the biota, including the relationship between chlorophyll and primary productivity, the productivity of zooplankton, and the dynamic interaction between phytoplankton and zooplankton, and between these populations and the physical environment are investigated. A towed submersible will be constructed which accommodates both an underwater LIDAR instrument and a multifrequency sonar.

  18. 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

  19. 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.

  20. Marine Export Production and Remineralization During Early Eocene Hyperthermal Events at ODP Site 1263, Walvis Ridge, ODP Site 1209, Shatsky Rise and ODP Site 1215, Equatorial Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Lewis, A.; Griffith, E. M.; Thomas, E.; Winguth, A. M. E.

    2017-12-01

    Understanding the impacts of global hyperthermal events on marine productivity and remineralization is important for understanding the reaction of the ocean to major climate change. Marine export production and remineralization was reconstructed using marine (pelagic) barite accumulation rates (BAR) coupled with records of benthic foraminiferal assemblages across the Paleocene - Eocene Thermal Maximum (PETM) at 55.3 Ma, Eocene Thermal Maximum 2 (ETM2) 2 Ma later, and ETM3 3.1 Ma after the PETM. Marine barite accumulates in deep sea sediment precipitating in the overlying water column during degradation of organic matter exported from the photic zone. Foraminiferal data indicate the amount of organic matter reaching the seafloor. We use the difference between these records to infer changes in rates of remineralization. We present data from ODP Site on Walvis Ridge, Southeastern Atlantic; ODP Site 1209 on Shatsky Rise, North Pacific; and ODP Site 1215, equatorial Pacific. Sites 1263 and 1215 had maximum BAR roughly centered over the maximum negative PETM CIE, whereas at Site 1209 the maximum was before the PETM. The maximum BAR across ETM2 and ETM3 (0.5 and 0.25 of that at the PETM, respectively) was centered over the maximum negative CIE at Site 1263. At Site 1209, the BAR (0.5 the maximum value before the PETM) peaked before ETM2. Barite concentration at Site 1215 was low across at the smaller hyperthermals, but the onset of ETM2 had a maximum value < 3% of the PETM, whereas the ETM3 maximum occurred during the CIE recovery and was < 10% of ETM2. Benthic foraminiferal data indicate decreased food arrival at the seafloor during elevated BAR, thus indicating enhanced remineralization. During the PETM, at all 3 sites, increases in barite coincided with reduced BFAR. Similar trends were observed during ETM2 at Sites 1263 and 1215, suggesting dramatic changes in remineralization over all hyperthermal events at these sites. Increased remineralization rates could partly

  1. 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

  2. Early lunar petrogenesis, oceanic and extraoceanic

    NASA Technical Reports Server (NTRS)

    Warren, P. H.; Wasson, J. T.

    1980-01-01

    An attempt is made to ascertain which (if any) pristine nonmare rocks, other than KREEPy ones, are not cumulates from the magma ocean. It is noted that the only pristine rocks having bulk densities low enough to have formed by floating above the magma ocean are the ferroan anorthosites, which are easily recognizable as a discrete subset of pristine rocks in general, on the basis of mineral composition relationships. The other class of pristine nonmare rocks, the Mg-rich rocks, did not form from the same magma that produced the ferroan anorthosites. It is suggested that they were formed in layered noritic-troctolitic plutons. These plutons, it is noted, were apparently intruded at, or slightly above, the boundary between the floated ferroan anorthosite crust and the underlying complementary mafic cumulates. It is thought that the parental magmas of the plutons may have arisen by partial melting of either deep mafic cumulates from the magma ocean or a still deeper, undifferentiated primordial layer that was not molten during the magma ocean period.

  3. The 360 Degree Fulldome Production "Clockwork Ocean"

    NASA Astrophysics Data System (ADS)

    Baschek, B.; Heinsohn, R.; Opitz, D.; Fischer, T.; Baschek, T.

    2016-02-01

    The investigation of submesoscale eddies and fronts is one of the leading oceanographic topics at the Ocean Sciences Meeting 2016. In order to observe these small and short-lived phenomena, planes equipped with high-resolution cameras and fast vessels were deployed during the Submesoscale Experiments (SubEx) leading to some of the first high-resolution observations of these eddies. In a future experiment, a zeppelin will be used the first time in marine sciences. The relevance of submesoscale processes for the oceans and the work of the eddy hunters is described in the fascinating 9-minute long 360 degree fulldome production Clockwork Ocean. The fully animated movie is introduced in this presentation taking the observer from the bioluminescence in the deep ocean to a view of our blue planet from space. The immersive media is used to combine fascination for a yet unknown environment with scientific education of a broad audience. Detailed background information is available at the parallax website www.clockwork-ocean.com. The Film is also available for Virtual Reality glasses and smartphones to reach a broader distribution. A unique Mobile Dome with an area of 70 m² and seats for 40 people is used for science education at events, festivals, for politicians and school classes. The spectators are also invited to participate in the experiments by presenting 360 degree footage of the measurements. The premiere of Clockwork Ocean was in July 2015 in Hamburg, Germany and will be worldwide available in English and German as of fall 2015. Clockwork Ocean is a film of the Helmholtz-Zentrum Geesthacht produced by Daniel Opitz and Ralph Heinsohn.

  4. New satellite altimetry products for coastal oceans

    NASA Astrophysics Data System (ADS)

    Dufau, Claire; Mercier, F.; Ablain, M.; Dibarboure, G.; Carrere, L.; Labroue, S.; Obligis, E.; Sicard, P.; Thibaut, P.; Birol, F.; Bronner, E.; Lombard, A.; Picot, N.

    Since the launch of Topex-Poseidon in 1992, satellite altimetry has become one of the most essential elements of the Earth's observing system. Its global view of the ocean state has permitted numerous improvements in the environment understanding, particularly in the global monitoring of climate changes and ocean circulation. Near the coastlines where human activities have a major impact on the ocean, satellite altimeter techniques are unfortunately limited by a growth of their error budget. This quality loss is due to land contamination in the altimetric and radiometric footprints but also to inaccurate geophysical corrections (tides, high-frequency processes linked to atmospheric forcing).Despite instrumental perturbations by emerged lands until 10 km (altimeter) and 50 km (radiometer) off the coasts, measurements are made and may contain useful information for coastal studies. In order to recover these data close to the coast, the French Spatial Agency (CNES) has funded the development of the PISTACH prototype dedicated to Jason-2 altimeter processing in coastal ocean. Since November 2008, these new satellite altimeter products have been providing new retracking solutions, several state-of-the-art or with higher resolution corrections in addition to standard fields. This presentation will present and illustrate this new set of satellite data for the coastal oceans.

  5. Reconstruction of early Cambrian ocean chemistry from Mo isotopes

    NASA Astrophysics Data System (ADS)

    Wen, Hanjie; Fan, Haifeng; Zhang, Yuxu; Cloquet, Christophe; Carignan, Jean

    2015-09-01

    The Neoproterozoic-Cambrian transition was a key time interval in the history of the Earth, especially for variations in oceanic and atmospheric chemical composition. However, two conflicting views exist concerning the nature of ocean chemistry across the Precambrian-Cambrian boundary. Abundant geochemical evidence suggests that oceanic basins were fully oxygenated by the late Ediacaran, while other studies provide seemingly conflicting evidence for anoxic deep waters, with ferruginous conditions [Fe(II)-enriched] persisting into the Cambrian. Here, two early Cambrian sedimentary platform and shelf-slope sections in South China were investigated to trace early Cambrian ocean chemistry from Mo isotopes. The results reveal that early Cambrian sediments deposited under oxic to anoxic/euxinic conditions have δ98/95Mo values ranging from -0.28‰ to 2.29‰, which suggests that early Cambrian seawater may have had δ98/95Mo values of at least 2.29‰, similar to modern oceans. The heaviest and relatively homogeneous δ98/95Mo values were recorded in siltstone samples formed under completely oxic conditions, which is considered that Mn oxide-free shuttling was responsible for such heavy δ98/95Mo value. Further, combined with Fe species data and the accumulation extent of Mo and U, the variation of δ98/95Mo values in the two studied sections demonstrate a redox-stratified ocean with completely oxic shallow water and predominantly anoxic (even euxinic) deeper water having developed early on, which eventually became completely oxygenated. This suggests that oceanic circulation at the time became reorganized, and such changes in oceanic chemistry may have been responsible for triggering the "Cambrian Explosion" of biological diversity.

  6. Carbon isotopic evidence for photosynthesis in Early Cambrian oceans

    NASA Astrophysics Data System (ADS)

    Surge, Donna M.; Savarese, Michael; Dodd, J. Robert; Lohmann, Kyger C.

    1997-06-01

    Were the first metazoan reefs ecologically similar to modern tropical reefs, enabling them to persist under oligotrophic conditions? We tested the hypothesis of ecological similarity by employing a geochemical approach. Petrography, cathodoluminescence, trace elements, and stable isotope analyses of primary precipitates of the Lower Cambrian Ajax Limestone, South Australia, indicate preservation of original C isotopic composition. All primary carbonate components exhibit C isotopic values similar to the composition of inorganically precipitated fibrous marine cements, suggesting that archaeocyaths and the calcimicrobe Epiphyton precipitated skeletal carbonate in equilibrium with ambient seawater in the absence of vital effects. Such data do not support the contention that archaeocyaths possessed photosymbionts. However, a +0.55‰ shift in δ13C occurs in reefs developed under shallower-water conditions relative to deeper reefs. This shift suggests the stratification of primary production in Early Cambrian oceans. The pattern is similar to that seen in the modern ocean, whereby significant photosynthesis modulates the C isotopic composition of the photic zone.

  7. Updating the Evidence for Oceans on Early Mars

    NASA Technical Reports Server (NTRS)

    Fairen, Alberto G.; Dohm, James M.; Oner, Tayfun; Ruiz, Javier; Rodriguez, Alexis P.; Schulze-Makuch, Dirk; Ormoe, Jens; McKay, Chris P.; Baker, Victor R.; Amils, Ricardo

    2004-01-01

    Different-sized bodies of water have been proposed to have occurred episodically in the lowlands of Mars throughout the planet's history, largely related to major stages of development of Tharsis and/or orbital obliquity. These water bodies range from large oceans in the Noachian-Early Hesperian, to a minor sea in the Late Hesperian, and dispersed lakes during the Amazonian. To evaluate the more recent discoveries regarding the oceanic possibility, here we perform a comprehensive analysis of the evolution of water on Mars, including: 1. Geological assessment of proposed shorelines; 2. A volumetric approximation to the plains-filing proposed oceans; 3. Geochemistry of the oceans and derived mineralogies; 4. Post-oceanic (i.e., Amazonian) evolution of the shorelines; and 5. Ultimate water evolution on Mars.

  8. On the photosynthetic potential in the very Early Archean oceans.

    PubMed

    Avila, Daile; Cardenas, Rolando; Martin, Osmel

    2013-02-01

    In this work we apply a mathematical model of photosynthesis to quantify the potential for photosynthetic life in the very Early Archean oceans. We assume the presence of oceanic blockers of ultraviolet radiation, specifically ferrous ions. For this scenario, our results suggest a potential for photosynthetic life greater than or similar to that in later eras/eons, such as the Late Archean and the current Phanerozoic eon.

  9. Net production of oxygen in the subtropical ocean.

    PubMed

    Riser, Stephen C; Johnson, Kenneth S

    2008-01-17

    The question of whether the plankton communities in low-nutrient regions of the ocean, comprising 80% of the global ocean surface area, are net producers or consumers of oxygen and fixed carbon is a key uncertainty in the global carbon cycle. Direct measurements in bottle experiments indicate net oxygen consumption in the sunlit zone, whereas geochemical evidence suggests that the upper ocean is a net source of oxygen. One possible resolution to this conflict is that primary production in the gyres is episodic and thus difficult to observe: in this model, oligotrophic regions would be net consumers of oxygen during most of the year, but strong, brief events with high primary production rates might produce enough fixed carbon and dissolved oxygen to yield net production as an average over the annual cycle. Here we examine the balance of oxygen production over three years at sites in the North and South Pacific subtropical gyres using the new technique of oxygen sensors deployed on profiling floats. We find that mixing events during early winter homogenize the upper water column and cause low oxygen concentrations. Oxygen then increases below the mixed layer at a nearly constant rate that is similar to independent measures of net community production. This continuous oxygen increase is consistent with an ecosystem that is a net producer of fixed carbon (net autotrophic) throughout the year, with episodic events not required to sustain positive oxygen production.

  10. Ocean Surface Topography Data Products and Tools

    NASA Technical Reports Server (NTRS)

    Case, Kelley E.; Bingham, Andrew W.; Berwin, Robert W.; Rigor, Eric M.; Raskin, Robert G.

    2004-01-01

    The Physical Oceanography Distributed Active Archiving Center (PO.DAAC), NASA's primary data center for archiving and distributing oceanographic data, is supporting the Jason and TOPEX/Poseidon satellite tandem missions by providing a variety of data products, tools, and distribution methods to the wider scientific and general community. PO.DAAC has developed several new data products for sea level residual measurements, providing a longterm climate data record from 1992 to the present These products provide compatible measurements of sea level residuals for the entire time series including the tandem TOPEX/Poseidon and Jason mission. Several data distribution tool. are available from NASA PO.DAAC. The Near-Real-Time Image Distribution Server (NEREIDS) provides quicklook browse images and binary data files The PO.DAAC Ocean ESIP Tool (POET) provides interactive, on-tine data subsetting and visualization for several altimetry data products.

  11. Ultraviolet radiation and the photobiology of earth's early oceans.

    PubMed

    Cockell, C S

    2000-10-01

    During the Archean era (3.9-2.5 Ga ago) the earth was dominated by an oceanic lithosphere. Thus, understanding how life arose and persisted in the Archean oceans constitutes a major challenge in understanding early life on earth. Using a radiative transfer model of the late Archean oceans, the photobiological environment of the photic zone and the surface microlayer is explored at the time before the formation of a significant ozone column. DNA damage rates might have been approximately three orders of magnitude higher in the surface layer of the Archean oceans than on the present-day oceans, but at 30 m depth, damage may have been similar to the surface of the present-day oceans. However at this depth the risk of being transported to surface waters in the mixed layer was high. The mixed layer may have been inhabited by a low diversity UV-resistant biota. But it could have been numerically abundant. Repair capabilities similar to Deinococcus radiodurans would be sufficient to survive in the mixed layer. Diversity may have been greater in the region below the mixed layer and above the light compensation point corresponding to today's 'deep chlorophyll maximum'. During much of the Archean the air-water interface was probably an uninhabitable extreme environment for neuston. The habitability of some regions of the photic zone is consistent with the evidence embodied in the geologic record, which suggests an oxygenated upper layer in the Archean oceans. During the early Proterozoic, as ozone concentrations increased to a column abundance above 1 x 10(17) cm-2, UV stress would have been reduced and possibly a greater diversity of organisms could have inhabited the mixed layer. However, nutrient upwelling from newly emergent continental crusts may have been more significant in increasing total planktonic abundance in the open oceans and coastal regions than photobiological factors. The phohobiological environment of the Archean oceans has implications for the potential

  12. Coalition releases declaration for healthy and productive oceans

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-06-01

    Coalition releases declaration for healthy and productive oceans A coalition of 13 countries or federal agencies participating in a new Global Partnership for Oceans (GPO) indicated its support for a “Declaration for Healthy and Productive Oceans to Help Reduce Poverty” on 16 June, just prior to the Rio+20 conference in Rio de Janeiro, Brazil.

  13. Isotope composition and volume of Earth’s early oceans

    PubMed Central

    Pope, Emily C.; Bird, Dennis K.; Rosing, Minik T.

    2012-01-01

    Oxygen and hydrogen isotope compositions of Earth’s seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but hydrogen’s was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25 ± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth’s oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH4 and CO2 concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth. PMID:22392985

  14. Isotope composition and volume of Earth's early oceans.

    PubMed

    Pope, Emily C; Bird, Dennis K; Rosing, Minik T

    2012-03-20

    Oxygen and hydrogen isotope compositions of Earth's seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but hydrogen's was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25 ± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth's oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH(4) and CO(2) concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth.

  15. Comparative analysis of GOCI ocean color products.

    PubMed

    Amin, Ruhul; Lewis, Mark David; Lawson, Adam; Gould, Richard W; Martinolich, Paul; Li, Rong-Rong; Ladner, Sherwin; Gallegos, Sonia

    2015-10-12

    The Geostationary Ocean Color Imager (GOCI) is the first geostationary ocean color sensor in orbit that provides bio-optical properties from coastal and open waters around the Korean Peninsula at unprecedented temporal resolution. In this study, we compare the normalized water-leaving radiance (nLw) products generated by the Naval Research Laboratory Automated Processing System (APS) with those produced by the stand-alone software package, the GOCI Data Processing System (GDPS), developed by the Korean Ocean Research & Development Institute (KORDI). Both results are then compared to the nLw measured by the above water radiometer at the Ieodo site. This above-water radiometer is part of the Aerosol Robotic NETwork (AeroNET). The results indicate that the APS and GDPS processed  correlates well within the same image slot where the coefficient of determination (r²) is higher than 0.84 for all the bands from 412 nm to 745 nm. The agreement between APS and the AeroNET data is higher when compared to the GDPS results. The Root-Mean-Squared-Error (RMSE) between AeroNET and APS data ranges from 0.24 [mW/(cm²srμm)] at 555 nm to 0.52 [mW/(cm²srμm)]  at 412 nm while RMSE between AeroNET and GDPS data ranges from 0.47 [mW/(cm²srμm)] at 443 nm to 0.69 [mW/(cm²srμm)]  at 490 nm.

  16. Comparative Analysis of GOCI Ocean Color Products

    PubMed Central

    Amin, Ruhul; Lewis, Mark David; Lawson, Adam; Gould, Richard W.; Martinolich, Paul; Li, Rong-Rong; Ladner, Sherwin; Gallegos, Sonia

    2015-01-01

    The Geostationary Ocean Color Imager (GOCI) is the first geostationary ocean color sensor in orbit that provides bio-optical properties from coastal and open waters around the Korean Peninsula at unprecedented temporal resolution. In this study, we compare the normalized water-leaving radiance (nLw) products generated by the Naval Research Laboratory Automated Processing System (APS) with those produced by the stand-alone software package, the GOCI Data Processing System (GDPS), developed by the Korean Ocean Research & Development Institute (KORDI). Both results are then compared to the nLw measured by the above water radiometer at the Ieodo site. This above-water radiometer is part of the Aerosol Robotic NETwork (AeroNET). The results indicate that the APS and GDPS processed nLw correlates well within the same image slot where the coefficient of determination (r2) is higher than 0.84 for all the bands from 412 nm to 745 nm. The agreement between APS and the AeroNET data is higher when compared to the GDPS results. The Root-Mean-Squared-Error (RMSE) between AeroNET and APS data ranges from 0.24 [mW/(cm2srμm)] at 555 nm to 0.52 [mW/(cm2srμm)] at 412 nm while RMSE between AeroNET and GDPS data ranges from 0.47 [mW/(cm2srμm)] at 443 nm to 0.69 [mW/(cm2srμm)] at 490 nm. PMID:26473861

  17. Models for ecological models: Ocean primary productivity

    Wikle, Christopher K.; Leeds, William B.; Hooten, Mevin B.

    2016-01-01

    The ocean accounts for more than 70% of planet Earth's surface, and it processes are critically important to marine and terrestrial life.  Ocean ecosystems are strongly dependent on the physical state of the ocean (e.g., transports, mixing, upwelling, runoff, and ice dynamics(.  As an example, consider the Coastal Gulf of Alaska (CGOA) region.

  18. Early ice retreat and ocean warming may induce copepod biogeographic boundary shifts in the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Feng, Zhixuan; Ji, Rubao; Campbell, Robert G.; Ashjian, Carin J.; Zhang, Jinlun

    2016-08-01

    Early ice retreat and ocean warming are changing various facets of the Arctic marine ecosystem, including the biogeographic distribution of marine organisms. Here an endemic copepod species, Calanus glacialis, was used as a model organism, to understand how and why Arctic marine environmental changes may induce biogeographic boundary shifts. A copepod individual-based model was coupled to an ice-ocean-ecosystem model to simulate temperature- and food-dependent copepod life history development. Numerical experiments were conducted for two contrasting years: a relatively cold and normal sea ice year (2001) and a well-known warm year with early ice retreat (2007). Model results agreed with commonly known biogeographic distributions of C. glacialis, which is a shelf/slope species and cannot colonize the vast majority of the central Arctic basins. Individuals along the northern boundaries of this species' distribution were most susceptible to reproduction timing and early food availability (released sea ice algae). In the Beaufort, Chukchi, East Siberian, and Laptev Seas where severe ocean warming and loss of sea ice occurred in summer 2007, relatively early ice retreat, elevated ocean temperature (about 1-2°C higher than 2001), increased phytoplankton food, and prolonged growth season created favorable conditions for C. glacialis development and caused a remarkable poleward expansion of its distribution. From a pan-Arctic perspective, despite the great heterogeneity in the temperature and food regimes, common biogeographic zones were identified from model simulations, thus allowing a better characterization of habitats and prediction of potential future biogeographic boundary shifts.

  19. 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

    Nowcast/Forecast System over the Gulf of Mexico from 2004-Mar 2011, the operational Naval Oceanographic Office (NAVOCEANO) regional USEast ocean nowcast/forecast system from early 2009 to present, and the NAVOCEANO operational regional AMSEAS (Gulf of Mexico/Caribbean) ocean nowcast/forecast system from its inception 25 June 2010 to present. AMSEAS provided one of the real-time ocean forecast products accessed by NOAA's Office of Response and Restoration from the NGI/NCDDC developmental OceanNOMADS during the Deep Water Horizon oil spill last year. The developmental server also includes archived, real-time Navy coastal forecast products off coastal Japan in support of U.S./Japanese joint efforts following the 2011 tsunami. Real-time NAVOCEANO output from regional prediction systems off Southern California and around Hawaii, currently available on the NCEP ftp server, are scheduled for archival on the developmental OceanNOMADS by late 2011 along with the next generation Navy/NOAA global ocean prediction output. Accession and archival of additional regions is planned as server capacities increase.

  20. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

    PubMed

    Umeda, Yuhei; Fukunaga, Nao; Sekine, Toshimori; Furukawa, Yoshihiro; Kakegawa, Takeshi; Kobayashi, Takamichi; Nakazawa, Hiromoto

    2016-01-01

    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

  1. Early summer southern China rainfall variability and its oceanic drivers

    NASA Astrophysics Data System (ADS)

    Li, Weijing; Ren, Hong-Chang; Zuo, Jinqing; Ren, Hong-Li

    2018-06-01

    Rainfall in southern China reaches its annual peak in early summer (May-June) with strong interannual variability. Using a combination of observational analysis and numerical modeling, the present study investigates the leading modes of this variability and its dynamic drivers. A zonal dipole pattern termed the southern China Dipole (SCD) is found to be the dominant feature in early summer during 1979-2014, and is closely related to a low-level anomalous anticyclone over the Philippine Sea (PSAC) and a Eurasian wave-train pattern over the mid-high latitudes. Linear regressions based on observations and numerical experiments using the CAM5 model suggest that the associated atmospheric circulation anomalies in early summer are linked to decaying El Niño-Southern Oscillation-like sea surface temperature (SST) anomalies in the tropical Pacific, basin-scale SST anomalies in the tropical Indian Ocean, and meridional tripole-like SST anomalies in the North Atlantic in the previous winter to early summer. The tropical Pacific and Indian Ocean SST anomalies primarily exert an impact on the SCD through changing the polarity of the PSAC, while the North Atlantic tripole-like SST anomalies mainly exert a downstream impact on the SCD by inducing a Eurasian wave-train pattern. The North Atlantic tripole-like SST anomalies also make a relatively weak contribution to the variations of the PSAC and SCD through a subtropical teleconnection. Modeling results indicate that the three-basin combined forcing has a greater impact on the SCD and associated circulation anomalies than the individual influence from any single oceanic basin.

  2. An alternative early opening scenario for the Central Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Labails, Cinthia; Olivet, Jean-Louis; Aslanian, Daniel; Roest, Walter R.

    2010-09-01

    The opening of the Central Atlantic Ocean basin that separated North America from northwest Africa is well documented and assumed to have started during the Late Jurassic. However, the early evolution and the initial breakup history of Pangaea are still debated: most of the existing models are based on one or multiple ridge jumps at the Middle Jurassic leaving the oldest crust on the American side, between the East Coast Magnetic Anomaly (ECMA) and the Blake Spur Magnetic Anomaly (BSMA). According to these hypotheses, the BSMA represents the limit of the initial basin and the footprint subsequent to the ridge jump. Consequently, the evolution of the northwest African margin is widely different from the northeast American margin. However, this setting is in contradiction with the existing observations. In this paper, we propose an alternative scenario for the continental breakup and the Mesozoic spreading history of the Central Atlantic Ocean. The new model is based on an analysis of geophysical data (including new seismic lines, an interpretation of the newly compiled magnetic data, and satellite derived gravimetry) and recently published results which demonstrate that the opening of the Central Atlantic Ocean started already during the Late Sinemurian (190 Ma), based on a new identification of the African conjugate to the ECMA and on the extent of salt provinces off Morocco and Nova Scotia. The identification of an African conjugate magnetic anomaly to BSMA, the African Blake Spur Magnetic Anomaly (ABSMA), together with the significant change in basement topography, are in good agreement with that initial reconstruction. The early opening history for the Central Atlantic Ocean is described in four distinct phases. During the first 20 Myr after the initial breakup (190-170 Ma, from Late Sinemurian to early Bajocian), oceanic accretion was extremely slow (˜ 0.8 cm/y). At the time of Blake Spur (170 Ma, early Bajocian), a drastic change occurred both in the relative

  3. Reconciling fisheries catch and ocean productivity

    PubMed Central

    Stock, Charles A.; Asch, Rebecca G.; Cheung, William W. L.; Dunne, John P.; Friedland, Kevin D.; Lam, Vicky W. Y.; Sarmiento, Jorge L.; Watson, Reg A.

    2017-01-01

    Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM). After removing a small number of lightly fished ecosystems, stark interregional differences in fish catch per unit area can be explained (r = 0.79) with an energy-based model that (i) considers dynamic interregional differences in benthic and pelagic energy pathways connecting phytoplankton and fish, (ii) depresses trophic transfer efficiencies in the tropics and, less critically, (iii) associates elevated trophic transfer efficiencies with benthic-predominant systems. Model catch estimates are generally within a factor of 2 of values spanning two orders of magnitude. Climate change projections show that the same macroecological patterns explaining dramatic regional catch differences in the contemporary ocean amplify catch trends, producing changes that may exceed 50% in some regions by the end of the 21st century under high-emissions scenarios. Models failing to resolve these trophodynamic patterns may significantly underestimate regional fisheries catch trends and hinder adaptation to climate change. PMID:28115722

  4. Reconciling fisheries catch and ocean productivity.

    PubMed

    Stock, Charles A; John, Jasmin G; Rykaczewski, Ryan R; Asch, Rebecca G; Cheung, William W L; Dunne, John P; Friedland, Kevin D; Lam, Vicky W Y; Sarmiento, Jorge L; Watson, Reg A

    2017-02-21

    Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM). After removing a small number of lightly fished ecosystems, stark interregional differences in fish catch per unit area can be explained ( r = 0.79) with an energy-based model that ( i ) considers dynamic interregional differences in benthic and pelagic energy pathways connecting phytoplankton and fish, ( ii ) depresses trophic transfer efficiencies in the tropics and, less critically, ( iii ) associates elevated trophic transfer efficiencies with benthic-predominant systems. Model catch estimates are generally within a factor of 2 of values spanning two orders of magnitude. Climate change projections show that the same macroecological patterns explaining dramatic regional catch differences in the contemporary ocean amplify catch trends, producing changes that may exceed 50% in some regions by the end of the 21st century under high-emissions scenarios. Models failing to resolve these trophodynamic patterns may significantly underestimate regional fisheries catch trends and hinder adaptation to climate change.

  5. Integration of WERA Ocean Radar into Tsunami Early Warning Systems

    NASA Astrophysics Data System (ADS)

    Dzvonkovskaya, Anna; Helzel, Thomas; Kniephoff, Matthias; Petersen, Leif; Weber, Bernd

    2016-04-01

    High-frequency (HF) ocean radars give a unique capability to deliver simultaneous wide area measurements of ocean surface current fields and sea state parameters far beyond the horizon. The WERA® ocean radar system is a shore-based remote sensing system to monitor ocean surface in near real-time and at all-weather conditions up to 300 km offshore. Tsunami induced surface currents cause increasing orbital velocities comparing to normal oceanographic situation and affect the measured radar spectra. The theoretical approach about tsunami influence on radar spectra showed that a tsunami wave train generates a specific unusual pattern in the HF radar spectra. While the tsunami wave is approaching the beach, the surface current pattern changes slightly in deep water and significantly in the shelf area as it was shown in theoretical considerations and later proved during the 2011 Japan tsunami. These observed tsunami signatures showed that the velocity of tsunami currents depended on a tsunami wave height and bathymetry. The HF ocean radar doesn't measure the approaching wave height of a tsunami; however, it can resolve the surface current velocity signature, which is generated when tsunami reaches the shelf edge. This strong change of the surface current can be detected by a phased-array WERA system in real-time; thus the WERA ocean radar is a valuable tool to support Tsunami Early Warning Systems (TEWS). Based on real tsunami measurements, requirements for the integration of ocean radar systems into TEWS are already defined. The requirements include a high range resolution, a narrow beam directivity of phased-array antennas and an accelerated data update mode to provide a possibility of offshore tsunami detection in real-time. The developed software package allows reconstructing an ocean surface current map of the area observed by HF radar based on the radar power spectrum processing. This fact gives an opportunity to issue an automated tsunami identification message

  6. Ocean color products from the Korean Geostationary Ocean Color Imager (GOCI).

    PubMed

    Wang, Menghua; Ahn, Jae-Hyun; Jiang, Lide; Shi, Wei; Son, SeungHyun; Park, Young-Je; Ryu, Joo-Hyung

    2013-02-11

    The first geostationary ocean color satellite sensor, Geostationary Ocean Color Imager (GOCI), which is onboard South Korean Communication, Ocean, and Meteorological Satellite (COMS), was successfully launched in June of 2010. GOCI has a local area coverage of the western Pacific region centered at around 36°N and 130°E and covers ~2500 × 2500 km(2). GOCI has eight spectral bands from 412 to 865 nm with an hourly measurement during daytime from 9:00 to 16:00 local time, i.e., eight images per day. In a collaboration between NOAA Center for Satellite Applications and Research (STAR) and Korea Institute of Ocean Science and Technology (KIOST), we have been working on deriving and improving GOCI ocean color products, e.g., normalized water-leaving radiance spectra (nLw(λ)), chlorophyll-a concentration, diffuse attenuation coefficient at the wavelength of 490 nm (Kd(490)), etc. The GOCI-covered ocean region includes one of the world's most turbid and optically complex waters. To improve the GOCI-derived nLw(λ) spectra, a new atmospheric correction algorithm was developed and implemented in the GOCI ocean color data processing. The new algorithm was developed specifically for GOCI-like ocean color data processing for this highly turbid western Pacific region. In this paper, we show GOCI ocean color results from our collaboration effort. From in situ validation analyses, ocean color products derived from the new GOCI ocean color data processing have been significantly improved. Generally, the new GOCI ocean color products have a comparable data quality as those from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the satellite Aqua. We show that GOCI-derived ocean color data can provide an effective tool to monitor ocean phenomenon in the region such as tide-induced re-suspension of sediments, diurnal variation of ocean optical and biogeochemical properties, and horizontal advection of river discharge. In particular, we show some examples of ocean

  7. Early Mars may have had a methanol ocean

    NASA Astrophysics Data System (ADS)

    Tang, Yan; Chen, Qianwang; Huang, Yujie

    2006-01-01

    The detection of gray crystalline hematite deposits on Mars by Thermal Emission Spectrometer (TES) has been used to argue for the presence of liquid water on Mars in the distant past. By methanol-thermal treatment of anhydrous FeCl 3 at low temperatures (70-160 °C), crystalline gray hematite with layered structure was synthesized, based on this result an alternative explanation for the origin of martian hematite deposits is suggested. Methane could be abundant in the early martian atmosphere; process such as photochemical oxidation of methane could result in the formation of ocean or pool of organic compounds such as methanol, which provides an environment for the formation of large-scale hematite deposits on Mars.

  8. Climate-driven trends in contemporary ocean productivity.

    PubMed

    Behrenfeld, Michael J; O'Malley, Robert T; Siegel, David A; McClain, Charles R; Sarmiento, Jorge L; Feldman, Gene C; Milligan, Allen J; Falkowski, Paul G; Letelier, Ricardo M; Boss, Emmanuel S

    2006-12-07

    Contributing roughly half of the biosphere's net primary production (NPP), photosynthesis by oceanic phytoplankton is a vital link in the cycling of carbon between living and inorganic stocks. Each day, more than a hundred million tons of carbon in the form of CO2 are fixed into organic material by these ubiquitous, microscopic plants of the upper ocean, and each day a similar amount of organic carbon is transferred into marine ecosystems by sinking and grazing. The distribution of phytoplankton biomass and NPP is defined by the availability of light and nutrients (nitrogen, phosphate, iron). These growth-limiting factors are in turn regulated by physical processes of ocean circulation, mixed-layer dynamics, upwelling, atmospheric dust deposition, and the solar cycle. Satellite measurements of ocean colour provide a means of quantifying ocean productivity on a global scale and linking its variability to environmental factors. Here we describe global ocean NPP changes detected from space over the past decade. The period is dominated by an initial increase in NPP of 1,930 teragrams of carbon a year (Tg C yr(-1)), followed by a prolonged decrease averaging 190 Tg C yr(-1). These trends are driven by changes occurring in the expansive stratified low-latitude oceans and are tightly coupled to coincident climate variability. This link between the physical environment and ocean biology functions through changes in upper-ocean temperature and stratification, which influence the availability of nutrients for phytoplankton growth. The observed reductions in ocean productivity during the recent post-1999 warming period provide insight on how future climate change can alter marine food webs.

  9. Ocean glider observations of iceberg-enhanced biological production in the northwestern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Biddle, Louise C.; Kaiser, Jan; Heywood, Karen J.; Thompson, Andrew F.; Jenkins, Adrian

    2015-01-01

    Icebergs affect local biological production around Antarctica. We used an ocean glider to observe the effects of a large iceberg that was advected by the Antarctic Slope Current along the continental slope in the northwestern Weddell Sea in early 2012. The high-resolution glider data reveal a pronounced effect of the iceberg on ocean properties, with oxygen concentrations of (13 ± 4) μmol kg-1 higher than levels in surrounding waters, which are most likely due to positive net community production. This response was confined to three areas of water in the direct vicinity of the iceberg track, each no larger than 2 km2. Our findings suggest that icebergs have an impact on Antarctic production presumably through local micronutrient injections, on a scale smaller than typical satellite observations of biological production in the Southern Ocean.

  10. The formation of magnetite in the early Archean oceans

    NASA Astrophysics Data System (ADS)

    Li, Y. L.

    2017-12-01

    Banded iron formations are iron- and silica-rich chemical sedimentary rocks that were deposited throughout much of the Precambrian. It is generally accepted that biological oxidation of dissolved Fe(II) led to the precipitation of a ferric oxyhydroxide phase, such as ferrihydrite, in the marine photic zone. Upon burial, ferrihydrite was either transformed into hematite through dehydration or it was reduced to magnetite via biological or abiological Fe(III) reduction coupled to the oxidation of buried microbial biomass. However, it has always been intriguing as to why the oldest BIFs are characteristically magnetite-rich, while BIFs formed after the Neoarchean are dominated by hematite. Here, we propose that some magnetite in early Archean BIF could have precipitated directly from seawater through the reaction of settling ferrihydrite and hot, Fe(II)-rich hydrothermal fluids that vented directly into the photic zone. We conducted experiments that showed the reaction of Fe(II) with biogenic ferric iron mats under strict anoxic conditions led to the formation of a metastable green rust phase that within hours transformed into magnetite at relatively high temperatures. At lower temperatures magnetite does not form. Our model further posits that with the progressive cooling of the Earth's oceans through Archean, the above reaction shut off, and magnetite was subsequently restricted to reactions associated with diagenesis and metamorphism.

  11. The formation of magnetite in the early Archean oceans

    NASA Astrophysics Data System (ADS)

    Li, Yi-Liang; Konhauser, Kurt O.; Zhai, Mingguo

    2017-05-01

    Banded iron formations (BIFs) are iron- and silica-rich chemical sedimentary rocks that were deposited throughout much of the Precambrian. The biological oxidation of dissolved Fe(II) led to the precipitation of a ferric oxyhydroxide phase, such as ferrihydrite, in the marine photic zone. Upon burial, ferrihydrite was either transformed into hematite through dehydration or it was reduced to magnetite via biological or abiological Fe(III) reduction coupled to the oxidation of buried microbial biomass. However, it has always been intriguing as to why the oldest BIFs are characteristically magnetite-rich, while BIFs formed after the Neoarchean are dominated by hematite. Here, we propose that some magnetite in early Archean BIF could have precipitated directly from seawater through the reaction of settling ferrihydrite and hot, Fe(II)-rich hydrothermal fluids that existed in the deeper waters. We conducted experiments that showed the reaction of Fe(II) with biogenic ferric iron mats under strict anoxic conditions lead to the formation of a metastable green rust phase that within hours transformed into magnetite. Our model further posits that with the progressive cooling and oxidation of the Earth's oceans, the above reaction shuts off, and magnetite was subsequently restricted to reactions associated with diagenesis and metamorphism.

  12. Production and export in a global ocean ecosystem model

    NASA Astrophysics Data System (ADS)

    Palmer, J. R.; Totterdell, I. J.

    2001-05-01

    The Hadley Centre Ocean Carbon Cycle (HadOCC) model is a coupled physical-biogeochemical model of the ocean 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, Global Biogeochem. Cycles, 10, 57). The HadOCC model finds high production in the sub-polar North Pacific and North Atlantic Oceans, 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 Ocean. 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 ocean, 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.

  13. Increased productivity in the subantarctic ocean during Heinrich events.

    PubMed

    Sachs, Julian P; Anderson, Robert F

    2005-04-28

    Massive iceberg discharges from the Northern Hemisphere ice sheets, 'Heinrich events', coincided with the coldest periods of the last ice age. There is widespread evidence for Heinrich events and their profound impact on the climate and circulation of the North Atlantic Ocean, but their influence beyond that region remains uncertain. Here we use a combination of molecular fingerprints of algal productivity and radioisotope tracers of sedimentation to document eight periods of increased productivity in the subpolar Southern Ocean during the past 70,000 years that occurred within 1,000-2,000 years of a Northern Hemisphere Heinrich event. We discuss possible causes for such a link, including increased supply of iron from upwelling and increased stratification during the growing season, which imply an alteration of the global ocean circulation during Heinrich events. The mechanisms linking North Atlantic iceberg discharges with subantarctic productivity remain unclear at this point. We suggest that understanding how the Southern Ocean was altered during these extreme climate perturbations is critical to understanding the role of the ocean in climate change.

  14. Use of Real Time Satellite Infrared and Ocean Color to Produce Ocean Products

    NASA Astrophysics Data System (ADS)

    Roffer, M. A.; Muller-Karger, F. E.; Westhaver, D.; Gawlikowski, G.; Upton, M.; Hall, C.

    2014-12-01

    Real-time data products derived from infrared and ocean color satellites are useful for several types of users around the world. Highly relevant applications include recreational and commercial fisheries, commercial towing vessel and other maritime and navigation operations, and other scientific and applied marine research. Uses of the data include developing sampling strategies for research programs, tracking of water masses and ocean fronts, optimizing ship routes, evaluating water quality conditions (coastal, estuarine, oceanic), and developing fisheries and essential fish habitat indices. Important considerations for users are data access and delivery mechanisms, and data formats. At this time, the data are being generated in formats increasingly available on mobile computing platforms, and are delivered through popular interfaces including social media (Facebook, Linkedin, Twitter and others), Google Earth and other online Geographical Information Systems, or are simply distributed via subscription by email. We review 30 years of applications and describe how we develop customized products and delivery mechanisms working directly with users. We review benefits and issues of access to government databases (NOAA, NASA, ESA), standard data products, and the conversion to tailored products for our users. We discuss advantages of different product formats and of the platforms used to display and to manipulate the data.

  15. Ocean Fertilization from Giant Icebergs on Earth and Early Mars

    NASA Astrophysics Data System (ADS)

    Uceda, E. R.; Fairen, A. G.; Rodriguez, J. A. P.; Woodworth-Lynas, C.

    2016-05-01

    Assuming that life existed on Mars coeval to glacial activity, enhanced concentrations of organic carbon could be anticipated near iceberg trails, analogous to what is observed in polar oceans on Earth.

  16. Effects of Earth's rotation on the early differentiation of a terrestrial magma ocean

    NASA Astrophysics Data System (ADS)

    Maas, Christian; Hansen, Ulrich

    2015-11-01

    Similar to other terrestrial planets like Moon and Mars, Earth experienced a magma ocean period about 4.5 billion years ago. On Earth differentiation processes in the magma ocean set the initial conditions for core formation and mantle evolution. During the magma ocean period Earth was rotating significantly faster than today. Further, the viscosity of the magma was low, thus that planetary rotation potentially played an important role for differentiation. However, nearly all previous studies neglect rotational effects. All in all, our results suggest that planetary rotation plays an important role for magma ocean crystallization. We employ a 3-D numerical model to study crystal settling in a rotating and vigorously convecting early magma ocean. We show that crystal settling in a terrestrial magma ocean is crucially affected by latitude as well as by rotational strength and crystal density. Due to rotation an inhomogeneous accumulation of crystals during magma ocean solidification with a distinct crystal settling between pole and equator could occur. One could speculate that this may have potentially strong effects on the magma ocean solidification time and the early mantle composition. It could support the development of a basal magma ocean and the formation of anomalies at the core-mantle boundary in the equatorial region, reaching back to the time of magma ocean solidification.

  17. Marine ecosystem resilience during extreme deoxygenation: the Early Jurassic oceanic anoxic event.

    PubMed

    Caswell, Bryony A; Frid, Christopher L J

    2017-01-01

    Global warming during the Early Jurassic, and associated widespread ocean deoxygenation, was comparable in scale with the changes projected for the next century. This study quantifies the impact of severe global environmental change on the biological traits of marine communities that define the ecological roles and functions they deliver. We document centennial-millennial variability in the biological trait composition of Early Jurassic (Toarcian) seafloor communities and examine how this changed during the event using biological traits analysis. Environmental changes preceding the global oceanic anoxic event (OAE) produced an ecological shift leading to stressed benthic palaeocommunities with reduced resilience to the subsequent OAE. Changes in traits and ecological succession coincided with major environmental changes; and were of similar nature and magnitude to those in severely deoxygenated benthic communities today despite the very different timescales. Changes in community composition were linked to local redox conditions whereas changes in populations of opportunists were driven by primary productivity. Throughout most of the OAE substitutions by tolerant taxa conserved the trait composition and hence functioning, but periods of severe deoxygenation caused benthic defaunation that would have resulted in functional collapse. Following the OAE recovery was slow probably because the global nature of the event restricted opportunities for recruitment from outside the basin. Our findings suggest that future systems undergoing deoxygenation may initially show functional resilience, but severe global deoxygenation will impact traits and ecosystem functioning and, by limiting the species pool, will slow recovery rates.

  18. Nucleobase and amino acid formation through impacts of meteorites on the early ocean

    NASA Astrophysics Data System (ADS)

    Furukawa, Yoshihiro; Nakazawa, Hiromoto; Sekine, Toshimori; Kobayashi, Takamichi; Kakegawa, Takeshi

    2015-11-01

    The emergence of life's building blocks on the prebiotic Earth was the first crucial step for the origins of life. Extraterrestrial delivery of intact amino acids and nucleobases is the prevailing hypothesis for their availability on prebiotic Earth because of the difficulties associated with the production of these organics from terrestrial carbon and nitrogen sources under plausible prebiotic conditions. However, the variety and amounts of these intact organics delivered by meteorites would have been limited. Previous shock-recovery experiments have demonstrated that meteorite impact reactions could have generated organics on the prebiotic Earth. Here, we report on the simultaneous formation of nucleobases (cytosine and uracil) found in DNA and/or RNA, various proteinogenic amino acids (glycine, alanine, serine, aspartic acid, glutamic acid, valine, leucine, isoleucine, and proline), non-proteinogenic amino acids, and aliphatic amines in experiments simulating reactions induced by extraterrestrial objects impacting on the early oceans. To the best of our knowledge, this is the first report of the formation of nucleobases from inorganic materials by shock conditions. In these experiments, bicarbonate was used as the carbon source. Bicarbonate, which is a common dissolved carbon species in CO2-rich atmospheric conditions, was presumably the most abundant carbon species in the early oceans and in post-impact plumes. Thus, the present results expand the possibility that impact-induced reactions generated various building blocks for life on prebiotic Earth in large quantities through the use of terrestrial carbon reservoirs.

  19. Evaluation of OSCAR ocean surface current product in the tropical Indian Ocean using in situ data

    NASA Astrophysics Data System (ADS)

    Sikhakolli, Rajesh; Sharma, Rashmi; Basu, Sujit; Gohil, B. S.; Sarkar, Abhijit; Prasad, K. V. S. R.

    2013-02-01

    The OSCAR (ocean surface current analysis real-time), which is a product derived from various satellite observations, has been evaluated in the tropical Indian Ocean (TIO) in two different ways. First, the OSCAR-derived monthly climatology has been compared with available drifter-derived climatology in the TIO. From the comparison of the two climatologies, one can infer that OSCAR product is able to capture the variabilities of the well-known surface current systems in the TIO reasonably well. Fourier analysis of the major current systems, as reproduced by OSCAR, shows that the dominant annual and semiannual periodicities, known to exist in these systems, have been faithfully picked up by OSCAR. Next, the evaluation has been carried out by comparing the OSCAR currents with currents measured by moored buoys. The zonal component of OSCAR-current is in good agreement with corresponding component of buoy-observed current with a correlation exceeding 0.7, while the match between the meridional components is poorer. The locations of the peaks of the mean and eddy kinetic energies are matching in both the climatologies, although the peak in the drifter climatology is stronger than the same in the OSCAR product. Finally, an important feature of Indian Ocean circulation, namely the reverse Wyrtki jet, occurring during anomalous dipole years, has been well-reproduced by OSCAR currents.

  20. An extraterrestrial trigger for the Early Cretaceous massive volcanism? Evidence from the paleo-Tethys Ocean.

    PubMed

    Tejada, M L G; Ravizza, G; Suzuki, K; Paquay, F S

    2012-01-01

    The Early Cretaceous Greater Ontong Java Event in the Pacific Ocean may have covered ca. 1% of the Earth's surface with volcanism. It has puzzled scientists trying to explain its origin by several mechanisms possible on Earth, leading others to propose an extraterrestrial trigger to explain this event. A large oceanic extraterrestrial impact causing such voluminous volcanism may have traces of its distal ejecta in sedimentary rocks around the basin, including the paleo-Tethys Ocean which was then contiguous with the Pacific Ocean. The contemporaneous marine sequence at central Italy, containing the sedimentary expression of a global oceanic anoxic event (OAE1a), may have recorded such ocurrence as indicated by two stratigraphic intervals with (187)Os/(188)Os indicative of meteoritic influence. Here we show, for the first time, that platinum group element abundances and inter-element ratios in this paleo-Tethyan marine sequence provide no evidence for an extraterrestrial trigger for the Early Cretaceous massive volcanism.

  1. An extraterrestrial trigger for the Early Cretaceous massive volcanism? Evidence from the paleo-Tethys Ocean

    PubMed Central

    Tejada, M. L. G.; Ravizza, G.; Suzuki, K.; Paquay, F. S.

    2012-01-01

    The Early Cretaceous Greater Ontong Java Event in the Pacific Ocean may have covered ca. 1% of the Earth's surface with volcanism. It has puzzled scientists trying to explain its origin by several mechanisms possible on Earth, leading others to propose an extraterrestrial trigger to explain this event. A large oceanic extraterrestrial impact causing such voluminous volcanism may have traces of its distal ejecta in sedimentary rocks around the basin, including the paleo-Tethys Ocean which was then contiguous with the Pacific Ocean. The contemporaneous marine sequence at central Italy, containing the sedimentary expression of a global oceanic anoxic event (OAE1a), may have recorded such ocurrence as indicated by two stratigraphic intervals with 187Os/188Os indicative of meteoritic influence. Here we show, for the first time, that platinum group element abundances and inter-element ratios in this paleo-Tethyan marine sequence provide no evidence for an extraterrestrial trigger for the Early Cretaceous massive volcanism. PMID:22355780

  2. Uncertainties in Coastal Ocean Color Products: Impacts of Spatial Sampling

    NASA Technical Reports Server (NTRS)

    Pahlevan, Nima; Sarkar, Sudipta; Franz, Bryan A.

    2016-01-01

    With increasing demands for ocean color (OC) products with improved accuracy and well characterized, per-retrieval uncertainty budgets, it is vital to decompose overall estimated errors into their primary components. Amongst various contributing elements (e.g., instrument calibration, atmospheric correction, inversion algorithms) in the uncertainty of an OC observation, less attention has been paid to uncertainties associated with spatial sampling. In this paper, we simulate MODIS (aboard both Aqua and Terra) and VIIRS OC products using 30 m resolution OC products derived from the Operational Land Imager (OLI) aboard Landsat-8, to examine impacts of spatial sampling on both cross-sensor product intercomparisons and in-situ validations of R(sub rs) products in coastal waters. Various OLI OC products representing different productivity levels and in-water spatial features were scanned for one full orbital-repeat cycle of each ocean color satellite. While some view-angle dependent differences in simulated Aqua-MODIS and VIIRS were observed, the average uncertainties (absolute) in product intercomparisons (due to differences in spatial sampling) at regional scales are found to be 1.8%, 1.9%, 2.4%, 4.3%, 2.7%, 1.8%, and 4% for the R(sub rs)(443), R(sub rs)(482), R(sub rs)(561), R(sub rs)(655), Chla, K(sub d)(482), and b(sub bp)(655) products, respectively. It is also found that, depending on in-water spatial variability and the sensor's footprint size, the errors for an in-situ validation station in coastal areas can reach as high as +/- 18%. We conclude that a) expected biases induced by the spatial sampling in product intercomparisons are mitigated when products are averaged over at least 7 km × 7 km areas, b) VIIRS observations, with improved consistency in cross-track spatial sampling, yield more precise calibration/validation statistics than that of MODIS, and c) use of a single pixel centered on in-situ coastal stations provides an optimal sampling size for

  3. Assessment of NOAA Processed OceanSat-2 Scatterometer Ocean Surface Vector Wind Products

    NASA Astrophysics Data System (ADS)

    Chang, P.; Jelenak, Z.; Soisuvarn, S.

    2011-12-01

    The Indian Space Research Organization (ISRO) launched the Oceansat-2 satellite on 23 September 2009. Oceansat-2 carries a radar scatterometer instrument (OSCAT) capable of measuring ocean surface vector winds (OSVW) and an ocean color monitor (OCM), which will retrieve sea spectral reflectance. Oceansat-2 is ISRO's second in a series of satellites dedicated to ocean research. It will provide continuity to the services and applications of the Oceansat-1 OCM data along with additional data from a Ku-band pencil beam scatterometer. Oceansat-2 is a three-axis, body stabilized spacecraft placed into a near circular sun-synchronous orbit, at an altitude of 720 kilometers (km), with an equatorial crossing time of around 1200 hours. ISRO, the National Oceanic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA) and the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) share the common goal of optimizing the quality and maximizing the utility of the Oceansat-2 data for the benefit of future global and regional scientific and operational applications. NOAA, NASA and EUMETSAT have been collaboratively working with ISRO on the assessment and analysis of OSCAT data to help facilitate continuation of QuikSCAT's decade-long Ku-band scatterometer data record. NOAA's interests are focused on the utilization of OSCAT data to support operational weather forecasting and warning in the marine environment. OSCAT has the potential to significantly mitigate the loss of NASA's QuikSCAT, which has negatively impacted NOAA's marine forecasting and warning services. Since March 2011 NOAA has been receiving near real time OSCAT measurements via EumetSat. NOAA has developed its own OSCAT wind processor. This processor produces ocean surface vector winds with resolution of 25km. Performance of NOAA OSCAT product will and its availability to larger user community will be presented and discussed.

  4. A basal magma ocean dynamo to explain the early lunar magnetic field

    NASA Astrophysics Data System (ADS)

    Scheinberg, Aaron L.; Soderlund, Krista M.; Elkins-Tanton, Linda T.

    2018-06-01

    The source of the ancient lunar magnetic field is an unsolved problem in the Moon's evolution. Theoretical work invoking a core dynamo has been unable to explain the magnitude of the observed field, falling instead one to two orders of magnitude below it. Since surface magnetic field strength is highly sensitive to the depth and size of the dynamo region, we instead hypothesize that the early lunar dynamo was driven by convection in a basal magma ocean formed from the final stages of an early lunar magma ocean; this material is expected to be dense, radioactive, and metalliferous. Here we use numerical convection models to predict the longevity and heat flow of such a basal magma ocean and use scaling laws to estimate the resulting magnetic field strength. We show that, if sufficiently electrically conducting, a magma ocean could have produced an early dynamo with surface fields consistent with the paleomagnetic observations.

  5. Thompson Receives 2013 Ocean Sciences Early Career Award: Response

    NASA Astrophysics Data System (ADS)

    Thompson, Andrew

    2014-09-01

    I would like to thank my nominator, Jess Adkins, as well as my supporters for their contributions to my nomination and the AGU Ocean Sciences section for its selection. It is an honor to join the past recipients of this award.

  6. Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle

    PubMed Central

    Lea-Smith, David J.; Biller, Steven J.; Davey, Matthew P.; Cotton, Charles A. R.; Perez Sepulveda, Blanca M.; Turchyn, Alexandra V.; Scanlan, David J.; Smith, Alison G.; Chisholm, Sallie W.; Howe, Christopher J.

    2015-01-01

    Hydrocarbons are ubiquitous in the ocean, where alkanes such as pentadecane and heptadecane can be found even in waters minimally polluted with crude oil. Populations of hydrocarbon-degrading bacteria, which are responsible for the turnover of these compounds, are also found throughout marine systems, including in unpolluted waters. These observations suggest the existence of an unknown and widespread source of hydrocarbons in the oceans. Here, we report that strains of the two most abundant marine cyanobacteria, Prochlorococcus and Synechococcus, produce and accumulate hydrocarbons, predominantly C15 and C17 alkanes, between 0.022 and 0.368% of dry cell weight. Based on global population sizes and turnover rates, we estimate that these species have the capacity to produce 2–540 pg alkanes per mL per day, which translates into a global ocean yield of ∼308–771 million tons of hydrocarbons annually. We also demonstrate that both obligate and facultative marine hydrocarbon-degrading bacteria can consume cyanobacterial alkanes, which likely prevents these hydrocarbons from accumulating in the environment. Our findings implicate cyanobacteria and hydrocarbon degraders as key players in a notable internal hydrocarbon cycle within the upper ocean, where alkanes are continually produced and subsequently consumed within days. Furthermore we show that cyanobacterial alkane production is likely sufficient to sustain populations of hydrocarbon-degrading bacteria, whose abundances can rapidly expand upon localized release of crude oil from natural seepage and human activities. PMID:26438854

  7. Zooplankton Gut Passage Mobilizes Lithogenic Iron for Ocean Productivity.

    PubMed

    Schmidt, Katrin; Schlosser, Christian; Atkinson, Angus; Fielding, Sophie; Venables, Hugh J; Waluda, Claire M; Achterberg, Eric P

    2016-10-10

    Iron is an essential nutrient for phytoplankton, but low concentrations limit primary production and associated atmospheric carbon drawdown in large parts of the world's oceans [1, 2]. Lithogenic particles deriving from aeolian dust deposition, glacial runoff, or river discharges can form an important source if the attached iron becomes dissolved and therefore bioavailable [3-5]. Acidic digestion by zooplankton is a potential mechanism for iron mobilization [6], but evidence is lacking. Here we show that Antarctic krill sampled near glacial outlets at the island of South Georgia (Southern Ocean) ingest large amounts of lithogenic particles and contain 3-fold higher iron concentrations in their muscle than specimens from offshore, which confirms mineral dissolution in their guts. About 90% of the lithogenic and biogenic iron ingested by krill is passed into their fecal pellets, which contain ∼5-fold higher proportions of labile (reactive) iron than intact diatoms. The mobilized iron can be released in dissolved form directly from krill or via multiple pathways involving microbes, other zooplankton, and krill predators. This can deliver substantial amounts of bioavailable iron and contribute to the fertilization of coastal waters and the ocean beyond. In line with our findings, phytoplankton blooms downstream of South Georgia are more intensive and longer lasting during years with high krill abundance on-shelf. Thus, krill crop phytoplankton but boost new production via their nutrient supply. Understanding and quantifying iron mobilization by zooplankton is essential to predict ocean productivity in a warming climate where lithogenic iron inputs from deserts, glaciers, and rivers are increasing [7-10]. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Mercator Ocean Forecasting Products: Fitting into the Users Needs

    NASA Astrophysics Data System (ADS)

    Baudel, S.; Toumazou, V.

    2006-07-01

    Mercator O cean is a French public initiative aimed to develop ocean forecast op erational systems based on ocean physical models assimilating routin ely r emote sensing (altimetry from Envisat, Jason-1, GFO and Topex/Poseidon), sea surface temperature (in the years to come SMO S sea surf ace salinities) and in situ data. The oth er essen tial and subsequent mission is to allow, to contr ibute and to further operational o ceanography downstream applications. For th at purpose, Mercator Ocean mak es its products available through two different ways: 1. Imag es on the web targeting the g eneral public Every w eek, more than 3000 maps are updated describ ing 3D modelled ocean: now cast, forecast for up to 14 d ays and hind cast, temp erature, salinity, surface current and other ocean par ameters, 5 dep ths from surface to bottom. These images ar e freely av ailab le on the web , excep t the zonal maps younger than 30 day s. For these, the user is expected to fill an on-line form, asking h is/her motiv ations and the use h e/she in tends to do w ith these maps. This con trolled access allows us to dr aw the profile of this aud ience: 370 users ( end of February 2006), represented by the "g eneral public" ( about 40%), resear chers (16%), sailing (13%), studen ts- teachers (10 %), public institutions (8%), in charge of State missions concerning oil dr ift prev ention, environment monitoring, and recreative or professional fishing (7 %). 2. Dig ital files targeting professional u ses The use of d igital files containing the Mer cator outpu ts 3D fields is th e most impor tant criter ia to evaluate the impact of th e usefulness of our products. Mercator has created 'showcase products', summar izing Mercator outpu ts on regular grid s in NetCDF format. Sever al ways are proposed to access these products : FTP and H TTP, in clud ing a LAS/Op endap server, wh ich allows the user to make extraction of a per iod/area/ver tical levels/ocean parameters, and enab ling continuous

  9. Production of fluorescent dissolved organic matter in Arctic Ocean sediments.

    PubMed

    Chen, Meilian; Kim, Ji-Hoon; Nam, Seung-Il; Niessen, Frank; Hong, Wei-Li; Kang, Moo-Hee; Hur, Jin

    2016-12-16

    Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical properties. The production of FDOM, coupled with the increase of nutrients, was observed above the sulfate-methane-transition-zone (SMTZ). The presence of FDOM was concurrent with sulfate reduction and increased alkalinity (R 2  > 0.96, p < 0.0001), suggesting a link to organic matter degradation. This inference was supported by the positive correlation (R 2  > 0.95, p < 0.0001) between the net production of FDOM and the modeled degradation rates of particulate organic carbon sulfate reduction. The production of FDOM was more pronounced in a shallow shelf site S1 with a total net production ranging from 17.9 to 62.3 RU for different FDOM components above the SMTZ depth of ca. 4.1 mbsf, which presumably underwent more accumulation of particulate organic matter than the other three deeper sites. The sediments were generally found to be the sources of CDOM and FDOM to the overlying water column, unearthing a channel of generally bio-refractory and pre-aged DOM to the oceans.

  10. Production of fluorescent dissolved organic matter in Arctic Ocean sediments

    NASA Astrophysics Data System (ADS)

    Chen, Meilian; Kim, Ji-Hoon; Nam, Seung-Il; Niessen, Frank; Hong, Wei-Li; Kang, Moo-Hee; Hur, Jin

    2016-12-01

    Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical properties. The production of FDOM, coupled with the increase of nutrients, was observed above the sulfate-methane-transition-zone (SMTZ). The presence of FDOM was concurrent with sulfate reduction and increased alkalinity (R2 > 0.96, p < 0.0001), suggesting a link to organic matter degradation. This inference was supported by the positive correlation (R2 > 0.95, p < 0.0001) between the net production of FDOM and the modeled degradation rates of particulate organic carbon sulfate reduction. The production of FDOM was more pronounced in a shallow shelf site S1 with a total net production ranging from 17.9 to 62.3 RU for different FDOM components above the SMTZ depth of ca. 4.1 mbsf, which presumably underwent more accumulation of particulate organic matter than the other three deeper sites. The sediments were generally found to be the sources of CDOM and FDOM to the overlying water column, unearthing a channel of generally bio-refractory and pre-aged DOM to the oceans.

  11. Production of fluorescent dissolved organic matter in Arctic Ocean sediments

    PubMed Central

    Chen, Meilian; Kim, Ji-Hoon; Nam, Seung-Il; Niessen, Frank; Hong, Wei-Li; Kang, Moo-Hee; Hur, Jin

    2016-01-01

    Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical properties. The production of FDOM, coupled with the increase of nutrients, was observed above the sulfate-methane-transition-zone (SMTZ). The presence of FDOM was concurrent with sulfate reduction and increased alkalinity (R2 > 0.96, p < 0.0001), suggesting a link to organic matter degradation. This inference was supported by the positive correlation (R2 > 0.95, p < 0.0001) between the net production of FDOM and the modeled degradation rates of particulate organic carbon sulfate reduction. The production of FDOM was more pronounced in a shallow shelf site S1 with a total net production ranging from 17.9 to 62.3 RU for different FDOM components above the SMTZ depth of ca. 4.1 mbsf, which presumably underwent more accumulation of particulate organic matter than the other three deeper sites. The sediments were generally found to be the sources of CDOM and FDOM to the overlying water column, unearthing a channel of generally bio-refractory and pre-aged DOM to the oceans. PMID:27982085

  12. Possible Significance of Early Paleozoic Fluctuations in Bottom Current Intensity, Northwest Iapetus Ocean

    NASA Astrophysics Data System (ADS)

    Lash, Gary G.

    1986-06-01

    Sedimentologic and geochemical characteristics of red and green deep water mudstone exposed in the central Appalachian orogen define climatically-induced fluctuations in bottom current intensity along the northwest flank of the Iapetus Ocean in Early and Middle Ordovician time. Red mudstone accumulated under the influence of moderate to vigorous bottom current velocities in oxygenated bottom water produced during climatically cool periods. Interbedded green mudstone accumulated at greater sedimentation rates, probably from turbidity currents, under the influence of reduced thermohaline circulation during global warming periods. The close association of green mudstone and carbonate turbidites of Early Ordovician (late Tremadocian to early Arenigian) age suggests that a major warming phase occurred at this time. Increasing temperatures reduced bottom current velocities and resulted in increased production of carbonate sediment and organic carbon on the carbonate platform of eastern North America. Much of the excess carbonate sediment and organic carbon was transported into deep water by turbidity currents. Although conclusive evidence is lacking, this eustatic event may reflect a climatic warming phase that followed the postulated glacio-eustatic Black Mountain event. Subsequent Middle Ordovician fluctuations in bottom current intensity recorded by thin red-green mudstone couplets probably reflect periodic growth and shrinkage of an ice cap rather than major glacial episodes.

  13. A more productive, but different, ocean after mitigation

    NASA Astrophysics Data System (ADS)

    John, Jasmin G.; Stock, Charles A.; Dunne, John P.

    2015-11-01

    Reversibility studies suggest a lagged recovery of global mean sea surface temperatures after mitigation, raising the question of whether a similar lag is likely for marine net primary production (NPP). Here we assess NPP reversibility with a mitigation scenario in which projected Representative Concentration Pathway (RCP) 8.5 forcings are applied out to 2100 and then reversed over the course of the following century in a fully coupled carbon-climate Earth System Model. In contrast to the temperature lag, we find a rapid increase in global mean NPP, including an overshoot to values above contemporary means. The enhanced NPP arises from a transient imbalance between the cooling surface ocean and continued warming in subsurface waters, which weakens upper ocean density gradients, resulting in deeper mixing and enhanced surface nitrate. We also find a marine ecosystem regime shift as persistent silicate depletion results in increased prevalence of large, non-diatom phytoplankton.

  14. Southern Ocean Seasonal Net Production from Satellite, Atmosphere, and Ocean Data Sets

    NASA Technical Reports Server (NTRS)

    Keeling, Ralph F.; Campbell, J. (Technical Monitor)

    2002-01-01

    A new climatology of monthly air-sea O2 flux was developed using the net air-sea heat flux as a template for spatial and temporal interpolation of sparse hydrographic data. The climatology improves upon the previous climatology of Najjar and Keeling in the Southern Hemisphere, where the heat-based approach helps to overcome limitations due to sparse data coverage. The climatology is used to make comparisons with productivity derived from CZCS images. The climatology is also used in support of an investigation of the plausible impact of recent global warming an oceanic O2 inventories.

  15. Seabird guano enhances phytoplankton production in the Southern Ocean.

    NASA Astrophysics Data System (ADS)

    Shatova, Olga; Wing, Stephen; Hoffmann, Linn; Jack, Lucy; Gault-Ringold, Melanie

    2015-04-01

    Great congregations of seabirds in sub-Antarctic and Antarctic coastal areas result in delivery of nutrient-rich guano to marine ecosystems that potentially enhances productivity and supports biodiversity in the region. Guano-derived bio-available micronutrients and macronutrients might be utilized by marine phytoplankton for photosynthetic production, however, mechanisms and significance of guano fertilization in the Southern Ocean are largely understudied. Over austral summers of 2012 and 2013 we performed a series of guano-enrichment phytoplankton incubation experiments with water samples collected from three different water masses in the Southern Ocean: Antarctic waters of the Ross sea and sub-Antarctic waters offshore the Otago Peninsula, both showing iron limitation of phytoplankton productivity in summer, and in the subtropical frontal zone offshore from the Snares Islands, which is generally micronutrient-repleted. Samples were enriched with known concentrations of guano-derived nutrients. Phytoplankton biomass increased significantly in guano-treated samples during all three incubation experiments (7-10 fold increase), while remained low in control samples. This response indicates that seabird guano provides nutrients that limit primary production in the Southern Ocean and that these nutrients are readily taken up by phytoplankton. Guano additions were compared to Fe and Macronutrient treatments (both added in quantities similar to those in the guano treatment). Phytoplankton biomass increased significantly in response to the Macronutrient treatment in the subtropical frontal zone, however, the response had a smaller magnitude compared to the guano treatment (2.8 µgL-1 vs 5.2 µgL-1) ; there was no significant effect of Fe on phytoplankton growth. This suggests the potential importance of synergistic effects of nutrients in guano. Incubation with sub-Antarctic waters showed that Fe and Macronutrients might be equally important for enhancement of

  16. Predicting plankton net community production in the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Serret, Pablo; Robinson, Carol; Fernández, Emilio; Teira, Eva; Tilstone, Gavin; Pérez, Valesca

    2009-07-01

    We present, test and implement two contrasting models to predict euphotic zone net community production (NCP), which are based on 14C primary production (PO 14CP) to NCP relationships over two latitudinal (ca. 30°S-45°N) transects traversing highly productive and oligotrophic provinces of the Atlantic Ocean (NADR, CNRY, BENG, NAST-E, ETRA and SATL, Longhurst et al., 1995 [An estimation of global primary production in the ocean from satellite radiometer data. Journal of Plankton Research 17, 1245-1271]). The two models include similar ranges of PO 14CP and community structure, but differ in the relative influence of allochthonous organic matter in the oligotrophic provinces. Both models were used to predict NCP from PO 14CP measurements obtained during 11 local and three seasonal studies in the Atlantic, Pacific and Indian Oceans, and from satellite-derived estimates of PO 14CP. Comparison of these NCP predictions with concurrent in situ measurements and geochemical estimates of NCP showed that geographic and annual patterns of NCP can only be predicted when the relative trophic importance of local vs. distant processes is similar in both modeled and predicted ecosystems. The system-dependent ability of our models to predict NCP seasonality suggests that trophic-level dynamics are stronger than differences in hydrodynamic regime, taxonomic composition and phytoplankton growth. The regional differences in the predictive power of both models confirm the existence of biogeographic differences in the scale of trophic dynamics, which impede the use of a single generalized equation to estimate global marine plankton NCP. This paper shows the potential of a systematic empirical approach to predict plankton NCP from local and satellite-derived P estimates.

  17. Giant Icebergs and Biological Productivity on Early Mars

    NASA Astrophysics Data System (ADS)

    Uceda, E.; Fairen, A. G.; Woodworth-Lynas, C.

    2016-12-01

    We have previously presented evidence for furrows, dump structures and chains of craters that we interpret as indication for giant iceberg transport and grounding on very cold oceans on early Mars, both in the northern plains and in the Hellas basin. Structures include: 1. Furrows: The furrows are located in elevated areas or on local topographic highs, particularly on the Hellas basin. We interpret these features in terms of iceberg rafting and grounding. 2. Chains of craters: High-resolution images of Utopia and Isidis Basins reveal chains of crater-like structures several hundred meters wide and 1 to 5 km long. 3. Dump structures: Dark boulder clusters are revealed at large scales by their slightly darker tonality with respect to the surrounding terrain. These clusters have sizes ranging from several hundred meters to 1-2 km. On Earth's oceans, giant icebergs release melting water containing nanoparticulate iron and other micronutrients, which support biological metabolism and growth to the near-coastal euphotic ecosystems, many of which are iron limited. This iron limitation of primary producers has been documented in large regions of the Earth's oceans, most notably in polar areas proximal to significant glacial activity, and is counterbalanced by the substantial enrichment of terrigenous material supplied by icebergs. The biological productivity extends hundreds of kilometres from the giant icebergs, and persists for over one month after the iceberg passes. Here we propose that giant iceberg activity on early Mars could have promoted a similar enhancing of biological productivity on the planet's oceans. The identification of specific biosignatures in icebergs trails on Earth could give clues as to what kind of biosignatures could be expected on the ancient Mars ocean floors, and where to look for them. In particular, assuming that life existed on Mars coeval to glacial activity, enhanced concentrations of organic carbon could be anticipated near giant iceberg

  18. Fish Productivity in Open-Ocean Gyre Systems in the Late Oligocene and Miocene

    NASA Astrophysics Data System (ADS)

    Cuevas, J. M.; Sibert, E. C.; Norris, R. D.

    2015-12-01

    Understanding how marine ecosystems respond to climate change is very important as we continue to warm the climate. Fish represent a critical protein source for a significant portion of the global population, and as such, an understanding of fish production and its interactions with climate change may help better prepare for the future. Ichthyoliths, fossil fish teeth and shark scales, are a novel fossil group which can be used as an indicator for fish productivity. Several important climate events occurred during the Miocene (7 to 23 Ma), including the Middle Miocene Climatic Optimum. Here we reconstruct fish production from across the Miocene from Pacific and Atlantic Ocean gyres. South Atlantic samples, from Deep Sea Drilling Program (DSDP) Site 522 spanning from 30 to 20 Ma, show fairly variable numbers in the Oligocene (ranging from 100 to 800 ich/cm2/yr), but stabilization in the Early Miocene (around 400 ich/cm2/yr), suggesting that the beginning of the Miocene brought consistent conditions for fish production. In the North Pacific, our record from Ocean Drilling Program (ODP) Site 886 shows a distinct crash in fish productivity at 11 Ma, from 3500 ich/cm2/yr to a steady decline around 100 ich/cm2/yr for the next million years. This crash is followed by a marked increase in the presence of diatoms and biogenous opal. This is somewhat surprising, since in modern oceanic systems, an increase in diatoms and other large-celled phytoplankton is associated with shorter, more efficient food chains and higher levels of fish. It is also interesting to note that denticles remain consistently low at both sites, indicating consistently low shark populations through this time period. Together, these results suggest that the Late Oligocene and Miocene was a time of variable fish production and provide a window into understanding of dynamic ecosystem changes through the Miocene in open-ocean gyre ecosystems.

  19. Ocean acidification alters early successional coral reef communities and their rates of community metabolism.

    PubMed

    Noonan, Sam H C; Kluibenschedl, Anna; Fabricius, Katharina E

    2018-01-01

    Ocean acidification is expected to alter community composition on coral reefs, but its effects on reef community metabolism are poorly understood. Here we document how early successional benthic coral reef communities change in situ along gradients of carbon dioxide (CO2), and the consequences of these changes on rates of community photosynthesis, respiration, and light and dark calcification. Ninety standardised benthic communities were grown on PVC tiles deployed at two shallow-water volcanic CO2 seeps and two adjacent control sites in Papua New Guinea. Along the CO2 gradient, both the upward facing phototrophic and the downward facing cryptic communities changed in their composition. Under ambient CO2, both communities were dominated by calcifying algae, but with increasing CO2 they were gradually replaced by non-calcifying algae (predominantly green filamentous algae, cyanobacteria and macroalgae, which increased from ~30% to ~80% cover). Responses were weaker in the invertebrate communities, however ascidians and tube-forming polychaetes declined with increasing CO2. Differences in the carbonate chemistry explained a far greater amount of change in communities than differences between the two reefs and successional changes from five to 13 months, suggesting community successions are established early and are under strong chemical control. As pH declined from 8.0 to 7.8, rates of gross photosynthesis and dark respiration of the 13-month old reef communities (upper and cryptic surfaces combined) significantly increased by 10% and 20%, respectively, in response to altered community composition. As a consequence, net production remained constant. Light and dark calcification rates both gradually declined by 20%, and low or negative daily net calcification rates were observed at an aragonite saturation state of <2.3. The study demonstrates that ocean acidification as predicted for the end of this century will strongly alter reef communities, and will significantly

  20. Ocean acidification alters early successional coral reef communities and their rates of community metabolism

    PubMed Central

    Kluibenschedl, Anna; Fabricius, Katharina E.

    2018-01-01

    Ocean acidification is expected to alter community composition on coral reefs, but its effects on reef community metabolism are poorly understood. Here we document how early successional benthic coral reef communities change in situ along gradients of carbon dioxide (CO2), and the consequences of these changes on rates of community photosynthesis, respiration, and light and dark calcification. Ninety standardised benthic communities were grown on PVC tiles deployed at two shallow-water volcanic CO2 seeps and two adjacent control sites in Papua New Guinea. Along the CO2 gradient, both the upward facing phototrophic and the downward facing cryptic communities changed in their composition. Under ambient CO2, both communities were dominated by calcifying algae, but with increasing CO2 they were gradually replaced by non-calcifying algae (predominantly green filamentous algae, cyanobacteria and macroalgae, which increased from ~30% to ~80% cover). Responses were weaker in the invertebrate communities, however ascidians and tube-forming polychaetes declined with increasing CO2. Differences in the carbonate chemistry explained a far greater amount of change in communities than differences between the two reefs and successional changes from five to 13 months, suggesting community successions are established early and are under strong chemical control. As pH declined from 8.0 to 7.8, rates of gross photosynthesis and dark respiration of the 13-month old reef communities (upper and cryptic surfaces combined) significantly increased by 10% and 20%, respectively, in response to altered community composition. As a consequence, net production remained constant. Light and dark calcification rates both gradually declined by 20%, and low or negative daily net calcification rates were observed at an aragonite saturation state of <2.3. The study demonstrates that ocean acidification as predicted for the end of this century will strongly alter reef communities, and will significantly

  1. The Modulation of Biological Production by Oceanic Mesoscale Turbulence

    NASA Astrophysics Data System (ADS)

    Lévy, Marina

    This chapter reviews the current state of knowledge on bio-physical interactions at mesoscale and at sub-mesoscale. It is focused on the mid-latitudes open ocean. From examples taken from my own studies or selected in the literature, I show how high-resolution process-oriented model studies have helped to improve our understanding. I follow a process oriented approach; I first discuss the role of mesoscale eddies in moderating the nutrient flux into the well-lit euphotic zone. Then I address the impact on biogeochemistry of transport occurring on a horizontal scale smaller than the scale of an eddy. I show that submesoscale processes modulate biogeochemical budgets in a number of ways, through intense upwelling of nutrients, subduction of phytoplankton, and horizontal stirring. Finally, I emphasize that mesoscale and submesoscale dynamics have a strong impact on productivity through their influence on the stratification of the surface of the ocean. These processes have in common that they concern the short-term, local effect of oceanic turbulence on biogeochemistry. Efforts are still needed before we can get a complete picture, which would also include the far-field long-term effect of the eddies.

  2. Abrupt global-ocean anoxia during the Late Ordovician-early Silurian detected using uranium isotopes of marine carbonates.

    PubMed

    Bartlett, Rick; Elrick, Maya; Wheeley, James R; Polyak, Victor; Desrochers, André; Asmerom, Yemane

    2018-05-21

    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 global 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 global-ocean redox record. The Hirnantian ocean 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 global-ocean redox conditions. The HOAE occurred during a global δ 13 C positive excursion, but lasted longer indicating that controls on the C budget were partially decoupled from global-ocean 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 ocean anoxic events (OAE), the HOAE occurred during peak and waning icehouse conditions rather than during greenhouse climates. We interpret that anoxia was driven by global cooling, which reorganized thermohaline circulation, decreased deep-ocean ventilation, enhanced nutrient fluxes, stimulated productivity, which lead to expanded oxygen minimum zones. Copyright © 2018 the Author(s). Published by PNAS.

  3. The making of a productivity hotspot in the coastal ocean.

    PubMed

    Wingfield, Dana K; Peckham, S Hoyt; Foley, David G; Palacios, Daniel M; Lavaniegos, Bertha E; Durazo, Reginaldo; Nichols, Wallace J; Croll, Donald A; Bograd, Steven J

    2011-01-01

    Highly productive hotspots in the ocean often occur where complex physical forcing mechanisms lead to aggregation of primary and secondary producers. Understanding how hotspots persist, however, requires combining knowledge of the spatio-temporal linkages between geomorphology, physical forcing, and biological responses with the physiological requirements and movement of top predators. Here we integrate remotely sensed oceanography, ship surveys, and satellite telemetry to show how local geomorphology interacts with physical forcing to create a region with locally enhanced upwelling and an adjacent upwelling shadow that promotes retentive circulation, enhanced year-round primary production, and prey aggregation. These conditions provide an area within the upwelling shadow where physiologically optimal water temperatures can be found adjacent to a region of enhanced prey availability, resulting in a foraging hotspot for loggerhead sea turtles (Caretta caretta) off the Baja California peninsula, Mexico. We have identified the set of conditions that lead to a persistent top predator hotspot, which increases our understanding of how highly migratory species exploit productive regions of the ocean. These results will aid in the development of spatially and environmentally explicit management strategies for marine species of conservation concern.

  4. Staging Life in an Early Warm ‘Seltzer’ Ocean

    DOE PAGES

    Schoonen, Martin; Smirnov, Alexander

    2016-12-01

    A period as short as 20 million years within the first 100 million years after the formation of the Moon may have set the stage for the origin of life. This atmosphere contained more carbon dioxide than any other period afterwards. The carbon dioxide sustained greenhouse conditions, accelerated the weathering of a primitive crust and may have led to conditions conducive to the formation of the building blocks of life. The conversion of CO 2 as well as N 2 may have been facilitated by clays, zeolites, sulfides and metal alloys formed as the crust reacted with a warm ‘seltzer’more » ocean. We used geochemical modeling to constrain the conditions favorable for the formation of these potential mineral catalysts.« less

  5. Staging Life in an Early Warm ‘Seltzer’ Ocean

    SciT

    Schoonen, Martin; Smirnov, Alexander

    A period as short as 20 million years within the first 100 million years after the formation of the Moon may have set the stage for the origin of life. This atmosphere contained more carbon dioxide than any other period afterwards. The carbon dioxide sustained greenhouse conditions, accelerated the weathering of a primitive crust and may have led to conditions conducive to the formation of the building blocks of life. The conversion of CO 2 as well as N 2 may have been facilitated by clays, zeolites, sulfides and metal alloys formed as the crust reacted with a warm ‘seltzer’more » ocean. We used geochemical modeling to constrain the conditions favorable for the formation of these potential mineral catalysts.« less

  6. NOAA activities in support of in situ validation observations for satellite ocean color products and related ocean science research

    NASA Astrophysics Data System (ADS)

    Lance, V. P.; DiGiacomo, P. M.; Ondrusek, M.; Stengel, E.; Soracco, M.; Wang, M.

    2016-02-01

    The NOAA/STAR ocean color program is focused on "end-to-end" production of high quality satellite ocean color products. In situ validation of satellite data is essential to produce the high quality, "fit for purpose" ocean color products that support users and applications in all NOAA line offices, as well as external (both applied and research) users. The first NOAA/OMAO (Office of Marine and Aviation Operations) sponsored research cruise dedicated to VIIRS SNPP validation was completed aboard the NOAA Ship Nancy Foster in November 2014. The goals and objectives of the 2014 cruise are highlighted in the recently published NOAA/NESDIS Technical Report. A second dedicated validation cruise is planned for December 2015 and will have been completed by the time of this meeting. The goals and objectives of the 2015 cruise will be discussed in the presentation. Participants and observations made will be reported. The NOAA Ocean Color Calibration/Validation (Cal/Val) team also works collaboratively with others programs. A recent collaboration with the NOAA Ocean Acidification program on the East Coast Ocean Acidification (ECOA) cruise during June-July 2015, where biogeochemical and optical measurements were made together, allows for the leveraging of in situ observations for satellite validation and for their use in the development of future ocean acidification satellite products. Datasets from these cruises will be formally archived at NOAA and Digital Object Identifier (DOI) numbers will be assigned. In addition, the NOAA Coast/OceanWatch Program is working to establish a searchable database. The beta version will begin with cruise data and additional in situ calibration/validation related data collected by the NOAA Ocean Color Cal/Val team members. A more comprehensive searchable NOAA database, with contributions from other NOAA ocean observation platforms and cruise collaborations is envisioned. Progress on these activities will be reported.

  7. Environmental variability and chum salmon production at the northwestern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Kim, Suam; Kang, Sukyung; Kim, Ju Kyoung; Bang, Minkyoung

    2017-12-01

    Chum salmon, Oncorhynchus keta, are distributed widely in the North Pacific Ocean, and about 76% of chum salmon were caught from Russian, Japanese, and Korean waters of the northwestern Pacific Ocean during the last 20 years. Although it has been speculated that the recent increase in salmon production was aided by not only the enhancement program that targeted chum salmon but also by favorable ocean conditions since the early 1990s, the ecological processes for determining the yield of salmon have not been clearly delineated. To investigate the relationship between yield and the controlling factors for ocean survival of chum salmon, a time-series of climate indices, seawater temperature, and prey availability in the northwestern Pacific including Korean waters were analyzed using some statistical tools. The results of cross-correlation function (CCF) analysis and cumulative sum (CuSum) of anomalies indicated that there were significant environmental changes in the North Pacific during the last century, and each regional stock of chum salmon responded to the Pacific Decadal Oscillation (PDO) differently: for Russian stock, the correlations between PDO index and catch were significantly negative with a time-lag of 0 and 1 years; for Japanese stock, significantly positive with a timelag of 0-2 years; and for Korean stock, positive but no significant correlation. The results of statistical analyses with Korean chum salmon also revealed that a coastal seawater temperature over 14°C and the return rate of spawning adults to the natal river produced a significant negative correlation.

  8. Accuracy assessment of satellite Ocean colour products in coastal waters.

    NASA Astrophysics Data System (ADS)

    Tilstone, G.; Lotliker, A.; Groom, S.

    2012-04-01

    The use of Ocean Colour Remote Sensing to monitor phytoplankton blooms in coastal waters is hampered by the absorption and scattering from substances in the water that vary independently of phytoplankton. In this paper we compare different ocean colour algorithms available for SeaWiFS, MODIS and MERIS with in situ observations of Remote Sensing Reflectance, Chlorophyll-a (Chla), Total Suspended Material and Coloured Dissolved Organic Material in coastal waters of the Arabian Sea, Bay of Bengal, North Sea and Western English Channel, which have contrasting inherent optical properties. We demonstrate a clustering method on specific-Inherent Optical Properties (sIOP) that gives accurate water quality products from MERIS data (HYDROPT) and also test the recently developed ESA CoastColour MERIS products. We found that for coastal waters of the Bay of Bengal, OC5 gave the most accurate Chla, for the Arabian Sea GSM and OC3M Chla were more accurate and for the North Sea and Western English Channel, MERIS HYDROPT were more accurate than standard algorithms. The reasons for these differences will be discussed. A Chla time series from 2002-2011 will be presented to illustrate differences in algorithms between coastal regions and inter- and intra-annual variability in phytoplankton blooms

  9. Uranium Stable Isotopes: A Proxy For Productivity Or Ocean Oxygenation?

    NASA Astrophysics Data System (ADS)

    Severmann, S.

    2015-12-01

    Uranium elemental abundances in sediments have traditionally been used to reconstruct primary productivity and carbon flux in the ocean. 238U/235U isotope compositions, in contrast, are currently understood to reflect the extent of bottom water anoxia in the ocean. A review of our current understanding of authigenic U enrichment mechanism into reducing sediments suggests that a revision of this interpretation is warranted. Specifically, the current interpretation of U isotope effects in suboxic vs. anoxic deposits has not taken into account the well-documented linear relationship with organic C burial rates. Although organic C rain rates (i.e., surface productivity) and bottom water oxygenation are clearly related, distinction between these two environmental controls is conceptually important as it relates to the mechanism of enhanced C burial and ultimately the strength of the biological pump. Here we will review new and existing data to test the hypothesis that the isotope composition of authigenic U in reducing sediments are best described by their relationship with parameters related to organic carbon delivery and burial, rather than bottom water oxygen concentration.

  10. Past climates primary productivity changes in the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Le Mézo, P. K.; Kageyama, M.; Bopp, L.; Beaufort, L.; Braconnot, P.; Bassinot, F. C.

    2016-02-01

    Organic climate recorders, e.g., coccolithophorids and foraminifera, are widely used to reconstruct past climate conditions, such as the Indian monsoon intensity and variability, since they are sensitive to climate-induced fluctuations of their environment. In the Indian Ocean, it is commonly accepted that a stronger summer monsoon will enhance productivity in the Arabian Sea and therefore the amount of organisms in a sediment core should reflect monsoon intensity. In this study, we use the coupled Earth System Model IPSLCM5A, which has a biogeochemical component PISCES that simulates primary production. We use 8 climate simulations of the IPSL-CM5A model, from -72kyr BP climate conditions to a preindustrial state. Our simulations have different orbital forcing (precession, obliquity and eccentricity), greenhouse gas concentrations as well as different ice sheet covers. The objective of this work is to characterize the mechanisms behind the changes in primary productivity between the different time periods. Our model shows that in climates where monsoon is enhanced (due to changes in precession) we do not necessarily see an increase in summer productivity in the Arabian Sea, and inversely. It seems that the glacial-interglacial state of the simulation is important in driving productivity changes in this region of the world. We try to explain the changes in productivity in the Arabian Sea with the local climate and then to link the changes in local climate to large scale atmospheric forcing and commonly used Indian monsoon definitions.

  11. Ocean Nitrogen Isotopic Change in the Early Eocene

    NASA Astrophysics Data System (ADS)

    Kast, E.; Stolper, D. A.; Higgins, J. A.; Ren, H. A.; Wang, X. T.; Sigman, D. M.

    2017-12-01

    The long term variability of the marine nitrogen (N) cycle is an open question. The Cenozoic provides a well-studied framework for investigating the marine N cycle over long time scales and across large climate transitions. However, only sparse bulk Cenozoic sediment δ15N data exist, the utility of which for reconstructing environmental conditions is unclear. We present a record of foraminifera-bound organic matter δ15N from the Paleocene to late Eocene. At three distant sites, foraminifera-bound δ15N decreases dramatically between 56 Ma and 50 Ma: from 14‰ to 2‰ in the northwest Pacific (ODP site 1209), from 12‰ to 4‰ in the southeast Atlantic (ODP site 1263), and from 9‰ to 4‰ in the northwest Atlantic (IODP site U1409). This foraminifera-bound δ15N change is on par, if not greater, than the largest changes that have been observed in bulk sediment δ15N over the last 600 million years. The shared change among the sites implies a change in mean δ15N of oceanic fixed N, which is thought to be sensitive to the ratio of water column to sedimentary denitrification, with a higher δ15N reflecting a greater proportion of denitrification occurring in the water column. Today, water column denitrification occurs in the shallow subsurface, in regions where these waters are suboxic. Thus, the δ15N decrease may reflect a slowing of water column denitrification, which can be generated by a decline in shallow subsurface suboxia. A key factor in the extent of shallow subsurface suboxia is the amount of "preformed oxygen," the initial concentration of dissolved O2 in the water that flows from the surface into the shallow subsurface: a decline in suboxia would require a rise in preformed oxygen from 56 to 50 Ma. The δ15N decline occurs before the onset of cooling in the Eocene, eliminating global temperature change as the driver of increased preformed oxygen. Instead we favor explanations that involve tectonically driven changes in continental configuration and

  12. Automated ocean color product validation for the Southern California Bight

    NASA Astrophysics Data System (ADS)

    Davis, Curtiss O.; Tufillaro, Nicholas; Jones, Burt; Arnone, Robert

    2012-06-01

    Automated match ups allow us to maintain and improve the products of current satellite ocean color sensors (MODIS, MERIS), and new sensors (VIIRS). As part of the VIIRS mission preparation, we have created a web based automated match up tool that provides access to searchable fields for date, site, and products, and creates match-ups between satellite (MODIS, MERIS, VIIRS), and in-situ measurements (HyperPRO and SeaPRISM). The back end of the system is a 'mySQL' database, and the front end is a `php' web portal with pull down menus for searchable fields. Based on selections, graphics are generated showing match-ups and statistics, and ascii files are created for downloads for the matchup data. Examples are shown for matching the satellite data with the data from Platform Eureka SeaPRISM off L.A. Harbor in the Southern California Bight.

  13. Biogenesis and early life on Earth and Europa: favored by an alkaline ocean?

    PubMed

    Kempe, Stephan; Kazmierczak, Jozef

    2002-01-01

    Recent discoveries about Europa--the probable existence of a sizeable ocean below its ice crust; the detection of hydrated sodium carbonates, among other salts; and the calculation of a net loss of sodium from the subsurface--suggest the existence of an alkaline ocean. Alkaline oceans (nicknamed "soda oceans" in analogy to terrestrial soda lakes) have been hypothesized also for early Earth and Mars on the basis of mass balance considerations involving total amounts of acids available for weathering and the composition of the early crust. Such an environment could be favorable to biogenesis since it may have provided for very low Ca2+ concentrations mandatory for the biochemical function of proteins. A rapid loss of CO2 from Europa's atmosphere may have led to freezing oceans. Alkaline brine bubbles embedded in ice in freezing and impact-thawing oceans could have provided a suitable environment for protocell formation and the large number of trials needed for biogenesis. Understanding these processes could be central to assessing the probability of life on Europa.

  14. Factors influencing particulate lipid production in the East Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Gašparović, B.; Frka, S.; Koch, B. P.; Zhu, Z. Y.; Bracher, A.; Lechtenfeld, O. J.; Neogi, S. B.; Lara, R. J.; Kattner, G.

    2014-07-01

    Extensive analyses of particulate lipids and lipid classes were conducted to gain insight into lipid production and related factors along the biogeochemical provinces of the Eastern Atlantic Ocean. Data are supported by particulate organic carbon (POC), chlorophyll a (Chl a), phaeopigments, Chl a concentrations and carbon content of eukaryotic micro-, nano- and picophytoplankton, including cell abundances for the latter two and for cyanobacteria and prokaryotic heterotrophs. We focused on the productive ocean surface (2 m depth and deep Chl a maximum (DCM). Samples from the deep ocean provided information about the relative reactivity and preservation potential of particular lipid classes. Surface and DCM particulate lipid concentrations (3.5-29.4 μg L-1) were higher than in samples from deep waters (3.2-9.3 μg L-1) where an increased contribution to the POC pool was observed. The highest lipid concentrations were measured in high latitude temperate waters and in the North Atlantic Tropical Gyral Province (13-25°N). Factors responsible for the enhanced lipid synthesis in the eastern Atlantic appeared to be phytoplankton size (micro, nano, pico) and the low nutrient status with microphytoplankton having the most expressed influence in the surface and eukaryotic nano- and picophytoplankton in the DCM layer. Higher lipid to Chl a ratios suggest enhanced lipid biosynthesis in the nutrient poorer regions. The various lipid classes pointed to possible mechanisms of phytoplankton adaptation to the nutritional conditions. Thus, it is likely that adaptation comprises the replacement of membrane phospholipids by non-phosphorus containing glycolipids under low phosphorus conditions. The qualitative and quantitative lipid compositions revealed that phospholipids were the most degradable lipids, and their occurrence decreased with increasing depth. In contrast, wax esters, possibly originating from zooplankton, survived downward transport probably due to the fast sinking

  15. Ocean thermal plantships for production of ammonia as the hydrogen carrier.

    SciT

    Panchal, C.B.; Pandolfini, P. P.; Kumm, W. H.

    2009-12-02

    Conventional petroleum, natural gas, and coal are the primary sources of energy that have underpinned modern civilization. Their continued availability in the projected quantities required and the impacts of emission of greenhouse gases (GHGs) on the environment are issues at the forefront of world concerns. New primary sources of energy are being sought that would significantly reduce the emissions of GHGs. One such primary source that can help supply energy, water, and fertilizer without GHG emissions is available in the heretofore unexploited thermal gradients of the tropical oceans. The world's oceans are the largest natural collector and reservoir of solarmore » energy. The potential of ocean energy is limitless for producing base-load electric power or ammonia as the hydrogen carrier and fresh water from seawater. However, until now, ocean energy has been virtually untapped. The general perception is that ocean thermal energy is limited to tropical countries. Therefore, the full potential of at-sea production of (1) ammonia as a hydrogen carrier and (2) desalinated water has not been adequately evaluated. Using ocean thermal plantships for the at-sea co-production of ammonia as a hydrogen carrier and desalinated water offer potential energy, environmental, and economic benefits that support the development of the technology. The introduction of a new widespread solution to our projected energy supply requires lead times of a decade or more. Although continuation of the ocean thermal program from the 1970s would likely have put us in a mitigating position in the early 2000s, we still have a window of opportunity to dedicate some of our conventional energy sources to the development of this renewable energy by the time new sources would be critically needed. The primary objective of this project is to evaluate the technical and economic viability of ocean thermal plantships for the production of ammonia as the hydrogen carrier. This objective is achieved by

  16. Adaptive capacity of the habitat modifying sea urchin Centrostephanus rodgersii to ocean warming and ocean acidification: performance of early embryos.

    PubMed

    Foo, Shawna A; Dworjanyn, Symon A; Poore, Alistair G B; Byrne, Maria

    2012-01-01

    Predicting effects of rapid climate change on populations depends on measuring the effects of climate stressors on performance, and potential for adaptation. Adaptation to stressful climatic conditions requires heritable genetic variance for stress tolerance present in populations. We quantified genetic variation in tolerance of early development of the ecologically important sea urchin Centrostephanus rodgersii to near-future (2100) ocean conditions projected for the southeast Australian global change hot spot. Multiple dam-sire crosses were used to quantify the interactive effects of warming (+2-4 °C) and acidification (-0.3-0.5 pH units) across twenty-seven family lines. Acidification, but not temperature, decreased the percentage of cleavage stage embryos. In contrast, temperature, but not acidification decreased the percentage of gastrulation. Cleavage success in response to both stressors was strongly affected by sire identity. Sire and dam identity significantly affected gastrulation and both interacted with temperature to determine developmental success. Positive genetic correlations for gastrulation indicated that genotypes that did well at lower pH also did well in higher temperatures. Significant genotype (sire) by environment interactions for both stressors at gastrulation indicated the presence of heritable variation in thermal tolerance and the ability of embryos to respond to changing environments. The significant influence of dam may be due to maternal provisioning (maternal genotype or environment) and/or offspring genotype. It appears that early development in this ecologically important sea urchin is not constrained in adapting to the multiple stressors of ocean warming and acidification. The presence of tolerant genotypes indicates the potential to adapt to concurrent warming and acidification, contributing to the resilience of C. rodgersii in a changing ocean.

  17. Adaptive Capacity of the Habitat Modifying Sea Urchin Centrostephanus rodgersii to Ocean Warming and Ocean Acidification: Performance of Early Embryos

    PubMed Central

    Foo, Shawna A.; Dworjanyn, Symon A.; Poore, Alistair G. B.; Byrne, Maria

    2012-01-01

    Background Predicting effects of rapid climate change on populations depends on measuring the effects of climate stressors on performance, and potential for adaptation. Adaptation to stressful climatic conditions requires heritable genetic variance for stress tolerance present in populations. Methodology/Principal Findings We quantified genetic variation in tolerance of early development of the ecologically important sea urchin Centrostephanus rodgersii to near-future (2100) ocean conditions projected for the southeast Australian global change hot spot. Multiple dam-sire crosses were used to quantify the interactive effects of warming (+2–4°C) and acidification (−0.3−0.5 pH units) across twenty-seven family lines. Acidification, but not temperature, decreased the percentage of cleavage stage embryos. In contrast, temperature, but not acidification decreased the percentage of gastrulation. Cleavage success in response to both stressors was strongly affected by sire identity. Sire and dam identity significantly affected gastrulation and both interacted with temperature to determine developmental success. Positive genetic correlations for gastrulation indicated that genotypes that did well at lower pH also did well in higher temperatures. Conclusions/Significance Significant genotype (sire) by environment interactions for both stressors at gastrulation indicated the presence of heritable variation in thermal tolerance and the ability of embryos to respond to changing environments. The significant influence of dam may be due to maternal provisioning (maternal genotype or environment) and/or offspring genotype. It appears that early development in this ecologically important sea urchin is not constrained in adapting to the multiple stressors of ocean warming and acidification. The presence of tolerant genotypes indicates the potential to adapt to concurrent warming and acidification, contributing to the resilience of C. rodgersii in a changing ocean. PMID

  18. Marine isoprene production and consumption in the mixed layer of the surface ocean - a field study over two oceanic regions

    NASA Astrophysics Data System (ADS)

    Booge, Dennis; Schlundt, Cathleen; Bracher, Astrid; Endres, Sonja; Zäncker, Birthe; Marandino, Christa A.

    2018-02-01

    Parameterizations of surface ocean isoprene concentrations are numerous, despite the lack of source/sink process understanding. Here we present isoprene and related field measurements in the mixed layer from the Indian Ocean and the eastern Pacific Ocean to investigate the production and consumption rates in two contrasting regions, namely oligotrophic open ocean and the coastal upwelling region. Our data show that the ability of different phytoplankton functional types (PFTs) to produce isoprene seems to be mainly influenced by light, ocean temperature, and salinity. Our field measurements also demonstrate that nutrient availability seems to have a direct influence on the isoprene production. With the help of pigment data, we calculate in-field isoprene production rates for different PFTs under varying biogeochemical and physical conditions. Using these new calculated production rates, we demonstrate that an additional significant and variable loss, besides a known chemical loss and a loss due to air-sea gas exchange, is needed to explain the measured isoprene concentration. We hypothesize that this loss, with a lifetime for isoprene between 10 and 100 days depending on the ocean region, is potentially due to degradation or consumption by bacteria.

  19. Production Characteristics of Oceanic Natural Gas Hydrate Reservoirs

    NASA Astrophysics Data System (ADS)

    Max, M. D.; Johnson, A. H.

    2014-12-01

    -water separation can begin within the seafloor, and specialized production techniques. NGH is the only oceanic hydrocarbon deposit in which pressure can be controlled within the reservoir by balancing conversion and extraction. Oceanic NGH has a very low environmental risk, which also serves to distinguish it from other deepwater hydrocarbon deposits.

  20. Boosted food web productivity through ocean acidification collapses under warming.

    PubMed

    Goldenberg, Silvan U; Nagelkerken, Ivan; Ferreira, Camilo M; Ullah, Hadayet; Connell, Sean D

    2017-10-01

    Future climate is forecast to drive bottom-up (resource driven) and top-down (consumer driven) change to food web dynamics and community structure. Yet, our predictive understanding of these changes is hampered by an over-reliance on simplified laboratory systems centred on single trophic levels. Using a large mesocosm experiment, we reveal how future ocean acidification and warming modify trophic linkages across a three-level food web: that is, primary (algae), secondary (herbivorous invertebrates) and tertiary (predatory fish) producers. Both elevated CO 2 and elevated temperature boosted primary production. Under elevated CO 2 , the enhanced bottom-up forcing propagated through all trophic levels. Elevated temperature, however, negated the benefits of elevated CO 2 by stalling secondary production. This imbalance caused secondary producer populations to decline as elevated temperature drove predators to consume their prey more rapidly in the face of higher metabolic demand. Our findings demonstrate how anthropogenic CO 2 can function as a resource that boosts productivity throughout food webs, and how warming can reverse this effect by acting as a stressor to trophic interactions. Understanding the shifting balance between the propagation of resource enrichment and its consumption across trophic levels provides a predictive understanding of future dynamics of stability and collapse in food webs and fisheries production. © 2017 John Wiley & Sons Ltd.

  1. Regional Ocean Products Portal: Transforming Information to Knowledge

    NASA Astrophysics Data System (ADS)

    Howard, M. K.; Kobara, S.; Gayanilo, F. C.; Baum, S. K.; Simoniello, C.; Jochens, A. E.

    2010-12-01

    .S. Integrated Ocean Observing System (IOOS). With IOOS guidance, and cooperation of regional data providers, GCOOS-RA has established a regional interoperable system of systems which has the potential to deliver marine, and coastal marine oceanographic, atmospheric, biogeochemical, and ecosystem related data in an automated and largely unattended way from sensors to products. GCOOS-RA devotes 10% of it’s funding to Education and Outreach activities and we have a number of modeling partners producing terabytes of output. With the interoperable parts of the data delivery system complete, our current challenge has been producing automated workflows that generate useful interactive graphical representations over the web. We have used a variety of commercial and free software packages. Some are net-enabled and can acquire remote datasets. Several are designed for 3D including ITTVIS IDL, Unidata IDV, and IVS’s Fledermaus. This talk will present a survey of software packages we’ve used, our successes and remaining challenges.

  2. 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 <span class="hlt">production</span> 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 <span class="hlt">production</span> were remarkably constant for the entire <span class="hlt">ocean</span>, which allowed a preliminary estimation of global primary <span class="hlt">productivity</span> as between 70 and 145 gt C yr-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy..tmp..777K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy..tmp..777K"><span>Inter comparison of Tropical Indian <span class="hlt">Ocean</span> features in different <span class="hlt">ocean</span> reanalysis <span class="hlt">products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karmakar, Ananya; Parekh, Anant; Chowdary, J. S.; Gnanaseelan, C.</p> <p>2017-09-01</p> <p>This study makes an inter comparison of <span class="hlt">ocean</span> state of the Tropical Indian <span class="hlt">Ocean</span> (TIO) in different <span class="hlt">ocean</span> reanalyses such as global <span class="hlt">ocean</span> data assimilation system (GODAS), ensemble coupled data assimilation (ECDA), <span class="hlt">ocean</span> reanalysis system 4 (ORAS4) and simple <span class="hlt">ocean</span> data assimilation (SODA) with reference to the in-situ buoy observations, satellite observed sea surface temperature (SST), EN4 analysis and <span class="hlt">ocean</span> surface current analysis real time (OSCAR). Analysis of mean state of SST and sea surface salinity (SSS) reveals that ORAS4 is better comparable with satellite observations as well as EN4 analysis, and is followed by SODA, ECDA and GODAS. The surface circulation in ORAS4 is closer to OSCAR compared to the other reanalyses. However mixed layer depth (MLD) is better simulated by SODA, followed by ECDA, ORAS4 and GODAS. Seasonal evolution of error indicates that the highest deviation in SST and MLD over the TIO exists during spring and summer in GODAS. Statistical analysis with concurrent data of EN4 for the period of 1980-2010 supports that the difference and standard deviation (variability strength) ratio for SSS and MLD is mostly greater than one. In general the strength of variability is overestimated by all the reanalyses. Further comparison with in-situ buoy observations supports that MLD errors over the equatorial Indian <span class="hlt">Ocean</span> (EIO) and the Bay of Bengal are higher than with EN4 analysis. Overall ORAS4 displays higher correlation and lower error among all reanalyses with respect to both EN4 analysis and buoy observations. Major issues in the reanalyses are the underestimation of upper <span class="hlt">ocean</span> stability in the TIO, underestimation of surface current in the EIO, overestimation of vertical shear of current and improper variability in different <span class="hlt">oceanic</span> variables. To improve the skill of reanalyses over the TIO, salinity vertical structure and upper <span class="hlt">ocean</span> circulation need to be better represented in reanalyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711348F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711348F"><span>The <span class="hlt">Early</span> Toarcian <span class="hlt">Oceanic</span> Anoxic Event and its sedimentary record in Switzerland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Montero-Serrano, Jean-Carlos</p> <p>2015-04-01</p> <p>In the Jurassic period, the <span class="hlt">Early</span> Toarcian <span class="hlt">Oceanic</span> Anoxic Event (T-OAE), about 183 Ma ago, was a global perturbation of paleoclimatic and paleoenvironmental conditions. This episode was associated with a crisis in marine carbonate accumulation, climate warming, an increase in sea level, <span class="hlt">ocean</span> acidification, enhanced continental weathering, whereas organic-rich sediments are noticeable for example in the Atlantic and in the Tethys. This episode is associated with a negative carbon excursion, which is recorded both in marine and terrestrial environments. The cause(s) of this environmental crisis remain(s) still controversial. Nevertheless, the development of negative δ13C excursions is commonly interpreted as due to the injection of isotopically-light carbon associated with gas hydrate dissociation, the thermal metamorphism of carbon-rich sediments and input of thermogenic and volcanogenic carbon related to the formation of the Karoo-Ferrar basaltic province in southern Gondwana (Hesselbo et al., 2000, 2007; Beerling et al., 2002; Cohen et al., 2004, 2007; McElwain et al., 2005, Beerling and Brentnall, 2007; Svensen et al., 2007; Hermoso et al., 2009, 2012; Mazzini et al., 2010). Several studies of the T-OAE have been conducted on sediments in central and northwest Europe, but only few data are available concerning the Swiss sedimentary records. Therefore, we focused on two sections in the Jura Plateau (canton Aargau): the Rietheim section (Montero-Serrano et al., submitted) and the Gipf section (current study). A multidisciplinary approach has been chosen and the tools to be used are based on sedimentological observations (sedimentary condensation, etc.), biostratigraphy, mineralogy (bulk-rock composition), facies and microfacies analysis (presence or absence of benthos), clay-mineralogy composition (climatic conditions), major and trace-element analyses (<span class="hlt">productivity</span>, redox conditions, etc.), phosphorus (trophic levels, anoxia), carbon isotopes and organic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP23A1382H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP23A1382H"><span><span class="hlt">Ocean</span> export <span class="hlt">production</span> and foraminiferal stable isotopes in the Antarctic Southern <span class="hlt">Ocean</span> across the mid-Pleistocene transition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hasenfratz, A. P.; Martinez-Garcia, A.; Jaccard, S.; Hodell, D. A.; Vance, D.; Bernasconi, S. M.; Greaves, M.; Haug, G. H.</p> <p>2014-12-01</p> <p>Changes in buoyancy forcing in the Antarctic Zone (AZ) of the Southern <span class="hlt">Ocean</span> are believed to play an instrumental role in modulating atmospheric CO2 concentrations during glacial cycles by regulating the transfer of carbon between the <span class="hlt">ocean</span> interior and the atmosphere. Indeed, a million-year-spanning high-resolution excess Barium record from the AZ of the South Atlantic (ODP 1094), which traces changes in export <span class="hlt">production</span>, shows decreased export <span class="hlt">production</span> during cold periods suggesting decreased overturning. Here, we extend this AZ export <span class="hlt">production</span> record back to 1.6 Myr. In addition, we present new carbon and oxygen isotope records of benthic and planktic foraminifera from the same site, complemented by Mg/Ca measurements in some intervals. The interpretation of these new data in the context of other South Atlantic records contributes to a better understanding of Southern <span class="hlt">Ocean</span> hydrography and its role in modulating glacial/interglacial cycles over the past 1.6 Myr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29732871','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29732871"><span>[Review of estimation on <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> by using remote sensing methods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Hong Yun; Zhou, Wei Feng; Ji, Shi Jian</p> <p>2016-09-01</p> <p>Accuracy estimation of <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> is of great significance in the assessment and management of fisheries resources, marine ecology systems, global change and other fields. The traditional measurement and estimation of <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> has to rely on in situ sample data by vessels. Satellite remote sensing has advantages of providing dynamic and eco-environmental parameters of <span class="hlt">ocean</span> surface at large scale in real time. Thus, satellite remote sensing has increasingly become an important means for <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> estimation on large spatio-temporal scale. Combining with the development of <span class="hlt">ocean</span> color sensors, the models to estimate the <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> by satellite remote sensing have been developed that could be mainly summarized as chlorophyll-based, carbon-based and phytoplankton absorption-based approach. The flexibility and complexity of the three kinds of models were presented in the paper. On this basis, the current research status for global estimation of <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> was analyzed and evaluated. In view of these, four research fields needed to be strengthened in further stu-dy: 1) Global <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span> estimation should be segmented and studied, 2) to dee-pen the research on absorption coefficient of phytoplankton, 3) to enhance the technology of <span class="hlt">ocea-nic</span> remote sensing, 4) to improve the in situ measurement of primary <span class="hlt">productivity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.P51A2116M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.P51A2116M"><span>Possible tidal resonance of the <span class="hlt">early</span> Earth's <span class="hlt">ocean</span> due to the lunar orbit evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Motoyama, M.; Tsunakawa, H.; Takahashi, F.</p> <p>2016-12-01</p> <p>The <span class="hlt">ocean</span> tide is one of the most important factors affecting the Earth's surface environment and the evolution of the Earth-Moon system (e.g. Goldreich, 1966). According to the Giant Impact hypothesis, the Moon was formed very near the Earth 4.6 billion years ago (Hartmann and Davis, 1979). At that time, the tidal force would be about several thousand times as strong as the present. However previous studies pointed out that significant attenuation of tidal waves might have occurred due to mechanical response of water motion (e.g. Hansen, 1982; Abe and Ooe, 2001), resulting in relatively calm state like the present <span class="hlt">ocean</span>.In the present study, we analyze tidal response of the <span class="hlt">ocean</span> on the <span class="hlt">early</span> Earth using a model of constant-depth <span class="hlt">ocean</span> covering all the surface of the rigid Earth. The examined modes of response are not only M2 corresponding to spherical harmonics Y22 but also others such as Y21, since the lunar orbital plane would be inclined.First, estimated is an <span class="hlt">ocean</span> depth for possible resonance of the individual mode. Eigen frequencies of the fluid on a rotating sphere with no friction are calculated on the basis of previous study (Longuet-Higgins, 1968). These frequencies depend on the Earth's rotation rate and the <span class="hlt">ocean</span> depth. The Earth's rotation period is assumed to have changed from 5 hours to 24 hours for the past 4.6 billion years (e.g. Mignard, 1980; Stacey and Davis, 2008). It is found that resonance could occur for diurnal modes of Y21 and Y31 with reasonable depths of the ancient <span class="hlt">ocean</span> (1300 - 5200 m).Then we obtain a 2D response function on a sphere with friction in order to estimate the tidal amplitude of the <span class="hlt">ocean</span> for main modes . The response function in the present study shows good agreement with the numerical simulation result of the tidal torque response of M2 (Abe et al., 1997). The calculation results suggest that diurnal modes of Y21 and Y31 would grown on the <span class="hlt">early</span> Earth, while the other modes would fairly be attenuated. In particular</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040089679&hterms=impacts+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dimpacts%2Bocean','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040089679&hterms=impacts+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dimpacts%2Bocean"><span>Impact melting of frozen <span class="hlt">oceans</span> on the <span class="hlt">early</span> Earth: implications for the origin of life</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bada, J. L.; Bigham, C.; Miller, S. L.</p> <p>1994-01-01</p> <p>Without sufficient greenhouse gases in the atmosphere, the <span class="hlt">early</span> Earth would have become a permanently frozen planet because the young Sun was less luminous than it is today. Several resolutions to this faint young Sun-frozen Earth paradox have been proposed, with an atmosphere rich in CO2 being the one generally favored. However, these models assume that there were no mechanisms for melting a once frozen <span class="hlt">ocean</span>. Here we show that bolide impacts between about 3.6 and 4.0 billion years ago could have episodically melted an ice-covered <span class="hlt">early</span> <span class="hlt">ocean</span>. Thaw-freeze cycles associated with bolide impacts could have been important for the initiation of abiotic reactions that gave rise to the first living organisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=43134','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=43134"><span>Impact melting of frozen <span class="hlt">oceans</span> on the <span class="hlt">early</span> Earth: Implications for the origin of life</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bada, J. L.; Bigham, C.; Miller, S. L.</p> <p>1994-01-01</p> <p>Without sufficient greenhouse gases in the atmosphere, the <span class="hlt">early</span> Earth would have become a permanently frozen planet because the young Sun was less luminous than it is today. Several resolutions to this faint young Sun-frozen Earth paradox have been proposed, with an atmosphere rich in CO2 being the one generally favored. However, these models assume that there were no mechanisms for melting a once frozen <span class="hlt">ocean</span>. Here we show that bolide impacts between about 3.6 and 4.0 billion years ago could have episodically melted an ice-covered <span class="hlt">early</span> <span class="hlt">ocean</span>. Thaw-freeze cycles associated with bolide impacts could have been important for the initiation of abiotic reactions that gave rise to the first living organisms. PMID:11539550</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.7907W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7907W"><span>Impact of Icebergs on Net Primary <span class="hlt">Productivity</span> in 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>Wu, Shuang-Ye; Hou, Shugui</p> <p>2017-04-01</p> <p><span class="hlt">Productivity</span> in the Southern <span class="hlt">Ocean</span> (SO) is iron-limited, and supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine environment. However, recent studies show that icebergs could provide comparable amount of bioavailable iron to the SO as aeolian dust. In addition, small scale areal studies suggest increased concentrations of chlorophyll, krill, and seabirds surrounding icebergs. Based on previous research, this study aims to examine whether iceberg occurrence has a significant impact on marine <span class="hlt">productivity</span> at the scale of the SO, using remote sensing data of iceberg occurrences and <span class="hlt">ocean</span> net primary <span class="hlt">productivity</span> (NPP) covering the period 2002-2014. The impacts of both large and small icebergs are examined in four major ecological zones of the SO: the continental shelf zone (CSZ), the seasonal ice zone (SIZ), the permanent open <span class="hlt">ocean</span> zone (POOZ) and the polar front zone (PFZ). We found that both large and small icebergs have an observable positive impact on NPP, but their impacts vary in different zones. Small icebergs on average increase NPP in most iron deficient zones: by 21% for the SIZ, 16% for the POOZ, and 12% for the PFZ, but have relatively small effect in the CSZ where iron is supplied from melt water and sediment input from the continent. Large icebergs on average increase the NPP by about 10%. Their impacts are stronger at higher latitudes, where they are more concentrated. From 1992-2014, there is a significant increasing trend for both small and large icebergs. The increase was most rapid in the <span class="hlt">early</span> 2000s, and has levelled off since then. As the climate continues to warm, the Antarctic Ice Sheet is expected to experience increased mass loss as a whole, which could lead to more icebergs in the region. Based on our study, this could result in higher level of NPP in the SO as a whole, providing a negative feedback for global warming.</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 Global <span class="hlt">Ocean</span> Data Analysis Project version 2 (GLODAPv2) - an internally consistent data <span class="hlt">product</span> 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 Global <span class="hlt">Ocean</span> Data Analysis Project (GLODAPv2) data <span class="hlt">product</span> is composed of data from 724 scientific cruises covering the global <span class="hlt">ocean</span>. It includes data assembled during the previous efforts GLODAPv1.1 (Global <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 <span class="hlt">product</span>. 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 <span class="hlt">products</span> with some new data added but a unique, internally consistent data <span class="hlt">product</span>. This compiled and adjusted data <span class="hlt">product</span> 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 <span class="hlt">product</span>, which is provided as a single global 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://adsabs.harvard.edu/abs/2017ClDy..tmp..180H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy..tmp..180H"><span>Enhanced influence of <span class="hlt">early</span>-spring tropical Indian <span class="hlt">Ocean</span> SST on the following <span class="hlt">early</span>-summer precipitation over Northeast China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Tingting; He, Shengping; Wang, Huijun; Hao, Xin</p> <p>2017-04-01</p> <p>The relationship between the tropical Indian <span class="hlt">Ocean</span> (TIO) and East Asian summer monsoon/precipitation has been documented in many studies. However, the precursor signals of summer precipitation in the TIO sea surface temperature (SST), which is important for climate prediction, have drawn little attention. This study identified a strong relationship between <span class="hlt">early</span>-spring TIO SST and subsequent <span class="hlt">early</span>-summer precipitation in Northeast China (NEC) since the late 1980s. For 1961-1986, the correlations between <span class="hlt">early</span>-spring TIO SST and <span class="hlt">early</span>-summer NEC precipitation were statistically insignificant; for 1989-2014, they were positively significant. Since the late 1980s, the <span class="hlt">early</span>-spring positive TIO SST anomaly was generally followed by a significant anomalous anticyclone over Japan; that facilitated anomalous southerly winds over NEC, conveying more moisture from the North Pacific. Further analysis indicated that an <span class="hlt">early</span> TIO SST anomaly showed robust persistence into <span class="hlt">early</span> summer. However, the <span class="hlt">early</span>-summer TIO SST anomaly displayed a more significant influence on simultaneous atmospheric circulation and further affected NEC precipitation since the late 1980s. In 1989-2014, the <span class="hlt">early</span>-summer Hadley and Ferrell cell anomalies associated with simultaneous TIO SST anomaly were much more significant and extended further north to mid-latitudes, which provided a dynamic foundation for the TIO-mid-latitude connection. Correspondingly, the TIO SST anomaly could lead to significant divergence anomalies over the Mediterranean. The advections of vorticity by the divergent component of the flow effectively acted as a Rossby wave source. Thus, an apparent Rossby wave originated from the Mediterranean and propagated east to East Asia; that further influenced the NEC precipitation through modulation to the atmospheric circulation (e.g., surface wind, moisture, vertical motion).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A51A0199L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A51A0199L"><span>Polyhalogenated Very Short Live Substances in the Atlantic <span class="hlt">Ocean</span>, and their Linkages with <span class="hlt">Ocean</span> Primary <span class="hlt">Production</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Yvon-Lewis, S. A.; Hu, L.; Bianchi, T. S.; Campbell, L.; Smith, R. W.</p> <p>2011-12-01</p> <p>The Halocarbon Air-Sea Transect - Atlantic (HalocAST-A) cruise was conducted aboard FS Polarstern during the ANT-XXVII/1 expedition. The ship departed from Bremerhaven, Germany on October 25th and arrived in Cape Town, South Africa on November 24th in 2010. The HalocAST-A cruise was devoted to studying air-sea fluxes of a suite of halocarbon compounds. Atmospheric mixing ratios and seawater concentrations of the halocarbons were continuously measured with the gas chromatograph - mass spectrometer (GC-MS). This study focuses on the polyhalogenated very short lived substances (VSLSs) such as bromoform (CHBr3), dibromomethane (CH2Br2), chlorodibromomethane (CHClBr2), and bromodichloromethane (CHBrCl2). The goal of this study is to examine the distributions of these compounds and possible relationship between their emissions and <span class="hlt">oceanic</span> primary <span class="hlt">production</span>. Therefore, along with the halocarbon concentrations, parameters like dissolved organic carbon concentrations, nutrient concentrations, pigment concentrations, and picoplankton and heterotrophic bacteria counts were also determined. The observed saturation anomalies indicated these VSLSs were supersaturated for almost the entire duration of the cruise. The highest seawater concentrations for these compounds were observed near the Canary Islands. Air mixing ratios were also elevated in this region. The net fluxes for CHBr3, CH2Br2, CHClBr2, and CHBrCl2 were 13.8 nmol m-2 d-1, 4.5 nmol m-2 d-1, 4.5 nmol m-2 d-1 and 1.2 nmol m-2 d-1, respectively. During the HalocAST-A cruise, these compounds exhibit similar trends with total chlorophyll a. Contributions from selected phytoplankton group will be further assessed through the use of individual pigment biomarkers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814279F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814279F"><span>The <span class="hlt">Early</span> Toarcian <span class="hlt">Oceanic</span> Anoxic Event: A Southern Hemisphere record from Chile</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Bernárdez, Enrique; Mattioli, Emanuela</p> <p>2016-04-01</p> <p>The <span class="hlt">Early</span> Toarcian was marked by important environmental changes, marine oxygen deficiency and extensive organic-rich sediment deposition (T-OAE; ˜182 Ma, <span class="hlt">Early</span> Jurassic). The T-OAE coincides with a marked negative carbon isotope excursion (CIE) recorded in marine carbonate, and marine and terrestrial organic carbon. This is commonly attributed to the massive release of isotopically light carbon to the atmospheric and <span class="hlt">oceanic</span> reservoirs derived from the destabilization of methane hydrates from marine sediments and/or the emissions of thermogenic methane from the eruption of the Karoo-Ferrar LIP (e.g., Hesselbo et al., 2000; Kemp et al., 2005; Svensen et al., 2007; Mazzini et al., 2010). Moreover, in most documented marine sections, this episode is marked by a generalized crisis in carbonate <span class="hlt">production</span> and marine invertebrate extinctions (e.g. Jenkyns, 1988; Röhl et al., 2005; Suan et al., 2001). Several studies of the T-OAE have been conducted on sediments in central and northwest Europe, but only few data are available from the Southern Hemisphere, leading to large uncertainty concerning the exact expression of this event in this part of the world. The aims of this study are to characterize the sediments deposited during the Andean equivalents of the tenuicostatum and falciferum European Zones and establish in which way the T-OAE affected this region. In the <span class="hlt">Early</span> Jurassic, the Andean basin was in a back-arc setting with marine corridors connected to Panthalassa. In this study, we have generated new high-resolution sedimentological, geochemical and mineralogical data from the sections of El Peñon and Quebrada Asiento, located in Chile in the northeastern area of the city of Copiapó, Atacama region. The biostratigraphy of these sections has been studied by von Hillebrandt and Schidt-Effing (1981) and complemented here by a biostratigraphy based on calcareous nannofossils. The sections consist of a succession of marl, limestone and siltstone of Pliensbachian and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10856212','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10856212"><span>Assessment of <span class="hlt">oceanic</span> <span class="hlt">productivity</span> with the triple-isotope composition of dissolved oxygen.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luz, B; Barkan, E</p> <p>2000-06-16</p> <p>Plant <span class="hlt">production</span> in the sea is a primary mechanism of global oxygen formation and carbon fixation. For this reason, and also because the <span class="hlt">ocean</span> is a major sink for fossil fuel carbon dioxide, much attention has been given to estimating marine primary <span class="hlt">production</span>. Here, we describe an approach for estimating <span class="hlt">production</span> of photosynthetic oxygen, based on the isotopic composition of dissolved oxygen of seawater. This method allows the estimation of integrated <span class="hlt">oceanic</span> <span class="hlt">productivity</span> on a time scale of weeks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr41B8.1165P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr41B8.1165P"><span>Calibration/validation of Landsat-Derived <span class="hlt">Ocean</span> Colour <span class="hlt">Products</span> in Boston Harbour</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pahlevan, Nima; Sheldon, Patrick; Peri, Francesco; Wei, Jianwei; Shang, Zhehai; Sun, Qingsong; Chen, Robert F.; Lee, Zhongping; Schaaf, Crystal B.; Schott, John R.; Loveland, Thomas</p> <p>2016-06-01</p> <p>The Landsat data archive provides a unique opportunity to investigate the long-term evolution of coastal ecosystems at fine spatial scales that cannot be resolved by <span class="hlt">ocean</span> colour (OC) satellite sensors. Recognizing Landsat's limitations in applications over coastal waters, we have launched a series of field campaigns in Boston Harbor and Massachusetts Bay (MA, USA) to validate OC <span class="hlt">products</span> derived from Landsat-8. We will provide a preliminary demonstration on the calibration/validation of the existing OC algorithms (atmospheric correction and in-water optical properties) to enhance monitoring efforts in Boston Harbor. To do so, Landsat optical images were first compared against <span class="hlt">ocean</span> colour <span class="hlt">products</span> over high-latitude regions. The in situ cruise data, including optical data (remote sensing reflectance) and water samples were analyzed to obtain insights into the optical and biogeochemical properties of near-surface waters. Along with the cruise data, three buoys were deployed in three locations across the Harbor to complement our database of concentrations of chlorophyll a, total suspended solids (TSS), and absorption of colour dissolved organic matter (CDOM). The data collected during the first year of the project are used to develop and/or tune OC algorithms. The data will be combined with historic field data to map in-water constituents back to the <span class="hlt">early</span> 1990's. This paper presents preliminary analysis of some of the data collected under Landsat-8 overpasses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME14B0608O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME14B0608O"><span>Marine mammal distribution in the open <span class="hlt">ocean</span>: a comparison of <span class="hlt">ocean</span> color data <span class="hlt">products</span> and levant time scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohern, J.</p> <p>2016-02-01</p> <p>Marine mammals are generally located in areas of enhanced surface primary <span class="hlt">productivity</span>, though they may forage much deeper within the water column and higher on the food chain. Numerous studies over the past several decades have utilized <span class="hlt">ocean</span> color data from remote sensing instruments (CZCS, MODIS, and others) to asses both the quantity and time scales over which surface primary <span class="hlt">productivity</span> relates to marine mammal distribution. In areas of sustained upwelling, primary <span class="hlt">productivity</span> may essentially grow in the secondary levels of <span class="hlt">productivity</span> (the zooplankton and nektonic species on which marine mammals forage). However, in many open <span class="hlt">ocean</span> habitats a simple trophic cascade does not explain relatively short time lags between enhanced surface <span class="hlt">productivity</span> and marine mammal presence. Other dynamic features that entrain prey or attract marine mammals may be responsible for the correlations between marine mammals and <span class="hlt">ocean</span> color. In order to investigate these features, two MODIS (moderate imaging spectroradiometer) data <span class="hlt">products</span>, the concentration as well as the standard deviation of surface chlorophyll were used in conjunction with marine mammal sightings collected within Ecuadorian waters. Time lags between enhanced surface chlorophyll and marine mammal presence were on the order of 2-4 weeks, however correlations were much stronger when the standard deviation of spatially binned images was used, rather than the chlorophyll concentrations. Time lags also varied between Balaenopterid and Odontocete cetaceans. Overall, the standard deviation of surface chlorophyll proved a useful tool for assessing potential relationships between marine mammal sightings and surface chlorophyll.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3690879','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3690879"><span>Evidence for reactive reduced phosphorus species in the <span class="hlt">early</span> Archean <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>Pasek, Matthew A.; Harnmeijer, Jelte P.; Buick, Roger; Gull, Maheen; Atlas, Zachary</p> <p>2013-01-01</p> <p>It has been hypothesized that before the emergence of modern DNA–RNA–protein life, biology evolved from an “RNA world.” However, synthesizing RNA and other organophosphates under plausible <span class="hlt">early</span> Earth conditions has proved difficult, with the incorporation of phosphorus (P) causing a particular problem because phosphate, where most environmental P resides, is relatively insoluble and unreactive. Recently, it has been proposed that during the Hadean–Archean heavy bombardment by extraterrestrial impactors, meteorites would have provided reactive P in the form of the iron–nickel phosphide mineral schreibersite. This reacts in water, releasing soluble and reactive reduced P species, such as phosphite, that could then be readily incorporated into prebiotic molecules. Here, we report the occurrence of phosphite in <span class="hlt">early</span> Archean marine carbonates at levels indicating that this was an abundant dissolved species in the <span class="hlt">ocean</span> before 3.5 Ga. Additionally, we show that schreibersite readily reacts with an aqueous solution of glycerol to generate phosphite and the membrane biomolecule glycerol–phosphate under mild thermal conditions, with this synthesis using a mineral source of P. Phosphite derived from schreibersite was, hence, a plausible reagent in the prebiotic synthesis of phosphorylated biomolecules and was also present on the <span class="hlt">early</span> Earth in quantities large enough to have affected the redox state of P in the <span class="hlt">ocean</span>. Phosphorylated biomolecules like RNA may, thus, have first formed from the reaction of reduced P species with the prebiotic organic milieu on the <span class="hlt">early</span> Earth. PMID:23733935</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LPICo2047.6105B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LPICo2047.6105B"><span><span class="hlt">Production</span> and Preservation of Sulfide Layering in Mercury's Magma <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>Boukare, C.-E.; Parman, S. W.; Parmentier, E. M.; Anzures, B. A.</p> <p>2018-05-01</p> <p>Mercury's magma <span class="hlt">ocean</span> (MMO) would have been sulfur-rich. At some point during MMO solidification, it likely became sulfide saturated. Here we present physiochemical models exploring sulfide layer formation and stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27558063','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27558063"><span><span class="hlt">Early</span> onset of industrial-era warming across the <span class="hlt">oceans</span> and continents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abram, Nerilie J; McGregor, Helen V; Tierney, Jessica E; Evans, Michael N; McKay, Nicholas P; Kaufman, Darrell S</p> <p>2016-08-25</p> <p>The evolution of industrial-era warming across the continents and <span class="hlt">oceans</span> provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post-ad 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical <span class="hlt">oceans</span> first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The <span class="hlt">early</span> onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as <span class="hlt">early</span> as the mid-nineteenth century and included an enhanced equatorial <span class="hlt">ocean</span> response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account.</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_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" 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_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</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="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26037825','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26037825"><span>Magma <span class="hlt">Ocean</span> Depth and Oxygen Fugacity in the <span class="hlt">Early</span> Earth--Implications for Biochemistry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Righter, Kevin</p> <p>2015-09-01</p> <p>A large class of elements, referred to as the siderophile (iron-loving) elements, in the Earth's mantle can be explained by an <span class="hlt">early</span> deep magma <span class="hlt">ocean</span> on the <span class="hlt">early</span> Earth in which the mantle equilibrated with metallic liquid (core liquid). This stage would have affected the distribution of some of the classic volatile elements that are also essential ingredients for life and biochemistry - H, C, S, and N. Estimates are made of the H, C, S, and N contents of Earth's <span class="hlt">early</span> mantle after core formation, considering the effects of variable temperature, pressure, oxygen fugacity, and composition on their partitioning. Assessment is made of whether additional, exogenous, sources are required to explain the observed mantle concentrations, and areas are identified where additional data and experimentation would lead to an improved understanding of this phase of Earth's history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21898980','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21898980"><span>[<span class="hlt">Production</span> of glass in <span class="hlt">early</span> middle ages].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zimmermann, Martin</p> <p>2011-01-01</p> <p>For the <span class="hlt">production</span> of glass three ingredients are necessary: sand, a flux to reduce the melting-temperature and calcium to reduce the danger of glass corrosion. The first objects of glass were made with calcium-rich ashes of halophytic plants, until, in the first millennium BC, the glassmakers began to use natron as a flux adding calcium deliberately or choosing a calcium-rich sand. Natron, a mineral applied to fertilize or to preserve, as a spice, a detergent or part of medical and cosmetic articles, was exploited in the regions south and east of the Mediterranean, so the Central European glassmakers had to import natron or the prefabricated raw glass for their work. Beginning in the 8th century AD in Central Europe the flux changed again: The glassmakers increasingly used ashes from wood growing in their native regions so becoming independent of the necessity to import the raw materials. There are various reasons for this change: First, the Mediterranean was no longer the trade area it had been at the time of the antique Roman Empire due to the activities of the Byzantine navy. Then, the climatic change in the 8th century and political upheavals during the 9th century in Egypt--being the main supplier of natron--caused a decrease in exploitation and trade with this good. Finally, the Egyptian state established a monopoly on the natron <span class="hlt">production</span>, causing a permanent price increase. Nevertheless, during the <span class="hlt">Early</span> Middle Ages natron was imported into Europe, although not necessarily for glass <span class="hlt">production</span>. The article shows that glassmakers of Central Europe were able to produce glass since the end of the Western Roman Empire on the basis of the transfer of raw materials and know-how from the East. From the 8th century onwards they emancipated themselves from the dependency on imports by discovering and using native materials for glass <span class="hlt">production</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.C21A0659F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.C21A0659F"><span>Downscaled ice-<span class="hlt">ocean</span> simulations for the Chukchi and Eastern Siberian Seas from an <span class="hlt">oceanic</span> re-analysis <span class="hlt">product</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fujisaki-Manome, A.; Wang, J.</p> <p>2016-12-01</p> <p>Arctic summer sea ice has been declining at the rate that is much faster than any climate models predict. While the accelerated sea ice melting in the recent few decades could be attributed to several mechanisms such as the Arctic temperature amplification and the ice-albedo feedback, this does not necessarily explain why climate models underestimate the observed rate of summer sea ice loss. Clearly, an improved understanding is needed in what processes could be missed in climate models and could play roles in unprecedented loss of sea ice. This study evaluates contributions of sub-mesoscale processes in the ice edge (i.e. the boundary region between open water and ice covered area), which include eddies, ice bands, and the vertical mixing associated with ice bands, to the melting of sea ice and how they explain the underestimation of sea ice loss in the current state-of-art climate models. The focus area is in the pacific side of the Arctic <span class="hlt">Ocean</span>. First, several <span class="hlt">oceanic</span> re-analysis <span class="hlt">products</span> including NCEP-Climate Forecast System Reanalysis (CFSR) and Modern-Era Retrospective Analysis for Research and Applications (MERRA) are evaluated in comparison with the in-situ observations from the Russian-American Long-term Census of the Arctic (RUSALCA) project. Second, the downscaled ice-<span class="hlt">ocean</span> simulations are conducted for the Chukchi and East Siberian Seas with initial and open boundary conditions provided from a selected <span class="hlt">oceanic</span> re-analysis <span class="hlt">product</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28784706','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28784706"><span>Photosynthetic oxygen <span class="hlt">production</span> in a warmer <span class="hlt">ocean</span>: the Sargasso Sea as a case study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Richardson, Katherine; Bendtsen, Jørgen</p> <p>2017-09-13</p> <p>Photosynthetic O 2 <span class="hlt">production</span> can be an important source of oxygen in sub-surface <span class="hlt">ocean</span> waters especially in permanently stratified oligotrophic regions of the <span class="hlt">ocean</span> where O 2 produced in deep chlorophyll maxima (DCM) is not likely to be outgassed. Today, permanently stratified regions extend across approximately 40% of the global <span class="hlt">ocean</span> and their extent is expected to increase in a warmer <span class="hlt">ocean</span>. Thus, predicting future <span class="hlt">ocean</span> oxygen conditions requires a better understanding of the potential response of photosynthetic oxygen <span class="hlt">production</span> to a warmer <span class="hlt">ocean</span>. Based on our own and published observations of water column processes in oligotrophic regions, we develop a one-dimensional water column model describing photosynthetic oxygen <span class="hlt">production</span> in the Sargasso Sea to quantify the importance of photosynthesis for the downward flux of O 2 and examine how it may be influenced in a warmer <span class="hlt">ocean</span>. Photosynthesis is driven in the model by vertical mixing of nutrients (including eddy-induced mixing) and diazotrophy and is found to substantially increase the downward O 2 flux relative to physical-chemical processes alone. Warming (2°C) surface waters does not significantly change oxygen <span class="hlt">production</span> at the DCM. Nor does a 15% increase in re-mineralization rate (assuming Q 10  = 2; 2°C warming) have significant effect on net sub-surface oxygen accumulation. However, changes in the relative <span class="hlt">production</span> of particulate (POM) and dissolved organic material (DOM) generate relatively large changes in net sub-surface oxygen <span class="hlt">production</span>. As POM/DOM <span class="hlt">production</span> is a function of plankton community composition, this implies plankton biodiversity and food web structure may be important factors influencing O 2 <span class="hlt">production</span> in a warmer <span class="hlt">ocean</span>.This article is part of the themed issue '<span class="hlt">Ocean</span> ventilation and deoxygenation in a warming world'. © 2017 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RSPTA.37560329R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RSPTA.37560329R"><span>Photosynthetic oxygen <span class="hlt">production</span> in a warmer <span class="hlt">ocean</span>: the Sargasso Sea as a case study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richardson, Katherine; Bendtsen, Jørgen</p> <p>2017-08-01</p> <p>Photosynthetic O2 <span class="hlt">production</span> can be an important source of oxygen in sub-surface <span class="hlt">ocean</span> waters especially in permanently stratified oligotrophic regions of the <span class="hlt">ocean</span> where O2 produced in deep chlorophyll maxima (DCM) is not likely to be outgassed. Today, permanently stratified regions extend across approximately 40% of the global <span class="hlt">ocean</span> and their extent is expected to increase in a warmer <span class="hlt">ocean</span>. Thus, predicting future <span class="hlt">ocean</span> oxygen conditions requires a better understanding of the potential response of photosynthetic oxygen <span class="hlt">production</span> to a warmer <span class="hlt">ocean</span>. Based on our own and published observations of water column processes in oligotrophic regions, we develop a one-dimensional water column model describing photosynthetic oxygen <span class="hlt">production</span> in the Sargasso Sea to quantify the importance of photosynthesis for the downward flux of O2 and examine how it may be influenced in a warmer <span class="hlt">ocean</span>. Photosynthesis is driven in the model by vertical mixing of nutrients (including eddy-induced mixing) and diazotrophy and is found to substantially increase the downward O2 flux relative to physical-chemical processes alone. Warming (2°C) surface waters does not significantly change oxygen <span class="hlt">production</span> at the DCM. Nor does a 15% increase in re-mineralization rate (assuming Q10 = 2; 2°C warming) have significant effect on net sub-surface oxygen accumulation. However, changes in the relative <span class="hlt">production</span> of particulate (POM) and dissolved organic material (DOM) generate relatively large changes in net sub-surface oxygen <span class="hlt">production</span>. As POM/DOM <span class="hlt">production</span> is a function of plankton community composition, this implies plankton biodiversity and food web structure may be important factors influencing O2 <span class="hlt">production</span> in a warmer <span class="hlt">ocean</span>. This article is part of the themed issue '<span class="hlt">Ocean</span> ventilation and deoxygenation in a warming world'.</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 Global <span class="hlt">Ocean</span> Data Analysis Project version 2 (GLODAPv2) – an internally consistent data <span class="hlt">product</span> 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 Global <span class="hlt">Ocean</span> Data Analysis Project (GLODAPv2) data <span class="hlt">product</span> is composed of data from 724 scientific cruises covering the global <span class="hlt">ocean</span>. It includes data assembled during the previous efforts GLODAPv1.1 (Global <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 <span class="hlt">product</span>. 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 <span class="hlt">products</span> with some new data added but a unique, internally consistent data <span class="hlt">product</span>. In conclusion, this compiled and adjusted data <span class="hlt">product</span> 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 Global <span class="hlt">Ocean</span> Data Analysis Project version 2 (GLODAPv2) – an internally consistent data <span class="hlt">product</span> for the world <span class="hlt">ocean</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciT</a></p> <p>Olsen, Are; Key, Robert M.; van Heuven, Steven</p> <p></p> <p>Version 2 of the Global <span class="hlt">Ocean</span> Data Analysis Project (GLODAPv2) data <span class="hlt">product</span> is composed of data from 724 scientific cruises covering the global <span class="hlt">ocean</span>. It includes data assembled during the previous efforts GLODAPv1.1 (Global <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 <span class="hlt">product</span>. 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 <span class="hlt">products</span> with some new data added but a unique, internally consistent data <span class="hlt">product</span>. In conclusion, this compiled and adjusted data <span class="hlt">product</span> 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/2017AGUFM.V43E0576C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.V43E0576C"><span><span class="hlt">Early</span> Permian mafic dikes in the Nagqu area, central Tibet, China, associated with embryonic <span class="hlt">oceanic</span> crust of the Meso-Tethys <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>Chen, S. S.; Fan, W. M.; Shi, R. D.; Gong, X. H.</p> <p>2017-12-01</p> <p>During the latest Carboniferous to <span class="hlt">early</span> Permian, a mantle plume initiated continental rifting along the northern Gondwana margin, which subsequently developed into the Meso-Tethys <span class="hlt">Ocean</span>. However, the nature and timing of the embryonic <span class="hlt">oceanic</span> crust of the Meso-Tethys <span class="hlt">Ocean</span> remains poorly understood. Here, we present for the first time a combined analysis of petrological, geochronological, geochemical, and Sr-Nd isotopic data for mafic rocks from the Nagqu area, central Tibet. Zircons from the mafic rocks yield a concordant age of ca. 277.8±1.8 Ma, which is slightly younger than the age of mantle plume activity (ca. 300-279 Ma), as represented by the large igneous province (LIP) on the northern Gondwana margin. Geochemical features suggest that the Nagqu mafic rocks, which display normal mid <span class="hlt">ocean</span> ridge basalt (N-MORB) affinities, are different from those of the LIP, which display <span class="hlt">oceanic</span> island basalt (OIB)-type affinities. The Nagqu mafic rocks result from a relatively high degree of melting of depleted asthenospheric mantle. Combined with observations from previous studies, we suggest that the late <span class="hlt">early</span> Permian Nagqu magmatism fully records processes of <span class="hlt">early</span> stage rifting and incipient formation of <span class="hlt">oceanic</span> crust. Moreover, the patterns of magmatism are consistent with patterns of rift-related sedimentation that records the transition from predominantly continental to marine deposition in the region during the Carboniferous-Permian. We therefore suggest that rifting of the eastern Cimmerian and northern Gondwana continents started at ca. 277.8 Ma, and the rifting culminated in the opening of the Meso-Tethys <span class="hlt">Ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.390..116F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.390..116F"><span>Organic geochemistry of the <span class="hlt">early</span> Toarcian <span class="hlt">oceanic</span> anoxic event in Hawsker Bottoms, Yorkshire, England</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>French, K. L.; Sepúlveda, J.; Trabucho-Alexandre, J.; Gröcke, D. R.; Summons, R. E.</p> <p>2014-03-01</p> <p>A comprehensive organic geochemical investigation of the Hawsker Bottoms outcrop section in Yorkshire, England has provided new insights about environmental conditions leading into and during the Toarcian <span class="hlt">oceanic</span> anoxic event (T-OAE; ∼183 Ma). Rock-Eval and molecular analyses demonstrate that the section is uniformly within the <span class="hlt">early</span> oil window. Hydrogen index (HI), organic petrography, polycyclic aromatic hydrocarbon (PAH) distributions, and tricyclic terpane ratios mark a shift to a lower relative abundance of terrigenous organic matter supplied to the sampling locality during the onset of the T-OAE and across a lithological transition. Unlike other ancient intervals of anoxia and extinction, biomarker indices of planktonic community structure do not display major changes or anomalous values. Depositional environment and redox indicators support a shift towards more reducing conditions in the sediment porewaters and the development of a seasonally stratified water column during the T-OAE. In addition to carotenoid biomarkers for green sulfur bacteria (GSB), we report the first occurrence of okenane, a marker of purple sulfur bacteria (PSB), in marine samples younger than ∼1.64 Ga. Based on modern observations, a planktonic source of okenane's precursor, okenone, would require extremely shallow photic zone euxinia (PZE) and a highly restricted depositional environment. However, due to coastal vertical mixing, the lack of planktonic okenone <span class="hlt">production</span> in modern marine sulfidic environments, and building evidence of okenone <span class="hlt">production</span> in mat-dwelling Chromatiaceae, we propose a sedimentary source of okenone as an alternative. Lastly, we report the first parallel compound-specific δC13 record in marine- and terrestrial-derived biomarkers across the T-OAE. The δC13 records of short-chain n-alkanes, acyclic isoprenoids, and long-chain n-alkanes all encode negative carbon isotope excursions (CIEs), and together, they support an injection of isotopically light</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA503626','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA503626"><span>Evaluation of Global <span class="hlt">Ocean</span> Data Assimilation Experiment <span class="hlt">Products</span> on South Florida Nested Simulations with the Hybrid Coordinate <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>2009-01-01</p> <p><span class="hlt">Ocean</span> Model 7:285-322 Halliwell GR Jr, Weisberg RH, Mayer DA (2003) A synthetic float analysis of upper-limb meridional overturning circulation ...encompasses a variety of coastal regions (the broad Southwest Florida shelf, the narrow Atlantic Keys shelf, the shallow Florida Bay, and Biscayne...<span class="hlt">products</span>. The results indicate that the successful hindcasting of circulation patterns in a coastal area that is characterized by complex topography and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4508965','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4508965"><span>The great 2012 Arctic <span class="hlt">Ocean</span> summer cyclone enhanced biological <span class="hlt">productivity</span> on the shelves</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Jinlun; Ashjian, Carin; Campbell, Robert; Hill, Victoria; Spitz, Yvette H; Steele, Michael</p> <p>2014-01-01</p> <p>[1] A coupled biophysical model is used to examine the impact of the great Arctic cyclone of <span class="hlt">early</span> August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic <span class="hlt">Ocean</span> (PSA). Model results indicate that the cyclone influences the marine planktonic ecosystem by enhancing <span class="hlt">productivity</span> on the shelves of the Chukchi, East Siberian, and Laptev seas during the storm. Although the cyclone's passage in the PSA lasted only a few days, the simulated biological effects on the shelves last 1 month or longer. At some locations on the shelves, primary <span class="hlt">productivity</span> (PP) increases by up to 90% and phytoplankton biomass by up to 40% in the wake of the cyclone. The increase in zooplankton biomass is up to 18% on 31 August and remains 10% on 15 September, more than 1 month after the storm. In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass. The biological gain on the shelves and loss in the central PSA are linked to two factors. (1) The cyclone enhances mixing in the upper <span class="hlt">ocean</span>, which increases nutrient availability in the surface waters of the shelves; enhanced mixing in the central PSA does not increase <span class="hlt">productivity</span> because nutrients there are mostly depleted through summer draw down by the time of the cyclone's passage. (2) The cyclone also induces divergence, resulting from the cyclone's low-pressure system that drives cyclonic sea ice and upper <span class="hlt">ocean</span> circulation, which transports more plankton biomass onto the shelves from the central PSA. The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the <span class="hlt">production</span> on average over the entire PSA is increased by the cyclone. Because the gain on the shelves is offset by the loss in the central PSA, the average increase over the entire PSA is moderate and lasts only about 10 days. The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26213671','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26213671"><span>The great 2012 Arctic <span class="hlt">Ocean</span> summer cyclone enhanced biological <span class="hlt">productivity</span> on the shelves.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Jinlun; Ashjian, Carin; Campbell, Robert; Hill, Victoria; Spitz, Yvette H; Steele, Michael</p> <p>2014-01-01</p> <p>[1] A coupled biophysical model is used to examine the impact of the great Arctic cyclone of <span class="hlt">early</span> August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic <span class="hlt">Ocean</span> (PSA). Model results indicate that the cyclone influences the marine planktonic ecosystem by enhancing <span class="hlt">productivity</span> on the shelves of the Chukchi, East Siberian, and Laptev seas during the storm. Although the cyclone's passage in the PSA lasted only a few days, the simulated biological effects on the shelves last 1 month or longer. At some locations on the shelves, primary <span class="hlt">productivity</span> (PP) increases by up to 90% and phytoplankton biomass by up to 40% in the wake of the cyclone. The increase in zooplankton biomass is up to 18% on 31 August and remains 10% on 15 September, more than 1 month after the storm. In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass. The biological gain on the shelves and loss in the central PSA are linked to two factors. (1) The cyclone enhances mixing in the upper <span class="hlt">ocean</span>, which increases nutrient availability in the surface waters of the shelves; enhanced mixing in the central PSA does not increase <span class="hlt">productivity</span> because nutrients there are mostly depleted through summer draw down by the time of the cyclone's passage. (2) The cyclone also induces divergence, resulting from the cyclone's low-pressure system that drives cyclonic sea ice and upper <span class="hlt">ocean</span> circulation, which transports more plankton biomass onto the shelves from the central PSA. The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the <span class="hlt">production</span> on average over the entire PSA is increased by the cyclone. Because the gain on the shelves is offset by the loss in the central PSA, the average increase over the entire PSA is moderate and lasts only about 10 days. The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1051563','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1051563"><span>A Wave Glider for Studies of Biofouling and <span class="hlt">Ocean</span> <span class="hlt">Productivity</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-11-07</p> <p>sensors for conductivity, water and air temperature , dissolved oxygen , chlorophyll-a fluorescence, wind speed and direction, barometric pressure, and...endurance, reduce fuel consumption , and reduce carbon emissions. During deployments, vessels encounter a range of planktonic assemblages and <span class="hlt">ocean</span>...with an acoustic Doppler current profiler, an optical camera system, and standard sensors for conductivity, water and air temperature , dissolved</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LPICo2084.4019S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LPICo2084.4019S"><span>Ferric Iron <span class="hlt">Production</span> in Magma <span class="hlt">Oceans</span> and Evolution of Mantle Oxidation State</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaefer, L.; Elkins-Tanton, L. T.; Pahlevan, K.</p> <p>2018-05-01</p> <p>Self-oxidation of the magma <span class="hlt">ocean</span> by ferric iron <span class="hlt">production</span> at high pressure may explain the mantle oxidation state of the Earth. Partitioning during fractional crystallization can further increase the mantle oxygen fugacity during solidification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006GeoRL..3318606S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GeoRL..3318606S"><span>Anoxia and high primary <span class="hlt">production</span> in the Paleogene central Arctic <span class="hlt">Ocean</span>: First detailed records from Lomonosov Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stein, Ruediger; Boucsein, Bettina; Meyer, Hanno</p> <p>2006-09-01</p> <p>Except for a few discontinuous fragments of the Late Cretaceous/<span class="hlt">Early</span> Cenozoic climate history and depositional environment, the paleoenvironmental evolution of the pre-Neogene central Arctic <span class="hlt">Ocean</span> was virtually unknown prior to the IODP Expedition 302 (Arctic <span class="hlt">Ocean</span> Coring Expedition-ACEX) drilling campaign on Lomonosov Ridge in 2004. Here we present detailed organic carbon (OC) records from the entire ca. 200 m thick Paleogene OC-rich section of the ACEX drill sites. These records indicate euxinic "Black Sea-type" conditions favorable for the preservation of labile aquatic (marine algae-type) OC occur throughout the upper part of the <span class="hlt">early</span> Eocene and the middle Eocene, explained by salinity stratification due to freshwater discharge. The superimposed short-term ("Milankovitch-type") variability in amount and composition of OC is related to changes in primary <span class="hlt">production</span> and terrigenous input. Prominent <span class="hlt">early</span> Eocene events of algae-type OC preservation coincide with global δ13C events such as the PETM and Elmo events. The Elmo δ13C Event has been identified in the Arctic <span class="hlt">Ocean</span> for the first time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5034254','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5034254"><span>The conservative behavior of dissolved organic carbon in surface waters of the southern Chukchi Sea, Arctic <span class="hlt">Ocean</span>, during <span class="hlt">early</span> summer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tanaka, Kazuki; Takesue, Nobuyuki; Nishioka, Jun; Kondo, Yoshiko; Ooki, Atsushi; Kuma, Kenshi; Hirawake, Toru; Yamashita, Youhei</p> <p>2016-01-01</p> <p>The spatial distribution of dissolved organic carbon (DOC) concentrations and the optical properties of dissolved organic matter (DOM) determined by ultraviolet-visible absorbance and fluorescence spectroscopy were measured in surface waters of the southern Chukchi Sea, western Arctic <span class="hlt">Ocean</span>, during the <span class="hlt">early</span> summer of 2013. Neither the DOC concentration nor the optical parameters of the DOM correlated with salinity. Principal component analysis using the DOM optical parameters clearly separated the DOM sources. A significant linear relationship was evident between the DOC and the principal component score for specific water masses, indicating that a high DOC level was related to a terrigenous source, whereas a low DOC level was related to a marine source. Relationships between the DOC and the principal component scores of the surface waters of the southern Chukchi Sea implied that the major factor controlling the distribution of DOC concentrations was the mixing of plural water masses rather than local <span class="hlt">production</span> and degradation. PMID:27658444</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3669312','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3669312"><span>Adverse Effects of <span class="hlt">Ocean</span> Acidification on <span class="hlt">Early</span> Development of Squid (Doryteuthis pealeii)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kaplan, Maxwell B.; Mooney, T. Aran; McCorkle, Daniel C.; Cohen, Anne L.</p> <p>2013-01-01</p> <p>Anthropogenic carbon dioxide (CO2) is being absorbed into the <span class="hlt">ocean</span>, altering seawater chemistry, with potentially negative impacts on a wide range of marine organisms. The <span class="hlt">early</span> life stages of invertebrates with internal and external aragonite structures may be particularly vulnerable to this <span class="hlt">ocean</span> acidification. Impacts to cephalopods, which form aragonite cuttlebones and statoliths, are of concern because of the central role they play in many <span class="hlt">ocean</span> ecosystems and because of their importance to global fisheries. Atlantic longfin squid (Doryteuthis pealeii), an ecologically and economically valuable taxon, were reared from eggs to hatchlings (paralarvae) under ambient and elevated CO2 concentrations in replicated experimental trials. Animals raised under elevated pCO2 demonstrated significant developmental changes including increased time to hatching and shorter mantle lengths, although differences were small. Aragonite statoliths, critical for balance and detecting movement, had significantly reduced surface area and were abnormally shaped with increased porosity and altered crystal structure in elevated pCO2-reared paralarvae. These developmental and physiological effects could alter squid paralarvae behavior and survival in the wild, directly and indirectly impacting marine food webs and commercial fisheries. PMID:23741298</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23741298','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23741298"><span>Adverse effects of <span class="hlt">ocean</span> acidification on <span class="hlt">early</span> development of squid (Doryteuthis pealeii).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaplan, Maxwell B; Mooney, T Aran; McCorkle, Daniel C; Cohen, Anne L</p> <p>2013-01-01</p> <p>Anthropogenic carbon dioxide (CO2) is being absorbed into the <span class="hlt">ocean</span>, altering seawater chemistry, with potentially negative impacts on a wide range of marine organisms. The <span class="hlt">early</span> life stages of invertebrates with internal and external aragonite structures may be particularly vulnerable to this <span class="hlt">ocean</span> acidification. Impacts to cephalopods, which form aragonite cuttlebones and statoliths, are of concern because of the central role they play in many <span class="hlt">ocean</span> ecosystems and because of their importance to global fisheries. Atlantic longfin squid (Doryteuthis pealeii), an ecologically and economically valuable taxon, were reared from eggs to hatchlings (paralarvae) under ambient and elevated CO2 concentrations in replicated experimental trials. Animals raised under elevated pCO2 demonstrated significant developmental changes including increased time to hatching and shorter mantle lengths, although differences were small. Aragonite statoliths, critical for balance and detecting movement, had significantly reduced surface area and were abnormally shaped with increased porosity and altered crystal structure in elevated pCO2-reared paralarvae. These developmental and physiological effects could alter squid paralarvae behavior and survival in the wild, directly and indirectly impacting marine food webs and commercial fisheries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A34E..06Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A34E..06Y"><span>The increasing control of the Atlantic <span class="hlt">Ocean</span> on ENSO after the <span class="hlt">early</span> 1990s</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, J. Y.; Paek, H.; Wang, L.; Lyu, K.</p> <p>2016-12-01</p> <p>The El Niño-Southern Oscillation (ENSO) is the most powerful interannual variability in Earth's climate system. Previous studies have emphasized processes within the tropical Pacific or Indian <span class="hlt">Oceans</span> for the generation of ENSO. Recent studies have increasingly suggested that the Atlantic <span class="hlt">Ocean</span> may play an active role in forcing ENSO variability. In this talk, we will present evidence from observational analyses and modeling experiments to show that the Atlantic <span class="hlt">Ocean</span> became more capable of influencing ENSO properties after the Atlantic Multidecadal Oscillation (AMO) changed to its positive phase in the <span class="hlt">early</span>-1990s. A wave source mechanism is proposed to explain how the positive phase of the AMO can intensify the North Pacific Subtropical High (NPSH) to change the ENSO from the Eastern Pacific (EP) type to the Central Pacific (CP) type. A sequence of processes are identified to suggest that the AMO can displace the Pacific Walker circulation, induce a wave source in the tropical central Pacific, and excite a barotropic wave train toward higher-latitudes to enhance the NPSH, which then triggers subtropical Pacific atmospheric forcing and atmosphere-<span class="hlt">ocean</span> coupling to increase the occurrence of the CP ENSO. An Atlantic capacitor mechanism is also proposed to explain how the positive phase of the AMO can intensify the quasi-biennial (QB) component of ENSO resulting in a more frequent occurrence of ENSO events. We will show that the capacitor mechanism works only after the AMO warmed up the Atlantic sea surface temperatures after the <span class="hlt">early</span>-1990s. The increased feedback from the Atlantic to the Pacific has enabled the Atlantic capacitor mechanism to intensify the biennial variability in the Pacific during the past two decades. Our suggestion is very different from the previous prevailing views that have emphasized the Indo-Pacific <span class="hlt">Oceans</span> as the pacemaker for the biennial variability in ENSO. The increasing control of the Atlantic has enabled the CP ENSO dynamics to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26PSL.472....1J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26PSL.472....1J"><span><span class="hlt">Ocean</span> forcing of Ice Sheet retreat in central west Greenland from LGM to the <span class="hlt">early</span> Holocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jennings, Anne E.; Andrews, John T.; Ó Cofaigh, Colm; Onge, Guillaume St.; Sheldon, Christina; Belt, Simon T.; Cabedo-Sanz, Patricia; Hillaire-Marcel, Claude</p> <p>2017-08-01</p> <p>Three radiocarbon dated sediment cores from trough mouth fans on the central west Greenland continental slope were studied to determine the timing and processes of Greenland Ice Sheet (GIS) retreat from the shelf edge during the last deglaciation and to test the role of <span class="hlt">ocean</span> forcing (i.e. warm <span class="hlt">ocean</span> water) thereon. Analyses of lithofacies, quantitative x-ray diffraction mineralogy, benthic foraminiferal assemblages, the sea-ice biomarker IP25, and δ18 O of the planktonic foraminifera Neogloboquadrina pachyderma sinistral from sediments in the interval from 17.5-10.8 cal ka BP provide consistent evidence for <span class="hlt">ocean</span> and ice sheet interactions during central west Greenland (CWG) deglaciation. The Disko and Uummannaq ice streams both retreated from the shelf edge after the last glacial maximum (LGM) under the influence of subsurface, warm Atlantic Water. The warm subsurface water was limited to depths below the ice stream grounding lines during the LGM, when the GIS terminated as a floating ice shelf in a sea-ice covered Baffin Bay. The deeper Uummannaq ice stream retreated first (ca. 17.1 cal ka BP), while the shallower Disko ice stream retreated at ca. 16.2 cal ka BP. The grounding lines were protected from accelerating mass loss (calving) by a buttressing ice shelf and by landward shallowing bathymetry on the outer shelf. Calving retreat was delayed until ca. 15.3 cal ka BP in the Uummannaq Trough and until 15.1 cal ka BP in the Disko Trough, during another interval of <span class="hlt">ocean</span> warming. Instabilities in the Laurentide, Innuitian and Greenland ice sheets with outlets draining into northern Baffin Bay periodically released cold, fresh water that enhanced sea ice formation and slowed GIS melt. During the Younger Dryas, the CWG records document strong cooling, lack of GIS meltwater, and an increase in iceberg rafted material from northern Baffin Bay. The ice sheet remained in the cross-shelf troughs until the <span class="hlt">early</span> Holocene, when it retreated rapidly by calving and strong</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_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" 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_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</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="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1211136L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1211136L"><span>Tsunami <span class="hlt">Early</span> Warning for the Indian <span class="hlt">Ocean</span> Region - Status and Outlook</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauterjung, Joern; Rudloff, Alexander; Muench, Ute; Gitews Project Team</p> <p>2010-05-01</p> <p>The German-Indonesian Tsunami <span class="hlt">Early</span> Warning System (GITEWS) for the Indian <span class="hlt">Ocean</span> region has gone into operation in Indonesia in November 2008. The system includes a seismological network, together with GPS stations and a network of GPS buoys additionally equipped with <span class="hlt">ocean</span> bottom pressure sensors and a tide gauge network. The different sensor systems have, for the most part, been installed and now deliver respective data either online or interactively upon request to the Warning Centre in Jakarta. Before 2011, however, the different components requires further optimization and fine tuning, local personnel needs to be trained and eventual problems in the daily operation have to be dealt with. Furthermore a company will be founded in the near future, which will guarantee a sustainable maintenance and operation of the system. This concludes the transfer from a temporarily project into a permanent service. This system established in Indonesia differs from other Tsunami Warning Systems through its application of modern scientific methods and technologies. New procedures for the fast and reliable determination of strong earthquakes, deformation monitoring by GPS, the modeling of tsunamis and the assessment of the situation have been implemented in the Warning System architecture. In particular, the direct incorporation of different sensors provides broad information already at the <span class="hlt">early</span> stages of <span class="hlt">Early</span> Warning thus resulting in a stable system and minimizing breakdowns and false alarms. The warning system is designed in an open and modular structure based on the most recent developments and standards of information technology. Therefore, the system can easily integrate additional sensor components to be used for other multi-hazard purposes e.g. meteorological and hydrological events. Up to now the German project group is cooperating in the Indian <span class="hlt">Ocean</span> region with Sri Lanka, the Maldives, Iran, Yemen, Tanzania and Kenya to set up the equipment primarily for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70156795','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70156795"><span>An <span class="hlt">early</span> to mid-Pleistocene deep Arctic <span class="hlt">Ocean</span> ostracode fauna with North Atlantic affinities</span></a></p> <p><a target="_blank" href=""></a></p> <p>DeNinno, Lauren H.; Cronin, Thomas M.; Rodriquez-Lazaro, J.; Brenner, Alec R.</p> <p>2015-01-01</p> <p>An <span class="hlt">early</span> to middle Pleistocene ostracode fauna was discovered in sediment core P1-93-AR-23 (P23, 76.95°N, 155.07°W) from 951 meter water depth from the Northwind Ridge, western Arctic <span class="hlt">Ocean</span>. Piston core P23 yielded more than 30,000 specimens and a total of about 30 species. Several <span class="hlt">early</span> to mid-Pleistocene species in the genera Krithe,Echinocythereis, Pterygocythereis, and Arcacythere are now extinct in the Arctic and show taxonomic affinities to North Atlantic <span class="hlt">Ocean</span> species. Our results suggest that there was a major ostracode faunal turnover during the global climate transitions known as the Mid-Pleistocene Transition (MPT, ~ 1.2 to 0.7 Ma) and the Mid-Brunhes Event (MBE, ~ 400 ka) reflecting the development of perennial sea ice during interglacial periods and large ice shelves during glacial periods over the last 400,000 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24100467','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24100467"><span>Developmental and physiological challenges of octopus (Octopus vulgaris) <span class="hlt">early</span> life stages under <span class="hlt">ocean</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>Repolho, Tiago; Baptista, Miguel; Pimentel, Marta S; Dionísio, Gisela; Trübenbach, Katja; Lopes, Vanessa M; Lopes, Ana Rita; Calado, Ricardo; Diniz, Mário; Rosa, Rui</p> <p>2014-01-01</p> <p>The ability to understand and predict the effects of <span class="hlt">ocean</span> warming (under realistic scenarios) on marine biota is of paramount importance, especially at the most vulnerable <span class="hlt">early</span> life stages. Here we investigated the impact of predicted environmental warming (+3 °C) on the development, metabolism, heat shock response and antioxidant defense mechanisms of the <span class="hlt">early</span> stages of the common octopus, Octopus vulgaris. As expected, warming shortened embryonic developmental time by 13 days, from 38 days at 18 °C to 25 days at 21 °C. Concomitantly, survival decreased significantly (~29.9 %). Size at hatching varied inversely with temperature, and the percentage of smaller premature paralarvae increased drastically, from 0 % at 18 °C to 17.8 % at 21 °C. The metabolic costs of the transition from an encapsulated embryo to a free planktonic form increased significantly with warming, and HSP70 concentrations and glutathione S-transferase activity levels were significantly magnified from late embryonic to paralarval stages. Yet, despite the presence of effective antioxidant defense mechanisms, <span class="hlt">ocean</span> warming led to an augmentation of malondialdehyde levels (an indicative of enhanced ROS action), a process considered to be one of the most frequent cellular injury mechanisms. Thus, the present study provides clues about how the magnitude and rate of <span class="hlt">ocean</span> warming will challenge the buffering capacities of octopus embryos and hatchlings' physiology. The prediction and understanding of the biochemical and physiological responses to warmer temperatures (under realistic scenarios) is crucial for the management of highly commercial and ecologically important species, such as O. vulgaris.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017TCry...11..707W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017TCry...11..707W"><span>Impact of icebergs on net primary <span class="hlt">productivity</span> in 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>Wu, Shuang-Ye; Hou, Shugui</p> <p>2017-03-01</p> <p><span class="hlt">Productivity</span> in the Southern <span class="hlt">Ocean</span> (SO) is iron-limited, and supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine environment. However, recent studies show that icebergs could provide a comparable amount of bioavailable iron to the SO as aeolian dust. In addition, small-scale areal studies suggest increased concentrations of chlorophyll, krill, and seabirds surrounding icebergs. Based on previous research, this study aims to examine whether iceberg occurrence has a significant impact on marine <span class="hlt">productivity</span> at the scale of the SO, using remote sensing data of iceberg occurrences and <span class="hlt">ocean</span> net primary <span class="hlt">productivity</span> (NPP) covering the period 2002-2014. The impacts of both large and small icebergs are examined in four major ecological zones of the SO: the continental shelf zone (CSZ), the seasonal ice zone (SIZ), the permanent open <span class="hlt">ocean</span> zone (POOZ), and the polar front zone (PFZ). We found that the presence of icebergs is associated with elevated levels of NPP, but the differences vary in different zones. Grid cells with small icebergs on average have higher NPP than other cells in most iron-deficient zones: 21 % higher for the SIZ, 16 % for the POOZ, and 12 % for the PFZ. The difference is relatively small in the CSZ where iron is supplied from meltwater and sediment input from the continent. In addition, NPP of grid cells adjacent to large icebergs on average is 10 % higher than that of control cells in the vicinity. The difference is larger at higher latitudes, where most large icebergs are concentrated. From 1992 to 2014, there is a significant increasing trend for both small and large icebergs. The increase was most rapid in the <span class="hlt">early</span> 2000s and has leveled off since then. As the climate continues to warm, the Antarctic Ice Sheet is expected to experience increased mass loss as a whole, which could lead to more icebergs in the region. Based on our study, this could result in a higher level of NPP in the SO as a whole</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017185','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017185"><span>Corrections to the MODIS Aqua Calibration Derived From MODIS Aqua <span class="hlt">Ocean</span> Color <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meister, Gerhard; Franz, Bryan Alden</p> <p>2013-01-01</p> <p><span class="hlt">Ocean</span> color <span class="hlt">products</span> such as, e.g., chlorophyll-a concentration, can be derived from the top-of-atmosphere radiances measured by imaging sensors on earth-orbiting satellites. There are currently three National Aeronautics and Space Administration sensors in orbit capable of providing <span class="hlt">ocean</span> color <span class="hlt">products</span>. One of these sensors is the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, whose <span class="hlt">ocean</span> color <span class="hlt">products</span> are currently the most widely used of the three. A recent improvement to the MODIS calibration methodology has used land targets to improve the calibration accuracy. This study evaluates the new calibration methodology and describes further calibration improvements that are built upon the new methodology by including <span class="hlt">ocean</span> measurements in the form of global temporally averaged water-leaving reflectance measurements. The calibration improvements presented here mainly modify the calibration at the scan edges, taking advantage of the good performance of the land target trending in the center of the scan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5633608','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5633608"><span>Estimating Primary <span class="hlt">Production</span> of Picophytoplankton Using the Carbon-Based <span class="hlt">Ocean</span> <span class="hlt">Productivity</span> Model: A Preliminary Study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liang, Yantao; Zhang, Yongyu; Wang, Nannan; Luo, Tingwei; Zhang, Yao; Rivkin, Richard B.</p> <p>2017-01-01</p> <p>Picophytoplankton are acknowledged to contribute significantly to primary <span class="hlt">production</span> (PP) in the <span class="hlt">ocean</span> while now the method to measure PP of picophytoplankton (PPPico) at large scales is not yet well established. Although the traditional 14C method and new technologies based on the use of stable isotopes (e.g., 13C) can be employed to accurately measure in situ PPPico, the time-consuming and labor-intensive shortage of these methods constrain their application in a survey on large spatiotemporal scales. To overcome this shortage, a modified carbon-based <span class="hlt">ocean</span> <span class="hlt">productivity</span> model (CbPM) is proposed for estimating the PPPico whose principle is based on the group-specific abundance, cellular carbon conversion factor (CCF), and temperature-derived growth rate of picophytoplankton. Comparative analysis showed that the estimated PPPico using CbPM method is significantly and positively related (r2 = 0.53, P < 0.001, n = 171) to the measured 14C uptake. This significant relationship suggests that CbPM has the potential to estimate the PPPico over large spatial and temporal scales. Currently this model application may be limited by the use of invariant cellular CCF and the relatively small data sets to validate the model which may introduce some uncertainties and biases. Model performance will be improved by the use of variable conversion factors and the larger data sets representing diverse growth conditions. Finally, we apply the CbPM-based model on the collected data during four cruises in the Bohai Sea in 2005. Model-estimated PPPico ranged from 0.1 to 11.9, 29.9 to 432.8, 5.5 to 214.9, and 2.4 to 65.8 mg C m-2 d-1 during March, June, September, and December, respectively. This study shed light on the estimation of global PPPico using carbon-based <span class="hlt">production</span> model. PMID:29051755</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMPP33B1554R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMPP33B1554R"><span>An atmosphere-<span class="hlt">ocean</span> GCM modelling study of the climate response to changing Arctic seaways in the <span class="hlt">early</span> Cenozoic.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, C. D.; Legrande, A. N.; Tripati, A. K.</p> <p>2008-12-01</p> <p>The report of fossil Azolla (a freshwater aquatic fern) in sediments from the Lomonosov Ridge suggests low salinity conditions occurred in the Arctic <span class="hlt">Ocean</span> in the <span class="hlt">early</span> Eocene. Restricted passages between the Arctic <span class="hlt">Ocean</span> and the surrounding <span class="hlt">oceans</span> are hypothesized to have caused this Arctic freshening. We investigate this scenario using a water-isotope enabled atmosphere-<span class="hlt">ocean</span> general circulation model with Eocene boundary conditions including 4xCO2, 7xCH4, altered bathymetry and topography, and an estimated distribution of Eocene vegetational types. In one experiment, <span class="hlt">oceanic</span> exchange between the Arctic <span class="hlt">Ocean</span> and other <span class="hlt">ocean</span> basins was restricted to two shallow (~250 m) seaways, one in the North Atlantic, the Greenland-Norwegian seaway, and the second connecting the Arctic <span class="hlt">Ocean</span> with the Tethys <span class="hlt">Ocean</span>, the Turgai Straits. In the restricted configuration, the Greenland-Norwegian seaway was closed and exchange through the Turgai Straits was limited to a depth of ~60 m. The simulations suggest that the severe restriction of Arctic seaways in the <span class="hlt">early</span> Eocene may have been sufficient to freshen Arctic <span class="hlt">Ocean</span> surface waters, conducive to Azolla blooms. When exchange with the Arctic <span class="hlt">Ocean</span> is limited, salinities in the upper several hundred meters of the water column decrease by ~10 psu. In some regions, surface salinity is within 2-3 psu of the reported maximum modern conditions tolerated by Azolla (~5 psu). In the restricted scenario, salt is stored preferentially in the North Atlantic and Tethys <span class="hlt">oceans</span>, resulting in enhanced meridional overturning, increased poleward heat transport in the North Atlantic western boundary current, and warming of surface and intermediate waters in the North Atlantic by several degrees. Increased sensible and latent heat fluxes from the North Atlantic <span class="hlt">Ocean</span>, combined with a reduction in cloud albedo, also lead to an increase in surface air temperature of over much of North America, Greenland and Eurasia. Our work is consistent with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070035051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070035051"><span>The Influence of Sea Ice on Primary <span class="hlt">Production</span> in the Southern <span class="hlt">Ocean</span>: A Satellite Perspective</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Walker O., Jr.; Comiso, Josefino C.</p> <p>2007-01-01</p> <p>Sea ice in the Southern <span class="hlt">Ocean</span> is a major controlling factor on phytoplankton <span class="hlt">productivity</span> and growth, but the relationship is modified by regional differences in atmospheric and oceanographic conditions. We used the phytoplankton biomass (binned at 7-day intervals), PAR and cloud cover data from SeaWiFS, ice concentrations data from SSM/I and AMSR-E, and sea-surface temperature data from AVHRR, in combination with a vertically integrated model to estimate primary <span class="hlt">productivity</span> throughout the Southern <span class="hlt">Ocean</span> (south of 60"s). We also selected six areas within the Southern <span class="hlt">Ocean</span> and analyzed the variability of the primary <span class="hlt">productivity</span> and trends through time, as well as the relationship of sea ice to <span class="hlt">productivity</span>. We found substantial interannual variability in <span class="hlt">productivity</span> from 1997 - 2005 in all regions of the Southern <span class="hlt">Ocean</span>, and this variability appeared to be driven in large part by ice dynamics. The most <span class="hlt">productive</span> regions of Antarctic waters were the continental shelves, which showed the earliest growth, the maximum biomass, and the greatest areal specific <span class="hlt">productivity</span>. In contrast, no large, sustained blooms occurred in waters of greater depth (> 1,000 m). We suggest that this is due to the slightly greater mixed layer depths found in waters off the continental shelf, and that the interactive effects of iron and irradiance (that is, increased iron requirements in low irradiance environments) result in the limitation of phytoplankton biomass over large regions of the Southern <span class="hlt">Ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PrOce.158..109T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PrOce.158..109T"><span>Micro-phytoplankton photosynthesis, primary <span class="hlt">production</span> and potential export <span class="hlt">production</span> in the Atlantic <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>Tilstone, Gavin H.; Lange, Priscila K.; Misra, Ankita; Brewin, Robert J. W.; Cain, Terry</p> <p>2017-11-01</p> <p>Micro-phytoplankton is the >20 μm component of the phytoplankton community and plays a major role in the global <span class="hlt">ocean</span> carbon pump, through the sequestering of anthropogenic CO2 and export of organic carbon to the deep <span class="hlt">ocean</span>. To evaluate the global impact of the marine carbon cycle, quantification of micro-phytoplankton primary <span class="hlt">production</span> is paramount. In this paper we use both in situ data and a satellite model to estimate the contribution of micro-phytoplankton to total primary <span class="hlt">production</span> (PP) in the Atlantic <span class="hlt">Ocean</span>. From 1995 to 2013, 940 measurements of primary <span class="hlt">production</span> were made at 258 sites on 23 Atlantic Meridional Transect Cruises from the United Kingdom to the South African or Patagonian Shelf. Micro-phytoplankton primary <span class="hlt">production</span> was highest in the South Subtropical Convergence (SSTC ∼ 409 ± 720 mg C m-2 d-1), where it contributed between 38 % of the total PP, and was lowest in the North Atlantic Gyre province (NATL ∼ 37 ± 27 mg C m-2 d-1), where it represented 18 % of the total PP. Size-fractionated photosynthesis-irradiance (PE) parameters measured on AMT22 and 23 showed that micro-phytoplankton had the highest maximum photosynthetic rate (PmB) (∼5 mg C (mg Chl a)-1 h-1) followed by nano- (∼4 mg C (mg Chl a)-1 h-1) and pico- (∼2 mg C (mg Chl a)-1 h-1). The highest PmB was recorded in the NATL and lowest in the North Atlantic Drift Region (NADR) and South Atlantic Gyre (SATL). The PE parameters were used to parameterise a remote sensing model of size-fractionated PP, which explained 84 % of the micro-phytoplankton in situ PP variability with a regression slope close to 1. The model was applied to the SeaWiFS time series from 1998-2010, which illustrated that micro-phytoplankton PP remained constant in the NADR, NATL, Canary Current Coastal upwelling (CNRY), Eastern Tropical Atlantic (ETRA), Western Tropical Atlantic (WTRA) and SATL, but showed a gradual increase in the Benguela Upwelling zone (BENG) and South Subtropical Convergence (SSTC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100017476','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100017476"><span>Analysis of Atmosphere-<span class="hlt">Ocean</span> Surface Flux Feedbacks in Recent Satellite and Model Reanalysis <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roberts, J. Brent; Robertson, F. R.; Clayson, C. A.</p> <p>2010-01-01</p> <p>Recent investigations have examined observations in an attempt to determine when and how the <span class="hlt">ocean</span> forces the atmosphere, and vice versa. These studies focus primarily on relationships between sea surface temperature anomalies and the turbulent and radiative surface heat fluxes. It has been found that both positive and negative feedbacks, which enhance or reduce sea surface temperature anomaly amplitudes, can be generated through changes in the surface boundary layer. Consequent changes in sea surface temperature act to change boundary layer characteristics through changes in static stability or turbulent fluxes. Previous studies over the global <span class="hlt">oceans</span> have used coarse-resolution observational and model <span class="hlt">products</span> such as ICOADS and the NCEP Reanalysis. This study focuses on documenting the atmosphere <span class="hlt">ocean</span> feedbacks that exist in recently produced higher resolution <span class="hlt">products</span>, namely the SeaFlux v1.0 <span class="hlt">product</span> and the NASA Modern Era Retrospective-Analysis for Research and Applications (MERRA). It has been noted in recent studies that evidence of <span class="hlt">oceanic</span> forcing of the atmosphere exists on smaller scales than the usually more dominant atmospheric forcing of the <span class="hlt">ocean</span>, particularly in higher latitudes. It is expected that use of these higher resolution <span class="hlt">products</span> will allow for a more comprehensive description of these small-scale <span class="hlt">ocean</span>-atmosphere feedbacks. The SeaFlux intercomparisons have revealed large scatter between various surface flux climatologies. This study also investigates the uncertainty in surface flux feedbacks based on several of these recent satellite based climatologies</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015307','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015307"><span>Assessment of NPP VIIRS <span class="hlt">Ocean</span> Color Data <span class="hlt">Products</span>: Hope and Risk</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Turpie, Kevin R.; Meister, Gerhard; Eplee, Gene; Barnes, Robert A.; Franz, Bryan; Patt, Frederick S.; Robinson, Wayne d.; McClain, Charles R.</p> <p>2010-01-01</p> <p>For several years, the NASA/Goddard Space Flight Center (GSFC) NPP VIIRS <span class="hlt">Ocean</span> Science Team (VOST) provided substantial scientific input to the NPP project regarding the use of Visible Infrared Imaging Radiometer Suite (VIIRS) to create science quality <span class="hlt">ocean</span> color data <span class="hlt">products</span>. This work has culminated into an assessment of the NPP project and the VIIRS instrument's capability to produce science quality <span class="hlt">Ocean</span> Color data <span class="hlt">products</span>. The VOST concluded that many characteristics were similar to earlier instruments, including SeaWiFS or MODIS Aqua. Though instrument performance and calibration risks do exist, it was concluded that programmatic and algorithm issues dominate concerns. Keywords: NPP, VIIRS, <span class="hlt">Ocean</span> Color, satellite remote sensing, climate data record.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.8475A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.8475A"><span>Mo isotope record of shales points to deep <span class="hlt">ocean</span> oxygenation in the <span class="hlt">early</span> Paleoproterozoic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asael, Dan; Scott, Clint; Rouxel, Olivier; Poulton, Simon; Lyons, Timothy; Javaux, Emmanuelle; Bekker, Andrey</p> <p>2014-05-01</p> <p>Two steps in Earth's surface oxidation lie at either end of the Proterozoic Eon. The first step, known as the Great Oxidation Event (GOE), occurred at ca. 2.32 Ga (1), when atmospheric oxygen first exceeded 0.001% of present atmospheric levels (2). The second step, occurred at ca. 0.58 Ga, resulting in the pervasive oxygenation of the deep <span class="hlt">oceans</span>, a feature that persisted through most of the Phanerozoic (3). The conventional model envisions two progressive and unidirectional increases in free oxygen. However, recent studies have challenged this simplistic view of the GOE (4, 5). A dramatic increase and decline in Earth oxidation state between 2.3 and 2.0 Ga is now well supported (6-9) and raises the question of how well-oxygenated the Earth surface was in the immediate aftermath of the GOE. In order to constrain the response of the deep <span class="hlt">oceans</span> to the GOE, we present a study of Mo isotope composition and Mo concentration from three key <span class="hlt">early</span> Paleoproterozoic black shale units with ages ranging from 2.32 to 2.06 Ga. Our results suggest high and unstable surface oxygen levels at 2.32 Ga, leading to an abrupt increase in Mo supply to the still globally anoxic <span class="hlt">ocean</span>, and producing extreme seawater Mo isotopic enrichments in these black shales. We thus infer a period of significant Mo isotopic Rayleigh effects and non-steady state behaviour of the Mo <span class="hlt">oceanic</span> system at the beginning of the GOE. Between 2.2-2.1 Ga, we observe smaller Mo isotopic variations and estimate the δ98Mo of seawater to be 1.42 ± 0.27 ‰W conclude that oxygen levels must have stabilized at a relatively high level and that the deep <span class="hlt">oceans</span> were oxygenated for the first time in Earth's history. By ca. 2.06 Ga, immediately after the Lomagundi Event, the Mo isotopic composition decreased dramatically to δ98MoSW = 0.80 ± 0.21 o reflecting the end of deep <span class="hlt">ocean</span> oxygenation and the return of largely anoxic deep <span class="hlt">oceans</span>. References: [1] A. Bekker et al., 2004, Nature 427, 117-20. [2] A. Pavlov and J</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA582705','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA582705"><span>Inter-Sensor Comparison of Satellite <span class="hlt">Ocean</span> Color <span class="hlt">Products</span> from GOCI and MODIS</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-02-26</p> <p>current map for this region. However the NOCOM modeled and GOCI measured data need to be validate using in-situ measurements. ...collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION...<span class="hlt">Ocean</span> Model (NCOM). 15. SUBJECT TERMS satellite <span class="hlt">ocean</span> color <span class="hlt">products</span>, GOCI, MODIS, phytoplankton 16. SECURITY CLASSIFICATION OF: a. REPORT</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.4966C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.4966C"><span>Experimental constrain of hydrogen <span class="hlt">production</span> during <span class="hlt">early</span> serpentinization stages</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clément, M.; Munoz, M.; Vidal, O.; Parra, T.</p> <p>2009-04-01</p> <p>Hydrothermal alteration of mantellic peridotites and ultramafic rocks along axial valleys of low spread <span class="hlt">oceanic</span> ridges plays a key role in different fundamental domains like, 1) energetic gaz <span class="hlt">production</span> (H2 and hydrocarbons) representing a potential source of energy for future generations, 2) formation of organic pre-biotic molecules in potential relation with the origin of life. Moreover, such complex volcanic-related alteration processes play fundamental role in economic geology, being widely associated to important polymetallic sulphides ore deposits. Recent researches proposed an initial hydrogen <span class="hlt">production</span> due to the integration of ferric iron in Fe,Mg-serpentine. To better understand the <span class="hlt">early</span> stages of hydrogen <span class="hlt">production</span>, a series of natural peridotite rocks have been experimentally exposed to hydrothermal conditions, up to 300°C, 300 bars during different time scales. Experiments have been performed in using autoclaves with a sampling gas system. A systematic mineralogical characterization of the new <span class="hlt">products</span> was carried out using classical spectroscopic tools. In particular, we focused on the iron behaviour using a redox and structural micro-XANES investigation. Redox information has been accurately derived from the pre-peak features previously calibrated from model compounds, while structural information about short and medium range order around iron has been extracted from the XANES region of the spectra, based both on experimental standards and ab-initio theoretical calculations. Two processes of oxidation emerged. Before two month experiment duration, serpentine displays a not negligible oxidation of ferrous iron in his structure (up to 60%), while after two months, iron oxides and hydroxides appear in the system. These results seem to correspond to natural observations. The iron coordination decreases linearly with time. It means that iron also integrates the serpentine tetrahedral sites. Moreover, high resolution µ-XAS maps on experimental samples</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T51F2985D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T51F2985D"><span>Leveraging Somali Basin Magnetic Anomalies to Constrain Gondwana Breakup and <span class="hlt">Early</span> Indian <span class="hlt">Ocean</span> Formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, J. K.; Lawver, L. A.; Norton, I. O.; Gahagan, L.</p> <p>2015-12-01</p> <p>The Somali Basin, found between the Horn of Africa and Madagascar was formed during the rifting of East and West Gondwana. Understanding the evolution of the basin has historically been hindered by enigmatic seafloor fabric and an apparent paucity of magnetic anomaly data. Recent iterations of satellite gravity data have revealed nearly complete fracture zones as well as a distinct extinct spreading ridge within the basin. Through a thorough compilation of available Somali Basin shiptrack profiles, we have been able to successfully model and interpret magnetic anomalies with exceptional detail. This complication is unrivaled in completeness and provides unprecedented insight into basin formation. Using this high quality data, we have interpreted magnetic anomalies M0r (120.8 Ma) to M24Bn (152.43 Ma) about the extinct ridge. The interpreted Somali Basin spreading rate and spreading direction, through anomaly M15n (135.76 Ma), are similar to those observed in the neighboring coeval Mozambique Basin. This similarity suggests that East Gondwana separated from West Gondwana as a cohesive unit, and that the internal rifting of East Gondwana began later around 135 Ma. Our magnetic anomaly interpretations have been combined with additional magnetic interpretations from around the Indian <span class="hlt">Ocean</span> to build a regionally consistent plate model of Gondwana breakup and <span class="hlt">early</span> Indian <span class="hlt">Ocean</span> formation. This plate model will be crucial for future efforts unraveling a precise history of East Gondwana fragmentation and constraining the formation of the Enderby Basin offshore East Antarctica and Bay of Bengal offshore East India.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23863855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23863855"><span>An <span class="hlt">early</span> underwater artificial vision model in <span class="hlt">ocean</span> investigations via independent component analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nian, Rui; Liu, Fang; He, Bo</p> <p>2013-07-16</p> <p>Underwater vision is one of the dominant senses and has shown great prospects in <span class="hlt">ocean</span> investigations. In this paper, a hierarchical Independent Component Analysis (ICA) framework has been established to explore and understand the functional roles of the higher order statistical structures towards the visual stimulus in the underwater artificial vision system. The model is inspired by characteristics such as the modality, the redundancy reduction, the sparseness and the independence in the <span class="hlt">early</span> human vision system, which seems to respectively capture the Gabor-like basis functions, the shape contours or the complicated textures in the multiple layer implementations. The simulation results have shown good performance in the effectiveness and the consistence of the approach proposed for the underwater images collected by autonomous underwater vehicles (AUVs).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3758639','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3758639"><span>An <span class="hlt">Early</span> Underwater Artificial Vision Model in <span class="hlt">Ocean</span> Investigations via Independent Component Analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nian, Rui; Liu, Fang; He, Bo</p> <p>2013-01-01</p> <p>Underwater vision is one of the dominant senses and has shown great prospects in <span class="hlt">ocean</span> investigations. In this paper, a hierarchical Independent Component Analysis (ICA) framework has been established to explore and understand the functional roles of the higher order statistical structures towards the visual stimulus in the underwater artificial vision system. The model is inspired by characteristics such as the modality, the redundancy reduction, the sparseness and the independence in the <span class="hlt">early</span> human vision system, which seems to respectively capture the Gabor-like basis functions, the shape contours or the complicated textures in the multiple layer implementations. The simulation results have shown good performance in the effectiveness and the consistence of the approach proposed for the underwater images collected by autonomous underwater vehicles (AUVs). PMID:23863855</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMIN33C1055A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMIN33C1055A"><span>NPOESS Preparatory Project Validation Program for <span class="hlt">Ocean</span> Data <span class="hlt">Products</span> from VIIRS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arnone, R.; Jackson, J. M.</p> <p>2009-12-01</p> <p>The National Polar-orbiting Operational Environmental Satellite Suite (NPOESS) Program, in partnership with National Aeronautical Space Administration (NASA), will launch the NPOESS Preparatory Project (NPP), a risk reduction and data continuity mission, prior to the first operational NPOESS launch. The NPOESS Program, in partnership with Northrop Grumman Aerospace Systems (NGAS), will execute the NPP Validation program to ensure the data <span class="hlt">products</span> comply with the requirements of the sponsoring agencies. Data from the NPP Visible/Infrared Imager/Radiometer Suite (VIIRS) will be used to produce Environmental Data Records (EDR's) of <span class="hlt">Ocean</span> Color/Chlorophyll and Sea Surface Temperature. The <span class="hlt">ocean</span> Cal/Val program is designed to address an “end to end” capability from sensor to end <span class="hlt">product</span> and is developed based on existing ongoing government satellite <span class="hlt">ocean</span> remote sensing capabilities that are currently in use with NASA research and Navy and NOAA operational <span class="hlt">products</span>. Therefore, the plan focuses on the extension of known reliable methods and capabilities currently used with the heritage sensors that will be extended to the NPP and NPOESS <span class="hlt">ocean</span> <span class="hlt">product</span> Cal/Val effort. This is not a fully “new” approach but it is designed to be the most reliable and cost effective approach to developing an automated Cal/Val system for VIIRS while retaining highly accurate procedures and protocols. This presentation will provide an overview of the approaches, data and schedule for the validation of the NPP VIIRS <span class="hlt">Ocean</span> environmental data <span class="hlt">products</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9999E..0JP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9999E..0JP"><span>Enhancing moderate-resolution <span class="hlt">ocean</span> color <span class="hlt">products</span> over coastal/inland waters (Conference Presentation)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pahlevan, Nima; Schott, John R.; Zibordi, Giuseppe</p> <p>2016-10-01</p> <p>With the successful launch of Landsat-8 in 2013 followed by a very recent launch of Sentinel-2A, we are entering a new area where frequent moderate resolution water quality <span class="hlt">products</span> over coastal/inland waters will be available to scientists and operational agencies. Although designed for land observations, the Operational Land Imager (OLI) has proven to provide high-fidelity <span class="hlt">products</span> in these aquatic systems where coarse-resolution <span class="hlt">ocean</span> color imagers fail to provide valid observations. High-quality, multi-scale <span class="hlt">ocean</span> color <span class="hlt">products</span> can give insights into the biogeochemical/physical processes from the upstream in watersheds, into near-shore regions, and further out in <span class="hlt">ocean</span> basins. In this research, we describe a robust cross-calibration approach, which facilitates seamless <span class="hlt">ocean</span> color <span class="hlt">products</span> at multi scales. The top-of-atmosphere (TOA) OLI imagery is cross-calibrated against near-simultaneous MODIS and VIIRS <span class="hlt">ocean</span> color observations in high-latitude regions. This allows for not only examining the overall relative performance of OLI but also for characterizing non-uniformity (i.e., banding) across its swath. The uncertainty of this approach is, on average, found to be less than 0.5% in the blue channels. The adjustments made for OLI TOA reflectance <span class="hlt">products</span> are then validated against in-situ measurements of remote sensing reflectance collected in research cruises or at the AERONET-OC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040129698','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040129698"><span>Two MODIS Aerosol <span class="hlt">Products</span> Over <span class="hlt">Ocean</span> on the Terra and Aqua CERES SSF Datasets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ignatov, Alexander; Minnis, Patrick; Loeb, Norman; Wielicki, Bruce; Miller, Walter; Sun-Mack, Sunny; Tanre, Didier; Remer, Lorraine; Laszlo, Istvan; Geier, Erika</p> <p>2004-01-01</p> <p>Over <span class="hlt">ocean</span>, two aerosol <span class="hlt">products</span> are reported on the Terra and Aqua CERES SSFs. Both are derived from MODIS, but using different sampling and aerosol algorithms. This study briefly summarizes these <span class="hlt">products</span>, and compares using 2 weeks of global Terra data from 15-21 December 2000, and 1-7 June 2001.</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_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" 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_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> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26984624','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26984624"><span>Silent <span class="hlt">oceans</span>: <span class="hlt">ocean</span> acidification impoverishes natural soundscapes by altering sound <span class="hlt">production</span> of the world's noisiest marine invertebrate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rossi, Tullio; Connell, Sean D; Nagelkerken, Ivan</p> <p>2016-03-16</p> <p>Soundscapes are multidimensional spaces that carry meaningful information for many species about the location and quality of nearby and distant resources. Because soundscapes are the sum of the acoustic signals produced by individual organisms and their interactions, they can be used as a proxy for the condition of whole ecosystems and their occupants. <span class="hlt">Ocean</span> acidification resulting from anthropogenic CO2 emissions is known to have profound effects on marine life. However, despite the increasingly recognized ecological importance of soundscapes, there is no empirical test of whether <span class="hlt">ocean</span> acidification can affect biological sound <span class="hlt">production</span>. Using field recordings obtained from three geographically separated natural CO2 vents, we show that forecasted end-of-century <span class="hlt">ocean</span> acidification conditions can profoundly reduce the biological sound level and frequency of snapping shrimp snaps. Snapping shrimp were among the noisiest marine organisms and the suppression of their sound <span class="hlt">production</span> at vents was responsible for the vast majority of the soundscape alteration observed. To assess mechanisms that could account for these observations, we tested whether long-term exposure (two to three months) to elevated CO2 induced a similar reduction in the snapping behaviour (loudness and frequency) of snapping shrimp. The results indicated that the soniferous behaviour of these animals was substantially reduced in both frequency (snaps per minute) and sound level of snaps produced. As coastal marine soundscapes are dominated by biological sounds produced by snapping shrimp, the observed suppression of this component of soundscapes could have important and possibly pervasive ecological consequences for organisms that use soundscapes as a source of information. This trend towards silence could be of particular importance for those species whose larval stages use sound for orientation towards settlement habitats. © 2016 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4810867','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4810867"><span>Silent <span class="hlt">oceans</span>: <span class="hlt">ocean</span> acidification impoverishes natural soundscapes by altering sound <span class="hlt">production</span> of the world's noisiest marine invertebrate</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rossi, Tullio; Connell, Sean D.; Nagelkerken, Ivan</p> <p>2016-01-01</p> <p>Soundscapes are multidimensional spaces that carry meaningful information for many species about the location and quality of nearby and distant resources. Because soundscapes are the sum of the acoustic signals produced by individual organisms and their interactions, they can be used as a proxy for the condition of whole ecosystems and their occupants. <span class="hlt">Ocean</span> acidification resulting from anthropogenic CO2 emissions is known to have profound effects on marine life. However, despite the increasingly recognized ecological importance of soundscapes, there is no empirical test of whether <span class="hlt">ocean</span> acidification can affect biological sound <span class="hlt">production</span>. Using field recordings obtained from three geographically separated natural CO2 vents, we show that forecasted end-of-century <span class="hlt">ocean</span> acidification conditions can profoundly reduce the biological sound level and frequency of snapping shrimp snaps. Snapping shrimp were among the noisiest marine organisms and the suppression of their sound <span class="hlt">production</span> at vents was responsible for the vast majority of the soundscape alteration observed. To assess mechanisms that could account for these observations, we tested whether long-term exposure (two to three months) to elevated CO2 induced a similar reduction in the snapping behaviour (loudness and frequency) of snapping shrimp. The results indicated that the soniferous behaviour of these animals was substantially reduced in both frequency (snaps per minute) and sound level of snaps produced. As coastal marine soundscapes are dominated by biological sounds produced by snapping shrimp, the observed suppression of this component of soundscapes could have important and possibly pervasive ecological consequences for organisms that use soundscapes as a source of information. This trend towards silence could be of particular importance for those species whose larval stages use sound for orientation towards settlement habitats. PMID:26984624</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.493...82D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.493...82D"><span><span class="hlt">Ocean</span> and atmosphere teleconnections modulate east tropical Pacific <span class="hlt">productivity</span> at late to middle Pleistocene terminations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diz, Paula; Hernández-Almeida, Iván; Bernárdez, Patricia; Pérez-Arlucea, Marta; Hall, Ian R.</p> <p>2018-07-01</p> <p>The modern Eastern Equatorial Pacific (EEP) is a key oceanographic region for regulating the Earth's climate system, accounting for between 5-10% of global marine <span class="hlt">production</span> whilst also representing a major source of carbon dioxide efflux to the atmosphere. Changes in <span class="hlt">ocean</span> dynamics linked to the nutrient supply from the Southern <span class="hlt">Ocean</span> have been suggested to have played a dominant role in regulating EEP <span class="hlt">productivity</span> over glacial-interglacial timescales of the past 500 ka. Yet, the full extent of the climate and <span class="hlt">oceanic</span> teleconnections and the mechanisms promoting the observed increase of <span class="hlt">productivity</span> occurring at glacial terminations remain poorly understood. Here we present multi-proxy, micropaleontological, geochemical and sedimentological records from the easternmost EEP to infer changes in atmospheric patterns and <span class="hlt">oceanic</span> processes potentially influencing regional primary <span class="hlt">productivity</span> over glacial-interglacial cycles of the mid-late Pleistocene (∼0-650 ka). These proxy data support a leading role for the north-south migration of the Intertropical Convergence Zone (ITCZ) in shaping past <span class="hlt">productivity</span> variability in the EEP. <span class="hlt">Productivity</span> increases during glacial periods and notably peaks at major and "extra" glacial terminations (those occurring 1-2 precession cycles after some major terminations) coincident with the inferred southernmost position of the ITCZ. The comparison of our reconstructions with proxy records of climate variability suggests the intensification of related extratropical atmospheric and <span class="hlt">oceanic</span> teleconnections during deglaciation events. These processes may have re-activated the supply of southern sourced nutrients to the EEP, potentially contributing to enhanced <span class="hlt">productivity</span> in the EEP and thus counterbalancing the <span class="hlt">oceanic</span> carbon dioxide outgassing at glacial terminations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.C31B0752L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.C31B0752L"><span>Changes in <span class="hlt">Ocean</span> Circulation with an Ice-Free Arctic: Reconstructing <span class="hlt">Early</span> Holocene Arctic <span class="hlt">Ocean</span> Circulation Using Geochemical Signals from Individual Neogloboquadrina pachyderma (sinistral) Shells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Livsey, C.; Spero, H. J.; Kozdon, R.</p> <p>2016-12-01</p> <p>The impacts of sea ice decrease and consequent hydrologic changes in the Arctic <span class="hlt">Ocean</span> will be experienced globally as <span class="hlt">ocean</span> and atmospheric temperatures continue to rise, though it is not evident to what extent. Understanding the structure of the Arctic water column during the <span class="hlt">early</span>/mid Holocene sea ice minimum ( 6-10 kya), a post-glacial analogue of a seasonally ice-free Arctic, will help us to predict what the changes we can expect as the Earth warms over the next century. Neogloboquadrina pachyderma (sinistral; Nps) is a species of planktonic foraminifera that dominates assemblages in the polar <span class="hlt">oceans</span>. This species grows its chambers (ontogenetic calcite) in the surface waters and subsequently descends through the water column to below the mixed layer where it quickly adds a thick crust of calcite (Kohfeld et al., 1996). Therefore, geochemical signals from both the surface waters and sub-mixed layer depths are captured within single Nps shells. We were able to target <5 μm - sized domains for δ18O using secondary ion mass spectrometry (SIMS), therefore capturing signals from both the ontogenetic and crust calcite in single Nps shells. This data was combined with laser ablation- inductively coupled mass spectrometry (LA-ICPMS) Mg/Ca profiles of trace metals through the two layers of calcite of the same shells, to determine the thermal structure of the water column. Combining δ18O, temperature, and salinity gradients from locations across the Arctic basin allow us to reconstruct the hydrography of the <span class="hlt">early</span> Holocene Arctic sea ice minimum. These results will be compared with modern Arctic water column characteristics in order to develop a conceptual model of Arctic <span class="hlt">Ocean</span> oceanographic change due to global warming. Kohfeld, K.E., Fairbanks, R.G., Smith, S.L., Walsh, I.D., 1996. Neogloboquadrina pachyderma(sinistral coiling) as paleoceanographic tracers in polar <span class="hlt">oceans</span>: Evidence from northeast water polynya plankton tows, sediment traps, and surface sediments</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GBioC..27..847B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GBioC..27..847B"><span>Combined constraints on global <span class="hlt">ocean</span> primary <span class="hlt">production</span> using 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.; Hashioka, Taketo; Quéré, Corinne Le</p> <p>2013-09-01</p> <p><span class="hlt">production</span> is at the base of the marine food web and plays a central role for global biogeochemical cycles. Yet global <span class="hlt">ocean</span> primary <span class="hlt">production</span> 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 <span class="hlt">ocean</span> biogeochemistry model that includes a mechanistic representation of photosynthesis and a new observational database of net primary <span class="hlt">production</span> (NPP) in the <span class="hlt">ocean</span>. We combine the model and observations to constrain particulate NPP in the <span class="hlt">ocean</span> 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 <span class="hlt">production</span>. 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 <span class="hlt">ocean</span> area in the South.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15..209D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15..209D"><span><span class="hlt">Ocean</span> acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO2 tolerance in phytoplankton <span class="hlt">productivity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deppeler, Stacy; Petrou, Katherina; Schulz, Kai G.; Westwood, Karen; Pearce, Imojen; McKinlay, John; Davidson, Andrew</p> <p>2018-01-01</p> <p>High-latitude <span class="hlt">oceans</span> are anticipated to be some of the first regions affected by <span class="hlt">ocean</span> acidification. Despite this, the effect of <span class="hlt">ocean</span> acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an <span class="hlt">early</span> spring, coastal marine microbial community in Prydz Bay to CO2 levels ranging from ambient (343 µatm) to 1641 µatm in six 650 L minicosms. <span class="hlt">Productivity</span> assays were performed to identify whether a CO2 threshold existed that led to a change in primary <span class="hlt">productivity</span>, bacterial <span class="hlt">productivity</span>, and the accumulation of chlorophyll a (Chl a) and particulate organic matter (POM) in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to <span class="hlt">ocean</span> acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO2 levels ≥ 1140 µatm negatively affected photosynthetic performance and Chl a-normalised primary <span class="hlt">productivity</span> (csGPP14C), causing significant reductions in gross primary <span class="hlt">production</span> (GPP14C), Chl a accumulation, nutrient uptake, and POM <span class="hlt">production</span>. However, there was no effect of CO2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs) and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO2 treatments ≥ 953 µatm (days 3-5), yet gross bacterial <span class="hlt">production</span> (GBP14C) remained unchanged and cell-specific bacterial <span class="hlt">productivity</span> (csBP14C) was reduced. Towards the end of the experiment, GBP14C and csBP14C markedly increased across all treatments regardless of CO2 availability. This coincided with increased organic matter availability (POC and PON) combined with improved efficiency of carbon uptake. Changes in phytoplankton community <span class="hlt">production</span> could have negative effects on the Antarctic food web and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.P23A2111M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.P23A2111M"><span>CO2-dominated Atmosphere in Equilibrium with NH3-H2O <span class="hlt">Ocean</span>: Application to <span class="hlt">Early</span> Titan and <span class="hlt">Ocean</span> Planets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marounina, N.; Grasset, O.; Tobie, G.; Carpy, S.</p> <p>2015-12-01</p> <p>During the accretion of Titan, impact heating may have been sufficient to allow the global melting of water ice (Monteux et al. 2014) and the release of volatile compounds, with CO2 and NH3 as main constituents (Tobie et al. 2012). Thus, on primitive Titan, it is thought that a massive atmosphere was in contact with a global water <span class="hlt">ocean</span>. Similar configurations may occur on temperate water-rich planets called <span class="hlt">ocean</span> planets (Léger et al. 2004, Kitzmann et al. 2015).Due to its rather low solubility in liquid water, carbon dioxide is expected to be one of the major components in the atmosphere. The atmospheric amount of CO2 is a key parameter for assessing the thermal evolution of the planetary surface because of its strong greenhouse effect. However, ammonia significantly affects the solubility of CO2 in water and hence the atmosphere-<span class="hlt">ocean</span> thermo-chemical equilibrium. For primitive Titan, estimating the mass, temperature and composition of the primitive atmosphere is important to determine mechanisms that led to the present-day N2-CH4 dominated atmosphere. Similarly, for <span class="hlt">ocean</span> planets, the influence of ammonia on the atmospheric abundance in CO2 has consequences for the definition of the habitable zone.To investigate the atmospheric composition of the water-rich worlds for a wide range of initial compositions, we have developed a vapor-liquid equilibrium model of the NH3-CO2-H2O system, where we account for the non-ideal comportment of both vapor and liquid phases and the ion speciation of volatiles dissolved in the aqueous phase. We show that adding NH3 to the CO2-H2O binary system induces an efficient absorption of the CO2 in the liquid phase and thus a lower CO2 partial pressure in the vapor phase. Indeed, the CO2 partial pressure remains low for the CO2/NH3 ratio of liquid concentrations lower than 0.5.Assuming various initial compositions of Titan's global water <span class="hlt">ocean</span>, we explore the thermal and compositional evolution of a massive primitive atmosphere using</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160003495','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160003495"><span>Are Ferroan Anorthosites Direct <span class="hlt">Products</span> of the Lunar Magma <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>Neal, C. R.; Draper, D. S.</p> <p>2016-01-01</p> <p>According to Lunar Magma <span class="hlt">Ocean</span> (LMO) theory, lunar samples that fall into the ferroan anorthosite (FAN) category represent the only samples we have of of the primordial crust of the Moon. Modeling indicates that plagioclase crystallizes after >70% LMO crystallization and formed a flotation crust, depending upon starting composition. The FAN group of highlands materials has been subdivided into mafic-magnesian, mafic-ferroan, anorthositic- sodic, and anorthositic-ferroan, although it is not clear how these subgroups are related. Recent radiogenic isotope work has suggested the range in FAN ages and isotopic systematics are inconsistent with formation of all FANs from the LMO. While an insulating lid could have theoretically extend the life of the LMO to explain the range of the published ages, are the FAN compositions consistent with crystallization from the LMO? As part of a funded Emerging Worlds proposal (NNX15AH76G), we examine this question through analysis of FAN samples. We compare the results with various LMO crystallization models, including those that incorporate the influence of garnet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4896356','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4896356"><span>Small pelagics in a changing <span class="hlt">ocean</span>: biological responses of sardine <span class="hlt">early</span> stages to warming</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Faleiro, Filipa; Pimentel, Marta; Pegado, Maria Rita; Bispo, Regina; Lopes, Ana Rita; Diniz, Mário S.; Rosa, Rui</p> <p>2016-01-01</p> <p>Small pelagic fishes are known to respond rapidly to changes in <span class="hlt">ocean</span> climate. In this study, we evaluate the effects of future environmental warming (+2°C) during the <span class="hlt">early</span> ontogeny of the European sardine, Sardina pilchardus. Warming reduced the survival of 30-day-old larvae by half. Length at hatching increased with temperature as expected, but no significant effect was observed on the length and growth at 30 days post-hatching. Warming did not significantly affect the thermal tolerance of sardine larvae, even though the mean lethal temperature increased by 1°C. In the warm conditions, sardine larvae showed signs of thermal stress, indicated by a pronounced increase in larval metabolism (Q10 = 7.9) and a 45% increase in the heat shock response. Lipid peroxidation was not significantly affected by the higher temperature, even though the mean value doubled. Warming did not affect the time larvae spent swimming, but decreased by 36% the frequency of prey attacks. Given the key role of these small pelagics in the trophic dynamics off the Western Iberian upwelling ecosystem, the negative effects of warming on the <span class="hlt">early</span> stages may have important implications for fish recruitment and ecosystem structure. PMID:27293764</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMED21D..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMED21D..07C"><span><span class="hlt">Early</span> Entry for Youth into the <span class="hlt">Ocean</span> Science Pipeline Through <span class="hlt">Ocean</span> Science School Camp and Summer Camp Programs: A Key Strategy for Enhancing Diversity in the <span class="hlt">Ocean</span> Sciences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crane, N. L.; Wasser, A.; Weiss, T.; Sullivan, M.; Jones, A.</p> <p>2004-12-01</p> <p>Educators, policymakers, employers and other stakeholders in <span class="hlt">ocean</span> and other geo-science fields face the continuing challenge of a lack of diversity in these fields. A particular challenge for educators and geo-science professionals promoting <span class="hlt">ocean</span> sciences is to create programs that have broad access, including access for underrepresented youth. Experiential learning in environments such as intensive multi-day science and summer camps can be a critical captivator and motivator for young people. Our data suggest that youth, especially underrepresented youth, may benefit from exposure to the <span class="hlt">oceans</span> and <span class="hlt">ocean</span> science through intensive, sustained (eg more than just an afternoon), hands-on, science-based experiences. Data from the more than 570 youth who have participated in Camp SEA Lab's academically based experiential <span class="hlt">ocean</span> science camp and summer programs provide compelling evidence for the importance of such programs in motivating young people. We have paid special attention to factors that might play a role in recruiting and retaining these young people in <span class="hlt">ocean</span> science fields. Over 50% of program attendees were underrepresented youth and on scholarship, which gives us a closer look at the impact of such programs on youth who would otherwise not have the opportunity to participate. Both cognitive (knowledge) and affective (personal growth and motivation) indicators were assessed through surveys and questionnaires. Major themes drawn from the data for knowledge growth and personal growth in Camp SEA Lab youth attendees will be presented. These will be placed into the larger context of critical factors that enhance recruitment and retention in the geo-science pipeline. Successful strategies and challenges for involving families and broadening access to specialized programs such as Camp SEA Lab will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....13847W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....13847W"><span>An investigation of siderophore <span class="hlt">production</span> by <span class="hlt">oceanic</span> Synechococcus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wisniewski, R. J.; Webb, E. A.; Moffett, J. W.</p> <p>2003-04-01</p> <p>Cyanobacteria are significant contributors to global primary <span class="hlt">production</span>. They can be found in warm high-nutrient, low-chlorophyll regions where low concentrations of iron are thought to limit primary <span class="hlt">productivity</span>. Determining how these organisms obtain iron is critical to understanding the biogeochemical cycle of iron and its role as a determinant of marine primary <span class="hlt">production</span>. Siderophore <span class="hlt">production</span> has been observed in halotolerant freshwater cyanobacteria (see C.G. Trick and co-authors) and marine heterotrophic bacteria (see A. Butler, M.G. Haygood and co-authors), but to date, siderophore <span class="hlt">production</span> in truly marine cyanobacteria has not been demonstrated. We examined the response of two marine Synechococcus species (WH7803 and WH8102) to iron stress. Axenic cultures of both Synechococcus species were grown under iron-stressed and iron-replete conditions. The supernatants of these cultures were examined using competitive ligand exchange-cathodic stripping voltammetry (CLE-CSV), a sensitive method of quantitative ligand detection. Observing ligand accumulation in culture is an analytical challenge due to the low cell densities and reduced growth rates of iron stressed marine cyanobacteria. Preliminary results suggest the presence of an iron-binding ligand in the iron-stressed cultures which was not present under iron-replete conditions. The amount of ligand produced by Synechococcus was approximately 1 × 10-18 mol/cell, comparable with the amount produced by marine heterotrophic bacteria (K. Barbeau, pers. comm.).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T43H..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T43H..08C"><span>Glacial cycles drive variations in the <span class="hlt">production</span> of <span class="hlt">oceanic</span> crust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crowley, J. W.; Katz, R. F.; Langmuir, C. H.; Huybers, P. J.</p> <p>2013-12-01</p> <p>Changes in sea level accompanying glacial cycles affect the static pressure within the asthenosphere; these variations could modulate melting rates beneath the mid-<span class="hlt">ocean</span> ridge system as well as crustal thickness. These effects can be investigated and quantified using models of ridges based on conservation of mass, momentum, energy, and composition for two phases (magma & mantle) and two thermodynamic components (enriched & depleted). The models predict that the sensitivity of crustal thickness to oscillations in sea-level depends on the period of oscillation, the spreading rate of the ridge, and the assumed permeability scale of the melting regime. In contrast to previous studies (Huybers & Langmuir, 2009 and Lund & Asimow, 2011), the new results indicate that effects are larger for ridges with faster spreading rates. They also show that the dominant period of variations in crustal thickness changes with spreading rate and permeability. Sea-level variations with periods in the range of 10 ky - 100 ky can result in significant changes in crustal thickness that are orders of magnitude larger than the sea-level variations that drive them. Accurately modelling this process requires the inclusion of two previously unaccounted for processes: (1) determining the volume of the melting regime that is consistent with the ridge spreading rate and (2) properly treating the transport of melt. These enable us to capture the non-linear dependencies on spreading rate and other model parameters. Spectral analysis of bathymetry at two ridge segments that have a symmetric bathymetric signal and hence are undisturbed by off-axis volcanism or ridge jumps reveals the presence of variability at frequencies associated with precession, obliquity, and the 100 ky glacial/inter-glacial variability. Furthermore, the faster spreading ridge has larger amplitude responses to changes in sea level and shows a proportionately greater response at higher frequencies. These observations reinforce the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GBioC..31.1528T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GBioC..31.1528T"><span>Buffering of <span class="hlt">Ocean</span> Export <span class="hlt">Production</span> by Flexible Elemental Stoichiometry of Particulate Organic Matter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanioka, Tatsuro; Matsumoto, Katsumi</p> <p>2017-10-01</p> <p>One of the most important factors that determine the <span class="hlt">ocean</span>-atmosphere carbon partitioning is the sinking of particulate organic matter (POM) from the surface <span class="hlt">ocean</span> to the deep <span class="hlt">ocean</span>. The amount of carbon (C) removed from the surface <span class="hlt">ocean</span> by this POM export <span class="hlt">production</span> depends critically on the elemental ratio in POM of C to nitrogen (N) and phosphorus (P), two essential elements that limit <span class="hlt">productivity</span>. Recent observations indicate that P:N:C in marine POM varies both spatially and temporally due to chemical, physical, and ecological dynamics. In a new approach to predicting a flexible P:C ratio, we developed a power law model with a stoichiometry sensitivity factor, which is able to relate P:C of POM to ambient phosphate concentration. The new factor is robust, measurable, and biogeochemically meaningful. Using the new stoichiometry sensitivity factor, we present a first-order estimate that P:C plasticity could buffer against a generally expected future reduction in global carbon export <span class="hlt">production</span> by up to 5% under a future warming scenario compared to a fixed, Redfield P:C. Further, we demonstrate that our new stoichiometry model can be implemented successfully and easily in a global model to reproduce the large-scale P:N:C variability in the <span class="hlt">ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15.1895G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15.1895G"><span>Biological <span class="hlt">production</span> in the Indian <span class="hlt">Ocean</span> upwelling zones - Part 1: refined estimation via the use of a variable compensation depth in <span class="hlt">ocean</span> carbon models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geethalekshmi Sreeush, Mohanan; Valsala, Vinu; Pentakota, Sreenivas; Venkata Siva Rama Prasad, Koneru; Murtugudde, Raghu</p> <p>2018-04-01</p> <p>Biological modelling approach adopted by the <span class="hlt">Ocean</span> Carbon-Cycle Model Intercomparison Project (OCMIP-II) provided amazingly simple but surprisingly accurate rendition of the annual mean carbon cycle for the global <span class="hlt">ocean</span>. Nonetheless, OCMIP models are known to have seasonal biases which are typically attributed to their bulk parameterisation of compensation depth. Utilising the criteria of surface Chl a-based attenuation of solar radiation and the minimum solar radiation required for <span class="hlt">production</span>, we have proposed a new parameterisation for a spatially and temporally varying compensation depth which captures the seasonality in the <span class="hlt">production</span> zone reasonably well. This new parameterisation is shown to improve the seasonality of CO2 fluxes, surface <span class="hlt">ocean</span> pCO2, biological export and new <span class="hlt">production</span> in the major upwelling zones of the Indian <span class="hlt">Ocean</span>. The seasonally varying compensation depth enriches the nutrient concentration in the upper <span class="hlt">ocean</span> yielding more faithful biological exports which in turn leads to accurate seasonality in the carbon cycle. The export <span class="hlt">production</span> strengthens by ˜ 70 % over the western Arabian Sea during the monsoon period and achieves a good balance between export and new <span class="hlt">production</span> in the model. This underscores the importance of having a seasonal balance in the model export and new <span class="hlt">productions</span> for a better representation of the seasonality of the carbon cycle over upwelling regions. The study also implies that both the biological and solubility pumps play an important role in the Indian <span class="hlt">Ocean</span> upwelling zones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008E%26PSL.271...88L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008E%26PSL.271...88L"><span>Toward an orbital chronology for the <span class="hlt">early</span> Aptian <span class="hlt">Oceanic</span> Anoxic Event (OAE1a, ~ 120 Ma)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Yong-Xiang; Bralower, Timothy J.; Montañez, Isabel P.; Osleger, David A.; Arthur, Michael A.; Bice, David M.; Herbert, Timothy D.; Erba, Elisabetta; Premoli Silva, Isabella</p> <p>2008-07-01</p> <p>The <span class="hlt">early</span> Aptian <span class="hlt">Oceanic</span> Anoxic Event (OAE1a, 120 Ma) represents a geologically brief time interval in the mid-Cretaceous greenhouse world that is characterized by increased organic carbon accumulation in marine sediments, sudden biotic changes, and abrupt carbon-isotope excursions indicative of significant perturbations to global carbon cycling. The brevity of these drastic environmental changes (< 10 6 year) and the typically 10 6 year temporal resolution of the available chronologies, however, represent a critical gap in our knowledge of OAE1a. We have conducted a high-resolution investigation of three widely distributed sections, including the Cismon APTICORE in Italy, Santa Rosa Canyon in northeastern Mexico, and Deep Sea Drilling Project (DSDP) Site 398 off the Iberian margin in the North Atlantic <span class="hlt">Ocean</span>, which represent a range of depositional environments where condensed and moderately expanded OAE1a intervals are recorded. The objectives of this study are to establish orbital chronologies for these sections and to construct a common, high-resolution timescale for OAE1a. Spectral analyses of the closely-spaced (corresponding to ~ 5 to 10 kyr) measurements of calcium carbonate content of the APTICORE, magnetic susceptibility (MS) and anhysteretic remanent magnetization (ARM) of the Santa Rosa samples, and MS, ARM and ARM/IRM, where IRM is isothermal remanent magnetization, of Site 398 samples reveal statistically significant cycles. These cycles exhibit periodicity ratios and modulation patterns similar to those of the mid-Cretaceous orbital cycles, suggesting that orbital variations may have modulated depositional processes. Orbital control allows us to estimate the duration of unique, globally identifiable stages of OAE1a. Although OAE1a had a duration of ~ 1.0 to 1.3 Myr, the initial perturbation represented by the negative carbon-isotope excursion was rapid, lasting for ~ 27-44 kyr. This estimate could serve as a basis for constraining triggering</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.B12C..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.B12C..03D"><span>Bacterial <span class="hlt">Production</span> and Enzymatic Activities in Deep-Sea Sediments of the Pacific <span class="hlt">Ocean</span>: Biogeochemical Implications of Different Temperature Constraints</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Danovaro, R.; Corinaldesi, C.; dell'Anno, A.</p> <p>2002-12-01</p> <p>The deep-sea bed, acting as the ultimate sink for organic material derived from the upper <span class="hlt">oceans</span> primary <span class="hlt">production</span>, is now assumed to play a key role in biogeochemical cycling of organic matter on global scale. <span class="hlt">Early</span> diagenesis of organic matter in marine sediments is dependent upon biological processes (largely mediated by bacterial activity) and by molecular diffusion. Organic matter reaching the sea floor by sedimentation is subjected to complex biogeochemical transformations that make organic matter largely unsuitable for direct utilization by benthic heterotrophs. Extracellular enzymatic activities in the sediment is generally recognized as the key step in the degradation and utilization of organic polymers by bacteria and a key role in biopolymeric carbon mobilization is played by aminopeptidase, alkaline phosphatase and glucosidase activities. In the present study we investigated bacterial density, bacterial C <span class="hlt">production</span> and exo-enzymatic activities (aminopeptidase, glucosidase and phosphatase activity) in deep-sea sediments of the Pacific <span class="hlt">Ocean</span> in relation with the biochemical composition of sediment organic matter (proteins, carbohydrates and lipids), in order to gather information on organic matter cycling and diagenesis. Benthic viral abundance was also measured to investigate the potential role of viruses on microbial loop functioning. Sediment samples were collected at eight stations (depth ranging from 2070-3100 m) along two transects located at the opposite side (north and south) of <span class="hlt">ocean</span> seismic ridge Juan Fernandez (along latitudes 33° 20' - 33° 40'), constituted by the submerged vulcanoes, which connects the Chilean coasts to Rapa Nui Island. Since the northern and southern sides of this ridge apparently displayed small but significant differences in deep-sea temperature (related to the general <span class="hlt">ocean</span> circulation), this sampling strategy allowed also investigating the role of different temperature constraints on bacterial activity and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP13A2271P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP13A2271P"><span>New Insights into Amino Acid Preservation in the <span class="hlt">Early</span> <span class="hlt">Oceans</span> using Modern Analytical Techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J.</p> <p>2015-12-01</p> <p>Protein- and non-protein-amino acids likely occupied the <span class="hlt">oceans</span> at the time of the origin and evolution of life. Primordial soup-, hydrothermal vent-, and meteoritic-processes likely contributed to this <span class="hlt">early</span> chemical inventory. Prebiotic synthesis and carbonaceous meteorite studies suggest that non-protein amino acids were likely more abundant than their protein-counterparts. Amino acid preservation before abiotic and biotic destruction is key to biomarker availability in paleoenvironments and remains an important uncertainty. To constrain primitive amino acid lifetimes, a 1992 archived seawater/beach sand mixture was spiked with D,L-alanine, D,L-valine (Val), α-aminoisobutyric acid (α-AIB), D,L-isovaline (Iva), and glycine (Gly). Analysis by high performance liquid chromatography with fluorescence detection (HPLC-FD) showed that only D-Val and non-protein amino acids were abundant after 2250 days. The mixture was re-analyzed in 2012 using HPLC-FD and a triple quadrupole mass spectrometer (QqQ-MS). The analytical results 20 years after the inception of the experiment were strikingly similar to those after 2250 days. To confirm that viable microorganisms were still present, the mixture was re-spiked with Gly in 2012. Aliquots were collected immediately after spiking, and at 5- and 9-month intervals thereafter. Final HPLC-FD/QqQ-MS analyses were performed in 2014. The 2014 analyses revealed that only α-AIB, D,L-Iva, and D-Val remained abundant. The disappearance of Gly indicated that microorganisms still lived in the mixture and were capable of consuming protein amino acids. These findings demonstrate that non-protein amino acids are minimally impacted by biological degradation and thus have very long lifetimes under these conditions. Primitive non-protein amino acids from terrestrial synthesis, or meteorite in-fall, likely experienced greater preservation than protein amino acids in paleo-<span class="hlt">oceanic</span> environments. Such robust molecules may have reached a steady</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150019459','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150019459"><span>New Insights into Amino Acid Preservation in the <span class="hlt">Early</span> <span class="hlt">Oceans</span> Using Modern Analytical Techniques</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parker, Eric T.; Brinton, Karen L.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.; Bada, Jeffrey L.</p> <p>2015-01-01</p> <p>Protein- and non-protein-amino acids likely occupied the <span class="hlt">oceans</span> at the time of the origin and evolution of life. Primordial soup-, hydrothermal vent-, and meteoritic-processes likely contributed to this <span class="hlt">early</span> chemical inventory. Prebiotic synthesis and carbonaceous meteorite studies suggest that non-protein amino acids were likely more abundant than their protein-counterparts. Amino acid preservation before abiotic and biotic destruction is key to biomarker availability in paleoenvironments and remains an important uncertainty. To constrain primitive amino acid lifetimes, a 1992 archived seawater/beach sand mixture was spiked with D,L-alanine, D,L-valine (Val), alpha-aminoisobutyric acid (alpha-AIB), D,L-isovaline (Iva), and glycine (Gly). Analysis by high performance liquid chromatography with fluorescence detection (HPLC-FD) showed that only D-Val and non-protein amino acids were abundant after 2250 days. The mixture was re-analyzed in 2012 using HPLC-FD and a triple quadrupole mass spectrometer (QqQ-MS). The analytical results 20 years after the inception of the experiment were strikingly similar to those after 2250 days. To confirm that viable microorganisms were still present, the mixture was re-spiked with Gly in 2012. Aliquots were collected immediately after spiking, and at 5- and 9-month intervals thereafter. Final HPLC-FD/QqQ-MS analyses were performed in 2014. The 2014 analyses revealed that only alpha-AIB, D,L-Iva, and D-Val remained abundant. The disappearance of Gly indicated that microorganisms still lived in the mixture and were capable of consuming protein amino acids. These findings demonstrate that non-protein amino acids are minimally impacted by biological degradation and thus have very long lifetimes under these conditions. Primitive non-protein amino acids from terrestrial synthesis, or meteorite in-fall, likely experienced great-er preservation than protein amino acids in paleo-<span class="hlt">oceanic</span> environments. Such robust molecules may have reached a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150011496&hterms=colours&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcolours','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150011496&hterms=colours&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcolours"><span>Assessment of Satellite <span class="hlt">Ocean</span> Colour Radiometry and Derived Geophysical <span class="hlt">Products</span>. Chapter 6.1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Melin, Frederic; Franz, Bryan A.</p> <p>2014-01-01</p> <p>Standardization of methods to assess and assign quality metrics to satellite <span class="hlt">ocean</span> color radiometry and derived geophysical <span class="hlt">products</span> has become paramount with the inclusion of the marine reflectance and chlorophyll-a concentration (Chla) as essential climate variables (ECV; [1]) and the recognition that optical remote sensing of the <span class="hlt">oceans</span> can only contribute to climate research if and when a continuous succession of satellite missions can be shown to collectively provide a consistent, long-term record with known uncertainties. In 20 years, the community has made significant advancements toward that objective, but providing a complete uncertainty budget for all <span class="hlt">products</span> and for all conditions remains a daunting task. In the retrieval of marine water-leaving radiance from observed top-of-atmosphere radiance, the sources of uncertainties include those associated with propagation of sensor noise and radiometric calibration and characterization errors, as well as a multitude of uncertainties associated with the modeling and removal of effects from the atmosphere and sea surface. This chapter describes some common approaches used to assess quality and consistency of <span class="hlt">ocean</span> color satellite <span class="hlt">products</span> and reviews the current status of uncertainty quantification in the field. Its focus is on the primary <span class="hlt">ocean</span> color <span class="hlt">product</span>, the spectrum of marine reflectance Rrs, but uncertainties in some derived <span class="hlt">products</span> such as the Chla or inherent optical properties (IOPs) will also be considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4896667','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4896667"><span><span class="hlt">Ocean</span> dynamics, not dust, have controlled equatorial Pacific <span class="hlt">productivity</span> over the past 500,000 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>Winckler, Gisela; Anderson, Robert F.; Jaccard, Samuel L.; Marcantonio, Franco</p> <p>2016-01-01</p> <p>Biological <span class="hlt">productivity</span> in the equatorial Pacific is relatively high compared with other low-latitude regimes, especially east of the dateline, where divergence driven by the trade winds brings nutrient-rich waters of the Equatorial Undercurrent to the surface. The equatorial Pacific is one of the three principal high-nutrient low-chlorophyll <span class="hlt">ocean</span> regimes where biological utilization of nitrate and phosphate is limited, in part, by the availability of iron. Throughout most of the equatorial Pacific, upwelling of water from the Equatorial Undercurrent supplies far more dissolved iron than is delivered by dust, by as much as two orders of magnitude. Nevertheless, recent studies have inferred that the greater supply of dust during ice ages stimulated greater utilization of nutrients within the region of upwelling on the equator, thereby contributing to the sequestration of carbon in the <span class="hlt">ocean</span> interior. Here we present proxy records for dust and for biological <span class="hlt">productivity</span> over the past 500 ky at three sites spanning the breadth of the equatorial Pacific <span class="hlt">Ocean</span> to test the dust fertilization hypothesis. Dust supply peaked under glacial conditions, consistent with previous studies, whereas proxies of export <span class="hlt">production</span> exhibit maxima during ice age terminations. Temporal decoupling between dust supply and biological <span class="hlt">productivity</span> indicates that other factors, likely involving <span class="hlt">ocean</span> dynamics, played a greater role than dust in regulating equatorial Pacific <span class="hlt">productivity</span>. PMID:27185933</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('http://adsabs.harvard.edu/abs/2016PNAS..113.6119W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PNAS..113.6119W"><span><span class="hlt">Ocean</span> dynamics, not dust, have controlled equatorial Pacific <span class="hlt">productivity</span> over the past 500,000 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winckler, Gisela; Anderson, Robert F.; Jaccard, Samuel L.; Marcantonio, Franco</p> <p>2016-05-01</p> <p>Biological <span class="hlt">productivity</span> in the equatorial Pacific is relatively high compared with other low-latitude regimes, especially east of the dateline, where divergence driven by the trade winds brings nutrient-rich waters of the Equatorial Undercurrent to the surface. The equatorial Pacific is one of the three principal high-nutrient low-chlorophyll <span class="hlt">ocean</span> regimes where biological utilization of nitrate and phosphate is limited, in part, by the availability of iron. Throughout most of the equatorial Pacific, upwelling of water from the Equatorial Undercurrent supplies far more dissolved iron than is delivered by dust, by as much as two orders of magnitude. Nevertheless, recent studies have inferred that the greater supply of dust during ice ages stimulated greater utilization of nutrients within the region of upwelling on the equator, thereby contributing to the sequestration of carbon in the <span class="hlt">ocean</span> interior. Here we present proxy records for dust and for biological <span class="hlt">productivity</span> over the past 500 ky at three sites spanning the breadth of the equatorial Pacific <span class="hlt">Ocean</span> to test the dust fertilization hypothesis. Dust supply peaked under glacial conditions, consistent with previous studies, whereas proxies of export <span class="hlt">production</span> exhibit maxima during ice age terminations. Temporal decoupling between dust supply and biological <span class="hlt">productivity</span> indicates that other factors, likely involving <span class="hlt">ocean</span> dynamics, played a greater role than dust in regulating equatorial Pacific <span class="hlt">productivity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27185933','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27185933"><span><span class="hlt">Ocean</span> dynamics, not dust, have controlled equatorial Pacific <span class="hlt">productivity</span> over the past 500,000 years.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Winckler, Gisela; Anderson, Robert F; Jaccard, Samuel L; Marcantonio, Franco</p> <p>2016-05-31</p> <p>Biological <span class="hlt">productivity</span> in the equatorial Pacific is relatively high compared with other low-latitude regimes, especially east of the dateline, where divergence driven by the trade winds brings nutrient-rich waters of the Equatorial Undercurrent to the surface. The equatorial Pacific is one of the three principal high-nutrient low-chlorophyll <span class="hlt">ocean</span> regimes where biological utilization of nitrate and phosphate is limited, in part, by the availability of iron. Throughout most of the equatorial Pacific, upwelling of water from the Equatorial Undercurrent supplies far more dissolved iron than is delivered by dust, by as much as two orders of magnitude. Nevertheless, recent studies have inferred that the greater supply of dust during ice ages stimulated greater utilization of nutrients within the region of upwelling on the equator, thereby contributing to the sequestration of carbon in the <span class="hlt">ocean</span> interior. Here we present proxy records for dust and for biological <span class="hlt">productivity</span> over the past 500 ky at three sites spanning the breadth of the equatorial Pacific <span class="hlt">Ocean</span> to test the dust fertilization hypothesis. Dust supply peaked under glacial conditions, consistent with previous studies, whereas proxies of export <span class="hlt">production</span> exhibit maxima during ice age terminations. Temporal decoupling between dust supply and biological <span class="hlt">productivity</span> indicates that other factors, likely involving <span class="hlt">ocean</span> dynamics, played a greater role than dust in regulating equatorial Pacific <span class="hlt">productivity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED289675.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED289675.pdf"><span><span class="hlt">Early</span> Fishing Peoples of Puget Sound. <span class="hlt">Ocean</span> Related Curriculum Activities. Revised Edition.</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>McNutt, Nan</p> <p></p> <p>The <span class="hlt">ocean</span> affects all of our lives. Therefore, awareness of and information about the interconnections between humans and <span class="hlt">oceans</span> are prerequisites to making sound decisions for the future. Project ORCA (<span class="hlt">Ocean</span> Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830060823&hterms=primary+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dprimary%2Bfunction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830060823&hterms=primary+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dprimary%2Bfunction"><span>Satellites for the study of <span class="hlt">ocean</span> primary <span class="hlt">productivity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, R. C.; Baker, K. S.</p> <p>1983-01-01</p> <p>The use of remote sensing techniques for obtaining estimates of global marine primary <span class="hlt">productivity</span> is examined. It is shown that remote sensing and multiplatform (ship, aircraft, and satellite) sampling strategies can be used to significantly lower the variance in estimates of phytoplankton abundance and of population growth rates from the values obtained using the C-14 method. It is noted that multiplatform sampling strategies are essential to assess the mean and variance of phytoplankton biomass on a regional or on a global basis. The relative errors associated with shipboard and satellite estimates of phytoplankton biomass and primary <span class="hlt">productivity</span>, as well as the increased statistical accuracy possible from the utilization of contemporaneous data from both sampling platforms, are examined. It is shown to be possible to follow changes in biomass and the distribution patterns of biomass as a function of time with the use of satellite imagery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=english+AND+morphology&pg=3&id=EJ850117','ERIC'); return false;" href="https://eric.ed.gov/?q=english+AND+morphology&pg=3&id=EJ850117"><span>Children's <span class="hlt">Early</span> <span class="hlt">Productivity</span> with Verbal Morphology</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>Wagner, Laura; Swensen, Lauren D.; Naigles, Letitia R.</p> <p>2009-01-01</p> <p>Three studies using the intermodal preferential looking paradigm examined onset of <span class="hlt">productive</span> comprehension of tense/aspect morphology in English. When can toddlers understand these forms with novel verbs and novel events? The first study used familiar verbs and showed that 26-36-month olds correctly matched a past/perfective form ("-ed" or…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JMS....17..245S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JMS....17..245S"><span>Primary <span class="hlt">productivity</span> of the Palmer Long Term Ecological Research Area and 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>Smith, R. C.; Baker, K. S.; Byers, M. L.; Stammerjohn, S. E.</p> <p>1998-11-01</p> <p>A major objective of the Palmer Long Term Ecological Research (Palmer LTER) project is to obtain a comprehensive understanding of the various components of the Antarctic marine ecosystem. Phytoplankton <span class="hlt">production</span> plays a key role in this so-called high nutrient, low chlorophyll environment, and factors that regulate <span class="hlt">production</span> include those that control cell growth (light, temperature, and nutrients) and those that control cell accumulation rate and hence population growth (water column stability, grazing, and sinking). Sea ice mediates several of these factors and frequently conditions the water column for a spring bloom which is characterized by a pulse of <span class="hlt">production</span> restricted in both time and space. This study models the spatial and temporal variability of primary <span class="hlt">production</span> within the Palmer LTER area west of the Antarctic Peninsula and discusses this <span class="hlt">production</span> in the context of historical data for the Southern <span class="hlt">Ocean</span>. Primary <span class="hlt">production</span> for the Southern <span class="hlt">Ocean</span> and the Palmer LTER area have been computed using both light-pigment <span class="hlt">production</span> models [Smith, R.C., Bidigare, R.R., Prézelin, B.B., Baker, K.S., Brooks, J.M., 1987. Optical characterization of primary <span class="hlt">productivity</span> across a coastal front. Mar. Biol. (96), 575-591; Bidigare, R.R., Smith, R.C., Baker, K.S., Marra, J., 1987. <span class="hlt">Oceanic</span> primary <span class="hlt">production</span> estimates from measurements of spectral irradiance and pigment concentrations. Global Biogeochem. Cycles (1), 171-186; Morel, A., Berthon, J.F., 1989. Surface pigments, algal biomass profiles and potential <span class="hlt">production</span> of the euphotic layer—relationships reinvestigated in view of remote-sensing applications. Limnol. Oceanogr. (34), 1545-1562] and an ice edge <span class="hlt">production</span> model [Nelson, D.M., Smith, W.O., 1986. Phytoplankton bloom dynamics of the western Ross Sea ice edge: II. Mesoscale cycling of nitrogen and silicon. Deep-Sea Res. (33), 1389-1412; Wilson, D.L., Smith, W.O., Nelson, D.M., 1986. Phytoplankton bloom dynamics of the Western Ross Sea ice edge: I</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040013011&hterms=dependency&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddependency','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040013011&hterms=dependency&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddependency"><span><span class="hlt">Ocean</span> Primary <span class="hlt">Production</span> Estimates from Terra MODIS and Their Dependency on Satellite Chlorophyll Alpha Algorithms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Essias, Wayne E.; Abbott, Mark; Carder, Kendall; Campbell, Janet; Clark, Dennis; Evans, Robert; Brown, Otis; Kearns, Ed; Kilpatrick, Kay; Balch, W.</p> <p>2003-01-01</p> <p>Simplistic models relating global satellite <span class="hlt">ocean</span> color, temperature, and light to <span class="hlt">ocean</span> net primary <span class="hlt">production</span> (ONPP) are sensitive to the accuracy and limitations of the satellite estimate of chlorophyll and other input fields, as well as the primary <span class="hlt">productivity</span> model. The standard MODIS ONPP <span class="hlt">product</span> uses the new semi-analytic chlorophyll algorithm as its input for two ONPP indexes. The three primary MODIS chlorophyll Q estimates from MODIS, as well as the SeaWiFS 4 chlorophyll <span class="hlt">product</span>, were used to assess global and regional performance in estimating ONPP for the full mission, but concentrating on 2001. The two standard ONPP algorithms were examined with 8-day and 39 kilometer resolution to quantify chlorophyll algorithm dependency of ONPP. Ancillary data (MLD from FNMOC, MODIS SSTD1, and PAR from the GSFC DAO) were identical. The standard MODIS ONPP estimates for annual <span class="hlt">production</span> in 2001 was 59 and 58 GT C for the two ONPP algorithms. Differences in ONPP using alternate chlorophylls were on the order of 10% for global annual ONPP, but ranged to 100% regionally. On all scales the differences in ONPP were smaller between MODIS and SeaWiFS than between ONPP models, or among chlorophyll algorithms within MODIS. Largest regional ONPP differences were found in the Southern <span class="hlt">Ocean</span> (SO). In the SO, application of the semi-analytic chlorophyll resulted in not only a magnitude difference in ONPP (2x), but also a temporal shift in the time of maximum <span class="hlt">production</span> compared to empirical algorithms when summed over standard <span class="hlt">oceanic</span> areas. The resulting increase in global ONPP (6-7 GT) is supported by better performance of the semi-analytic chlorophyll in the SO and other high chlorophyll regions. The differences are significant in terms of understanding regional differences and dynamics of <span class="hlt">ocean</span> carbon transformations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC51F1081J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC51F1081J"><span>Modeling seasonality of ice and <span class="hlt">ocean</span> carbon <span class="hlt">production</span> in the Arctic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, M.; Deal, C. M.; Ji, R.</p> <p>2011-12-01</p> <p>In the Arctic <span class="hlt">Ocean</span>, both phytoplankton and sea ice algae are important contributors to the primary <span class="hlt">production</span> and the arctic food web. Copepod in the arctic regions have developed their feeding habit depending on the timing between the ice algal bloom and the subsequent phytoplankton bloom. A mismatch of the timing due to climate changes could have dramatic consequences on the food web as shown by some regional observations. In this study, a global coupled ice-<span class="hlt">ocean</span>-ecosystem model was used to assess the seasonality of the ice algal and phytoplankton blooms in the arctic. The ice-<span class="hlt">ocean</span> ecosystem modules are fully coupled in the physical model POP-CICE (Parallel <span class="hlt">Ocean</span> Program- Los Alamos Sea Ice Model). The model results are compared with various observations. The modeled ice and <span class="hlt">ocean</span> carbon <span class="hlt">production</span> were analyzed by regions and their linkage to the physical environment changes (such as changes of ice concentration and water temperature, and light intensity etc.) between low- and high-ice years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GBioC..30.1756S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GBioC..30.1756S"><span>The CAFE model: A net <span class="hlt">production</span> model for global <span class="hlt">ocean</span> phytoplankton</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silsbe, Greg M.; Behrenfeld, Michael J.; Halsey, Kimberly H.; Milligan, Allen J.; Westberry, Toby K.</p> <p>2016-12-01</p> <p>The Carbon, Absorption, and Fluorescence Euphotic-resolving (CAFE) net primary <span class="hlt">production</span> model is an adaptable framework for advancing global <span class="hlt">ocean</span> <span class="hlt">productivity</span> assessments by exploiting state-of-the-art satellite <span class="hlt">ocean</span> 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 <span class="hlt">ocean</span> color measurements into a mechanistic and accurate model of phytoplankton growth rates (μ) and net phytoplankton <span class="hlt">production</span> (NPP). The CAFE model calculates NPP as the <span class="hlt">product</span> 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 <span class="hlt">oceanic</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGD....1013897C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGD....1013897C"><span><span class="hlt">Ocean</span> acidification effects in the <span class="hlt">early</span> life-stages of summer flounder, Paralichthys dentatus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambers, R. C.; Candelmo, A. C.; Habeck, E. A.; Poach, M. E.; Wieczorek, D.; Cooper, K. R.; Greenfield, C. E.; Phelan, B. A.</p> <p>2013-08-01</p> <p>The limited available evidence about effects of high CO2 and acidification of our <span class="hlt">oceans</span> on fish suggests that effects will differ across fish species, be subtle, and interact with other stressors. An experimental framework was implemented that includes the use of (1) multiple marine fish species of relevance to the northeastern USA that differ in their ecologies including spawning season and habitat; (2) a wide yet realistic range of environmental conditions (i.e., concurrent manipulation of CO2 levels and water temperatures), and (3) a diverse set of response variables related to fish sensitivity to elevated CO2 levels, water temperatures, and their interactions. This report is on an array of <span class="hlt">early</span> life-history responses of summer flounder (Paralichthys dentatus), an ecologically and economically important flatfish of this region, to a wide range of pH and CO2 levels. Survival of summer flounder embryos was reduced by 50% below local ambient conditions (7.8 pH, 775 ppm pCO2) when maintained at the intermediate conditions (7.4 pH, 1860 ppm pCO2), and by 75% below local ambient when maintained at the most acidic conditions tested (7.1 pH, 4715 ppm pCO2). This pattern of reduced survival of embryos at higher CO2 levels was consistent among three females used as sources of embryos. Sizes and shapes of larvae were altered by elevated CO2 levels with longer larvae in more acidic waters. This pattern of longer larvae was evident at hatching (although longer hatchlings had less energy reserves) to midway through the larval period. Larvae from the most acidic conditions initiated metamorphosis at earlier ages and smaller sizes than those from more moderate and ambient conditions. Tissue damage was evident in older larvae (age 14 to 28 d post-hatching) from both elevated CO2 levels. Damage included liver sinusoid dilation, focal hyperplasia on the epithelium, separation of the trunk muscle bundles, and dilation of the liver sinusoids and central veins. Cranial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPP14A0534K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPP14A0534K"><span>The Importance of Subsurface <span class="hlt">Production</span> for Carbon Export - Evidence from Past <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>Kemp, A. E. S.</p> <p>2016-02-01</p> <p>The maxim of the geological concept of uniformitarianism is "the present is the key to the past", but in the context of our temporally and spatially minimal observational record of modern <span class="hlt">ocean</span> biogeochemical processes, ancient <span class="hlt">ocean</span> sediments may provide critical evidence of the key species involved in carbon flux. Specifically, laminated marine sediments that preserve the seasonal flux cycle represent "palaeo-sediment traps" that vastly expand our knowledge of the operations of the marine biological carbon pump. Several key subsurface-dwelling diatom taxa, hitherto thought to be biogeochemically insignificant, are dominant components of ancient marine sediments. For example, the sapropels and equivalent horizons that have accumulated in the Mediterranean over the past 5 million years, contain abundant rhizosolenid and hemiaulid diatoms. These deposits contain the highest concentrations of organic carbon and there is extensive evidence that this was produced by subsurface <span class="hlt">production</span> in a deep chlorophyll maximum. The highly stratified conditions that led to this subsurface <span class="hlt">production</span> and carbon flux are in contrast to prevailing views that have held upwelling systems as those with the highest potential for export in the global <span class="hlt">ocean</span>. Similarly, studies of ancient "greenhouse" periods such as the Cretaceous, with highly stratified <span class="hlt">oceans</span> and which are potential analogues for future climate change, show evidence for extensive subsurface <span class="hlt">production</span>. Together with emerging evidence from stratified regions of the modern <span class="hlt">ocean</span>, such as the subtropical gyres, insights from these ancient <span class="hlt">oceans</span> suggest that a reappraisal is required of current views on key phytoplankton producers and their role the operation of the marine biological carbon pump.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25014366','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25014366"><span>Interactive effects of <span class="hlt">ocean</span> acidification, elevated temperature, and reduced salinity on <span class="hlt">early</span>-life stages of the pacific oyster.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ko, Ginger W K; Dineshram, R; Campanati, Camilla; Chan, Vera B S; Havenhand, Jon; Thiyagarajan, Vengatesen</p> <p>2014-09-02</p> <p><span class="hlt">Ocean</span> acidification (OA) effects on larvae are partially attributed for the rapidly declining oyster <span class="hlt">production</span> in the Pacific Northwest region of the United States. This OA effect is a serious concern in SE Asia, which produces >80% of the world's oysters. Because climate-related stressors rarely act alone, we need to consider OA effects on oysters in combination with warming and reduced salinity. Here, the interactive effects of these three climate-related stressors on the larval growth of the Pacific oyster, Crassostrea gigas, were examined. Larvae were cultured in combinations of temperature (24 and 30 °C), pH (8.1 and 7.4), and salinity (15 psu and 25 psu) for 58 days to the <span class="hlt">early</span> juvenile stage. Decreased pH (pH 7.4), elevated temperature (30 °C), and reduced salinity (15 psu) significantly delayed pre- and post-settlement growth. Elevated temperature lowered the larval lipid index, a proxy for physiological quality, and negated the negative effects of decreased pH on attachment and metamorphosis only in a salinity of 25 psu. The negative effects of multiple stressors on larval metamorphosis were not due to reduced size or depleted lipid reserves at the time of metamorphosis. Our results supported the hypothesis that the C. gigas larvae are vulnerable to the interactions of OA with reduced salinity and warming in Yellow Sea coastal waters now and in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGD....12....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....12....1M"><span>Effects of CO2-driven <span class="hlt">ocean</span> acidification on <span class="hlt">early</span> life stages of marine medaka (Oryzias melastigma)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mu, J.; Jin, F.; Wang, J.; Zheng, N.; Cong, Y.</p> <p>2015-01-01</p> <p>The potential effects of elevated CO2 level and reduced carbonate saturation state in marine environment on fishes and other non-calcified organisms are still poorly known. In present study, we investigated the effects of <span class="hlt">ocean</span> acidification on embryogenesis and organogenesis of newly hatched larvae of marine medaka (Oryzias melastigma) after 21 d exposure of eggs to different artificially acidified seawater (pH 7.6 and 7.2, respectively), and compared with those in control group (pH 8.2). Results showed that CO2-driven seawater acidification (pH 7.6 and 7.2) had no detectable effect on hatching time, hatching rate, and heart rate of embryos. However, the deformity rate of larvae in pH 7.2 treatment was significantly higher than that in control treatment. The left and right sagitta areas did not differ significantly from each other in each treatment. However, the mean sagitta area of larvae in pH 7.6 treatment was significantly smaller than that in the control (p = 0.024). These results suggest that although marine medaka might be more tolerant of elevated CO2 than some other fishes, the effect of elevated CO2 level on the calcification of otolith is likely to be the most susceptibly physiological process of pH regulation in <span class="hlt">early</span> life stage of marine medaka.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26724195','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26724195"><span>Amino and fatty acid dynamics of octopus (Octopus vulgaris) <span class="hlt">early</span> life stages under <span class="hlt">ocean</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>Lopes, Vanessa M; Faleiro, Filipa; Baptista, Miguel; Pimentel, Marta S; Paula, José R; Couto, Ana; Bandarra, Narcisa; Anacleto, Patrícia; Marques, António; Rosa, Rui</p> <p>2016-01-01</p> <p>The <span class="hlt">oceans</span> are becoming warmer, and the higher temperatures are expected to have a major impact on marine life at different levels of biological organization, especially at the most vulnerable <span class="hlt">early</span> life stages. Thus, we hypothesize that the future warmer scenarios (here +3 °C) will affect the biochemical composition (amino acid - AA, and fatty acid-FA) of octopod (Octopus vulgaris) embryos and recently-hatched pelagic paralarvae. The main essential amino acids found in octopus embryos were arginine, leucine and lysine; while aspartic and glutamic acids, and taurine were the main non-essential amino acids. Palmitic, eicosapentaenoic and docosahexaenoic acids were the main FAs found in octopus tissues. Relevant ontogenetic changes were observed, namely a steep decrease in the content of many AAs, and a selective retention of FAs, thus evidencing the protein-based metabolism of these cephalopods. Temperature per si did not elicit significant changes in the overall FA composition, but was responsible for a significant decrease in the content of several AAs, indicating increased embryonic consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27196957','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27196957"><span>Tsunami waves extensively resurfaced the shorelines of an <span class="hlt">early</span> Martian <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>Rodriguez, J Alexis P; Fairén, Alberto G; Tanaka, Kenneth L; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R; Glines, Natalie</p> <p>2016-05-19</p> <p>It has been proposed that ~3.4 billion years ago an <span class="hlt">ocean</span> fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on <span class="hlt">early</span> Mars, tsunamis played a major role in generating and resurfacing coastal terrains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872529','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872529"><span>Tsunami waves extensively resurfaced the shorelines of an <span class="hlt">early</span> Martian <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>Rodriguez, J. Alexis P.; Fairén, Alberto G.; Tanaka, Kenneth L.; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S.; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R.; Glines, Natalie</p> <p>2016-01-01</p> <p>It has been proposed that ~3.4 billion years ago an <span class="hlt">ocean</span> fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on <span class="hlt">early</span> Mars, tsunamis played a major role in generating and resurfacing coastal terrains. PMID:27196957</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B42B..08Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B42B..08Z"><span>Exploring the Disappearing <span class="hlt">Ocean</span> Micro Plastic Mystery: New Insights from Dissolved Organic Carbon photo <span class="hlt">production</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, L.; Zhao, S.; Li, D.; Stubbins, A.</p> <p>2017-12-01</p> <p>Emerging as a novel planetary threat, plastic waste, dominated by millimeter-sized plastic (microplastic), is omnipresent in the <span class="hlt">oceans</span>, posing broad environmental threats. However, only 1% of the microplastic waste exported from the land is found in the <span class="hlt">ocean</span>. Most of the lost fraction is in the form of microplastics. The fate of these buoyant plastic fragments is a fundamental gap in our understanding of the fate and impact of plastics in marine ecosystems. To date, an effective sink for the lost microplastics has not been found. In this study, dissolved organic carbon (DOC) photo-<span class="hlt">production</span> from the three dominant forms of <span class="hlt">ocean</span> microplastics was assessed. These plastics were: 1) Polyethylene (PE) both for postconsumer samples and pure standard samples; 2) polypropylene (PP); and, expanded polystyrene (EPS). In addition, a Neustonic microplastic samples from the North Pacific Gyre were irradiated. These real-world samples were dominated by PE ( 80%). All samples were placed in seawater, in quartz flasks, and irradiated in a solar simulator for 2 months. During irradiation, DOC photo-<span class="hlt">production</span> from PP, EPS, and the PE standard was exponential, while DOC photo-<span class="hlt">production</span> from postconsumer PE and the Neustonic samples was linear. Scanning electron microscopy indicated surface ablation and micro-fragmentation during the irradiation of the three plastics that showed exponential DOC <span class="hlt">production</span> (PP, EPS and standard PE), suggesting the increase in photo-reactivity of these plastics was a result of an increase in their surface to volume ratios and therefore their per-unit mass light exposure. Based on DOC <span class="hlt">production</span>, the half-life of the microplastics ranged from 0.26 years for EPS to 86 years for PE, suggesting sunlight is a major removal term for buoyant <span class="hlt">oceanic</span> microplastics. With respect to the broader carbon cycle, we conservatively estimate that plastic photodegradation releases 6 to 17 thousand metric tons of radiocarbon dead DOC to the surface <span class="hlt">ocean</span> each year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PrOce.158..130B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PrOce.158..130B"><span>Modelling size-fractionated primary <span class="hlt">production</span> in the Atlantic <span class="hlt">Ocean</span> from remote sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brewin, Robert J. W.; Tilstone, Gavin H.; Jackson, Thomas; Cain, Terry; Miller, Peter I.; Lange, Priscila K.; Misra, Ankita; Airs, Ruth L.</p> <p>2017-11-01</p> <p>Marine primary <span class="hlt">production</span> influences the transfer of carbon dioxide between the <span class="hlt">ocean</span> and atmosphere, and the availability of energy for the pelagic food web. Both the rate and the fate of organic carbon from primary <span class="hlt">production</span> are dependent on phytoplankton size. A key aim of the Atlantic Meridional Transect (AMT) programme has been to quantify biological carbon cycling in the Atlantic <span class="hlt">Ocean</span> and measurements of total primary <span class="hlt">production</span> have been routinely made on AMT cruises, as well as additional measurements of size-fractionated primary <span class="hlt">production</span> on some cruises. Measurements of total primary <span class="hlt">production</span> collected on the AMT have been used to evaluate remote-sensing techniques capable of producing basin-scale estimates of primary <span class="hlt">production</span>. Though models exist to estimate size-fractionated primary <span class="hlt">production</span> from satellite data, these have not been well validated in the Atlantic <span class="hlt">Ocean</span>, and have been parameterised using measurements of phytoplankton pigments rather than direct measurements of phytoplankton size structure. Here, we re-tune a remote-sensing primary <span class="hlt">production</span> model to estimate <span class="hlt">production</span> in three size fractions of phytoplankton (<2 μm, 2-10 μm and >10 μm) in the Atlantic <span class="hlt">Ocean</span>, using measurements of size-fractionated chlorophyll and size-fractionated photosynthesis-irradiance experiments conducted on AMT 22 and 23 using sequential filtration-based methods. The performance of the remote-sensing technique was evaluated using: (i) independent estimates of size-fractionated primary <span class="hlt">production</span> collected on a number of AMT cruises using 14C on-deck incubation experiments and (ii) Monte Carlo simulations. Considering uncertainty in the satellite inputs and model parameters, we estimate an average model error of between 0.27 and 0.63 for log10-transformed size-fractionated <span class="hlt">production</span>, with lower errors for the small size class (<2 μm), higher errors for the larger size classes (2-10 μm and >10 μm), and errors generally higher in oligotrophic waters</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29472033','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29472033"><span>Impact of <span class="hlt">ocean</span> acidification and warming on the <span class="hlt">productivity</span> of a rock pool community.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Legrand, Erwann; Riera, Pascal; Bohner, Olivier; Coudret, Jérôme; Schlicklin, Ferdinand; Derrien, Marie; Martin, Sophie</p> <p>2018-05-01</p> <p>This study examined experimentally the combined effect of <span class="hlt">ocean</span> acidification and warming on the <span class="hlt">productivity</span> of rock pool multi-specific assemblages, composed of coralline algae, fleshy algae, and grazers. Natural rock pool communities experience high environmental fluctuations. This may confer physiological advantage to rock pool communities when facing predicted acidification and warming. The effect of <span class="hlt">ocean</span> acidification and warming have been assessed at both individual and assemblage level to examine the importance of species interactions in the response of assemblages. We hypothesized that rock pool assemblages have physiological advantage when facing predicted <span class="hlt">ocean</span> acidification and warming. Species exhibited species-specific responses to increased temperature and pCO 2 . Increased temperature and pCO 2 have no effect on assemblage photosynthesis, which was mostly influenced by fleshy algal primary <span class="hlt">production</span>. The response of coralline algae to <span class="hlt">ocean</span> acidification and warming depended on the season, which evidenced the importance of physiological adaptations to their environment in their response to climate change. We suggest that rock pool assemblages are relatively robust to changes in temperature and pCO 2 , in terms of primary <span class="hlt">production</span>. Copyright © 2018 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010871','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010871"><span>Near-Cloud Aerosol Properties from the 1 Km Resolution MODIS <span class="hlt">Ocean</span> <span class="hlt">Product</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Varnai, Tamas; Marshak, Alexander</p> <p>2014-01-01</p> <p>This study examines aerosol properties in the vicinity of clouds by analyzing high-resolution atmospheric correction parameters provided in the MODIS (Moderate Resolution Imaging Spectroradiometer) <span class="hlt">ocean</span> color <span class="hlt">product</span>. The study analyzes data from a 2 week long period of September in 10 years, covering a large area in the northeast Atlantic <span class="hlt">Ocean</span>. The results indicate that on the one hand, the Quality Assessment (QA) flags of the <span class="hlt">ocean</span> color <span class="hlt">product</span> successfully eliminate cloud-related uncertainties in <span class="hlt">ocean</span> parameters such as chlorophyll content, but on the other hand, using the flags introduces a sampling bias in atmospheric <span class="hlt">products</span> such as aerosol optical thickness (AOT) and Angstrom exponent. Therefore, researchers need to select QA flags by balancing the risks of increased retrieval uncertainties and sampling biases. Using an optimal set of QA flags, the results reveal substantial increases in optical thickness near clouds-on average the increase is 50% for the roughly half of pixels within 5 km from clouds and is accompanied by a roughly matching increase in particle size. Theoretical simulations show that the 50% increase in 550nm AOT changes instantaneous direct aerosol radiative forcing by up to 8W/m2 and that the radiative impact is significantly larger if observed near-cloud changes are attributed to aerosol particles as opposed to undetected cloud particles. These results underline that accounting for near-cloud areas and understanding the causes of near-cloud particle changes are critical for accurate calculations of direct aerosol radiative forcing.</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('https://www.ncbi.nlm.nih.gov/pubmed/16943835','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16943835"><span>Controls on tropical Pacific <span class="hlt">Ocean</span> <span class="hlt">productivity</span> revealed through nutrient stress diagnostics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Behrenfeld, Michael J; Worthington, Kirby; Sherrell, Robert M; Chavez, Francisco P; Strutton, Peter; McPhaden, Michael; Shea, Donald M</p> <p>2006-08-31</p> <p>In situ enrichment experiments have shown that the growth of bloom-forming diatoms in the major high-nitrate low-chlorophyll (HNLC) regions of the world's <span class="hlt">oceans</span> is limited by the availability of iron. Yet even the largest of these manipulative experiments represents only a small fraction of an <span class="hlt">ocean</span> basin, and the responses observed are strongly influenced by the proliferation of rare species rather than the growth of naturally dominant populations. Here we link unique fluorescence attributes of phytoplankton to specific physiological responses to nutrient stress, and use these relationships to evaluate the factors that constrain phytoplankton growth in the tropical Pacific <span class="hlt">Ocean</span> on an unprecedented spatial scale. On the basis of fluorescence measurements taken over 12 years, we delineate three major ecophysiological regimes in this region. We find that iron has a key function in regulating phytoplankton growth in both HNLC and oligotrophic waters near the Equator and further south, whereas nitrogen and zooplankton grazing are the primary factors that regulate biomass <span class="hlt">production</span> in the north. Application of our findings to the interpretation of satellite chlorophyll fields shows that <span class="hlt">productivity</span> in the tropical Pacific basin may be 1.2-2.5 Pg C yr(-1) lower than previous estimates have suggested, a difference that is comparable to the global change in <span class="hlt">ocean</span> <span class="hlt">production</span> that accompanied the largest El Niño to La Niña transition on record.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.U52A0007V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.U52A0007V"><span>Numerical Mantle Convection Models of Crustal Formation in an <span class="hlt">Oceanic</span> Environment in the <span class="hlt">Early</span> Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Thienen, P.; van den Berg, A. P.; Vlaar, N. J.</p> <p>2001-12-01</p> <p>The generation of basaltic crust in the <span class="hlt">early</span> Earth by partial melting of mantle rocks, subject to investigation in this study, is thought to be a first step in the creation of proto-continents (consisting largely of felsic material), since partial melting of basaltic material was probably an important source for these more evolved rocks. In the <span class="hlt">early</span> Archean the earth's upper mantle may have been hotter than today by as much as several hundred degrees centigrade. As a consequence, partial melting in shallow convective upwellings would have produced a layering of basaltic crust and underlying depleted (lherzolitic-harzburgitic) mantle peridotite which is much thicker than found under modern day <span class="hlt">oceanic</span> ridges. When a basaltic crustal layer becomes sufficiently thick, a phase transition to eclogite may occur in the lower parts, which would cause delamination of this dense crustal layer and recycling of dense eclogite into the upper mantle. This recycling mechanism may have contributed significantly to the <span class="hlt">early</span> cooling of the earth during the Archean (Vlaar et al., 1994). The delamination mechanism which limits the build-up of a thick basaltic crustal layer is switched off after sufficient cooling of the upper mantle has taken place. We present results of numerical modelling experiments of mantle convection including pressure release partial melting. The model includes a simple approximate melt segregation mechanism and basalt to eclogite phase transition, to account for the dynamic accumulation and recycling of the crust in an upper mantle subject to secular cooling. Finite element methods are used to solve for the viscous flow field and the temperature field, and lagrangian particle tracers are used to represent the evolving composition due to partial melting and accumulation of the basaltic crust. We find that this mechanism creates a basaltic crust of several tens of kilometers thickness in several hundreds of million years. This is accompanied by a cooling of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMDI13A2630W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMDI13A2630W"><span><span class="hlt">Early</span> Depositional History of the Eocene Izu-Bonin Mariana Arc, Western Pacific <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>Waldman, R.; Marsaglia, K. M.; Tepley, F. J., III</p> <p>2015-12-01</p> <p>Expedition 351 of the International <span class="hlt">Ocean</span> Discovery Program cored an Eocene section at Site U1438 in the Philippine Sea that provides insight into the <span class="hlt">early</span> history of the Izu-Bonin arc. Subduction here is hypothesized to have initiated spontaneously, leaving a characteristic depositional sequence of post-subduction-initiation localized extension and volcanism. We conducted detailed macroscopic and microscopic study of the cores of the lowermost 100m of volcaniclastic and sedimentary rocks (Unit IV) directly overlying subduction initiation igneous basement, to identify depositional facies and trends. We subdivided Unit IV into three subunits based on lithologic characteristics. Transitions between the subunits are relatively abrupt, occurring within the length of a single core. The lowermost subunit (IVA) consists of 4 meters of laminated pelagic claystone with thin beds of graded volcaniclastic siltstone, and fine-grained tuff laminae composed of plagioclase feldspar and green-brown amphibole. The middle subunit (IVB) comprises 51 meters of texturally variable, thick-bedded, coarse-grained gravity flow deposits. These are composed of volcaniclastic sandstone and conglomerate containing glassy and tachylitic volcanic grains as well as sedimentary lithic fragments, along with traces of shallow-water carbonate bioclasts. Subunit IVB sediments are poorer in feldspar than IVA and contain only trace amphibole. They show variable grain rounding and an upsection increase in vitric components. Tachylite grains range from sub-angular to well rounded throughout, and other volcanic grain types show upward increases in angularity and vesicularity. The abrupt transition from pelagic sediments in subunit IVA to shallow-water-sourced gravity flows in subunit IVB suggests a rapid emergence of shallow-water to subaerial volcanic center <span class="hlt">early</span> in the arc's development. The upper part of subunit IVB also contains igneous intrusions, providing possible evidence for more proximal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME54B0927G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME54B0927G"><span>Monitoring Land Based Sources of Pollution over Coral Reefs using VIIRS <span class="hlt">Ocean</span> Color <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geiger, E.; Strong, A. E.; Eakin, C. M.; Wang, M.; Hernandez, W. J.; Cardona Maldonado, M. A.; De La Cour, J. L.; Liu, G.; Tirak, K.; Heron, S. F.; Skirving, W. J.; Armstrong, R.; Warner, R. A.</p> <p>2016-02-01</p> <p>NOAA's Coral Reef Watch (CRW) program and the NESDIS <span class="hlt">Ocean</span> Color Team are developing new <span class="hlt">products</span> to monitor land based sources of pollution (LBSP) over coral reef ecosystems using the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the S-NPP satellite. LBSP are a major threat to corals that can cause disease and mortality, disrupt critical ecological reef functions, and impede growth, reproduction, and larval settlement, among other impacts. From VIIRS, near-real-time satellite <span class="hlt">products</span> of Chlorophyll-a, Kd(490), and sea surface temperature are being developed for three U.S. Coral Reef Task Force priority watershed sites - Ka'anapali (West Maui, Hawai'i), Faga'alu (American Samoa), and Guánica Bay (Puerto Rico). Background climatological levels of these parameters are being developed to construct anomaly <span class="hlt">products</span>. Time-series data are being generated to monitor changes in water quality in near-real-time and provide information on historical variations, especially following significant rain events. A pilot calibration/validation field study of the VIIRS-based <span class="hlt">ocean</span> color <span class="hlt">products</span> is underway in Puerto Rico; we plan to expand this validation effort to the other two watersheds. Working with local resource managers, we have identified a focal area for <span class="hlt">product</span> development and validation for each watershed and its associated local reefs. This poster will present preliminary results and identify a path forward to ensure marine resource managers understand and correctly use the new <span class="hlt">ocean</span> color <span class="hlt">products</span>, and to help NOAA CRW refine its satellite <span class="hlt">products</span> to maximize their benefit to coral reef management. NOAA - National <span class="hlt">Oceanic</span> and Atmospheric Administration NESDIS - NOAA/National Environmental Satellite, Data, and Information Service S-NPP - Suomi National Polar-orbiting Partnership</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AtmEn..45.4291H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AtmEn..45.4291H"><span>A linkage between Asian dust, dissolved iron and marine export <span class="hlt">production</span> in the deep <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>Han, Yongxiang; Zhao, Tianliang; Song, Lianchun; Fang, Xiaomin; Yin, Yan; Deng, Zuqin; Wang, Suping; Fan, Shuxian</p> <p>2011-08-01</p> <p>Iron-addition experiments have revealed that iron supply exerts controls on biogeochemical cycles in the <span class="hlt">ocean</span> and ultimately influences the Earth's climate system. The iron hypothesis in its broad outlines has been proved to be correct. However, the hypothesis needs to be verified with an observable biological response to specific dust deposition events. Plankton growth following the Asian dust storm over <span class="hlt">Ocean</span> Station PAPA (50°N, 145°W) in the North Pacific <span class="hlt">Ocean</span> in April 2001 was the first supportive evidence of natural aeolian iron inputs to <span class="hlt">ocean</span>; The data were obtained through the SeaWiFS satellite and robot carbon explorers by Bishop et al. Using the NARCM modeling results in this study, the calculated total dust deposition flux was 35 mg m -2 per day in PAPA region from the dust storm of 11-13 April, 2001 into 0.0615 mg m -2 d -1 (about 1100 nM) soluble iron in the surface layer at Station PAPA. It was enough for about 1100 nM to enhance the efficiency of the marine biological pump and trigger the rapid increase of POC and chlorophyll. The iron fertilization hypothesis therefore is plausible. However, even if this specific dust event can support the iron fertilization hypothesis, long-term observation data are lacking in marine export <span class="hlt">production</span> and continental dust. In this paper, we also conducted a simple correlation analysis between the diatoms and foraminifera at about 3000 m and 4000 m at two subarctic Pacific stations and the dust aerosol <span class="hlt">production</span> from China's mainland. The correlation coefficient between marine export <span class="hlt">production</span> and dust storm frequency in the core area of the dust storms was significantly high, suggesting that aerosols generated by Asian dust storm are the source of iron for organic matter fixation in the North Pacific <span class="hlt">Ocean</span>. These results suggest that there could be an interlocking chain for the change of atmospheric dust aerosol-soluble iron-marine export <span class="hlt">production</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GBioC..28...14E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GBioC..28...14E"><span>Annual net community <span class="hlt">production</span> and the biological carbon flux 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>Emerson, Steven</p> <p>2014-01-01</p> <p>The flux of biologically produced organic matter from the surface <span class="hlt">ocean</span> (the biological pump), over an annual cycle, is equal to the annual net community <span class="hlt">production</span> (ANCP). Experimental determinations of ANCP at <span class="hlt">ocean</span> time series sites using a variety of different metabolite mass balances have made it possible to evaluate the accuracy of sediment trap fluxes and satellite-determined <span class="hlt">ocean</span> carbon export. ANCP values at the Hawaii <span class="hlt">Ocean</span> Time-series (HOT), the Bermuda Atlantic Time-series Study (BATS), <span class="hlt">Ocean</span> Station Papa (OSP) are 3 ± 1 mol C m-2 yr-1—much less variable than presently suggested by satellite remote sensing measurements and global circulation models. ANCP determined from mass balances at these locations are 3-4 times particulate organic carbon fluxes measured in sediment traps. When the roles of dissolved organic carbon (DOC) flux, zooplankton migration, and depth-dependent respiration are considered these differences are reconciled at HOT and OSP but not at BATS, where measured particulate fluxes are about 3 times lower than expected. Even in the cases where sediment trap fluxes are accurate, it is not possible to "scale up" these measurements to determine ANCP without independent determinations of geographically variable DOC flux and zooplankton migration. Estimates of ANCP from satellite remote sensing using net primary <span class="hlt">production</span> determined by the carbon-based <span class="hlt">productivity</span> model suggests less geographic variability than its predecessor (the vertically generalized <span class="hlt">productivity</span> model) and brings predictions at HOT and OSP closer to measurements; however, satellite-predicted ANCP at BATS is still 3 times too low.</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 <span class="hlt">production</span> 2. Estimation at global 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 <span class="hlt">production</span> 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 global 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 global annual <span class="hlt">production</span> 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 global <span class="hlt">productivity</span> 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 global numbers have to be cautiously considered. Improving the reliability of the primary <span class="hlt">production</span> estimates implies (1) new global 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('http://adsabs.harvard.edu/abs/2015EGUGA..17.9349K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9349K"><span>Relation between <span class="hlt">Ocean</span> SST Dipoles and Downwind Continental Croplands Assessed for <span class="hlt">Early</span> Management Using Satellite-based Photosynthesis Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaneko, Daijiro</p> <p>2015-04-01</p> <p>Crop-monitoring systems with the unit of carbon-dioxide sequestration for environmental issues related to climate adaptation to global warming have been improved using satellite-based photosynthesis and meteorological conditions. <span class="hlt">Early</span> management of crop status is desirable for grain <span class="hlt">production</span>, stockbreeding, and bio-energy providing that the seasonal climate forecasting is sufficiently accurate. Incorrect seasonal forecasting of crop <span class="hlt">production</span> can damage global social activities if the recognized conditions are unsatisfied. One cause of poor forecasting related to the atmospheric dynamics at the Earth surface, which reflect the energy budget through land surface, especially the <span class="hlt">oceans</span> and atmosphere. Recognition of the relation between SST anomalies (e.g. ENSO, Atlantic Niño, Indian dipoles, and Ningaloo Niño) and crop <span class="hlt">production</span>, as expressed precisely by photosynthesis or the sequestrated-carbon rate, is necessary to elucidate the mechanisms related to poor <span class="hlt">production</span>. Solar radiation, surface air temperature, and water stress all directly affect grain vegetation photosynthesis. All affect stomata opening, which is related to the water balance or definition by the ratio of the Penman potential evaporation and actual transpiration. Regarding stomata, present data and reanalysis data give overestimated values of stomata opening because they are extended from wet models in forests rather than semi-arid regions commonly associated with wheat, maize, and soybean. This study applies a complementary model based on energy conservation for semi-arid zones instead of the conventional Penman-Monteith method. Partitioning of the integrated Net PSN enables precise estimation of crop yields by modifying the semi-closed stomata opening. Partitioning predicts <span class="hlt">production</span> more accurately using the cropland distribution already classified using satellite data. Seasonal crop forecasting should include near-real-time monitoring using satellite-based process crop models to avoid</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ASPC..351..524W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ASPC..351..524W"><span>The HERSCHEL/PACS <span class="hlt">early</span> Data <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wieprecht, E.; Wetzstein, M.; Huygen, R.; Vandenbussche, B.; De Meester, W.</p> <p>2006-07-01</p> <p>ESA's Herschel Space Observatory to be launched in 2007, is the first space observatory covering the full far-infrared and submillimeter wavelength range (60 - 670 microns). The Photodetector Array Camera & Spectrometer (PACS) is one of the three science instruments. It contains two Ge:Ga photoconductor arrays and two bolometer arrays to perform imaging line spectroscopy and imaging photometry in the 60 - 210 micron wavelength band. The HERSCHEL ground segment (Herschel Common Science System - HCSS) is implemented using JAVA technology and written in a common effort by the HERSCHEL Science Center and the three instrument teams. The PACS Common Software System (PCSS) is based on the HCSS and used for the online and offline analysis of PACS data. For telemetry bandwidth reasons PACS science data are partially processed on board, compressed, cut into telemetry packets and transmitted to the ground. These steps are instrument mode dependent. We will present the software model which allows to reverse the discrete on board processing steps and evaluate the data. After decompression and reconstruction the detector data and instrument status information are organized in two main PACS <span class="hlt">Products</span>. The design of these JAVA classes considers the individual sampling rates, data formats, memory and performance optimization aspects and comfortable user interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14.5675L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14.5675L"><span>Climate engineering and the <span class="hlt">ocean</span>: effects on biogeochemistry and primary <span class="hlt">production</span></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.; Tjiputra, Jerry; Muri, Helene</p> <p>2017-12-01</p> <p>Here we use an Earth system model with interactive biogeochemistry to project future <span class="hlt">ocean</span> biogeochemistry impacts from the large-scale deployment of three different radiation management (RM) climate engineering (also known as geoengineering) methods: stratospheric aerosol injection (SAI), marine sky brightening (MSB), and cirrus cloud thinning (CCT). We apply RM such that the change in radiative forcing in the RCP8.5 emission scenario is reduced to the change in radiative forcing in the RCP4.5 scenario. The resulting global mean sea surface temperatures in the RM experiments are comparable to those in RCP4.5, but there are regional differences. The forcing from MSB, for example, is applied over the <span class="hlt">oceans</span>, so the cooling of the <span class="hlt">ocean</span> is in some regions stronger for this method of RM than for the others. Changes in <span class="hlt">ocean</span> net primary <span class="hlt">production</span> (NPP) are much more variable, but SAI and MSB give a global decrease comparable to RCP4.5 (˜ 6 % in 2100 relative to 1971-2000), while CCT gives a much smaller global decrease of ˜ 3 %. Depending on the RM methods, the spatially inhomogeneous changes in <span class="hlt">ocean</span> NPP are related to the simulated spatial change in the NPP drivers (incoming radiation, temperature, availability of nutrients, and phytoplankton biomass) but mostly dominated by the circulation changes. In general, the SAI- and MSB-induced changes are largest in the low latitudes, while the CCT-induced changes tend to be the weakest of the three. The results of this work underscore the complexity of climate impacts on NPP and highlight the fact that changes are driven by an integrated effect of multiple environmental drivers, which all change in different ways. These results stress the uncertain changes to <span class="hlt">ocean</span> <span class="hlt">productivity</span> in the future and advocate caution at any deliberate attempt at large-scale perturbation of the Earth system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRC..119.1237Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.1237Z"><span>Decadal variations of Pacific North Equatorial Current bifurcation from multiple <span class="hlt">ocean</span> <span class="hlt">products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhai, Fangguo; Wang, Qingye; Wang, Fujun; Hu, Dunxin</p> <p>2014-02-01</p> <p>In this study, we examine the decadal variations of the Pacific North Equatorial Current (NEC) bifurcation latitude (NBL) averaged over upper 100 m and underlying dynamics over the past six decades using 11 <span class="hlt">ocean</span> <span class="hlt">products</span>, including seven kinds of <span class="hlt">ocean</span> reanalyzes based on <span class="hlt">ocean</span> data assimilation systems, two kinds of numerical simulations without assimilating observations and two kinds of objective analyzes based on in situ observations only. During the period of 1954-2007, the multiproduct mean of decadal NBL anomalies shows maxima around 1965/1966, 1980/1981, 1995/1996, and 2003/2004, and minima around 1958, 1971/1972, 1986/1987, and 2000/2001, respectively. The NBL decadal variations are related to the first Empirical Orthogonal Function mode of decadal anomalies of sea surface height (SSH) in the northwestern tropical Pacific <span class="hlt">Ocean</span>, which shows spatially coherent variation over the whole region and explains most of the total variance. Further regression and composite analyzes indicate that northerly/southerly NBL corresponds to negative/positive SSH anomalies and cyclonic/anticyclonic gyre anomalies in the northwestern tropical Pacific <span class="hlt">Ocean</span>. These decadal circulation variations and thus the decadal NBL variations are governed mostly by the first two vertical modes and attribute the most to the first baroclinic mode. The NBL decadal variation is highly positively correlated with the tropical Pacific decadal variability (TPDV) around the zero time lag. With a lead of about half the decadal cycle the NBL displays closer but negative relationship to TPDV in four <span class="hlt">ocean</span> <span class="hlt">products</span>, possibly manifesting the dynamical role of the circulation in the northwestern tropical Pacific in the phase-shifting of TPDV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5019231','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5019231"><span>The role of biology in planetary evolution: cyanobacterial primary <span class="hlt">production</span> in low‐oxygen Proterozoic <span class="hlt">oceans</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>Bryant, Donald A.; Macalady, Jennifer L.</p> <p>2016-01-01</p> <p>Summary Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well‐preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane‐derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the <span class="hlt">production</span> of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O 2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co‐occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low‐oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in <span class="hlt">early</span> Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic</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 Global Per Capita Agricultural <span class="hlt">Production</span> 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 globalization, most people still eat food that was grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or <span class="hlt">production</span> declines. Local agricultural <span class="hlt">production</span>, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural <span class="hlt">production</span>, 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 global 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 <span class="hlt">production</span>. Global per capita cereal <span class="hlt">production</span> will potentially decline by 14 percent between 2008 and 2030. Climate change is likely to further affect food <span class="hlt">production</span>, 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.gpo.gov/fdsys/pkg/FR-2012-02-21/pdf/2012-3957.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-02-21/pdf/2012-3957.pdf"><span>77 FR 9947 - Guidance for Industry: <span class="hlt">Early</span> Clinical Trials With Live Biotherapeutic <span class="hlt">Products</span>: Chemistry...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-02-21</p> <p>...] Guidance for Industry: <span class="hlt">Early</span> Clinical Trials With Live Biotherapeutic <span class="hlt">Products</span>: Chemistry, Manufacturing... ``Guidance for Industry: <span class="hlt">Early</span> Clinical Trials With Live Biotherapeutic <span class="hlt">Products</span>: Chemistry, Manufacturing... for Industry: <span class="hlt">Early</span> Clinical Trials With Live Biotherapeutic <span class="hlt">Products</span>: Chemistry, Manufacturing, and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMPP32A..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMPP32A..06S"><span>Paleogene blackshales in the central Arctic <span class="hlt">Ocean</span> and paleoenvironment: Anoxia vs. high primary <span class="hlt">production</span> vs. terrigenous input</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stein, R.; Weller, P.; Boucsein, B.</p> <p>2006-12-01</p> <p>During IODP Expedition 302 (Arctic <span class="hlt">Ocean</span> Coring Experiment ACEX), the first scientific drilling campaign in the permantly ice-covered central Arctic <span class="hlt">Ocean</span> on Lomonosov Ridge, a 430 m thick sequence of upper Cretaceaous to Quaternary sediments has been drilled. Here we present detailed organic carbon (OC) records from the entire ca. 200 m thick, upper Paleocene to middle Eocene blackshale-type section of the ACEX drill sites, characterized by OC contents of about 1 to 6%. Based on a multi-proxy organic geochemical approach (hydrogen indices, C/N and C/S ratios, stable carbon isotopes, biomarkers, and maceral composition), organic-carbon sources and paleoenvironmental conditions were reconstructed. The late Paleocene interval is characterized by oxic conditions and a predominance of reworked terrigenous OC. In contrast, euxinic "Black Sea-type" conditions favorable for the preservation of labile aquatic (marine algae-type) OC occur throughout the upper part of the <span class="hlt">early</span> Eocene and the middle Eocene, explained by salinity stratification due to freshwater discharge. The superimposed short-term ("Milankovitch-type") variability in amount and composition of OC is related to changes in primary <span class="hlt">production</span> and terrigenous input. Prominent <span class="hlt">early</span> Eocene events of algae-type OC preservation coincide with global 13C events such as the Paleocene- Eocece Thermal Maximum (PETM) and Elmo events. During Eocene times of anoxia, OC accumulation rates were 5-20 times higher than modern ones. Whereas very low organic carbon accumulation rates of about 0.005 gC cm-2 ky-1 are typical for the modern (Holocene) central Arctic <span class="hlt">Ocean</span> on Lomonosov Ridge, values of up to 0.1-0.15 gC cm-2 ky-1 were calculated for the Eocene ACEX section. Because major part of the OC deposited during Eocene times is of aquatic (marine) origin and the OC deposited during Holocene times is almost entirely of terrigenous origin, the difference between the modern and Eocene situation becomes even more drastic when</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/973333','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/973333"><span>Subsurface Hybrid Power Options for Oil & Gas <span class="hlt">Production</span> at Deep <span class="hlt">Ocean</span> Sites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciT</a></p> <p>Farmer, J C; Haut, R; Jahn, G</p> <p>2010-02-19</p> <p>An investment in deep-sea (deep-<span class="hlt">ocean</span>) hybrid power systems may enable certain off-shore oil and gas exploration and <span class="hlt">production</span>. Advanced deep-<span class="hlt">ocean</span> drilling and <span class="hlt">production</span> operations, locally powered, may provide commercial access to oil and gas reserves otherwise inaccessible. Further, subsea generation of electrical power has the potential of featuring a low carbon output resulting in improved environmental conditions. Such technology therefore, enhances the energy security of the United States in a green and environmentally friendly manner. The objective of this study is to evaluate alternatives and recommend equipment to develop into hybrid energy conversion and storage systems for deep <span class="hlt">ocean</span> operations.more » Such power systems will be located on the <span class="hlt">ocean</span> floor and will be used to power offshore oil and gas exploration and <span class="hlt">production</span> operations. Such power systems will be located on the <span class="hlt">oceans</span> floor, and will be used to supply oil and gas exploration activities, as well as drilling operations required to harvest petroleum reserves. The following conceptual hybrid systems have been identified as candidates for powering sub-surface oil and gas <span class="hlt">production</span> operations: (1) PWR = Pressurized-Water Nuclear Reactor + Lead-Acid Battery; (2) FC1 = Line for Surface O{sub 2} + Well Head Gas + Reformer + PEMFC + Lead-Acid & Li-Ion Batteries; (3) FC2 = Stored O2 + Well Head Gas + Reformer + Fuel Cell + Lead-Acid & Li-Ion Batteries; (4) SV1 = Submersible Vehicle + Stored O{sub 2} + Fuel Cell + Lead-Acid & Li-Ion Batteries; (5) SV2 = Submersible Vehicle + Stored O{sub 2} + Engine or Turbine + Lead-Acid & Li-Ion Batteries; (6) SV3 = Submersible Vehicle + Charge at Docking Station + ZEBRA & Li-Ion Batteries; (7) PWR TEG = PWR + Thermoelectric Generator + Lead-Acid Battery; (8) WELL TEG = Thermoelectric Generator + Well Head Waste Heat + Lead-Acid Battery; (9) GRID = <span class="hlt">Ocean</span> Floor Electrical Grid + Lead-Acid Battery; and (10) DOC = Deep <span class="hlt">Ocean</span> Current + Lead-Acid Battery.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017659','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017659"><span>Corrections to MODIS Terra Calibration and Polarization Trending Derived from <span class="hlt">Ocean</span> Color <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meister, Gerhard; Eplee, Robert E.; Franz, Bryan A.</p> <p>2014-01-01</p> <p>Remotely sensed <span class="hlt">ocean</span> color <span class="hlt">products</span> require highly accurate top-of-atmosphere (TOA) radiances, on the order of 0.5% or better. Due to incidents both prelaunch and on-orbit, meeting this requirement has been a consistent problem for the MODIS instrument on the Terra satellite, especially in the later part of the mission. The NASA <span class="hlt">Ocean</span> Biology Processing Group (OBPG) has developed an approach to correct the TOA radiances of MODIS Terra using spatially and temporally averaged <span class="hlt">ocean</span> color <span class="hlt">products</span> from other <span class="hlt">ocean</span> color sensors (such as the SeaWiFS instrument on Orbview-2 or the MODIS instrument on the Aqua satellite). The latest results suggest that for MODIS Terra, both linear polarization parameters of the Mueller matrix are temporally evolving. A change to the functional form of the scan angle dependence improved the quality of the derived coefficients. Additionally, this paper demonstrates that simultaneously retrieving polarization and gain parameters improves the gain retrieval (versus retrieving the gain parameter only).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160006520','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160006520"><span>Understanding <span class="hlt">Oceanic</span> Heavy Precipitation Using Scatterometer, Satellite Precipitation, and Reanalysis <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Garg, Piyush; Nesbitt, Stephen W.; Lang, Timothy J.; Chronis, Themis</p> <p>2016-01-01</p> <p>The primary aim of this study is to understand the heavy precipitation events over <span class="hlt">Oceanic</span> regions using vector wind retrievals from space based scatterometers in combination with precipitation <span class="hlt">products</span> from satellite and model reanalysis <span class="hlt">products</span>. Heavy precipitation over <span class="hlt">oceans</span> is a less understood phenomenon and this study tries to fill in the gaps which may lead us to a better understanding of heavy precipitation over <span class="hlt">oceans</span>. Various phenomenon may lead to intense precipitation viz. MJO (Madden-Julian Oscillation), Extratropical cyclones, MCSs (Mesoscale Convective Systems), that occur inside or outside the tropics and if we can decipher the physical mechanisms behind occurrence of heavy precipitation, then it may lead us to a better understanding of such events which further may help us in building more robust weather and climate models. During a heavy precipitation event, scatterometer wind observations may lead us to understand the governing dynamics behind that event near the surface. We hypothesize that scatterometer winds can observe significant changes in the near-surface circulation and that there are global relationships among these quantities. To the degree to which this hypothesis fails, we will learn about the regional behavior of heavy precipitation-producing systems over the <span class="hlt">ocean</span>. We use a "precipitation feature" (PF) approach to enable statistical analysis of a large database of raining features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910059077&hterms=pacific+ocean+phytoplankton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpacific%2Bocean%2Bphytoplankton','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910059077&hterms=pacific+ocean+phytoplankton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpacific%2Bocean%2Bphytoplankton"><span>Role of eddy pumping in enhancing primary <span class="hlt">production</span> in the <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>Falkowski, Paul G.; Kolber, Zbigniew; Ziemann, David; Bienfang, Paul K.</p> <p>1991-01-01</p> <p>Eddy pumping is considered to explain the disparity between geochemical estimates and biological measurements of exported <span class="hlt">production</span>. Episodic nutrient injections from the <span class="hlt">ocean</span> into the photic zone can be generated by eddy pumping, which biological measurements cannot sample accurately. The enhancement of <span class="hlt">production</span> is studied with respect to a cyclonic eddy in the subtropical Pacific. A pump-and-probe fluorimeter generates continuous vertical profiles of primary <span class="hlt">productivity</span> from which the contributions of photochemical and nonphotochemical processes to fluorescence are derived. A significant correlation is observed between the fluorescence measurements and radiocarbon measurements. The results indicate that eddy pumping has an important effect on phytoplankton <span class="hlt">production</span> and that this <span class="hlt">production</span> is near the maximum relative specific growth rates. Based on the <span class="hlt">production</span> enhancement observed in this case, eddy pumping increases total primary <span class="hlt">production</span> by only 20 percent and does not account for all enhancement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....10928V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....10928V"><span>Crustal formation and recycling in an <span class="hlt">oceanic</span> environment in the <span class="hlt">early</span> Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Thienen, P.; van den Berg, A. P.; Vlaar, N. J.</p> <p>2003-04-01</p> <p>Several lines of evidence indicate higher mantle temperatures (by some hundreds of degrees) during the <span class="hlt">early</span> history of the Earth. Due to the strong effect of temperature on viscosity as well as on the degree of melting, this enforces a geodynamic regime which is different from the present plate tectonics, and in which smaller scale processes play a more important role. Upwelling of a hotter mantle produces a thicker <span class="hlt">oceanic</span> crust, of which the lower part may reside in the eclogite stability field. This facilitates delamination, making room for fresh mantle material which may partly melt and add new material to the crust (Vlaar et al., 1994). We present results of numerical thermo-chemical convection models including a simple approximate melt segregation mechanism in which we investigate this alternative geodynamic regime, and its effect on the cooling history and chemical evolution of the mantle. Our results show that the mechanism is capable of working on two scales. On a small scale, involving the lower boundary of the crust, delaminations and downward transport of eclogite into the upper mantle takes place. On a larger scale, involving the entire crustal column, (parts of) the crust may episodically sink into the mantle and be replaced by a fresh crust. Both are capable of significantly and rapidly cooling a hot upper mantle by driving partial melting and thus the generation of new crust. After some hundreds of millions of years, as the temperature drops, the mechanism shuts itself off, and the cooling rate significantly decreases. Vlaar, N.J., P.E. van Keken and A.P. van den Berg (1994), Cooling of the Earth in the Archaean: consequences of pressure-release melting in a hotter mantle, Earth and Planetary Science Letters, vol 121, pp. 1-18</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/2006GBioC..20.4S04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GBioC..20.4S04K"><span><span class="hlt">Production</span> of giant marine diatoms and their export at <span class="hlt">oceanic</span> frontal zones: Implications for Si and C flux from stratified <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>Kemp, A. E. S.; Pearce, R. B.; Grigorov, I.; Rance, J.; Lange, C. B.; Quilty, P.; Salter, I.</p> <p>2006-12-01</p> <p>From a synthesis of recent <span class="hlt">oceanic</span> observations and paleo-data it is evident that certain species of giant diatoms including Rhizosolenia spp. Thalassiothrix spp. and Ethmodiscus rex may become concentrated at <span class="hlt">oceanic</span> frontal zones and subsequently form episodes of mass flux to the sediment. Within the nutrient bearing waters advecting towards frontal boundaries, these species are generally not dominant, but they appear selectively segregated at fronts, and thus may dominate the export flux. Ancient Thalassiothrix diatom mat deposits in the eastern equatorial Pacific and beneath the Polar Front in the Southern <span class="hlt">Ocean</span> record the highest open <span class="hlt">ocean</span> sedimentation rates ever documented and represent vast sinks of silica and carbon. Several of the species involved are adapted to a stratified water column and may thrive in Deep Chlorophyll Maxima. Thus in <span class="hlt">oceanic</span> regions and/or at times prone to enhanced surface water stratification (e.g., during meltwater pulses) they provide a mechanism for generating substantial biomass at depth and its subsequent export with concomitant implications for Si export and C drawdown. This ecology has important implications for <span class="hlt">ocean</span> biogeochemical models suggesting that more than one diatom "functional type" should be used. In spite of the importance of these giant diatoms for biogeochemical cycling, their large size coupled with the constraints of conventional oceanographic survey schemes and techniques means that they are undersampled. An improved insight into these key species will be an important prerequisite for enhancing our understanding of marine biogeochemical cycling and for assessing the impacts of climate change on <span class="hlt">ocean</span> export <span class="hlt">production</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMPP31C1504C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMPP31C1504C"><span>Response of marine biota to a period of <span class="hlt">oceanic</span> anoxia during the Toarcian (<span class="hlt">Early</span> Jurassic)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caswell, B. A.; Coe, A. L.; Cohen, A. S.</p> <p>2008-12-01</p> <p>The <span class="hlt">early</span> Toarcian <span class="hlt">Oceanic</span> Anoxic Event (OAE; 183 Ma) was associated with a species level extinction of marine fauna and a crisis in the marine phytoplankton. The event lasted c. 250 ka and was characterised by a large, negative C-isotope excursion (CIE) of ~-7 per mil in marine organic matter, marine carbonates and fossilized wood. Geochemical evidence suggests that there was a contemporaneous increase in seawater temperature of 6-13° C that was accompanied by a large increase in the rate of global weathering. The present study documents changes in marine macrofauna in the <span class="hlt">early</span> Toarcian at a high resolution and explores how species composition and biometric measurements are linked to geochemical changes. Reanalysis of the published palaeontological data for the Toarcian OAE suggests three apparent extinction horizons on a global and regional scale. The youngest of these horizons coincides exactly with the initial decrease in δ13C, and with the initial increases in sea surface temperature, continental weathering rates and seawater anoxia. New species range data were collected during this study from Toarcian sections in N Yorkshire, England. The results show distinct relationships with high resolution geochemical datasets (Cohen et al. 2007; Pearce et al. 2008). For example, there was an almost complete absence of fauna for 1750-12500 years immediately after each of the four abrupt shifts that make up the overall CIE. Only one bivalve species, Pseudomytiloides dubius, occurs in high abundance throughout the event, except within these discrete horizons. Increased epifaunal bivalve diversity and the reappearance of infauna indicate a brief return to relatively oxygenated conditions towards the end of the CIE. Biometric data were obtained for the two dominant bivalve species P. dubius and Bositra radiata from over 226 stratigraphic levels across the event. The data show that shell size is related to fluctuating seawater anoxia as recorded from Mo abundance and Mo</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PalOc..26.4222H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PalOc..26.4222H"><span>Quantifying export <span class="hlt">production</span> in the Southern <span class="hlt">Ocean</span>: Implications for the Baxs proxy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernandez-Sanchez, Maria T.; Mills, Rachel A.; Planquette, HéLèNe; Pancost, Richard D.; Hepburn, Laura; Salter, Ian; Fitzgeorge-Balfour, Tania</p> <p>2011-12-01</p> <p>The water column and sedimentary Baxs distribution around the Crozet Plateau is used to decipher the controls and timing of barite formation and to evaluate how export <span class="hlt">production</span> signals are recorded in sediments underlying a region of natural Fe fertilization within the Fe limited Southern <span class="hlt">Ocean</span>. Export <span class="hlt">production</span> estimated from preserved, vertical sedimentary Baxs accumulation rates are compared with published export fluxes assessed from an integrated study of the biological carbon pump to determine the validity of Baxs as a quantitative proxy under different Fe supply conditions typical of the Southern <span class="hlt">Ocean</span>. Detailed assessment of the geochemical partitioning of Ba in sediments and the lithogenic end-member allows appropriate correction of the bulk Ba content and determination of the Baxs content of sediments and suspended particles. The upper water column distribution of Baxs is extremely heterogeneous spatially and temporally. Organic carbon/Baxs ratios in deep traps from the Fe fertilized region are similar to other <span class="hlt">oceanic</span> settings allowing quantification of the inferred carbon export based on established algorithms. There appears to be some decoupling of POC and Ba export in the Fe limited region south of the Plateau. The export <span class="hlt">production</span> across the Crozet Plateau inferred from the Baxs sedimentary proxy indicates that the Fe fertilized area to the north of the Plateau experiences enhanced export relative to equivalent Southern <span class="hlt">Ocean</span> settings throughout the Holocene and that this influence may also have impacted the site to the south for significant periods. This interpretation is corroborated by alternative <span class="hlt">productivity</span> proxies (opal accumulation, 231Paxs/230Thxs). Baxs can be used to quantify export <span class="hlt">production</span> in complex settings such as naturally Fe-fertilized (volcanoclastic) areas, providing appropriate lithogenic correction is undertaken, and sediment focusing is corrected for along with evaluation of barite preservation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.7771Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.7771Y"><span>Future change in <span class="hlt">ocean</span> <span class="hlt">productivity</span>: Is the Arctic the new Atlantic?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yool, A.; Popova, E. E.; Coward, A. C.</p> <p>2015-12-01</p> <p>One of the most characteristic features in <span class="hlt">ocean</span> <span class="hlt">productivity</span> is the North Atlantic spring bloom. Responding to seasonal increases in irradiance and stratification, surface phytopopulations rise significantly, a pattern that visibly tracks poleward into summer. While blooms also occur in the Arctic <span class="hlt">Ocean</span>, they are constrained by the sea-ice and strong vertical stratification that characterize this region. However, Arctic sea-ice is currently declining, and forecasts suggest this may lead to completely ice-free summers by the mid-21st century. Such change may open the Arctic up to Atlantic-style spring blooms, and do so at the same time as Atlantic <span class="hlt">productivity</span> is threatened by climate change-driven <span class="hlt">ocean</span> stratification. Here we use low and high-resolution instances of a coupled <span class="hlt">ocean</span>-biogeochemistry model, NEMO-MEDUSA, to investigate <span class="hlt">productivity</span>. Drivers of present-day patterns are identified, and changes in these across a climate change scenario (IPCC RCP 8.5) are analyzed. We find a globally significant decline in North Atlantic <span class="hlt">productivity</span> (> -20%) by 2100, and a correspondingly significant rise in the Arctic (> +50%). However, rather than the future Arctic coming to resemble the current Atlantic, both regions are instead transitioning to a common, low nutrient regime. The North Pacific provides a counterexample where nutrients remain high and <span class="hlt">productivity</span> increases with elevated temperature. These responses to climate change in the Atlantic and Arctic are common between model resolutions, suggesting an independence from resolution for key impacts. However, some responses, such as those in the North Pacific, differ between the simulations, suggesting the reverse and supporting the drive to more fine-scale resolutions. This article was corrected on 5 JAN 2016. See the end of the full text for details.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009847','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009847"><span>NASA In Situ Data Needs to Support the Operational Calibration and Validation of <span class="hlt">Ocean</span> Color Satellite Data <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Werdel, P. Jeremy</p> <p>2012-01-01</p> <p>Calibrating <span class="hlt">ocean</span> color satellite instruments and validating their data <span class="hlt">products</span> requires temporal and spatial abundances of high quality in situ oceanographic data. The Consortium for <span class="hlt">Ocean</span> Leadership <span class="hlt">Ocean</span> Observing Initiative (OOl) is currently implementing a distributed array of in-water sensors that could provide a significant contribution to future <span class="hlt">ocean</span> color activities. This workshop will scope the optimal way to use and possibly supplement the planned OOl infrastructure to maximize its utility and relevance for calibration and validation activities that support existing and planned NASA <span class="hlt">ocean</span> color missions. Here, I present the current state of the art of NASA validation of <span class="hlt">ocean</span> color data <span class="hlt">products</span>, with attention to autonomous time-series (e.g., the AERONET -OC network of above-water radiometers), and outline NASA needs for data quality assurance metrics and adherence to community-vetted data collection protocols</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19..624T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19..624T"><span>Long distance transport of eclogite and blueschist during <span class="hlt">early</span> Pacific <span class="hlt">Ocean</span> subduction rollback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamblyn, Renee; Hand, Martin; Kelsey, David; Phillips, Glen; Anczkiewicz, Robert</p> <p>2017-04-01</p> <p>The Tasmanides in eastern Australia represent a period of continental crustal growth on the western margin of the Pacific <span class="hlt">Ocean</span> associated with slab rollback from the Cambrian until the Triassic. During rollback numerical models predict that subduction <span class="hlt">products</span> can become trapped in the forearc (Geyra et al., 2002), and can migrate with the trench as it retreats. In a long-lived subduction controlled regime such as the Tasmanides, this should result in an accumulation of subduction <span class="hlt">products</span> with protracted geochronological and metamorphic histories. U-Pb, Lu-Hf, Sm-Nd and Ar-Ar geochronology and phase equilibria modelling of lawsonite-eclogite and garnet blueschist in the Southern New England Fold Belt in Australia demonstrate that high-P low-T rocks remained within a subduction setting for c. 40 Ma, from c. 500 to 460 Ma. High-P metamorphic rocks initially formed close to the Australian cratonic margin during the late Cambrian, and were subsequently transported over 1500 Ma oceanward, during which time subducted material continued to accumulate, resulting in the development of complex mélange which records eclogite and blueschist metamorphism and partial exhumation over 40 Ma. The duration of refrigerated metamorphism approximates the extensional evolution of the upper plate which culminated in the development of the Lachlan Fold Belt. The protracted record of eclogite and blueschist metamorphism indicates that rapid exhumation is not necessarily required for preservation of high-pressure metamorphic rocks from subduction systems. Reference: Gerya, T. V., Stockhert, B., & Perchuk, A. L. (2002). Exhumation of high-pressure metamorphic rocks in a subduction channel: A numerical simulation. Tectonics, 21(6), 6-1-6-19. doi:10.1029/2002tc001406</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020016072&hterms=marine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmarine','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020016072&hterms=marine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmarine"><span>Validation of <span class="hlt">Ocean</span> Color Satellite Data <span class="hlt">Products</span> in Under Sampled Marine Areas. Chapter 6</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Subramaniam, Ajit; Hood, Raleigh R.; Brown, Christopher W.; Carpenter, Edward J.; Capone, Douglas G.</p> <p>2001-01-01</p> <p>The planktonic marine cyanobacterium, Trichodesmium sp., is broadly distributed throughout the oligotrophic marine tropical and sub-tropical <span class="hlt">oceans</span>. Trichodesmium, which typically occurs in macroscopic bundles or colonies, is noteworthy for its ability to form large surface aggregations and to fix dinitrogen gas. The latter is important because primary <span class="hlt">production</span> supported by N2 fixation can result in a net export of carbon from the surface waters to deep <span class="hlt">ocean</span> and may therefore play a significant role in the global carbon cycle. However, information on the distribution and density of Trichodesmium from shipboard measurements through the oligotrophic <span class="hlt">oceans</span> is very sparse. Such estimates are required to quantitatively estimate total global rates of N2 fixation. As a result current global rate estimates are highly uncertain. Thus in order to understand the broader biogeochemical importance of Trichodesmium and N2 fixation in the <span class="hlt">oceans</span>, we need better methods to estimate the global temporal and spatial variability of this organism. One approach that holds great promise is satellite remote sensing. Satellite <span class="hlt">ocean</span> color sensors are ideal instruments for estimating global phytoplankton biomass, especially that due to episodic blooms, because they provide relatively high frequency synoptic information over large areas. Trichodesmium has a combination of specific ultrastructural and biochemical features that lend themselves to identification of this organism by remote sensing. Specifically, these features are high backscatter due to the presence of gas vesicles, and absorption and fluorescence of phycoerythrin. The resulting optical signature is relatively unique and should be detectable with satellite <span class="hlt">ocean</span> color sensors such as the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2440A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2440A"><span>Reduced prokaryotic heterotrophic <span class="hlt">production</span> at in situ pressure conditions in the dark <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>Amano-Sato, Chie; Sintes, Eva; Reinthaler, Thomas; Utsumi, Motoo; Herndl, Gerhard J.</p> <p>2017-04-01</p> <p>Prokaryotic heterotrophic <span class="hlt">production</span> (PHP) is a key process in the <span class="hlt">ocean</span>'s biological carbon cycle. About 50% of the <span class="hlt">oceanic</span> PHP takes place in the dark <span class="hlt">ocean</span> characterized by low temperature and high hydrostatic pressure, which increases by 1 MPa (10 atm) every 100 m depth. However, rate measurements of PHP are usually performed under atmospheric pressure conditions. Yet, the difference in pressure conditions and the handling of the samples on board may introduce biases in the PHP measurements. To determine PHP at in situ conditions, we developed an in situ microbial incubator (ISMI) designed to autonomously sample and incubate seawater down to a depth of 4000 m. Natural prokaryotic communities from the North Atlantic and Pacific <span class="hlt">Oceans</span> were incubated in the ISMI with 5 nM 3H-leucine at different depths ranging between 10 and 3200 m. For comparison, atmospheric pressure incubations at in situ temperature were also conducted. PHP and single cell activity assessed by microautoradiography combined with catalyzed reporter deposition fluorescence in situ hybridization (MICRO-CARD-FISH) were determined. PHP obtained under in situ pressure conditions was generally lower than under atmospheric pressure conditions, suggesting that incubation under atmospheric pressure on board stimulates activity of dark <span class="hlt">ocean</span> prokaryotes. The ratio between the bulk PHP obtained under in situ and under atmospheric pressure conditions decreased with depth. Moreover, MICRO-CARD-FISH revealed that some specific prokaryotic groups are apparently more affected by the hydrostatic pressure condition than others. Our results suggest that PHP in the dark <span class="hlt">ocean</span> might be lower than assumed based on measurements under surface pressure conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME54B2390B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME54B2390B"><span>Near Real Time Operational Satellite <span class="hlt">Ocean</span> Color <span class="hlt">Products</span> From NOAA OSPO CoastWatch Okeanos System:: Status and Challenges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banghua Yan, B.</p> <p>2016-02-01</p> <p>Near real-time (NRT) <span class="hlt">ocean</span> color (OC) satellite operation <span class="hlt">products</span> are generated and distributed in NOAA Okeanos Operational <span class="hlt">Product</span> System, by using the CWAPS including the Multi-Sensor Level (MSL) 12 and the chlorophyll-a frontal algorithms. Current OC operational <span class="hlt">products</span> include daily chlorophyll concentration (anomaly), water turbidity, remote sensing reflectance and chlorophyll frontal <span class="hlt">products</span> from Moderate-resolution Imaging Spectroradiometer (MODIS)/Aqua. The <span class="hlt">products</span> have been widely applied to USA local and state ecosystem research, ecosystem observations, and fisheries managements for coastal and regional forecasting of <span class="hlt">ocean</span> water quality, phytoplankton concentrations, and primary <span class="hlt">production</span>. Users of the <span class="hlt">products</span> have the National <span class="hlt">Ocean</span> Service, National Marine Fisheries Service, National Weather Service, and <span class="hlt">Oceanic</span> and Atmospheric Research. Recently, the OC <span class="hlt">products</span> are being extended to S-NPP VIIRS to provide global NRT <span class="hlt">ocean</span> color <span class="hlt">products</span> to user community suh as National Weatrher Service for application for Global Data Assimilation System and Real-Time <span class="hlt">Ocean</span> Forecast System. However, there remain some challenges in application of the <span class="hlt">products</span> due to certain <span class="hlt">product</span> quality and coverage issues. Recent efforts were made to provide a comprehensive web-based Quality Assurance (QA) tool for monitoring OC <span class="hlt">products</span> quality in near real time mode, referring to http://www.ospo.noaa.gov/<span class="hlt">Products/ocean</span>/color_new/color.htm. The new QA monitoring tool includes but not limited to the following advanced features applicable for MODIS/Aqua and NPP/VIIRS OC <span class="hlt">products</span>: 1) Monitoring <span class="hlt">product</span> quality in NRT mode; 2) Monitoring the availability and quality of OC <span class="hlt">products</span> with time; 3) Detecting anomalous OC <span class="hlt">products</span> due to low valid pixels and other quality issues. As an example, potential application and challenges of the <span class="hlt">ocean</span> color <span class="hlt">products</span> to <span class="hlt">oceanic</span> oil spill detection are investigated. It is thus expected that the Okeanos <span class="hlt">ocean</span> color operational system in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030063259&hterms=5S&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D5S','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030063259&hterms=5S&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D5S"><span>Were <span class="hlt">Ocean</span> Impacts an Important Mechanism to Deliver Meteoritic Organic Matter to the <span class="hlt">Early</span> Earth? Some Inferences from Eltanin</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kyte, Frank T.; Gersonde, Rainer; Kuhn. Gerhard</p> <p>2002-01-01</p> <p>Several workers have addressed the potential for extraterrestrial delivery of volatles, including water and complex organic compounds, to the <span class="hlt">early</span> Earth. For example, Chyba and Sagan (1992) argued that since impacts would destroy organic matter, most extraterrestrial organics must be delivered in the fine-fractions of interplanetary dust. More recent computer simulations (Pierazzo and Chyba, 1999), however, have shown that substantial amounts of amino acids may survive the impacts of large (km-sized) comets and that this may exceed the amounts derived from IDPs or Miller-Urey synthesis in the atmosphere. Once an <span class="hlt">ocean</span> developed on the <span class="hlt">early</span> Earth, impacts of small ,asteroids and comets into deep-<span class="hlt">ocean</span> basins were potentially common and may have been the most likely events to deliver large amounts of organics. The deposits of the late Pliocene impact of the Eltanin asteroid into the Bellingshausen Sea provide the only record of a deep-<span class="hlt">ocean</span> (approx. 5 km) impact that can be used to constrain models of these events. This impact was first discovered in 1981 as an Ir anomaly in sediment cores collected by the USNS Eltanin in 1965 (Kyte et al., 1981). In 1995, Polarstem expedition ANT XII/4 made the first geological survey of the suspected impact region. Three sediment cores sampled around the San Martin seamounts (approx. 57.5S, 91 W) contained well-preserved impact deposits that include disturbed <span class="hlt">ocean</span> sediments and meteoritic impact ejecta (Gersonde et al., 1997). The latter is composed of shock- melted asteroidal materials and unmelted meteorites. In 2001, the FS Polarstem returned to the impact area during expedition ANT XVIII/5a. At least 16 cores were recovered that contain ejecta deposits. These cores and geophysical data from the expedition can be used to map the effects of the impact over a large region of the <span class="hlt">ocean</span> floor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.7849S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.7849S"><span>Late Jurassic - <span class="hlt">Early</span> Cretaceous convergent margins of Northeastern Asia with Northwestern Pacific and Proto-Arctic <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>Sokolov, Sergey; Luchitskaya, Marina; Tuchkova, Marianna; Moiseev, Artem; Ledneva, Galina</p> <p>2013-04-01</p> <p>Continental margin of Northeastern Asia includes many island arc terranes that differ in age and tectonic position. Two convergent margins are reconstructed for Late Jurassic - <span class="hlt">Early</span> Cretaceous time: Uda-Murgal and Alazeya - Oloy island arc systems. A long tectonic zone composed of Upper Jurassic to Lower Cretaceous volcanic and sedimentary rocks is recognized along the Asian continent margin from the Mongol-Okhotsk thrust-fold belt on the south to the Chukotka Peninsula on the north. This belt represents the Uda-Murgal arc, which was developed along the convergent margin between Northeastern Asia and Northwestern Meso-Pacific. Several segments are identified in this arc based upon the volcanic and sedimentary rock assemblages, their respective compositions and basement structures. The southern and central parts of the Uda-Murgal island arc system were a continental margin belt with heterogeneous basement represented by metamorphic rocks of the Siberian craton, the Verkhoyansk terrigenous complex of Siberian passive margin and the Koni-Taigonos late Paleozoic to <span class="hlt">early</span> Mesozoic island arc with accreted <span class="hlt">oceanic</span> terranes. At the present day latitude of the Pekulney and Chukotka segments there was an ensimatic island arc with relicts of the South Anyui <span class="hlt">oceanic</span> basin in backarc basin. Alazeya-Oloy island arc systems consists of Paleozoic and Mesozoic complexes that belong to the convergent margin between Northeastern Asia and Proto-Artic <span class="hlt">Ocean</span>. It separated structures of the North American and Siberian continents. The Siberian margin was active whereas the North American margin was passive. The Late Jurassic was characterized by termination of a spreading in the Proto-Arctic <span class="hlt">Ocean</span> and transformation of the latter into the closing South Anyui turbidite basin. In the beginning the <span class="hlt">oceanic</span> lithosphere and then the Chukotka microcontinent had been subducted beneath the Alazeya-Oloy volcanic belt</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4438723','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4438723"><span>Shallow methylmercury <span class="hlt">production</span> in the marginal sea ice zone of the central Arctic <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>Heimbürger, Lars-Eric; Sonke, Jeroen E.; Cossa, Daniel; Point, David; Lagane, Christelle; Laffont, Laure; Galfond, Benjamin T.; Nicolaus, Marcel; Rabe, Benjamin; van der Loeff, Michiel Rutgers</p> <p>2015-01-01</p> <p>Methylmercury (MeHg) is a neurotoxic compound that threatens wildlife and human health across the Arctic region. Though much is known about the source and dynamics of its inorganic mercury (Hg) precursor, the exact origin of the high MeHg concentrations in Arctic biota remains uncertain. Arctic coastal sediments, coastal marine waters and surface snow are known sites for MeHg <span class="hlt">production</span>. Observations on marine Hg dynamics, however, have been restricted to the Canadian Archipelago and the Beaufort Sea (<79°N). Here we present the first central Arctic <span class="hlt">Ocean</span> (79–90°N) profiles for total mercury (tHg) and MeHg. We find elevated tHg and MeHg concentrations in the marginal sea ice zone (81–85°N). Similar to other open <span class="hlt">ocean</span> basins, Arctic MeHg concentration maxima also occur in the pycnocline waters, but at much shallower depths (150–200 m). The shallow MeHg maxima just below the <span class="hlt">productive</span> surface layer possibly result in enhanced biological uptake at the base of the Arctic marine food web and may explain the elevated MeHg concentrations in Arctic biota. We suggest that Arctic warming, through thinning sea ice, extension of the seasonal sea ice zone, intensified surface <span class="hlt">ocean</span> stratification and shifts in plankton ecodynamics, will likely lead to higher marine MeHg <span class="hlt">production</span>. PMID:25993348</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28550281','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28550281"><span>Decadal Variations in Eastern Canada's Taiga Wood Biomass <span class="hlt">Production</span> Forced by <span class="hlt">Ocean</span>-Atmosphere Interactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boucher, Etienne; Nicault, Antoine; Arseneault, Dominique; Bégin, Yves; Karami, Mehdi Pasha</p> <p>2017-05-26</p> <p>Across Eastern Canada (EC), taiga forests represent an important carbon reservoir, but the extent to which climate variability affects this ecosystem over decades remains uncertain. Here, we analyze an extensive network of black spruce (Picea mariana Mill.) ring width and wood density measurements and provide new evidence that wood biomass <span class="hlt">production</span> is influenced by large-scale, internal <span class="hlt">ocean</span>-atmosphere processes. We show that while black spruce wood biomass <span class="hlt">production</span> is primarily governed by growing season temperatures, the Atlantic <span class="hlt">ocean</span> conveys heat from the subtropics and influences the decadal persistence in taiga forests <span class="hlt">productivity</span>. Indeed, we argue that 20-30 years periodicities in Sea Surface Temperatures (SSTs) as part of the the Atlantic Multi-decadal Oscillation (AMO) directly influence heat transfers to adjacent lands. Winter atmospheric conditions associated with the North Atlantic Oscillation (NAO) might also impact EC's taiga forests, albeit indirectly, through its effect on SSTs and sea ice conditions in surrounding seas. Our work emphasizes that taiga forests would benefit from the combined effects of a warmer atmosphere and stronger <span class="hlt">ocean</span>-to-land heat transfers, whereas a weakening of these transfers could cancel out, for decades or longer, the positive effects of climate change on Eastern Canada's largest ecosystem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRG..119..929R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRG..119..929R"><span>UV sensitivity of planktonic net community <span class="hlt">production</span> in <span class="hlt">ocean</span> surface waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Regaudie-de-Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.</p> <p>2014-05-01</p> <p>The net plankton community metabolism of <span class="hlt">oceanic</span> surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we test the sensitivity of net community <span class="hlt">production</span> (NCP) to UVB of planktonic communities in surface waters across contrasting regions of the <span class="hlt">ocean</span>. We observed here that UVB radiation affects net plankton community <span class="hlt">production</span> at the <span class="hlt">ocean</span> surface, imposing a shift in NCP by, on average, 50% relative to the values measured when excluding partly UVB. Our results show that under full solar radiation, the metabolic balance shows the prevalence of net heterotrophic community <span class="hlt">production</span>. The demonstration of an important effect of UVB radiation on NCP in surface waters presented here is of particular relevance in relation to the increased UVB radiation derived from the erosion of the stratospheric ozone layer. Our results encourage design future research to further our understanding of UVB effects on the metabolic balance of plankton communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25993348','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25993348"><span>Shallow methylmercury <span class="hlt">production</span> in the marginal sea ice zone of the central Arctic <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>Heimbürger, Lars-Eric; Sonke, Jeroen E; Cossa, Daniel; Point, David; Lagane, Christelle; Laffont, Laure; Galfond, Benjamin T; Nicolaus, Marcel; Rabe, Benjamin; van der Loeff, Michiel Rutgers</p> <p>2015-05-20</p> <p>Methylmercury (MeHg) is a neurotoxic compound that threatens wildlife and human health across the Arctic region. Though much is known about the source and dynamics of its inorganic mercury (Hg) precursor, the exact origin of the high MeHg concentrations in Arctic biota remains uncertain. Arctic coastal sediments, coastal marine waters and surface snow are known sites for MeHg <span class="hlt">production</span>. Observations on marine Hg dynamics, however, have been restricted to the Canadian Archipelago and the Beaufort Sea (<79 °N). Here we present the first central Arctic <span class="hlt">Ocean</span> (79-90 °N) profiles for total mercury (tHg) and MeHg. We find elevated tHg and MeHg concentrations in the marginal sea ice zone (81-85 °N). Similar to other open <span class="hlt">ocean</span> basins, Arctic MeHg concentration maxima also occur in the pycnocline waters, but at much shallower depths (150-200 m). The shallow MeHg maxima just below the <span class="hlt">productive</span> surface layer possibly result in enhanced biological uptake at the base of the Arctic marine food web and may explain the elevated MeHg concentrations in Arctic biota. We suggest that Arctic warming, through thinning sea ice, extension of the seasonal sea ice zone, intensified surface <span class="hlt">ocean</span> stratification and shifts in plankton ecodynamics, will likely lead to higher marine MeHg <span class="hlt">production</span>.</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 <span class="hlt">Production</span> Model for the Global <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 global carbon cycle, understanding how net primary <span class="hlt">production</span> (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 global <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/2008AGUFM.V24A..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.V24A..04E"><span>Evolution and <span class="hlt">Production</span> of Calcareous Nannoplankton During the Cretaceous as Proxies of LIP-induced <span class="hlt">Oceanic</span> Fertilization, Acidification and Anoxia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Erba, E.; Bottini, C.; Tiraboschi, D.</p> <p>2008-12-01</p> <p>Through the Phanerozoic, biota have been intimately linked to Earth's degassing inducing major changes in composition and structure of the <span class="hlt">ocean</span>-atmosphere system. Emplacement of large igneous provinces (LIPs) has been the primary natural source of atmCO2 with dramatic consequences on climate and ecosystems. During the mid-Cretaceous the Ontong Java-Manihiki and Caribbean Plateaus LIPs are recognized as responsible of pCO2 as high as 2000 ppm. Coeval biocalcification crises occurred in pelagic and neritic settings, suggesting a causal link between high concentrations of carbon dioxide and drops in benthic and planktonic calcifiers' efficiency. Within the <span class="hlt">oceanic</span> biosphere, calcareous nannoplankton play a key-role as: (1) is widespread and consists of cosmopolitan and endemic taxa; (2) has a 220 My-long evolutionary history; (3) is one the most effective calcite producers; (4) is relevant for the C cycle; (5) is extremely sensitive to environmental variations. Diversity pulses of Cretaceous calcareous nannoplankton are grossly coeval with LIP construction, climate and sea-level changes, variations in <span class="hlt">ocean</span> structure and composition, suggesting that evolutionary patterns are closely linked to environmental modifications. We explored time-intervals of LIP formation marked by nannoplankton adaptation/evolution, quantifying evolutionary rates, species richness, abundance, calcite <span class="hlt">production</span> and morphometry. High-resolution investigations of the initial phase of both <span class="hlt">early</span> Aptian <span class="hlt">oceanic</span> anoxic event (OAE) 1a and latest Cenomanian OAE 2 pointed out major evolutionary changes, decreases in heavily calcified nannoliths and occurrence of dwarf coccoliths. Nannoplankton calcification crises and dwarfism is here interpreted as forced by rapidly increasing pCO2 during formation of the Ontong Java-Maniniki and Caribbean Plateaus. Alternatively or concurrently, calcification crash and dwarfism might result from enhanced fertility associated to OAE1a and OAE2 regardless of <span class="hlt">ocean</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP14A..04G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP14A..04G"><span>Using Triple Oxygen Isotope Analyses of Biogenic Carbonate to Reconstruct <span class="hlt">Early</span> Triassic <span class="hlt">Ocean</span> Oxygen Isotopic Values and Temperatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gibbons, J. A.; Sharp, Z. D.; Atudorei, V.</p> <p>2017-12-01</p> <p>The calcite-water triple oxygen isotope fractionation is used to determine isotopic equilibrium and ancient <span class="hlt">ocean</span> oxygen isotopic values and temperatures. Unlike conventional δ18O analysis where the formation water's isotopic value is assumed, paired δ17O-δ18O measurements allow for the water's isotopic composition to be calculated because there is only one unique solution for equilibrium fractionation using Δ17O-δ18O values (where Δ17O=δ17O-0.528δ18O). To a first approximation, the calcite-water equilibrium fractionation factor, θ (where θ=ln17α/ln18α), varies with temperature by 0.00001/°. The calcite-water equilibrium fractionation line was determined at two temperatures, 30° and 0°, by using modern carbonate samples that formed in <span class="hlt">ocean</span> water with a δ18O value of 0‰. The θ values for the 30° and 0° samples are 0.52515 and 0.52486, respectively. Oxygen values were measured using complete fluorination in nickel tubes with BrF5 as the reaction reagent. We calibrated all oxygen values to the SMOW-SLAP scale by measuring SMOW, SLAP, San Carlos olivine, NBS-18, NBS-19, and PDB. The triple oxygen isotope calcite-water equilibrium fractionation line was applied to well preserved <span class="hlt">Early</span> Triassic ammonite shells from the Western United States. Based on paired δ17O-δ18O measurements, the samples did not form in equilibrium with an ice-free <span class="hlt">ocean</span> with an oxygen isotopic value of -1‰ or the modern <span class="hlt">ocean</span> value of 0‰. Assuming the calcite is still primary and formed in equilibrium with the <span class="hlt">ocean</span> water, our data indicate that the δ18O value of the <span class="hlt">ocean</span> in the <span class="hlt">early</span> Triassic was 3-5‰ lower than modern. Samples from the Smithian thermal maximum formed in water 10° warmer than samples from after the thermal maximum. Paired δ17O-δ18O measurements of pristine ancient carbonates may provide a better understanding of past <span class="hlt">ocean</span> conditions during climate change events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GPC...162...53F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GPC...162...53F"><span>The <span class="hlt">Early</span> Toarcian <span class="hlt">oceanic</span> anoxic event: Paleoenvironmental and paleoclimatic change across the Alpine Tethys (Switzerland)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Montero-Serrano, Jean-Carlos</p> <p>2018-03-01</p> <p>Paleoenvironmental and paleoclimatic change associated with the Toarcian <span class="hlt">oceanic</span> anoxic event (T-OAE) was evaluated in five successions located in Switzerland. They represent different paleogeographic settings across the Alpine Tethys: the northern shelf (Gipf, Riniken and Rietheim), the Sub-Briançonnais basin (Creux de l'Ours), and the Lombardian basin (Breggia). The multi-proxy approach chosen (whole-rock and clay mineralogy, phosphorus, major and trace elements) shows that local environmental conditions modulated the response to the T-OAE across the Alpine Tethys. On the northern shelf and in the Sub-Briançonnais basin, high kaolinite contents and detrital proxies (detrital index, Ti, Zr, Si) in the T-OAE interval suggest a change towards a warmer and more humid climate coupled with an increase in the chemical weathering rates. In contrast, low kaolinite content in the Lombardian basin is likely related to a more arid climate along the southern Tethys margin and/or to a deeper and more distal setting. Redox-sensitive trace-element (V, Mo, Cu, Ni) enrichments in the T-OAE intervals reveal that dysoxic to anoxic conditions developed on the northern shelf, whereas reducing conditions were less severe in the Sub-Briançonnais basin. In the Lombardian basin well-oxygenated bottom water conditions prevailed. Phosphorus (P) speciation analysis was performed at Riniken and Creux de l'Ours. This is the first report of P speciation data for T-OAE sections, clearly suggesting that high P contents during this time interval are mainly linked to the presence of an authigenic phases and fish remains. The development of oxygen-depleted conditions during the T-OAE seems to have promoted the release of the organic-bound P back into the water column, thereby further sustaining primary <span class="hlt">productivity</span> in a positive feedback loop.</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 global per capita agricultural <span class="hlt">production</span> and warming <span class="hlt">oceans</span> threaten food security</span></a></p> <p><a target="_blank" href=""></a></p> <p>Funk, Christopher C.; Brown, Molly E.</p> <p>2009-01-01</p> <p>Despite accelerating globalization, most people still eat food that is grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or <span class="hlt">production</span> declines. Local agricultural <span class="hlt">production</span>, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural <span class="hlt">production</span>, 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 global 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 <span class="hlt">production</span>. Global per capita cereal <span class="hlt">production</span> will potentially decline by 14% between 2008 and 2030. Climate change is likely to further affect food <span class="hlt">production</span>, 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('https://ntrs.nasa.gov/search.jsp?R=19910063775&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dbiomass%2Bproduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910063775&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dbiomass%2Bproduction"><span>Basin-scale estimates of <span class="hlt">oceanic</span> primary <span class="hlt">production</span> by remote sensing - The North Atlantic</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Platt, Trevor; Caverhill, Carla; Sathyendranath, Shubha</p> <p>1991-01-01</p> <p>The monthly averaged CZCS data for 1979 are used to estimate annual primary <span class="hlt">production</span> at <span class="hlt">ocean</span> basin scales in the North Atlantic. The principal supplementary data used were 873 vertical profiles of chlorophyll and 248 sets of parameters derived from photosynthesis-light experiments. Four different procedures were tested for calculation of primary <span class="hlt">production</span>. The spectral model with nonuniform biomass was considered as the benchmark for comparison against the other three models. The less complete models gave results that differed by as much as 50 percent from the benchmark. Vertically uniform models tended to underestimate primary <span class="hlt">production</span> by about 20 percent compared to the nonuniform models. At horizontal scale, the differences between spectral and nonspectral models were negligible. The linear correlation between biomass and estimated <span class="hlt">production</span> was poor outside the tropics, suggesting caution against the indiscriminate use of biomass as a proxy variable for primary <span class="hlt">production</span>.</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 Global Phytoplankton, Nutrients, and Primary <span class="hlt">Production</span></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 global <span class="hlt">oceans</span>. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary <span class="hlt">production</span>. 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 global <span class="hlt">ocean</span> primary <span class="hlt">production</span>. Global 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 <span class="hlt">production</span> (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. Global 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('http://adsabs.harvard.edu/abs/2005AGUFMPP51C0617B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMPP51C0617B"><span>A Giant Arctic Freshwater Pond at the end of the <span class="hlt">Early</span> Eocene; Implications for <span class="hlt">Ocean</span> Heat Transport and Carbon Cycling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brinkhuis, H.; Schouten, S.; Collinson, M. E.; Sluijs, A.; Sinninghe-Damste, J. S.; Dickens, G. R.; Huber, M.; Cronin, T. M.; Bujak, J. P.; Stein, R.; Eldrett, J. S.; Harding, I. C.; Sangiorgi, F.</p> <p>2005-12-01</p> <p>In the last decades remains of the free-floating, fresh water fern Azolla have been found in unusually high abundances in basal middle Eocene (~48.5 Ma) marine sediments deposited in all Nordic seas. While generally taken to signal some `freshwater input', their source and significance were not determined. Through palynological and organic geochemical analyses of unique cores obtained from unprecedented Arctic <span class="hlt">Ocean</span> drilling (IODP 302 - ACEX) we show that the brackish surface conditions that prevailed in the Arctic <span class="hlt">Ocean</span> through the late Paleocene and <span class="hlt">early</span> Eocene culminated in the deposition of laminated organic rich deposits yielding huge amounts of remains of Azolla. This, plus e.g., low diversity dinoflagellate assemblages, and concomitant low BIT values, indicates in-situ Azolla growth, and that the surface of the Arctic <span class="hlt">Ocean</span> episodically resembled a giant fresh water pond over an interval altogether lasting ~800,000 years. The Arctic Basin thus constituted the main source of the freshwater pulses found elsewhere, reaching as far south as the southern North Sea.TEX86-derived surface temperatures were 13-14°C before and after the Azolla interval and only 10°C during the event, which may be related to obstruction of pole ward <span class="hlt">ocean</span> heat transport and/or increased carbon burial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PalOc..31.1532Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PalOc..31.1532Z"><span>Expanded oxygen minimum zones during the late Paleocene-<span class="hlt">early</span> Eocene: Hints from multiproxy comparison and <span class="hlt">ocean</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>Zhou, X.; Thomas, E.; Winguth, A. M. E.; Ridgwell, A.; Scher, H.; Hoogakker, B. A. A.; Rickaby, R. E. M.; Lu, Z.</p> <p>2016-12-01</p> <p>Anthropogenic warming could well drive depletion of <span class="hlt">oceanic</span> oxygen in the future. Important insight into the relationship between deoxygenation and warming can be gleaned from the geological record, but evidence is limited because few <span class="hlt">ocean</span> oxygenation records are available for past greenhouse climate conditions. We use I/Ca in benthic foraminifera to reconstruct late Paleocene through <span class="hlt">early</span> Eocene bottom and pore water redox conditions in the South Atlantic and Southern Indian <span class="hlt">Oceans</span> and compare our results with those derived from Mn speciation and the Ce anomaly in fish teeth. We conclude that waters with lower oxygen concentrations were widespread at intermediate depths (1.5-2 km), whereas bottom waters were more oxygenated at the deepest site, in the Southeast Atlantic <span class="hlt">Ocean</span> (>3 km). Epifaunal benthic foraminiferal I/Ca values were higher in the late Paleocene, especially at low-oxygen sites, than at well-oxygenated modern sites, indicating higher seawater total iodine concentrations in the late Paleocene than today. The proxy-based bottom water oxygenation pattern agrees with the site-to-site O2 gradient as simulated in a comprehensive climate model (Community Climate System Model Version 3), but the simulated absolute dissolved O2 values are low (< 35 µmol/kg), while higher O2 values ( 60-100 µmol/kg) were obtained in an Earth system model (Grid ENabled Integrated Earth system model). Multiproxy data together with improvements in boundary conditions and model parameterization are necessary if the details of past oceanographic oxygenation are to be resolved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27966594','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27966594"><span>Meteorite Impact-Induced Rapid NH3 <span class="hlt">Production</span> on <span class="hlt">Early</span> Earth: Ab Initio Molecular Dynamics Simulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shimamura, Kohei; Shimojo, Fuyuki; Nakano, Aiichiro; Tanaka, Shigenori</p> <p>2016-12-14</p> <p>NH 3 is an essential molecule as a nitrogen source for prebiotic amino acid syntheses such as the Strecker reaction. Previous shock experiments demonstrated that meteorite impacts on ancient <span class="hlt">oceans</span> would have provided a considerable amount of NH 3 from atmospheric N 2 and <span class="hlt">oceanic</span> H 2 O through reduction by meteoritic iron. However, specific <span class="hlt">production</span> mechanisms remain unclear, and impact velocities employed in the experiments were substantially lower than typical impact velocities of meteorites on the <span class="hlt">early</span> Earth. Here, to investigate the issues from the atomistic viewpoint, we performed multi-scale shock technique-based ab initio molecular dynamics simulations. The results revealed a rapid <span class="hlt">production</span> of NH 3 within several picoseconds after the shock, indicating that shocks with greater impact velocities would provide further increase in the yield of NH 3 . Meanwhile, the picosecond-order <span class="hlt">production</span> makes one expect that the important nitrogen source precursors of amino acids were obtained immediately after the impact. It was also observed that the reduction of N 2 proceeded according to an associative mechanism, rather than a dissociative mechanism as in the Haber-Bosch process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PrOce..78..135K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PrOce..78..135K"><span>Modeling <span class="hlt">ocean</span> primary <span class="hlt">production</span>: Sensitivity to spectral resolution of attenuation and absorption of light</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kettle, Helen; Merchant, Chris J.</p> <p>2008-08-01</p> <p>Modeling the vertical penetration of photosynthetically active radiation (PAR) through the <span class="hlt">ocean</span>, and its utilization by phytoplankton, is fundamental to simulating marine primary <span class="hlt">production</span>. The variation of attenuation and absorption of light with wavelength suggests that photosynthesis should be modeled at high spectral resolution, but this is computationally expensive. To model primary <span class="hlt">production</span> in global 3d models, a balance between computer time and accuracy is necessary. We investigate the effects of varying the spectral resolution of the underwater light field and the photosynthetic efficiency of phytoplankton ( α∗), on primary <span class="hlt">production</span> using a 1d coupled ecosystem <span class="hlt">ocean</span> turbulence model. The model is applied at three sites in the Atlantic <span class="hlt">Ocean</span> (CIS (∼60°N), PAP (∼50°N) and ESTOC (∼30°N)) to include the effect of different meteorological forcing and parameter sets. We also investigate three different methods for modeling α∗ - as a fixed constant, varying with both wavelength and chlorophyll concentration [Bricaud, A., Morel, A., Babin, M., Allali, K., Claustre, H., 1998. Variations of light absorption by suspended particles with chlorophyll a concentration in <span class="hlt">oceanic</span> (case 1) waters. Analysis and implications for bio-optical models. J. Geophys. Res. 103, 31033-31044], and using a non-spectral parameterization [Anderson, T.R., 1993. A spectrally averaged model of light penetration and photosynthesis. Limnol. Oceanogr. 38, 1403-1419]. After selecting the appropriate ecosystem parameters for each of the three sites we vary the spectral resolution of light and α∗ from 1 to 61 wavebands and study the results in conjunction with the three different α∗ estimation methods. The results show modeled estimates of <span class="hlt">ocean</span> primary <span class="hlt">productivity</span> are highly sensitive to the degree of spectral resolution and α∗. For accurate simulations of primary <span class="hlt">production</span> and chlorophyll distribution we recommend a spectral resolution of at least six wavebands</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A51I3147H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A51I3147H"><span>An Inter-calibrated Passive Microwave Brightness Temperature Data Record and <span class="hlt">Ocean</span> <span class="hlt">Products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hilburn, K. A.; Wentz, F. J.</p> <p>2014-12-01</p> <p>Inter-calibration of passive microwave sensors has been the subject of on-going activity at Remote Sensing Systems (RSS) since 1974. RSS has produced a brightness temperature TB data record that spans the last 28 years (1987-2014) from inter-calibrated passive microwave sensors on 14 satellites: AMSR-E, AMSR2, GMI, SSMI F08-F15, SSMIS F16-F18, TMI, WindSat. Accompanying the TB record are a suite of <span class="hlt">ocean</span> <span class="hlt">products</span> derived from the TBs that provide a 28-year record of wind speed, water vapor, cloud liquid, and rain rate; and 18 years (1997-2014) of sea surface temperatures, corresponding to the period for which 6 and/or 10 GHz measurements are available. Crucial to the inter-calibration and <span class="hlt">ocean</span> <span class="hlt">product</span> retrieval are a highly accurate radiative transfer model RTM. The RSS RTM has been continually refined for over 30 years and is arguably the most accurate model in the 1-100 GHz spectrum. The current generation of TB and <span class="hlt">ocean</span> <span class="hlt">products</span>, produced using the latest version of the RTM, is called Version-7. The accuracy of the Version-7 inter-calibration is estimated to be 0.1 K, based on inter-satellite comparisons and validation of the <span class="hlt">ocean</span> <span class="hlt">products</span> against in situ measurements. The data record produced by RSS has had a significant scientific impact. Over just the last 14 years (2000-2013) RSS data have been used in 743 peer-reviewed journal articles. This is an average of 4.5 peer-reviewed papers published every month made possible with RSS data. Some of the most important scientific contributions made by RSS data have been to the study of the climate. The AR5 Report "Climate Change 2013: The Physical Science Basis" by the Intergovernmental Panel on Climate Change (IPCC), the internationally accepted authority on climate change, references 20 peer-reviewed journal papers from RSS scientists. The report makes direct use of RSS water vapor data, RSS atmospheric temperatures from MSU/AMSU, and 9 other datasets that are derived from RSS data. The RSS TB data record is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850052896&hterms=abbott+lab&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dabbott%2Blab','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850052896&hterms=abbott+lab&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dabbott%2Blab"><span>Estimating <span class="hlt">ocean</span> <span class="hlt">production</span> from satellite-derived chlorophyll - Insights from the EASTROPAC data set</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eppley, R. W.; Stewart, E.; Abbott, M. R.; Owen, R. W.</p> <p>1985-01-01</p> <p>The EASTROPAC expedition took place in 1967-68 in the eastern tropical Pacific <span class="hlt">Ocean</span>. Primary <span class="hlt">production</span> was related to near-surface chlorophyll in these data. Much of the variability in the relation was due to the light-history of the phytoplankton and its photoadaptive state. This was due to changes in the depth of mixing of the surface waters more than changes in insolation. Accurate estimates of <span class="hlt">production</span> from satellite chlorophyll measurements may require knowledge of the temporal and spatial variation in mixing of this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26709562','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26709562"><span>Publication <span class="hlt">Productivity</span> of <span class="hlt">Early</span>-Career Orthopedic Trauma Surgeons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hake, Mark E; Lee, John J; Goulet, James A</p> <p>2016-01-01</p> <p>The goals of this study were to: (1) define the publication <span class="hlt">productivity</span> of <span class="hlt">early</span>-career orthopedic trauma surgeons over time; (2) compare the <span class="hlt">early</span>-career publication <span class="hlt">productivity</span> of recent orthopedic trauma fellowship graduates vs their more senior colleagues; and (3) determine the proportion of fellowship graduates who meet the Orthopaedic Trauma Association (OTA) publication criteria for active membership <span class="hlt">early</span> in their careers. Orthopedic trauma fellowship graduates from 1982 to 2007 were analyzed. A literature search was performed for each fellow's publications for the 6-year period beginning the year of fellowship graduation. Publication <span class="hlt">productivity</span> was compared between <span class="hlt">early</span> and recent groups of graduates, 1987 to 1991 and 2003 to 2007, respectively. Fulfillment of OTA publication criteria was determined. Seventy-nine percent of graduates contributed to 1 or more publications. The recent group produced more total publications per graduate (4.06 vs 3.29, P=.01) and more coauthor publications (2.60 vs 2.04, P=.019) than the <span class="hlt">early</span> group. The number of first-author publications did not differ between groups (1.46 vs 1.25, P=.26). A greater percentage of the recent group met current OTA publication criteria compared with the <span class="hlt">early</span> group (51% vs 35%, P=.04). The findings showed that recent orthopedic trauma graduates had increased publication <span class="hlt">productivity</span> compared with their more senior colleagues, although a proportion had not qualified for active OTA membership 6 years into their career. Overall, these data are encouraging and suggest that young orthopedic trauma surgeons remain committed to sustaining a high level of academic excellence. Copyright 2016, SLACK Incorporated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CliPa...8..215J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CliPa...8..215J"><span>Warm Middle Jurassic-<span class="hlt">Early</span> Cretaceous high-latitude sea-surface temperatures from 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>Jenkyns, H. C.; Schouten-Huibers, L.; Schouten, S.; Sinninghe Damsté, J. S.</p> <p>2012-02-01</p> <p>Although a division of the Phanerozoic climatic modes of the Earth into "greenhouse" and "icehouse" phases is widely accepted, whether or not polar ice developed during the relatively warm Jurassic and Cretaceous Periods is still under debate. In particular, there is a range of isotopic and biotic evidence that favours the concept of discrete "cold snaps", marked particularly by migration of certain biota towards lower latitudes. Extension of the use of the palaeotemperature proxy TEX86 back to the Middle Jurassic indicates that relatively warm sea-surface conditions (26-30 °C) existed from this interval (∼160 Ma) to the <span class="hlt">Early</span> Cretaceous (∼115 Ma) in the Southern <span class="hlt">Ocean</span>, with a general warming trend through the Late Jurassic followed by a general cooling trend through the <span class="hlt">Early</span> Cretaceous. The lowest sea-surface temperatures are recorded from around the Callovian-Oxfordian boundary, an interval identified in Europe as relatively cool, but do not fall below 25 °C. The <span class="hlt">early</span> Aptian <span class="hlt">Oceanic</span> Anoxic Event, identified on the basis of published biostratigraphy, total organic carbon and carbon-isotope stratigraphy, records an interval with the lowest, albeit fluctuating <span class="hlt">Early</span> Cretaceous palaeotemperatures (∼26 °C), recalling similar phenomena recorded from Europe and the tropical Pacific <span class="hlt">Ocean</span>. Extant belemnite δ18O data, assuming an isotopic composition of waters inhabited by these fossils of -1‰ SMOW, give palaeotemperatures throughout the Upper Jurassic-Lower Cretaceous interval that are consistently lower by ∼14 °C than does TEX86 and the molluscs likely record conditions below the thermocline. The long-term, warm climatic conditions indicated by the TEX86 data would only be compatible with the existence of continental ice if appreciable areas of high altitude existed on Antarctica, and/or in other polar regions, during the Mesozoic Era.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28923289','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28923289"><span>Impact of <span class="hlt">ocean</span> acidification on the <span class="hlt">early</span> development and escape behavior of marine medaka (Oryzias melastigma).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Xiaojie; Song, Lulu; Chen, Yi; Ran, Haoyu; Song, Jiakun</p> <p>2017-10-01</p> <p><span class="hlt">Ocean</span> acidification is predicted to affect a wide diversity of marine organisms. However, no studies have reported the effects of <span class="hlt">ocean</span> acidification on Indian <span class="hlt">Ocean</span> fish. We have used the Indian <span class="hlt">Ocean</span> medaka (Oryzias melastigma) as a model species for a marine fish that lives in coastal waters. We investigated the impact of <span class="hlt">ocean</span> acidification on the embryonic development and the stereotyped escape behavior (mediated by the Mauthner cell) in newly hatched larvae. Newly fertilized eggs of medaka were reared in seawater at three different partial pressures of carbon dioxide (pCO 2 ): control at 450 μatm, moderate at 1160 μatm, and high at 1783 μatm. Hatch rates, embryonic duration, and larval malformation rates were compared and were not significantly different between the treatments and the control. In the high pCO 2 group, however, the yolks of larvae were significantly smaller than in the control group, and the newly hatched larvae were significantly longer than the larvae in the control. In the moderate pCO 2 group, the eye distance decreased significantly. No significantly negative growth effects were observed in the larvae when exposed to pCO 2 levels that are predicted as a result of <span class="hlt">ocean</span> acidification in the next 100-200 years. Larvae reared under control conditions readily produced C-start escape behavior to mechanosensory stimuli; however, in the moderate and high pCO 2 experimental groups, the probabilities of C-start were significantly lower than those of the control group. Therefore, the sensory integration needed for the C-start escape behavior appears to be vulnerable to <span class="hlt">ocean</span> acidification. Altered behavior in marine larval fish, particularly behaviors involved in escape from predation, could have potentially negative implications to fish populations, and, further, to the marine ecosystems at the levels of CO 2 projected for the future. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE52B..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE52B..04A"><span>Environmental factors controlling phytoplankton <span class="hlt">productivity</span> and phenology in 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>Ardyna, M.; Claustre, H.; Sallee, J. B.; Gentili, B.; D'Ortenzio, F.</p> <p>2016-02-01</p> <p>The Southern <span class="hlt">Ocean</span> (SO), highly sensitive to climate change, is currently experiencing a rapid warming and freshening. Such drastic hydrographical changes may significantly alter the SO's biological carbon pump (i.e., the efficiency of primary <span class="hlt">production</span> and its transfers to higher trophic levels and/or sequestration to depth). However, before making any predictions, a better understanding of the biogeography and environmental factors controlling phytoplankton processes (i.e., <span class="hlt">productivity</span> and phenology) in the Southern <span class="hlt">Ocean</span> is clearly needed. We present here a bio-regionalization of the SO from satellite-derived observations, where a range of three orders of magnitude of <span class="hlt">productivity</span> is observed. A clear latitudinal gradient in the bloom initiation was underpinned following the light regime, with some exception in well-mixed and sea-ice edge areas. Environmental factors controlling the phytoplankton phenology and <span class="hlt">productivity</span> appear to be completely decoupled. Phytoplankton <span class="hlt">productivity</span> in the SO is clearly associated to both shallow areas and front locations, where iron limitation seems to be less pronounced. These findings will give us a more comprehensive understanding in both space and time of the limiting factors of PP (i.e., nutrients, light-mixing regime…), which are of fundamental interest for identifying and explaining potential ongoing changes in SO's marine ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PalOc...9..723L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PalOc...9..723L"><span>Quantitative estimation of surface <span class="hlt">ocean</span> <span class="hlt">productivity</span> and bottom water oxygen concentration using benthic foraminifera</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loubere, Paul</p> <p>1994-10-01</p> <p>An electronic supplement of this material may be obtained on adiskette or Anonymous FTP from KOSMOS.AGU.ORG. (LOGIN toAGU's FTP account using ANONYMOUS as the usemame andGUEST as the password. Go to the right directory by typing CDAPEND. Type LS to see what files are available. Type GET and thename of the file to get it. Finally, type EXIT to leave the system.)(Paper 94PA01624, Quantitative estimation of surface oceanproductivity and bottom water concentration using benthicforaminifera, by P. Loubere). Diskette may be ordered from AmericanGeophysical Union, 2000 Florida Avenue, N.W., Washington, DC20009; $15.00. Payment must accompany order.Quantitative estimation of surface <span class="hlt">ocean</span> <span class="hlt">productivity</span> and bottom water oxygen concentration with benthic foraminifera was attempted using 70 samples from equatorial and North Pacific surface sediments. These samples come from a well defined depth range in the <span class="hlt">ocean</span>, between 2200 and 3200 m, so that depth related factors do not interfere with the estimation. Samples were selected so that foraminifera were well preserved in the sediments and temperature and salinity were nearly uniform (T = 1.5° C; S = 34.6‰). The sample set was also assembled so as to minimize the correlation often seen between surface <span class="hlt">ocean</span> <span class="hlt">productivity</span> and bottom water oxygen values (r² = 0.23 for prediction purposes in this case). This procedure reduced the chances of spurious results due to correlations between the environmental variables. The samples encompass a range of <span class="hlt">productivities</span> from about 25 to >300 gC m-2 yr-1, and a bottom water oxygen range from 1.8 to 3.5 ml/L. Benthic foraminiferal assemblages were quantified using the >62 µm fraction of the sediments and 46 taxon categories. MANOVA multivariate regression was used to project the faunal matrix onto the two environmental dimensions using published values for <span class="hlt">productivity</span> and bottom water oxygen to calibrate this operation. The success of this regression was measured with the multivariate r</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23506807','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23506807"><span><span class="hlt">Early</span> rationality in action perception and <span class="hlt">production</span>? A theoretical exposition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Paulus, Markus; Király, Ildikó</p> <p>2013-10-01</p> <p>Within recent years, the question of <span class="hlt">early</span> rationality in action perception and <span class="hlt">production</span> has become a topic of great interest in developmental psychology. On the one hand, studies have provided evidence for rational action perception and action imitation even in very young infants. On the other hand, scholars have recently questioned these interpretations and proposed that the ability to rationally evaluate actions is not yet in place in infancy. Others have examined the development of the ability to make rational action choices and have indicated limitations of young children's ability to act rationally. This editorial to the special issue on <span class="hlt">Early</span> Rationality in Action Perception and <span class="hlt">Production</span>? introduces the reader to the current debate. It elucidates the underlying theoretical assumptions that drive the debate on whether or not young children's action perception and <span class="hlt">production</span> is rational. Finally, it summarizes the papers and their contributions to the theoretical debate. Copyright © 2013 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP23B1308W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP23B1308W"><span>A Possible Late Paleocene-<span class="hlt">Early</span> Eocene <span class="hlt">Ocean</span> Acidification Event Recoded in the Adriatic Carbonate Platform</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weiss, A.; Martindale, R. C.; Kosir, A.; Oefinger, J.</p> <p>2017-12-01</p> <p>The Paleocene-Eocene Thermal Maximum (PETM) event ( 56.3 Ma) was a period of massive carbon release into the Earth system, resulting in significant shifts in <span class="hlt">ocean</span> chemistry. It has been proposed that <span class="hlt">ocean</span> acidification - a decrease in the pH and carbonate saturation state of the water as a result of dissolved carbon dioxide in sea water - occurred in both the shallow and deep marine realms. <span class="hlt">Ocean</span> acidification would have had a devastating impact on the benthic ecosystem, and has been proposed as the cause of decreased carbonate deposition in marine sections and coral reef collapse during the late Paleocene. To date, however, the only physical evidence of Paleocene-Eocene <span class="hlt">ocean</span> acidification has been shown for offshore sites (i.e., a shallow carbonate compensation depth), but isotope analysis (i.e. B, I/Ca) suggests that acidification occurred in the shallow shelves as well. Several sites in the Kras region of Slovenia, has been found to contain apparent erosion surfaces coeval with the Paleocene-Eocene Boundary. We have investigated these potentially acidified horizons using petrography, stable carbon isotopes, cathodoluminescence, and elemental mapping. These datasets will inform whether the horizons formed by seafloor dissolution in an acidified <span class="hlt">ocean</span>, or are due to subaerial exposure, or burial diagenesis (i.e. stylotization). Physical erosion and diagenesis can easily be ruled out based on field relationships and petrography, but the other potential causes must be analyzed more critically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PNAS..115.4105K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PNAS..115.4105K"><span>Constraining the climate and <span class="hlt">ocean</span> pH of the <span class="hlt">early</span> Earth with a geological carbon cycle model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krissansen-Totton, Joshua; Arney, Giada N.; Catling, David C.</p> <p>2018-04-01</p> <p>The <span class="hlt">early</span> Earth’s environment is controversial. Climatic estimates range from hot to glacial, and inferred marine pH spans strongly alkaline to acidic. Better understanding of <span class="hlt">early</span> climate and <span class="hlt">ocean</span> chemistry would improve our knowledge of the origin of life and its coevolution with the environment. Here, we use a geological carbon cycle model with <span class="hlt">ocean</span> chemistry to calculate self-consistent histories of climate and <span class="hlt">ocean</span> pH. Our carbon cycle model includes an empirically justified temperature and pH dependence of seafloor weathering, allowing the relative importance of continental and seafloor weathering to be evaluated. We find that the Archean climate was likely temperate (0–50 °C) due to the combined negative feedbacks of continental and seafloor weathering. <span class="hlt">Ocean</span> pH evolves monotonically from 6.6‑0.4+0.6 (2σ) at 4.0 Ga to 7.0‑0.5+0.7 (2σ) at the Archean–Proterozoic boundary, and to 7.9‑0.2+0.1 (2σ) at the Proterozoic–Phanerozoic boundary. This evolution is driven by the secular decline of pCO2, which in turn is a consequence of increasing solar luminosity, but is moderated by carbonate alkalinity delivered from continental and seafloor weathering. Archean seafloor weathering may have been a comparable carbon sink to continental weathering, but is less dominant than previously assumed, and would not have induced global glaciation. We show how these conclusions are robust to a wide range of scenarios for continental growth, internal heat flow evolution and outgassing history, greenhouse gas abundances, and changes in the biotic enhancement of weathering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29610313','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29610313"><span>Constraining the climate and <span class="hlt">ocean</span> pH of the <span class="hlt">early</span> Earth with a geological carbon cycle model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krissansen-Totton, Joshua; Arney, Giada N; Catling, David C</p> <p>2018-04-17</p> <p>The <span class="hlt">early</span> Earth's environment is controversial. Climatic estimates range from hot to glacial, and inferred marine pH spans strongly alkaline to acidic. Better understanding of <span class="hlt">early</span> climate and <span class="hlt">ocean</span> chemistry would improve our knowledge of the origin of life and its coevolution with the environment. Here, we use a geological carbon cycle model with <span class="hlt">ocean</span> chemistry to calculate self-consistent histories of climate and <span class="hlt">ocean</span> pH. Our carbon cycle model includes an empirically justified temperature and pH dependence of seafloor weathering, allowing the relative importance of continental and seafloor weathering to be evaluated. We find that the Archean climate was likely temperate (0-50 °C) due to the combined negative feedbacks of continental and seafloor weathering. <span class="hlt">Ocean</span> pH evolves monotonically from [Formula: see text] (2σ) at 4.0 Ga to [Formula: see text] (2σ) at the Archean-Proterozoic boundary, and to [Formula: see text] (2σ) at the Proterozoic-Phanerozoic boundary. This evolution is driven by the secular decline of pCO 2 , which in turn is a consequence of increasing solar luminosity, but is moderated by carbonate alkalinity delivered from continental and seafloor weathering. Archean seafloor weathering may have been a comparable carbon sink to continental weathering, but is less dominant than previously assumed, and would not have induced global glaciation. We show how these conclusions are robust to a wide range of scenarios for continental growth, internal heat flow evolution and outgassing history, greenhouse gas abundances, and changes in the biotic enhancement of weathering. Copyright © 2018 the Author(s). Published by PNAS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5910859','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5910859"><span>Constraining the climate and <span class="hlt">ocean</span> pH of the <span class="hlt">early</span> Earth with a geological carbon cycle model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Krissansen-Totton, Joshua; Arney, Giada N.</p> <p>2018-01-01</p> <p>The <span class="hlt">early</span> Earth’s environment is controversial. Climatic estimates range from hot to glacial, and inferred marine pH spans strongly alkaline to acidic. Better understanding of <span class="hlt">early</span> climate and <span class="hlt">ocean</span> chemistry would improve our knowledge of the origin of life and its coevolution with the environment. Here, we use a geological carbon cycle model with <span class="hlt">ocean</span> chemistry to calculate self-consistent histories of climate and <span class="hlt">ocean</span> pH. Our carbon cycle model includes an empirically justified temperature and pH dependence of seafloor weathering, allowing the relative importance of continental and seafloor weathering to be evaluated. We find that the Archean climate was likely temperate (0–50 °C) due to the combined negative feedbacks of continental and seafloor weathering. <span class="hlt">Ocean</span> pH evolves monotonically from 6.6−0.4+0.6 (2σ) at 4.0 Ga to 7.0−0.5+0.7 (2σ) at the Archean–Proterozoic boundary, and to 7.9−0.2+0.1 (2σ) at the Proterozoic–Phanerozoic boundary. This evolution is driven by the secular decline of pCO2, which in turn is a consequence of increasing solar luminosity, but is moderated by carbonate alkalinity delivered from continental and seafloor weathering. Archean seafloor weathering may have been a comparable carbon sink to continental weathering, but is less dominant than previously assumed, and would not have induced global glaciation. We show how these conclusions are robust to a wide range of scenarios for continental growth, internal heat flow evolution and outgassing history, greenhouse gas abundances, and changes in the biotic enhancement of weathering. PMID:29610313</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45.1490S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45.1490S"><span>Pan-Arctic Distribution of Bioavailable Dissolved Organic Matter and Linkages With <span class="hlt">Productivity</span> in <span class="hlt">Ocean</span> Margins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, Yuan; Benner, Ronald; Kaiser, Karl; Fichot, Cédric G.; Whitledge, Terry E.</p> <p>2018-02-01</p> <p>Rapid environmental changes in the Arctic <span class="hlt">Ocean</span> affect plankton <span class="hlt">productivity</span> and the bioavailability of dissolved organic matter (DOM) that supports microbial food webs. We report concentrations of dissolved organic carbon (DOC) and yields of amino acids (indicators of labile DOM) in surface waters across major Arctic margins. Concentrations of DOC and bioavailability of DOM showed large pan-Arctic variability that corresponded to varying hydrological conditions and ecosystem <span class="hlt">productivity</span>, respectively. Widespread hot spots of labile DOM were observed over <span class="hlt">productive</span> inflow shelves (Chukchi and Barents Seas), in contrast to oligotrophic interior margins (Kara, Laptev, East Siberian, and Beaufort Seas). Amino acid yields in outflow gateways (Canadian Archipelago and Baffin Bay) indicated the prevalence of semilabile DOM in sea ice covered regions and sporadic <span class="hlt">production</span> of labile DOM in ice-free waters. Comparing these observations with surface circulation patterns indicated varying shelf subsidies of bioavailable DOM to Arctic deep basins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930071518&hterms=primary+data&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dprimary%2Bdata','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930071518&hterms=primary+data&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dprimary%2Bdata"><span>Estimators of primary <span class="hlt">production</span> for interpretation of remotely sensed data on <span class="hlt">ocean</span> color</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Platt, Trevor; Sathyendranath, Shubha</p> <p>1993-01-01</p> <p>The theoretical basis is explained for some commonly used estimators of daily primary <span class="hlt">production</span> in a vertically uniform water column. These models are recast into a canonical form, with dimensionless arguments, to facilitate comparison with each other and with an analytic solution. The limitations of each model are examined. The values of the photoadaptation parameter I(k) observed in the <span class="hlt">ocean</span> are analyzed, and I(k) is used as a scale to normalize the surface irradiance. The range of this scaled irradiance is presented. An equation is given for estimation of I(k) from recent light history. It is shown how the models for water column <span class="hlt">production</span> can be adapted for estimation of the <span class="hlt">production</span> in finite layers. The distinctions between model formulation, model implementation and model evaluation are discussed. Recommendations are given on the choice of algorithm for computation of daily <span class="hlt">production</span> according to the degree of approximation acceptable in the result.</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('https://www.ncbi.nlm.nih.gov/pubmed/26549614','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26549614"><span>The role of biology in planetary evolution: cyanobacterial primary <span class="hlt">production</span> in low-oxygen Proterozoic <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>Hamilton, Trinity L; Bryant, Donald A; Macalady, Jennifer L</p> <p>2016-02-01</p> <p>Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well-preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane-derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the <span class="hlt">production</span> of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co-occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low-oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in <span class="hlt">early</span> Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic photosynthesis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160014496&hterms=layer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlayer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160014496&hterms=layer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlayer"><span>The Open-<span class="hlt">Ocean</span> Sensible Heat Flux and Its Significance for Arctic Boundary Layer Mixing During <span class="hlt">Early</span> Fall</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ganeshan, Manisha; Wu, Dongliang</p> <p>2016-01-01</p> <p>The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL) clouds and seasonal sea ice growth. The open-<span class="hlt">ocean</span> sensible heat flux, a crucial mechanism of excessive <span class="hlt">ocean</span> heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multiyear Japanese cruise-ship observations from RV Mirai over the open Arctic <span class="hlt">Ocean</span> to characterize the surface sensible heat flux (SSHF) during <span class="hlt">early</span> fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum <span class="hlt">ocean</span>-atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime), yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure) followed by the highly stable (stratus) regime. Overall, it can explain 10 of the open <span class="hlt">ocean</span> BL height variability, whereas cloud-driven (moisture and radiative) mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the RV Mirai for better understanding and</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 Global Modeling for Extreme Crop <span class="hlt">Production</span> 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 <span class="hlt">production</span> can elucidate complex mechanisms under seasonal climate anomalies. The models have progressed through their combination with global climate reanalysis, environmental satellite data, and harvest data on the ground. This study examined adaptation of crop <span class="hlt">production</span> to advancing abnormal phenomena related to global climate change. Global environmental surface conditions, i.e., vegetation, surface air temperature, and sea surface temperature observed by satellites, enable global modeling of crop <span class="hlt">production</span> 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. Global environmental surface conditions, e.g., vegetation, surface air temperature, and sea surface temperature observed by satellites, enable global modeling of crop <span class="hlt">production</span> 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 global 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 global 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('https://ntrs.nasa.gov/search.jsp?R=19900034464&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=19900034464&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dworlds%2Boceans"><span>Impact delivery and erosion of planetary <span class="hlt">oceans</span> in the <span class="hlt">early</span> inner solar system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chyba, Christopher F.</p> <p>1990-01-01</p> <p>The terrestrial planets may have acquired <span class="hlt">oceans</span> of water (and other surface volatiles) as a late-accreting veneer from impacts of comets and carbonaceous asteroids during the period of heavy bombardment 4.5 to 3.5 Gyr ago. On any given body, the efficiency of this mechanism depended on a competition between impact delivery of new volatiles and impact erosion of those already present. For the larger worlds of the inner Solar System, this competition strongly favored the net accumulation of planetary <span class="hlt">oceans</span>.</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 <span class="hlt">Production</span> in the Global <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 <span class="hlt">Production</span> (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 global 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 global maps of nitrate generated from multi-year data sets. To aid in our algorithm development efforts and to ensure that our ESDRs are truly global in nature, we are currently in the process of assembling a large database of nutrients from oceanographic institutions all over the world. Once our <span class="hlt">products</span> are developed and our algorithms are fine-tuned, large-scale data <span class="hlt">production</span> 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 <span class="hlt">products</span> and then as mature ESDRs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26PSL.451..138S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26PSL.451..138S"><span>Testing the limits in a greenhouse <span class="hlt">ocean</span>: Did low nitrogen availability limit marine <span class="hlt">productivity</span> during the end-Triassic mass extinction?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schoepfer, Shane D.; Algeo, Thomas J.; Ward, Peter D.; Williford, Kenneth H.; Haggart, James W.</p> <p>2016-10-01</p> <p>The end-Triassic mass extinction has been characterized as a 'greenhouse extinction', related to rapid atmospheric warming and associated changes in <span class="hlt">ocean</span> circulation and oxygenation. The response of the marine nitrogen cycle to these oceanographic changes, and the extent to which mass extinction intervals represent a deviation in nitrogen cycling from other ice-free 'greenhouse' periods of Earth history, remain poorly understood. The well-studied Kennecott Point section in Haida Gwaii, British Columbia, Canada, was deposited in the open Panthalassic <span class="hlt">Ocean</span>, and is used here as a test case to better understand changes in the nitrogen cycle and marine <span class="hlt">productivity</span> from the pre-crisis greenhouse of the Rhaetian to the latest-Rhaetian crisis interval. We estimated marine <span class="hlt">productivity</span> from the late Norian to the <span class="hlt">early</span> Hettangian using TOC- and P-based paleoproductivity transform equations, and then compared these estimates to records of sedimentary nitrogen isotopes, redox-sensitive trace elements, and biomarker data. Major negative excursions in δ15N (to ≤ 0 ‰) correspond to periods of depressed marine <span class="hlt">productivity</span>. During these episodes, the development of a stable pycnocline below the base of the photic zone suppressed vertical mixing and limited N availability in surface waters, leading to low <span class="hlt">productivity</span> and increased nitrogen fixation, as well as ecological stresses in the photic zone. The subsequent shoaling of euxinic waters into the <span class="hlt">ocean</span> surface layer was fatal for most Triassic marine fauna, although the introduction of regenerated NH4+ into the photic zone may have allowed phytoplankton <span class="hlt">productivity</span> to recover. These results indicate that the open-<span class="hlt">ocean</span> nitrogen cycle was influenced by climatic changes during the latest Triassic, despite having existed in a greenhouse state for over 50 million years previously, and that low N availability limited marine <span class="hlt">productivity</span> for hundreds of thousands of years during the end-Triassic crisis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005DSRII..52..757A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005DSRII..52..757A"><span>Linking <span class="hlt">oceanic</span> food webs to coastal <span class="hlt">production</span> and growth rates of Pacific salmon ( Oncorhynchus spp.), using models on three scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aydin, Kerim Y.; McFarlane, Gordon A.; King, Jacquelynne R.; Megrey, Bernard A.; Myers, Katherine W.</p> <p>2005-03-01</p> <p>Three independent modeling methods—a nutrient-phytoplankton-zooplankton (NPZ) model (NEMURO), a food web model (Ecopath/Ecosim), and a bioenergetics model for pink salmon ( Oncorhynchus gorbuscha)—were linked to examine the relationship between seasonal zooplankton dynamics and annual food web <span class="hlt">productive</span> potential for Pacific salmon feeding and growing in the Alaskan subarctic gyre ecosystem. The linked approach shows the importance of seasonal and ontogenetic prey switching for zooplanktivorous pink salmon, and illustrates the critical role played by lipid-rich forage species, especially the gonatid squid Berryteuthis anonychus, in connecting zooplankton to upper trophic level <span class="hlt">production</span> in the subarctic North Pacific. The results highlight the need to uncover natural mechanisms responsible for accelerated late winter and <span class="hlt">early</span> spring growth of salmon, especially with respect to climate change and zooplankton bloom timing. Our results indicate that the best match between modeled and observed high-seas pink salmon growth requires the inclusion of two factors into bioenergetics models: (1) decreasing energetic foraging costs for salmon as zooplankton are concentrated by the spring shallowing of pelagic mixed-layer depth and (2) the ontogenetic switch of salmon diets from zooplankton to squid. Finally, we varied the timing and input levels of coastal salmon <span class="hlt">production</span> to examine effects of density-dependent coastal processes on <span class="hlt">ocean</span> feeding; coastal processes that place relatively minor limitations on salmon growth may delay the seasonal timing of ontogenetic diet shifts and thus have a magnified effect on overall salmon growth rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8950W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8950W"><span>Interpolate with DIVA and view the <span class="hlt">products</span> in <span class="hlt">Ocean</span>Browser : what's up ?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watelet, Sylvain; Barth, Alexander; Beckers, Jean-Marie; Troupin, Charles</p> <p>2017-04-01</p> <p>The Data-Interpolating Variational Analysis (DIVA) software is a statistical tool designed to reconstruct a continuous field from discrete measurements. This method is based on the numerical implementation of the Variational Inverse Model (VIM), which consists of a minimization of a cost function, allowing the choice of the analyzed field fitting at best the data sets without presenting unrealistic strong variations. The problem is solved efficiently using a finite-element method. This method, equivalent to the Optimal Interpolation, is particularly suited to deal with irregularly-spaced observations and produces outputs on a regular grid (2D, 3D or 4D). The results are stored in NetCDF files, the most widespread format in the earth sciences community. <span class="hlt">Ocean</span>Browser is a web-service that allows one to visualize gridded fields on-line. Within the SeaDataNet and EMODNET (Chemical lot) projects, several national <span class="hlt">ocean</span> data centers have created gridded climatologies of different <span class="hlt">ocean</span> properties using the data analysis software DIVA. In order to give a common viewing service to those interpolated <span class="hlt">products</span>, the GHER has developed <span class="hlt">Ocean</span>Browser which is based on open standards from the Open Geospatial Consortium (OGC), in particular Web Map Service (WMS) and Web Feature Service (WFS). These standards define a protocol for describing, requesting and querying two-dimensional maps at a given depth and time. DIVA and <span class="hlt">Ocean</span>Browser are both softwares tools which are continuously upgraded and distributed for free through frequent version releases. The development is funded by the EMODnet and SeaDataNet projects and include many discussions and feedback from the users community. Here, we present two recent major upgrades. First, we have implemented a "customization" of DIVA analyses following the sea bottom, using the bottom depth gradient as a new source of information. The weaker the slope of the bottom <span class="hlt">ocean</span>, the higher the correlation length. This correlation length being</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1013721','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1013721"><span><span class="hlt">Early</span> Student Support for the Study of Inertial Motions in 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>2015-09-30</p> <p>Dosser, Hayley V., Sasan J. Ghaemsaidi, Thomas Peacock , and Luc Rainville, x. Internal Wave 5 Propagation and Stability in the Western Arctic...<span class="hlt">Ocean</span>. In preparation for J. Phys. Oceanogr. Ghaemsaidi, Sasan J., Hayley V. Dosser, Luc Rainville, and Thomas Peacock , 2015. The impact of multiple</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatGe..10...14L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatGe..10...14L"><span>Evidence for an <span class="hlt">early</span> wet Moon from experimental crystallization of the lunar magma <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>Lin, Yanhao; Tronche, Elodie J.; Steenstra, Edgar S.; van Westrenen, Wim</p> <p>2017-01-01</p> <p>The Moon is thought to have been covered initially by a deep magma <span class="hlt">ocean</span>, its gradual solidification leading to the formation of the plagioclase-rich highland crust. We performed a high-pressure, high-temperature experimental study of lunar mineralogical and geochemical evolution during magma <span class="hlt">ocean</span> solidification that yields constraints on the presence of water in the earliest lunar interior. In the experiments, a deep layer containing both olivine and pyroxene is formed in the first ~50% of crystallization, β-quartz forms towards the end of crystallization, and the last per cent of magma remaining is extremely iron rich. In dry experiments, plagioclase appears after 68 vol.% solidification and yields a floatation crust with a thickness of ~68 km, far above the observed average of 34-43 km based on lunar gravity. The volume of plagioclase formed during crystallization is significantly less in water-bearing experiments. Using the relationship between magma water content and the resulting crustal thickness in the experiments, and considering uncertainties in initial lunar magma <span class="hlt">ocean</span> depth, we estimate that the Moon may have contained at least 270 to 1,650 ppm water at the time of magma <span class="hlt">ocean</span> crystallization, suggesting the Earth-Moon system was water-rich from the start.</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 Global <span class="hlt">Ocean</span> Net Primary <span class="hlt">Production</span>: 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 global scales remains one of the greatest challenges in global <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 global <span class="hlt">ocean</span> primary <span class="hlt">production</span> 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 global 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 <span class="hlt">production</span> will impact the global 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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5894891','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5894891"><span>Performance metrics for the assessment of satellite data <span class="hlt">products</span>: an <span class="hlt">ocean</span> color case study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Seegers, Bridget N.; Stumpf, Richard P.; Schaeffer, Blake A.; Loftin, Keith A.; Werdell, P. Jeremy</p> <p>2018-01-01</p> <p>Performance assessment of <span class="hlt">ocean</span> color satellite data has generally relied on statistical metrics chosen for their common usage and the rationale for selecting certain metrics is infrequently explained. Commonly reported statistics based on mean squared errors, such as the coefficient of determination (r2), root mean square error, and regression slopes, are most appropriate for Gaussian distributions without outliers and, therefore, are often not ideal for <span class="hlt">ocean</span> color algorithm performance assessment, which is often limited by sample availability. In contrast, metrics based on simple deviations, such as bias and mean absolute error, as well as pair-wise comparisons, often provide more robust and straightforward quantities for evaluating <span class="hlt">ocean</span> color algorithms with non-Gaussian distributions and outliers. This study uses a SeaWiFS chlorophyll-a validation data set to demonstrate a framework for satellite data <span class="hlt">product</span> assessment and recommends a multi-metric and user-dependent approach that can be applied within science, modeling, and resource management communities. PMID:29609296</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 Global <span class="hlt">Ocean</span> Carbon Flux Estimates to Forcing by Reanalysis <span class="hlt">Products</span></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 <span class="hlt">products</span> 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 global <span class="hlt">oceans</span>. Global air-sea carbon fluxes and pCO2 were relatively insensitive to the choice of forcing reanalysis. All global 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. Global 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/2010AGUFM.U33A0013S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.U33A0013S"><span>Evolution of <span class="hlt">Early</span> Paleoproterozoic <span class="hlt">Ocean</span> Chemistry as Recorded by Black Shales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scott, C.; Bekker, A.; Lyons, T. W.; Planavsky, N. J.; Wing, B. A.</p> <p>2010-12-01</p> <p>In recent years, Precambrian biogeochemists have focused largely on the abundance, speciation and isotopic composition of major and trace elements preserved in organic carbon-rich black shales in order to track the co-evolution of <span class="hlt">ocean</span> chemistry and life on Earth. Despite the fact that the period from 2.5 to 2.0 Ga hosted major events in Earth’s history, such as the Great Oxidation Event (GOE), an era of global glaciations, a massive and long-lived carbon isotope excursion and the end to banded iron formation (BIF) deposition, each with the potential to directly alter global biogeochemical cycles, it is perhaps best known for its unknowns. In order to help close this gap in our understanding of the evolution of Precambrian <span class="hlt">ocean</span> chemistry we present a detailed biogeochemical study of Paleoproterozoic black shales deposited between 2.5 and 2.0 Ga. Our study integrates Fe speciation, trace metal chemistry and C, S and N isotope analyses to provide a thorough characterization of marine biogeochemical cycles as they responded to the GOE and set the stage for the demise of BIFs at ca. 1.8 Ga. Our data reveal an <span class="hlt">ocean</span> that was both surprising similar to, and demonstrably different from, Archean and later Proterozoic <span class="hlt">oceans</span>. Of particular interest, we find that ferruginous and euxinic conditions co-existed during this period and that sea water trace metal inventories fluctuated dramatically in conjunction with major carbon isotope excursions. By comparing our Paleoproterozoic contribution with recent biogeochemical studies of other Precambrian black shales we can begin to track first order changes in <span class="hlt">ocean</span> chemistry without the major time gaps that have plagued previous attempts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.5046U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.5046U"><span>Eddy-driven nutrient transport and associated upper-<span class="hlt">ocean</span> primary <span class="hlt">production</span> along the Kuroshio</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uchiyama, Yusuke; Suzue, Yota; Yamazaki, Hidekatsu</p> <p>2017-06-01</p> <p>The Kuroshio is one of the most energetic western boundary currents accompanied by vigorous eddy activity both on mesoscale and submesoscale, which affects biogeochemical processes in the upper <span class="hlt">ocean</span>. We examine the primary <span class="hlt">production</span> around the Kuroshio off Japan using a climatological <span class="hlt">ocean</span> modeling based on the Regional <span class="hlt">Oceanic</span> Modeling System (ROMS) coupled with a nitrogen-based nutrient, phytoplankton and zooplankton, and detritus (NPZD) biogeochemical model in a submesoscale eddy-permitting configuration. The model indicates significant differences of the biogeochemical responses to eddy activities in the Kuroshio Region (KR) and Kuroshio Extension Region (KE). In the KR, persisting cyclonic eddies developed between the Kuroshio and coastline are responsible for upwelling-induced eutrophication. However, the eddy-induced vertical nutrient flux counteracts and promotes pronounced southward and downward diapycnal nutrient transport from the mixed-layer down beneath the main body of the Kuroshio, which suppresses the near-surface <span class="hlt">productivity</span>. In contrast, the KE has a 23.5% higher <span class="hlt">productivity</span> than the KR, even at comparable eddy intensity. Upward nutrient transport prevails near the surface due to predominant cyclonic eddies, particularly to the north of the KE, where the downward transport barely occurs, except at depths deeper than 400 m and to a much smaller degree than in the KR. The eddy energy conversion analysis reveals that the combination of shear instability around the mainstream of the Kuroshio with prominent baroclinic instability near the Kuroshio front is essential for the generation of eddies in the KR, leading to the increase of the eddy-induced vertical nitrate transport around the Kuroshio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO11A..08W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO11A..08W"><span>Scientific assessment of accuracy, skill and reliability of <span class="hlt">ocean</span> probabilistic forecast <span class="hlt">products</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, M.; Rowley, C. D.; Barron, C. N.; Hogan, P. J.</p> <p>2016-02-01</p> <p>As <span class="hlt">ocean</span> operational centers are increasingly adopting and generating probabilistic forecast <span class="hlt">products</span> for their customers with valuable forecast uncertainties, how to assess and measure these complicated probabilistic forecast <span class="hlt">products</span> objectively is challenging. The first challenge is how to deal with the huge amount of the data from the ensemble forecasts. The second one is how to describe the scientific quality of probabilistic <span class="hlt">products</span>. In fact, probabilistic forecast accuracy, skills, reliability, resolutions are different attributes of a forecast system. We briefly introduce some of the fundamental metrics such as the Reliability Diagram, Reliability, Resolution, Brier Score (BS), Brier Skill Score (BSS), Ranked Probability Score (RPS), Ranked Probability Skill Score (RPSS), Continuous Ranked Probability Score (CRPS), and Continuous Ranked Probability Skill Score (CRPSS). The values and significance of these metrics are demonstrated for the forecasts from the US Navy's regional ensemble system with different ensemble members. The advantages and differences of these metrics are studied and clarified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=productivity&pg=6&id=EJ971216','ERIC'); return false;" href="https://eric.ed.gov/?q=productivity&pg=6&id=EJ971216"><span><span class="hlt">Early</span> Morphological <span class="hlt">Productivity</span> in Hungarian: Evidence from Sentence Repetition and Elicited <span class="hlt">Production</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>Gabor, Balint; Lukacs, Agnes</p> <p>2012-01-01</p> <p>This paper investigates <span class="hlt">early</span> <span class="hlt">productivity</span> of morpheme use in Hungarian children aged between 2 ; 1 and 5 ; 3. Hungarian has a rich morphology which is the core marker of grammatical functions. A new method is introduced using the novel word paradigm in a sentence repetition task with masked inflections (i.e. a disguised elicited <span class="hlt">production</span> task).…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3368925','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3368925"><span><span class="hlt">Ocean</span> Warming Enhances Malformations, Premature Hatching, Metabolic Suppression and Oxidative Stress in the <span class="hlt">Early</span> Life Stages of a Keystone Squid</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rosa, Rui; Pimentel, Marta S.; Boavida-Portugal, Joana; Teixeira, Tatiana; Trübenbach, Katja; Diniz, Mário</p> <p>2012-01-01</p> <p>Background The knowledge about the capacity of organisms’ <span class="hlt">early</span> life stages to adapt to elevated temperatures is very limited but crucial to understand how marine biota will respond to global warming. Here we provide a comprehensive and integrated view of biological responses to future warming during the <span class="hlt">early</span> ontogeny of a keystone invertebrate, the squid Loligo vulgaris. Methodology/Principal Findings Recently-spawned egg masses were collected and reared until hatching at present day and projected near future (+2°C) temperatures, to investigate the ability of <span class="hlt">early</span> stages to undergo thermal acclimation, namely phenotypic altering of morphological, behavioural, biochemical and physiological features. Our findings showed that under the projected near-future warming, the abiotic conditions inside the eggs promoted metabolic suppression, which was followed by premature hatching. Concomitantly, the less developed newborns showed greater incidence of malformations. After hatching, the metabolic burst associated with the transition from an encapsulated embryo to a planktonic stage increased linearly with temperature. However, the greater exposure to environmental stress by the hatchlings seemed to be compensated by physiological mechanisms that reduce the negative effects on fitness. Heat shock proteins (HSP70/HSC70) and antioxidant enzymes activities constituted an integrated stress response to <span class="hlt">ocean</span> warming in hatchlings (but not in embryos). Conclusions/Significance The stressful abiotic conditions inside eggs are expected to be aggravated under the projected near-future <span class="hlt">ocean</span> warming, with deleterious effects on embryo survival and growth. Greater feeding challenges and the lower thermal tolerance limits of the hatchlings are strictly connected to high metabolic demands associated with the planktonic life strategy. Yet, we found some evidence that, in the future, the <span class="hlt">early</span> stages might support higher energy demands by adjusting some cellular functional properties</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170000013&hterms=tsunami&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170000013&hterms=tsunami&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtsunami"><span>Tsunami Waves Extensively Resurfaced the Shorelines of an <span class="hlt">Early</span> Martian <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>Rodriguez, J. A. P.; Fairen, A. G.; Linares, R.; Zarroca, M.; Platz, T.; Komatsu, G.; Kargel, J. S.; Gulick, V.; Jianguo, Y.; Higuchi, K.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170000013'); toggleEditAbsImage('author_20170000013_show'); toggleEditAbsImage('author_20170000013_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170000013_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170000013_hide"></p> <p>2016-01-01</p> <p>Viking image-based mapping of a widespread deposit covering most of the northern low-lands of Mars led to the proposal by Parker et al. that the deposit represents the vestiges of an enormous <span class="hlt">ocean</span> that existed approx. 3.4 Ga. Later identified as the Vastitas Borealis Formation, the latest geologic map of Mars identifies this deposit as the Late Hesperian lowland unit (lHl). This deposit is typically bounded by raised lobate margins. In addition, some margins have associated rille channels, which could have been produced sub-aerially by the back-wash of high-energy tsunami waves. Radar-sounding data indicate that the deposit is ice-rich. However, until now, the lack of wave-cut shoreline features and the presence of lobate margins have remained an im-pediment to the acceptance of the paleo-<span class="hlt">ocean</span> hypothesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMOS53B1097W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMOS53B1097W"><span>Salinity of the <span class="hlt">Early</span> and Middle Eocene Arctic <span class="hlt">Ocean</span> From Oxygen Isotope Analysis of Fish Bone Carbonate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waddell, L. M.; Moore, T. C.</p> <p>2006-12-01</p> <p>Plate tectonic reconstructions indicate that the Arctic was largely isolated from the world <span class="hlt">ocean</span> during the <span class="hlt">early</span> and middle Eocene, with exchange limited to shallow, and possibly intermittent, connections to the North Atlantic and Tethys (via the Turgay Strait). Relative isolation, combined with an intensification of the hydrologic cycle under an Eocene greenhouse climate, is suspected to have led to the development of a low- salinity surface water layer in the Arctic that could have affected deep and intermediate convection in the North Atlantic. Sediment cores recently recovered from the Lomonosov Ridge by the IODP 302 Arctic Coring Expedition (ACEX) allow for the first assessment of the salinity of the Arctic <span class="hlt">Ocean</span> during the <span class="hlt">early</span> and middle Eocene. Stable isotope analysis performed on the structural carbonate of fish bone apatite from ~30 samples between the ages of ~55 and ~44 myr yielded δ18O values between -6.84‰ and -2.96‰ VPDB, with a mean value of -4.89‰. From the δ18O values we calculate that the Arctic <span class="hlt">Ocean</span> was probably brackish during most of the <span class="hlt">early</span> and middle Eocene, with an average salinity of 19 to 24‰. Negative excursions in the δ18O record (<-6‰) indicate three events during which the salinity of the Arctic surface waters was severely lowered: the Paleocene Eocene Thermal Maximum (PETM), the Azolla event at ~49 Ma, and a third previously unidentified event at ~46 Ma. During the PETM, low salinities developed under conditions of increased regional precipitation and runoff associated with extreme high latitude warmth and possible tectonic uplift in the North Atlantic. During the other two low-salinity events, sea level was lowered by ~20-30 m, implying a possible severing of Arctic connections to the world <span class="hlt">ocean</span>. The most positive δ18O value (-2.96‰) occurs at ~45 Ma, the age of the youngest dropstone discovered in the ACEX sediments, and may therefore correspond to a climatic cooling rather than a high salinity event.</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/2017AGUFMOS33A1451G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS33A1451G"><span>ENSO-Modulation of Plankton <span class="hlt">Production</span> in the Northern Gulf of Mexico: A High-Resolution <span class="hlt">Ocean</span>-Biogeochemical Model Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gomez, F. A.; Lee, S. K.; Liu, Y.; Hernandez, F., Jr.; Lamkin, J. T.</p> <p>2017-12-01</p> <p>Previous studies have suggested that El Nino-Southern Oscillation (ENSO) plays a role in modulating phytoplankton biomass and the reproductive success of marine species in the Gulf of Mexico (GoM). However, characterizations of ENSO-related ecosystem responses such as plankton <span class="hlt">production</span> have not been fully addressed for the region. Here we examine ENSO impacts on biogeochemical processes within coastal and open <span class="hlt">ocean</span> domains in the GoM, using a three dimensional high-resolution <span class="hlt">ocean</span>-biogeochemical model, forced with historical surface fluxes and river run-off for 1979 - 2014. Enhanced precipitation across southern US during El Nino winter increases freshwater discharge and nutrient load into the GoM mainly via the Mississippi-Atchafalaya River. Those anomalies lead to reduced salinity and greater concentration of dissolved inorganic nitrogen and plankton <span class="hlt">production</span> in the northern shelf especially during winter. In addition, the frequency of northerly wind anomalies that cool the upper <span class="hlt">ocean</span> increases during El Nino. The negative surface heat flux anomalies further decrease vertical thermal stratification and thus increase phytoplankton <span class="hlt">production</span> during <span class="hlt">early</span> spring in the northern deep GoM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1014392','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1014392"><span><span class="hlt">Early</span> Student Support for a Process Study of <span class="hlt">Oceanic</span> Responses to Typhoons</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-09-30</p> <p>effect of these <span class="hlt">oceanic</span> processes on air–sea fluxes during tropical cyclone passage will aid understanding of storm dynamics and structure. The ocean’s... Coriolis force, and the wind stress. This assumption is justified using the PWP3D model simulation. Before passage of the tropical cyclone eye, the...momentum balance is nearly linear, with a negligible pressure gradient effect . Most of the observed horizontal kinetic energy is within the upper 100 m</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BGeo...13.1037A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BGeo...13.1037A"><span>Negligible effects of <span class="hlt">ocean</span> acidification on Eurytemora affinis (Copepoda) offspring <span class="hlt">production</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Almén, Anna-Karin; Vehmaa, Anu; Brutemark, Andreas; Bach, Lennart; Lischka, Silke; Stuhr, Annegret; Furuhagen, Sara; Paul, Allanah; Bermúdez, J. Rafael; Riebesell, Ulf; Engström-Öst, Jonna</p> <p>2016-02-01</p> <p><span class="hlt">Ocean</span> acidification is caused by increasing amounts of carbon dioxide dissolving in the <span class="hlt">oceans</span> leading to lower seawater pH. We studied the effects of lowered pH on the calanoid copepod Eurytemora affinis during a mesocosm experiment conducted in a coastal area of the Baltic Sea. We measured copepod reproductive success as a function of pH, chlorophyll a concentration, diatom and dinoflagellate biomass, carbon to nitrogen (C : N) ratio of suspended particulate organic matter, as well as copepod fatty acid composition. The laboratory-based experiment was repeated four times during 4 consecutive weeks, with water and copepods sampled from pelagic mesocosms enriched with different CO2 concentrations. In addition, oxygen radical absorbance capacity (ORAC) of animals from the mesocosms was measured weekly to test whether the copepod's defence against oxidative stress was affected by pH. We found no effect of pH on offspring <span class="hlt">production</span>. Phytoplankton biomass, as indicated by chlorophyll a concentration and dinoflagellate biomass, had a positive effect. The concentration of polyunsaturated fatty acids in the females was reflected in the eggs and had a positive effect on offspring <span class="hlt">production</span>, whereas monounsaturated fatty acids of the females were reflected in their eggs but had no significant effect. ORAC was not affected by pH. From these experiments we conclude that E. affinis seems robust against direct exposure to <span class="hlt">ocean</span> acidification on a physiological level, for the variables covered in the study. E. affinis may not have faced acute pH stress in the treatments as the species naturally face large pH fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGD....1217093A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....1217093A"><span>Negligible effects of <span class="hlt">ocean</span> acidification on Eurytemora affinis (Copepoda) offspring <span class="hlt">production</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Almén, A.-K.; Vehmaa, A.; Brutemark, A.; Bach, L.; Lischka, S.; Stuhr, A.; Furuhagen, S.; Paul, A.; Bermúdez, R.; Riebesell, U.; Engström-Öst, J.</p> <p>2015-10-01</p> <p><span class="hlt">Ocean</span> acidification is caused by increasing amounts of carbon dioxide dissolving in the <span class="hlt">oceans</span> leading to lower seawater pH. We studied the effects of lowered pH on the calanoid copepod Eurytemora affinis during a mesocosm experiment conducted in a coastal area of the Baltic Sea. We measured copepod reproductive success as a function of pH, chlorophyll a concentration, diatom and dinoflagellate biomass, carbon to nitrogen (C : N) ratio of suspended particulate organic matter, as well as copepod fatty acid composition. The laboratory-based experiment was repeated four times during four consecutive weeks, with water and copepods sampled from pelagic mesocosms enriched with different CO2 concentrations. In addition, oxygen radical absorbance capacity (ORAC) of animals from the mesocosms was measured weekly to test whether the copepod's defence against oxidative stress was affected by pH. We found no effect of pH on offspring <span class="hlt">production</span>. Phytoplankton biomass, as indicated by chlorophyll a concentration, had a strong positive effect. The concentration of polyunsaturated fatty acids in the females were reflected in the eggs and had a positive effect on offspring <span class="hlt">production</span>, whereas monounsaturated fatty acids of the females were reflected in their eggs but had no significant effect. ORAC was not affected by pH. From these experiments we conclude that E. affinis seems robust against direct exposure to <span class="hlt">ocean</span> acidification on a physiological level, for the variables covered in the study. E. affinis may not have faced acute pH stress in the treatments as the species naturally face large pH fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3578572','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3578572"><span>Gradients in microbial methanol uptake: <span class="hlt">productive</span> coastal upwelling waters to oligotrophic gyres in the Atlantic <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>Dixon, Joanna L; Sargeant, Stephanie; Nightingale, Philip D; Colin Murrell, J</p> <p>2013-01-01</p> <p>Methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. We report the first microbial methanol carbon assimilation rates (k) in <span class="hlt">productive</span> coastal upwelling waters of up to 0.117±0.002 d−1 (∼10 nmol l−1 d−1). On average, coastal upwelling waters were 11 times greater than open <span class="hlt">ocean</span> northern temperate (NT) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (EU) waters; suggesting that all upwelling waters upon reaching the surface (⩽20 m), contain a microbial population that uses a relatively high amount of carbon (0.3–10 nmol l−1 d−1), derived from methanol, to support their growth. In open <span class="hlt">ocean</span> Atlantic regions, microbial uptake of methanol into biomass was significantly lower, ranging between 0.04–0.68 nmol l−1 d−1. Microbes in the Mauritanian coastal upwelling used up to 57% of the total methanol for assimilation of the carbon into cells, compared with an average of 12% in the EU, and 1% in NT and gyre waters. Several methylotrophic bacterial species were identified from open <span class="hlt">ocean</span> Atlantic waters using PCR amplification of mxaF encoding methanol dehydrogenase, the key enzyme in bacterial methanol oxidation. These included Methylophaga sp., Burkholderiales sp., Methylococcaceae sp., Ancylobacter aquaticus, Paracoccus denitrificans, Methylophilus methylotrophus, Methylobacterium oryzae, Hyphomicrobium sp. and Methylosulfonomonas methylovora. Statistically significant correlations for upwelling waters between methanol uptake into cells and both chlorophyll a concentrations and methanol oxidation rates suggest that remotely sensed chlorophyll a images, in these <span class="hlt">productive</span> areas, could be used to derive total methanol biological loss rates, a useful tool for atmospheric and marine climatically active gas modellers, and air–sea exchange scientists. PMID:23178665</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010GPC....73..114M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010GPC....73..114M"><span>An <span class="hlt">Early</span>-Middle Guadalupian (Permian) isotopic record from a mid-<span class="hlt">oceanic</span> carbonate buildup: Akiyoshi Limestone, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Musashi, Masaaki; Isozaki, Yukio; Kawahata, Hodaka</p> <p>2010-08-01</p> <p>In order to understand the oceanographic changes before the Guadalupian-Lopingian (Permian) boundary mass extinction event, we investigated the isotopic compositions of the inorganic carbon and the oxygen ( δ13C carb and δ18O carb) of the Guadalupian (Middle Permian) shallow marine carbonates deposited on a seamount-top in the superocean Panthalassa. The drilled samples were obtained at Kaerimizu in the Akiyoshi area, SW Japan. We focused on the Roadian-Wordian (Middle Guadalupian) interval that spans over 7 fusuline zones; i.e. the Parafusulina kaerimizuensis Zone ( Pk Z.), Afghanella ozawai Zone ( Ao Z.), Neoschwagerina craticulifera robusta Zone ( Ncr Z.), Verbeekina verbeeki-Afghanella schenki Zone ( Vv-As Z.), Neoschwageina fusiformis Zone ( Nf Z.), Verbeekina verbeeki Zone ( Vv Z.), and Colania douvillei Zone ( Cd Z.), in ascending order. Analytical results showed that the δ13C carb values stayed almost constant around + 3.0‰ PDB in the Pk Z., Ao Z. and the lower half of the Ncr Z., and those in the upper-section gradually decreased down to -2.0‰, of which the lowest was found in the Cd Z. We statistically extracted the samples with presumably better preserved δ13C carb values in the Kaerimizu section ranged between + 0.5 and + 4.0‰ with average values of δ13C carb of + 2.7 ± 1.0‰, on the basis of δ13C carb- δ18O carb characterization. This interval shows a monotonous decrease in δ13C carb values from ca + 4.0‰ to + 2.0‰. This indicates that the primary <span class="hlt">productivity</span> might be generally high in the Wordian mid-<span class="hlt">oceanic</span> domain but slightly declined in the Late Wordian. The studied <span class="hlt">Early</span>-Middle Guadalupian interval is chemostratigraphically correlated with the other mid-Pansalassan paleo-atoll limestone e.g. Iwato Formation in Japan, suggesting that the relatively high δ13C carb (over + 3.0‰) of seawater predominated in shallow mid-superocean during the middle Middle Permian.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010BGeo....7.3549P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010BGeo....7.3549P"><span>Fueling export <span class="hlt">production</span>: nutrient return pathways from the deep <span class="hlt">ocean</span> and their dependence on the Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palter, J. B.; Sarmiento, J. L.; Gnanadesikan, A.; Simeon, J.; Slater, R. D.</p> <p>2010-11-01</p> <p>In the Southern <span class="hlt">Ocean</span>, mixing and upwelling in the presence of heat and freshwater surface fluxes transform subpycnocline water to lighter densities as part of the upward branch of the Meridional Overturning Circulation (MOC). One hypothesized impact of this transformation is the restoration of nutrients to the global pycnocline, without which biological <span class="hlt">productivity</span> at low latitudes would be significantly reduced. Here we use a novel set of modeling experiments to explore the causes and consequences of the Southern <span class="hlt">Ocean</span> nutrient return pathway. Specifically, we quantify the contribution to global <span class="hlt">productivity</span> of nutrients that rise from the <span class="hlt">ocean</span> interior in the Southern <span class="hlt">Ocean</span>, the northern high latitudes, and by mixing across the low latitude pycnocline. In addition, we evaluate how the strength of the Southern <span class="hlt">Ocean</span> winds and the parameterizations of subgridscale processes change the dominant nutrient return pathways in the <span class="hlt">ocean</span>. Our results suggest that nutrients upwelled from the deep <span class="hlt">ocean</span> in the Antarctic Circumpolar Current and subducted in Subantartic Mode Water support between 33 and 75% of global export <span class="hlt">production</span> between 30° S and 30° N. The high end of this range results from an <span class="hlt">ocean</span> model in which the MOC is driven primarily by wind-induced Southern <span class="hlt">Ocean</span> upwelling, a configuration favored due to its fidelity to tracer data, while the low end results from an MOC driven by high diapycnal diffusivity in the pycnocline. In all models, nutrients exported in the SAMW layer are utilized and converted rapidly (in less than 40 years) to remineralized nutrients, explaining previous modeling results that showed little influence of the drawdown of SAMW surface nutrients on atmospheric carbon concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010BGD.....7.4045P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010BGD.....7.4045P"><span>Fueling primary <span class="hlt">productivity</span>: nutrient return pathways from the deep <span class="hlt">ocean</span> and their dependence on the Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palter, J. B.; Sarmiento, J. L.; Gnanadesikan, A.; Simeon, J.; Slater, D.</p> <p>2010-06-01</p> <p>In the Southern <span class="hlt">Ocean</span>, mixing and upwelling in the presence of heat and freshwater surface fluxes transform subpycnocline water to lighter densities as part of the upward branch of the Meridional Overturning Circulation (MOC). One hypothesized impact of this transformation is the restoration of nutrients to the global pycnocline, without which biological <span class="hlt">productivity</span> at low latitudes would be catastrophically reduced. Here we use a novel set of modeling experiments to explore the causes and consequences of the Southern <span class="hlt">Ocean</span> nutrient return pathway. Specifically, we quantify the contribution to global <span class="hlt">productivity</span> of nutrients that rise from the <span class="hlt">ocean</span> interior in the Southern <span class="hlt">Ocean</span>, the northern high latitudes, and by mixing across the low latitude pycnocline. In addition, we evaluate how the strength of the Southern <span class="hlt">Ocean</span> winds and the parameterizations of subgridscale processes change the dominant nutrient return pathways in the <span class="hlt">ocean</span>. Our results suggest that nutrients upwelled from the deep <span class="hlt">ocean</span> in the Antarctic Circumpolar Current and subducted in Subantartic Mode Water support between 33 and 75% of global primary <span class="hlt">productivity</span> between 30° S and 30° N. The high end of this range results from an <span class="hlt">ocean</span> model in which the MOC is driven primarily by wind-induced Southern <span class="hlt">Ocean</span> upwelling, a configuration favored due to its fidelity to tracer data, while the low end results from an MOC driven by high diapycnal diffusivity in the pycnocline. In all models, the high preformed nutrients subducted in the SAMW layer are converted rapidly (in less than 40 years) to remineralized nutrients, explaining previous modeling results that showed little influence of the drawdown of SAMW surface nutrients on atmospheric carbon concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.5210B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.5210B"><span>Biome-specific scaling of <span class="hlt">ocean</span> <span class="hlt">productivity</span>, temperature, and carbon export efficiency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Britten, Gregory L.; Primeau, François W.</p> <p>2016-05-01</p> <p>Mass conservation and metabolic theory place constraints on how marine export <span class="hlt">production</span> (EP) scales with net primary <span class="hlt">productivity</span> (NPP) and sea surface temperature (SST); however, little is empirically known about how these relationships vary across ecologically distinct <span class="hlt">ocean</span> biomes. Here we compiled in situ observations of EP, NPP, and SST and used statistical model selection theory to demonstrate significant biome-specific scaling relationships among these variables. Multiple statistically similar models yield a threefold variation in the globally integrated carbon flux (~4-12 Pg C yr-1) when applied to climatological satellite-derived NPP and SST. Simulated NPP and SST input variables from a 4×CO2 climate model experiment further show that biome-specific scaling alters the predicted response of EP to simulated increases of atmospheric CO2. These results highlight the need to better understand distinct pathways of carbon export across unique ecological biomes and may help guide proposed efforts for in situ observations of the <span class="hlt">ocean</span> carbon cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5014014','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5014014"><span>Seabird diversity hotspot linked to <span class="hlt">ocean</span> <span class="hlt">productivity</span> in the Canary Current Large Marine Ecosystem</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Attrill, Martin J.; Becker, Peter H.; Egevang, Carsten; Furness, Robert W.; Grémillet, David; Kopp, Matthias; Lescroël, Amélie; Matthiopoulos, Jason; Peter, Hans-Ulrich; Phillips, Richard A.</p> <p>2016-01-01</p> <p>Upwelling regions are highly <span class="hlt">productive</span> habitats targeted by wide-ranging marine predators and industrial fisheries. In this study, we track the migratory movements of eight seabird species from across the Atlantic; quantify overlap with the Canary Current Large Marine Ecosystem (CCLME) and determine the habitat characteristics that drive this association. Our results indicate the CCLME is a biodiversity hotspot for migratory seabirds; all tracked species and more than 70% of individuals used this upwelling region. Relative species richness peaked in areas where sea surface temperature averaged between 15 and 20°C, and correlated positively with chlorophyll a, revealing the optimum conditions driving bottom-up trophic effects for seabirds. Marine vertebrates are not confined by international boundaries, making conservation challenging. However, by linking diversity to <span class="hlt">ocean</span> <span class="hlt">productivity</span>, our research reveals the significance of the CCLME for seabird populations from across the Atlantic, making it a priority for conservation action. PMID:27531154</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910041717&hterms=ocean+climate+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Docean%2Bclimate%2Bchanges','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910041717&hterms=ocean+climate+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Docean%2Bclimate%2Bchanges"><span>Biological <span class="hlt">production</span> models as elements of coupled, atmosphere-<span class="hlt">ocean</span> models 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>Platt, Trevor; Sathyendranath, Shubha</p> <p>1991-01-01</p> <p>Process models of phytoplankton <span class="hlt">production</span> are discussed with respect to their suitability for incorporation into global-scale numerical <span class="hlt">ocean</span> circulation models. Exact solutions are given for integrals over the mixed layer and the day of analytic, wavelength-independent models of primary <span class="hlt">production</span>. Within this class of model, the bias incurred by using a triangular approximation (rather than a sinusoidal one) to the variation of surface irradiance through the day is computed. Efficient computation algorithms are given for the nonspectral models. More exact calculations require a spectrally sensitive treatment. Such models exist but must be integrated numerically over depth and time. For these integrations, resolution in wavelength, depth, and time are considered and recommendations made for efficient computation. The extrapolation of the one-(spatial)-dimension treatment to large horizontal scale is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27531154','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27531154"><span>Seabird diversity hotspot linked to <span class="hlt">ocean</span> <span class="hlt">productivity</span> in the Canary Current Large Marine Ecosystem.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grecian, W James; Witt, Matthew J; Attrill, Martin J; Bearhop, Stuart; Becker, Peter H; Egevang, Carsten; Furness, Robert W; Godley, Brendan J; González-Solís, Jacob; Grémillet, David; Kopp, Matthias; Lescroël, Amélie; Matthiopoulos, Jason; Patrick, Samantha C; Peter, Hans-Ulrich; Phillips, Richard A; Stenhouse, Iain J; Votier, Stephen C</p> <p>2016-08-01</p> <p>Upwelling regions are highly <span class="hlt">productive</span> habitats targeted by wide-ranging marine predators and industrial fisheries. In this study, we track the migratory movements of eight seabird species from across the Atlantic; quantify overlap with the Canary Current Large Marine Ecosystem (CCLME) and determine the habitat characteristics that drive this association. Our results indicate the CCLME is a biodiversity hotspot for migratory seabirds; all tracked species and more than 70% of individuals used this upwelling region. Relative species richness peaked in areas where sea surface temperature averaged between 15 and 20°C, and correlated positively with chlorophyll a, revealing the optimum conditions driving bottom-up trophic effects for seabirds. Marine vertebrates are not confined by international boundaries, making conservation challenging. However, by linking diversity to <span class="hlt">ocean</span> <span class="hlt">productivity</span>, our research reveals the significance of the CCLME for seabird populations from across the Atlantic, making it a priority for conservation action. © 2016 The Authors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29062103','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29062103"><span>Recycled iron fuels new <span class="hlt">production</span> in the eastern equatorial Pacific <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>Rafter, Patrick A; Sigman, Daniel M; Mackey, Katherine R M</p> <p>2017-10-24</p> <p>Nitrate persists in eastern equatorial Pacific surface waters because phytoplankton growth fueled by nitrate (new <span class="hlt">production</span>) is limited by iron. Nitrate isotope measurements provide a new constraint on the controls of surface nitrate concentration in this region and allow us to quantify the degree and temporal variability of nitrate consumption. Here we show that nitrate consumption in these waters cannot be fueled solely by the external supply of iron to these waters, which occurs by upwelling and dust deposition. Rather, a substantial fraction of nitrate consumption must be supported by the recycling of iron within surface waters. Given plausible iron recycling rates, seasonal variability in nitrate concentration on and off the equator can be explained by upwelling rate, with slower upwelling allowing for more cycles of iron regeneration and uptake. The efficiency of iron recycling in the equatorial Pacific implies the evolution of ecosystem-level mechanisms for retaining iron in surface <span class="hlt">ocean</span> settings where it limits <span class="hlt">productivity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27522173','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27522173"><span>The impact of CO2-driven <span class="hlt">ocean</span> acidification on <span class="hlt">early</span> development and calcification in the sea urchin Strongylocentrotus intermedius.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhan, Yaoyao; Hu, Wanbin; Zhang, Weijie; Liu, Minbo; Duan, Lizhu; Huang, Xianya; Chang, Yaqing; Li, Cong</p> <p>2016-11-15</p> <p>The impact of CO 2 -driven <span class="hlt">ocean</span> acidification(OA) on <span class="hlt">early</span> development and calcification in the sea urchin Strongylocentrotus intermedius cultured in northern Yellow Sea was investigated by comparing fertilization success, <span class="hlt">early</span> cleavage rate, hatching rate of blastulae, larvae survival rate at 70h post-fertilization, larval morphology and calcification under present natural seawater condition (pH=8.00±0.03) and three laboratory-controlled acidified conditions (OA 1 , △pH=-0.3units; OA 2 , △pH=-0.4units; OA 3 , △pH=-0.5units) projected by IPCC for 2100. Results showed that pH decline had no effect on the overall fertilization, however, with decreased pH, delayed <span class="hlt">early</span> embryonic cleavage, reduced hatching rate of blastulae and four-armed larvae survival rate at 70h post-fertilization, impaired larval symmetry, shortened larval spicules, and corrosion spicule structure were observed in all OA-treated groups as compared to control, which indicated that CO 2 -driven OA affected <span class="hlt">early</span> development and calcification in S. intermedius negatively. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999GBioC..13..115L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999GBioC..13..115L"><span>Quantitative estimation of global patterns of surface <span class="hlt">ocean</span> biological <span class="hlt">productivity</span> and its seasonal variation on timescales from centuries to millennia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loubere, Paul; Fariduddin, Mohammad</p> <p>1999-03-01</p> <p>We present a quantitative method, based on the relative abundances of benthic foraminifera in deep-sea sediments, for estimating surface <span class="hlt">ocean</span> biological <span class="hlt">productivity</span> over the timescale of centuries to millennia. We calibrate the method using a global data set composed of 207 samples from the Atlantic, Pacific, and Indian <span class="hlt">Oceans</span> from a water depth range between 2300 and 3600 m. The sample set was developed so that other, potentially significant, environmental variables would be uncorrelated to overlying surface <span class="hlt">ocean</span> <span class="hlt">productivity</span>. A regression of assemblages against <span class="hlt">productivity</span> yielded an r2 = 0.89 demonstrating a strong <span class="hlt">productivity</span> signal in the faunal data. In addition, we examined assemblage response to annual variability in biological <span class="hlt">productivity</span> (seasonality). Our data set included a range of seasonalities which we quantified into a seasonality index using the pigment color bands from the coastal zone color scanner (CZCS). The response of benthic foraminiferal assemblage composition to our seasonality index was tested with regression analysis. We obtained a statistically highly significant r2 = 0.75. Further, discriminant function analysis revealed a clear separation among sample groups based on surface <span class="hlt">ocean</span> <span class="hlt">productivity</span> and our seasonality index. Finally, we tested the response of benthic foraminiferal assemblages to three different modes of seasonality. We observed a distinct separation of our samples into groups representing low seasonal variability, strong seasonality with a single main <span class="hlt">productivity</span> event in the year, and strong seasonality with multiple <span class="hlt">productivity</span> events in the year. Reconstructing surface <span class="hlt">ocean</span> biological <span class="hlt">productivity</span> with benthic foraminifera will aid in modeling marine biogeochemical cycles. Also, estimating mode and range of annual seasonality will provide insight to changing <span class="hlt">oceanic</span> processes, allowing the examination of the mechanisms causing changes in the marine biotic system over time. This article contains supplementary</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5134028','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5134028"><span>Effects of sea ice cover on satellite-detected primary <span class="hlt">production</span> in the Arctic <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>Lee, Zhongping; Mitchell, B. Greg; Nevison, Cynthia D.</p> <p>2016-01-01</p> <p>The influence of decreasing Arctic sea ice on net primary <span class="hlt">production</span> (NPP) in the Arctic <span class="hlt">Ocean</span> has been considered in multiple publications but is not well constrained owing to the potentially large errors in satellite algorithms. In particular, the Arctic <span class="hlt">Ocean</span> is rich in coloured dissolved organic matter (CDOM) that interferes in the detection of chlorophyll a concentration of the standard algorithm, which is the primary input to NPP models. We used the quasi-analytic algorithm (Lee et al. 2002 Appl. Opti. 41, 5755−5772. (doi:10.1364/AO.41.005755)) that separates absorption by phytoplankton from absorption by CDOM and detrital matter. We merged satellite data from multiple satellite sensors and created a 19 year time series (1997–2015) of NPP. During this period, both the estimated annual total and the summer monthly maximum pan-Arctic NPP increased by about 47%. Positive monthly anomalies in NPP are highly correlated with positive anomalies in open water area during the summer months. Following the earlier ice retreat, the start of the high-<span class="hlt">productivity</span> season has become earlier, e.g. at a mean rate of −3.0 d yr−1 in the northern Barents Sea, and the length of the high-<span class="hlt">productivity</span> period has increased from 15 days in 1998 to 62 days in 2015. While in some areas, the termination of the <span class="hlt">productive</span> season has been extended, owing to delayed ice formation, the termination has also become earlier in other areas, likely owing to limited nutrients. PMID:27881759</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP44B..07R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP44B..07R"><span>Surface Nutrient Utilisation and <span class="hlt">Productivity</span> During Glacial-Interglacial Periods from the Equatorial Indian <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>R, C. K.; Bhushan, R.; Agnihotri, R.; Sawlani, R.; Jull, A. J. T.</p> <p>2016-12-01</p> <p>Seawaters and underlying sediments off Sri Lanka provide a unique marine realm affected by both branches of Northern Indian <span class="hlt">Ocean</span> i.e. Arabian Sea (AS) and Bay of Bengal (BOB). AS and BOB are known for their distinct response to southwest monsoon. AS experiencing mainly winds and upwelling while BOB receives precipitation driven surface runoff from the Indian sub-continent. Multiple proxies were measured on a radiocarbon dated sediment core raised off Sri Lanka; their down core variations were used to understand <span class="hlt">oceanic</span> history (nutrient utilisation, surface <span class="hlt">productivity</span>, nature of organic matter) spanning last glacial-interglacial cycle ( 26 to 2.5 ka BP). Variations in CaCO3, biogenic silica (BSi) and δ15N from 26 ka to 12.5 ka BP indicate the region was experiencing high surface <span class="hlt">productivity</span> with probably reduced surface nutrient utilisation efficiency. Sedimentary δ15N depth profile is decoupled from down core variations of major <span class="hlt">productivity</span> indices (e.g. CaCO3, OC), hinting plausibly partial utilization of nutrients in the mixed layer (photic zone). δ13C of OC and C/N (wt. ratio) clearly reveal the terrestrial origin of organic matter at 15 ka BP, a period known for witnessing onset of deglaciation in northern hemisphere. δ13C minimum at 9 ka BP indicates intense monsoonal activity during this time coinciding well with solar insolation (June) maximum of the northern hemisphere. With the onset of Holocene ( 11 ka BP), δ15N variations appear to correlate with BSi and Ba/Ti indicating enhanced utilization of available nutrients at surface. Suggesting surface <span class="hlt">productivity</span> over the region was probably micro-nutrient limited. The increased inventory of terrestrial runoff in Holocene probably demonstrates enhanced carbon sequestration capability of the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27881759','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27881759"><span>Effects of sea ice cover on satellite-detected primary <span class="hlt">production</span> in the Arctic <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>Kahru, Mati; Lee, Zhongping; Mitchell, B Greg; Nevison, Cynthia D</p> <p>2016-11-01</p> <p>The influence of decreasing Arctic sea ice on net primary <span class="hlt">production</span> (NPP) in the Arctic <span class="hlt">Ocean</span> has been considered in multiple publications but is not well constrained owing to the potentially large errors in satellite algorithms. In particular, the Arctic <span class="hlt">Ocean</span> is rich in coloured dissolved organic matter (CDOM) that interferes in the detection of chlorophyll a concentration of the standard algorithm, which is the primary input to NPP models. We used the quasi-analytic algorithm (Lee et al 2002 Appl. Opti. 41, 5755-5772. (doi:10.1364/AO.41.005755)) that separates absorption by phytoplankton from absorption by CDOM and detrital matter. We merged satellite data from multiple satellite sensors and created a 19 year time series (1997-2015) of NPP. During this period, both the estimated annual total and the summer monthly maximum pan-Arctic NPP increased by about 47%. Positive monthly anomalies in NPP are highly correlated with positive anomalies in open water area during the summer months. Following the earlier ice retreat, the start of the high-<span class="hlt">productivity</span> season has become earlier, e.g. at a mean rate of -3.0 d yr -1 in the northern Barents Sea, and the length of the high-<span class="hlt">productivity</span> period has increased from 15 days in 1998 to 62 days in 2015. While in some areas, the termination of the <span class="hlt">productive</span> season has been extended, owing to delayed ice formation, the termination has also become earlier in other areas, likely owing to limited nutrients. © 2016 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10422E..1KC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10422E..1KC"><span>Intersatellite comparisons and evaluations of three <span class="hlt">ocean</span> color <span class="hlt">products</span> along the Zhejiang coast, eastern China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, Qiyuan; Wang, Difeng; Gong, Fang; Pan, Delu; Hao, Zengzhou; Wang, Tianyu; Zhu, Qiankun</p> <p>2017-10-01</p> <p>With its broad spatial coverage and fine temporal resolution, <span class="hlt">ocean</span> color remote sensing data represents an effective tool for monitoring large areas of <span class="hlt">ocean</span>, and has the potential to provide crucial information in coastal waters where routine monitoring is either lacking or unsatisfactory. The semi-analytical or empirical algorithms that work well in Case 1 waters encounter many problems in offshore areas where the water is often optically complex and presents difficulties for atmospheric correction. Zhejiang is one of the most developed provinces in eastern China, and its adjacent seas have been greatly affected by recent rapid economic development. Various islands and semi-closed bays along the Zhejiang coast promote the formation of muddy tidal flats. Moreover, large quantities of terrestrial substances coming down with the Yangtze River and other local rivers also have a great impact on the coastal waters of the province. MODIS, VIIRS and GOCI are three commonly used <span class="hlt">ocean</span> color sensors covering the East China Sea. Several <span class="hlt">ocean</span> color <span class="hlt">products</span> such as remote-sensing reflectance (Rrs) and the concentrations of chlorophyll a (Chl-a) and total suspended matter (TSM) of the above three sensors on the Zhejiang coast have been evaluated. Cloud-free satellite images with synchronous field measurements taken between 2012 and 2015 were used for comparison. It is shown that there is a good correlation between the MODIS and GOCI spectral data, while some outliers were found in the VIIRS images. The low signal-to-noise ratio at short wavelengths in highly turbid waters also reduced the correlation between different sensors. In addition, it was possible to obtain more valid data with GOCI in shallow waters because of the use of an appropriate atmospheric correction algorithm. The standard Chl-a and TSM <span class="hlt">products</span> of the three satellites were also evaluated, and it was found that the Chl-a and TSM concentrations calculated by the OC3G and Case 2 algorithms, respectively</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMPP12B..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMPP12B..05S"><span>Phosphorus, Barium and Bioactive Metals (Zn, Cu, Co) in Coral Aragonite: Relationships to Upper <span class="hlt">Ocean</span> <span class="hlt">Productivity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sherrell, R. M.; Lavigne, M. G.; Linsley, B. K.</p> <p>2006-12-01</p> <p>Coral records of surface <span class="hlt">ocean</span> properties related to primary <span class="hlt">productivity</span> could reveal much about the history of upper <span class="hlt">ocean</span> biogeochemistry over decades to centuries, but are currently relatively undeveloped. This presentation will explore the utility of high-resolution records of P/Ca, Ba/Ca, and the micronutrient metals Zn/Ca, Cu/Ca, and Co/Ca. Using high sensitivity laser ablation ICP-MS, we have obtained multi-year records of these variables with ~ bi-weekly resolution and seasonal dating for Porites corals from Rarotonga (21S, 159W) and Clipperton Atoll (10N, 109W) Results are compared to data for Porites and Acropora spp. grown in culture at Rutgers University, to explore the applicability of cultured corals for quantifying the effects of seawater chemistry on trace elements in coralline aragonite. The P/Ca results suggest lattice-bound incorporation and encourage the development of a surface <span class="hlt">ocean</span> PO4 proxy details will be presented by LaVigne et al. elsewhere in this session. At Rarotonga, Ba/Ca shows regular, ~ annual, 2-5 week duration spikes a factor of 2-3 higher than the ~ constant background signal, appearing in austral spring- summer. These are not associated with runoff or authigenic mineral incorporation, and are similar to Ba spikes observed at least twice in the literature. We explore the hypothesis that these signals are related to biogenic organically-bound or barite Ba in the ambient surface water, and might therefore serve as a proxy of phytoplankton bloom intensity during the most <span class="hlt">productive</span> part of the year. Potential mechanisms of incorporation must include the possibility of suspended particulate elements finding a route to permanent sequestration in the skeleton. Laser ablation values for Zn, and Cu are similar at Rarotonga and Clipperton, and higher by factors of 500 and 15 than literature values for cleaned aragonite analyzed in solution, while our Co/Ca values are the lowest ever determined. Seasonal and shorter scale variations at</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/2017AsBio..17..287R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AsBio..17..287R"><span>False Negatives for Remote Life Detection on <span class="hlt">Ocean</span>-Bearing Planets: Lessons from the <span class="hlt">Early</span> Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reinhard, Christopher T.; Olson, Stephanie L.; Schwieterman, Edward W.; Lyons, Timothy W.</p> <p>2017-04-01</p> <p><span class="hlt">Ocean</span>-atmosphere chemistry on Earth has undergone dramatic evolutionary changes throughout its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has centered on refining our understanding of false positives for remote life detection, much less attention has been paid to the possibility of false negatives, that is, cryptic biospheres that are widespread and active on a planet's surface but are ultimately undetectable or difficult to detect in the composition of a planet's atmosphere. Here, we summarize recent developments from geochemical proxy records and Earth system models that provide insight into the long-term evolution of the most readily detectable potential biosignature gases on Earth - oxygen (O2), ozone (O3), and methane (CH4). We suggest that the canonical O2-CH4 disequilibrium biosignature would perhaps have been challenging to detect remotely during Earth's ˜4.5-billion-year history and that in general atmospheric O2/O3 levels have been a poor proxy for the presence of Earth's biosphere for all but the last ˜500 million years. We further suggest that detecting atmospheric CH4 would have been problematic for most of the last ˜2.5 billion years of Earth's history. More broadly, we stress that internal <span class="hlt">oceanic</span> recycling of biosignature gases will often render surface biospheres on <span class="hlt">ocean</span>-bearing silicate worlds cryptic, with the implication that the planets most conducive to the development and maintenance of a pervasive biosphere will often be challenging to characterize via conventional atmospheric biosignatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28418704','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28418704"><span>False Negatives for Remote Life Detection on <span class="hlt">Ocean</span>-Bearing Planets: Lessons from the <span class="hlt">Early</span> Earth.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reinhard, Christopher T; Olson, Stephanie L; Schwieterman, Edward W; Lyons, Timothy W</p> <p>2017-04-01</p> <p><span class="hlt">Ocean</span>-atmosphere chemistry on Earth has undergone dramatic evolutionary changes throughout its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has centered on refining our understanding of false positives for remote life detection, much less attention has been paid to the possibility of false negatives, that is, cryptic biospheres that are widespread and active on a planet's surface but are ultimately undetectable or difficult to detect in the composition of a planet's atmosphere. Here, we summarize recent developments from geochemical proxy records and Earth system models that provide insight into the long-term evolution of the most readily detectable potential biosignature gases on Earth-oxygen (O 2 ), ozone (O 3 ), and methane (CH 4 ). We suggest that the canonical O 2 -CH 4 disequilibrium biosignature would perhaps have been challenging to detect remotely during Earth's ∼4.5-billion-year history and that in general atmospheric O 2 /O 3 levels have been a poor proxy for the presence of Earth's biosphere for all but the last ∼500 million years. We further suggest that detecting atmospheric CH 4 would have been problematic for most of the last ∼2.5 billion years of Earth's history. More broadly, we stress that internal <span class="hlt">oceanic</span> recycling of biosignature gases will often render surface biospheres on <span class="hlt">ocean</span>-bearing silicate worlds cryptic, with the implication that the planets most conducive to the development and maintenance of a pervasive biosphere will often be challenging to characterize via conventional atmospheric biosignatures. Key Words: Biosignatures-Oxygen-Methane-Ozone-Exoplanets-Planetary habitability. Astrobiology 17, 287-297.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5399744','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5399744"><span>False Negatives for Remote Life Detection on <span class="hlt">Ocean</span>-Bearing Planets: Lessons from the <span class="hlt">Early</span> Earth</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Olson, Stephanie L.; Schwieterman, Edward W.; Lyons, Timothy W.</p> <p>2017-01-01</p> <p>Abstract <span class="hlt">Ocean</span>-atmosphere chemistry on Earth has undergone dramatic evolutionary changes throughout its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has centered on refining our understanding of false positives for remote life detection, much less attention has been paid to the possibility of false negatives, that is, cryptic biospheres that are widespread and active on a planet's surface but are ultimately undetectable or difficult to detect in the composition of a planet's atmosphere. Here, we summarize recent developments from geochemical proxy records and Earth system models that provide insight into the long-term evolution of the most readily detectable potential biosignature gases on Earth—oxygen (O2), ozone (O3), and methane (CH4). We suggest that the canonical O2-CH4 disequilibrium biosignature would perhaps have been challenging to detect remotely during Earth's ∼4.5-billion-year history and that in general atmospheric O2/O3 levels have been a poor proxy for the presence of Earth's biosphere for all but the last ∼500 million years. We further suggest that detecting atmospheric CH4 would have been problematic for most of the last ∼2.5 billion years of Earth's history. More broadly, we stress that internal <span class="hlt">oceanic</span> recycling of biosignature gases will often render surface biospheres on <span class="hlt">ocean</span>-bearing silicate worlds cryptic, with the implication that the planets most conducive to the development and maintenance of a pervasive biosphere will often be challenging to characterize via conventional atmospheric biosignatures. Key Words: Biosignatures—Oxygen—Methane—Ozone—Exoplanets—Planetary habitability. Astrobiology 17, 287–297. PMID:28418704</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5429P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5429P"><span>FixO3 : <span class="hlt">Early</span> progress towards Open <span class="hlt">Ocean</span> observatory Data Management Harmonisation</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; Huber, Robert; Lampitt, Richard</p> <p>2014-05-01</p> <p>Since 2002 there has been a sustained effort, supported as European framework projects, to harmonise both the technology and the data management of Open <span class="hlt">Ocean</span> fixed observatories run by European nations. FixO3 started in September 2013, and for 4 years will coordinate the convergence of data management best practice across a constellation of moorings in the Atlantic, in both hemispheres, and in the Mediterranean. To ensure the continued existence of these unique sources of oceanographic data as sustained observatories it is vital to improve access to the data collected, both in terms of methods of presentation, real-time availability, long-term archiving and quality assurance. The data management component of FixO3 will improve access to marine observatory data by harmonizing data management standards and workflows covering the complete life cycle of data from real time data acquisition to long-term archiving. Legal and data policy aspects will be examined to identify transnational barriers to open-access to marine observatory data. A harmonised FixO3 data policy is being synthesised from the partner's existing policies, which will overcome the identified barriers, and provide a formal basis for data exchange between FixO3 infrastructures. Presently, the interpretation and implementation of accepted standards has considerable incompatibilities within the observatory community, and these different approaches will be unified into the FixO3 approach. Further, FixO3 aims to harmonise data management and standardisation efforts with other European and international marine data and observatory infrastructures. The FixO3 synthesis will build on the standards established in other European infrastructures such as EDMONET, SEADATANET, PANGAEA, EuroSITES (European contribution to JCOMMP <span class="hlt">Ocean</span>SITES programme), and My<span class="hlt">Ocean</span> (the Marine Core Service for GMES) infrastructures as well as relevant international infrastructures and data centres such as the ICOS <span class="hlt">Ocean</span> Thematic Centre</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.tmp.1321W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.tmp.1321W"><span>Suitability of Open-<span class="hlt">Ocean</span> Instrumentation for Use in Near-Field Tsunami <span class="hlt">Early</span> Warning Along Seismically Active Subduction Zones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williamson, Amy L.; Newman, Andrew V.</p> <p>2018-05-01</p> <p>Over the past decade, the number of open-<span class="hlt">ocean</span> gauges capable of parsing information about a passing tsunami has steadily increased, particularly through national cable networks and international buoyed efforts such as the Deep-<span class="hlt">ocean</span> Assessment and Reporting of Tsunami (DART). This information is analyzed to disseminate tsunami warnings to affected regions. However, most current warnings that incorporate tsunami are directed at mid- and far-field localities. In this study, we analyze the region surrounding four seismically active subduction zones, Cascadia, Japan, Chile, and Java, for their potential to facilitate local tsunami <span class="hlt">early</span> warning using such systems. We assess which locations currently have instrumentation in the right locations for direct tsunami observations with enough time to provide useful warning to the nearest affected coastline—and which are poorly suited for such systems. Our primary findings are that while some regions are ill-suited for this type of <span class="hlt">early</span> warning, such as the coastlines of Chile, other localities, like Java, Indonesia, could incorporate direct tsunami observations into their hazard forecasts with enough lead time to be effective for coastal community emergency response. We take into account the effect of tsunami propagation with regard to shallow bathymetry on the fore-arc as well as the effect of earthquake source placement. While it is impossible to account for every type of off-shore tsunamigenic event in these locales, this study aims to characterize a typical large tsunamigenic event occurring in the shallow part of the megathrust as a guide in what is feasible with <span class="hlt">early</span> tsunami warning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS53C1986C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS53C1986C"><span><span class="hlt">Ocean</span> Acidification Effects on the <span class="hlt">Early</span> Life-Stages of Commercially Important Flatfish of the Northeast USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambers, R. C.; Habeck, E. A.; Candelmo, A. C.; Poach, M.; Wieczorek, D.; Phelan, B.; Caldarone, E.; Cooper, K. R.</p> <p>2012-12-01</p> <p>The limited available evidence about effects on finfish of high CO2 levels and acidification of our <span class="hlt">oceans</span> suggests that effects will differ across fish species, be subtle, and interact with other stressors. A carefully planned, experimental framework was developed to cast an extensive yet strategic inferential net. Three key elements of our approach are the use of 1) multiple marine finfish species of relevance to the northeastern USA that differ in their ecologies including spawning season and habitat of <span class="hlt">early</span> life-stages; 2) a wide yet realistic range of environmental conditions (i.e., concurrent manipulation of CO2 levels and water temperatures), and 3) a diverse set of response variables related to fish sensitivity to elevated CO2 levels, water temperatures, and their interactions. The response variable set reflects fish condition, fitness, and likelihood of recruitment, and includes measures of viability, physiology, histopathology, growth, development, and behavior expressed during fish <span class="hlt">early</span> life-stages (i.e., gametes, embryos, and larvae). <span class="hlt">Early</span> life-stages were chosen due to the anticipation of their vulnerability to acid-base challenges in their environment. To date, factorial experiments have been implemented on summer flounder (Paralichthys dentatus) and winter flounder (Pseudopleuronectes americanus). Initial results reveal survival of summer flounder embryos is compromised by pH < 7.7 (CO2 > 790 ppm). These results were similar across offspring groups (i.e., embryos from different parents). Winter flounder are larger at hatching when exposed to high CO2 levels in the coolest environment implemented in our experiments (range 4 to 10 ○C). Further responses of advanced larvae of both flounder species are currently being assessed for evidence of other whole body, component organ, and biochemical impairment. This study will aid researchers and resource managers in identifying species types, life-stages, and biotic responses that are most sensitive to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5287B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5287B"><span>Coccolithophore export <span class="hlt">production</span> during the last deglaciation at ODP Site 1089 (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>Balestrieri, Chiara; Ziveri, Patrizia; Mortyn, Peter Graham; Fornaciari, Eliana; Agnini, Claudia</p> <p>2017-04-01</p> <p>In order to assess the Southern <span class="hlt">Ocean</span> carbonate budget change during the last deglaciation we evaluated the significance of calcification changes observed in calcareous nannofossil assemblages. In particular, we analysed coccolithophore assemblages from TNO57-21, a site survey core drilled as part of ODP Site 1089 (40°57'S; 9°53'E, 4620 m water depth), over the last 25 ky in the Subantarctic South Atlantic. This region is characterized by strong hydrographic gradients and ODP Site 1089 is optimally located in order to monitor the evolution of the Subtropical Front and Subpolar Front and the Agulhas Current (Flores et al., 2003) through time. The mean sedimentation rate is in the range of 15-20 cm/kyr, and the recovery of coccolith-bearing sediments provides a powerful tool to study deep-sea carbonate export <span class="hlt">production</span> at high-resolution. Much of the CO2 drawdown from the atmosphere has been proposed to be stored into the deep <span class="hlt">ocean</span> but evidence for increased carbon storage are still elusive (Martínez- Botí et al., 2015). Here, we present data on the Florisphaera profunda index and CaCO3 concentrations per gram of dry sediment, which were used to intepret the <span class="hlt">productivity</span> trend during the last 25 kyr. These data clearly show a decrease in carbonate <span class="hlt">production</span> throughout the last deglaciation. Moreover, we have calculated the Calcidiscus leptoporus-Emiliania huxleyi dissolution index (CEX'), which suggests a strong link between increasing coccolith dissolution and the evolution of the bottom water mass dynamics during Termination 1 (TI). Finally, mass estimations of the coccolith carbonate allow us to assess the role of each species as carbonate producers across this time span. These results reveal that during the last 25 ky the <span class="hlt">productivity</span> was influenced by the mid-latitude westerlies, the study site was bathed by different bottom water masses, and was affected by a shoaling of the lysocline during T1 and the Holocene. References Flores J-A., Marino M., Sierro</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PrOce.110..107H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PrOce.110..107H"><span>Synthesis of integrated primary <span class="hlt">production</span> in the Arctic <span class="hlt">Ocean</span>: II. In situ and remotely sensed estimates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hill, Victoria J.; Matrai, Patricia A.; Olson, Elise; Suttles, S.; Steele, Mike; Codispoti, L. A.; Zimmerman, Richard C.</p> <p>2013-03-01</p> <p>Recent warming of surface waters, accompanied by reduced ice thickness and extent may have significant consequences for climate-driven changes of primary <span class="hlt">production</span> (PP) in the Arctic <span class="hlt">Ocean</span> (AO). However, it has been difficult to obtain a robust benchmark estimate of pan-Arctic PP necessary for evaluating change. This paper provides an estimate of pan-Arctic PP prior to significant warming from a synthetic analysis of the ARCSS-PP database of in situ measurements collected from 1954 to 2007 and estimates derived from satellite-based observations from 1998 to 2007. Vertical profiles of in situ chlorophyll a (Chl a) and PP revealed persistent subsurface peaks in biomass and PP throughout the AO during most of the summer period. This was contradictory with the commonly assumed exponential decrease in PP with depth on which prior satellite-derived estimates were based. As remotely sensed Chl a was not a good predictor of integrated water column Chl a, accurate satellite-based modeling of vertically integrated primary <span class="hlt">production</span> (IPPsat), requires knowledge of the subsurface distribution of phytoplankton, coincident with the remotely sensed <span class="hlt">ocean</span> color measurements. We developed an alternative approach to modeling PP from satellite observations by incorporating climatological information on the depths of the euphotic zone and the mixed layer that control the distribution of phytoplankton that significantly improved the fidelity of satellite derived PP to in situ observations. The annual IPP of the Arctic <span class="hlt">Ocean</span> combining both in situ and satellite based estimates was calculated here to be a minimum of 466 ± 94 Tg C yr-1 and a maximum of 993 ± 94 Tg C yr-1, when corrected for subsurface <span class="hlt">production</span>. Inflow shelf seas account for 75% of annual IPP, while the central basin and Beaufort northern sea were the regions with the lowest annual integrated <span class="hlt">productivity</span>, due to persistently stratified, oligotrophic and ice-covered conditions. Although the expansion of summertime</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9746Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9746Z"><span>A Remaining Open Paleogeography of Paleo-Asian <span class="hlt">Ocean</span> by <span class="hlt">Early</span> Permian, Paleomagnetic Constraints from Eastern CAOB</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Donghai; Huang, Baochun; Zhao, Jie; Meert, Joseph; Zhang, Ye; Liang, Yalun; Bai, Qianhui; Zhao, Qian; Zhou, Tinghong</p> <p>2017-04-01</p> <p>We carry out a combined paleomagnetic and U-Pb geochronologic study on Paleozoic strata ranging from Lower Devonian to Upper Permian in mid-eastern Inner Mongolia, NE China with the purpose of puzzling out the timing and location of the final closure of Paleo-Asian <span class="hlt">Ocean</span> (PAO), and thus provides further implications for the evolution of eastern Central Asian Orogenic Belt (CAOB). Inside North Margin of North China Block (NMNCB), 20 sites from Middle Permian Elitu formation and 9 sites from Lower Permian Sanmianjing formation yields a high temperature Characteristic Remanent Magnetism (ChRM) of Dg=330.9, Ig=54.3, Kg=4.9, a95g=14.9 N= 24 before and Ds=347.4, Is=38.1, Ks=28.6, a95s=5.6, N=24 after tilt correction. 13 sites from Songliao-Xilinhot Block (SXB) isolate a ChRM of Dg=196.6, Ig=36.4, Kg=18.0, a95g=11.1, N=13; Ds=222.9, Is=20.5, Ks=15.7 a95s=11.9, N=13 with a positive fold test, which suggests a likely primary magnetization. Inside of Khingan-Airgin Sum Block (KAB), 2 different component is extracted from Lower Devonian Niqiuhe formation, Upper Carboniferous Baoligaomiao formation and Lower Permian Dashizhai formation. A high temperature Component A (Dg=28.3, Ig=29.7, Kg=24.4, a95g=6.6, N= 21; Ds=49.8, Is=62.1, Ks=57.4, a95s=4.2, N=21) with a synfolding origin is derived from 21 sites of Baoligaomiao formation in west KAB, which is traditionally named as Uliastai passive continental margin, whilst 11 sites from Lower Devonian Niqiuhe formation in east KAB generate a post-folding Component B (Dg=196.6, Ig=36.4, Kg=18.0, a95g=11.1, N=11; Ds=222.9, Is=20.5, Ks=15.7, a95s=11.9, N=11) with a possible remagnetization in <span class="hlt">early</span> Permian suggested by widely exposed granitic intrusion of 299 Ma in adjacent areas. Accordingly, 4 paleomagnetic poles are calculated as <span class="hlt">early</span>-middle Permian of NMNCB (Plat=67.9°N, Plong=326.7°E, A95=4.2°), <span class="hlt">early</span> Permian of SXB (Plat=45.3°N, Plong=250.3°E, A95=5.8°), late Carboniferous of west KAB (Plat=55.1°N, Plong=187.8°E, A95=6.2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19556256','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19556256"><span>Effects of <span class="hlt">ocean</span> acidification on the <span class="hlt">early</span> life history of a tropical marine fish.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Munday, Philip L; Donelson, Jennifer M; Dixson, Danielle L; Endo, Geoff G K</p> <p>2009-09-22</p> <p>Little is known about how fishes and other non-calcifying marine organisms will respond to the increased levels of dissolved CO(2) and reduced sea water pH that are predicted to occur over the coming century. We reared eggs and larvae of the orange clownfish, Amphiprion percula, in sea water simulating a range of <span class="hlt">ocean</span> acidification scenarios for the next 50-100 years (current day, 550, 750 and 1030 ppm atmospheric CO(2)). CO(2) acidification had no detectable effect on embryonic duration, egg survival and size at hatching. In contrast, CO(2) acidification tended to increase the growth rate of larvae. By the time of settlement (11 days post-hatching), larvae from some parental pairs were 15 to 18 per cent longer and 47 to 52 per cent heavier in acidified water compared with controls. Larvae from other parents were unaffected by CO(2) acidification. Elevated CO(2) and reduced pH had no effect on the maximum swimming speed of settlement-stage larvae. There was, however, a weak positive relationship between length and swimming speed. Large size is usually considered to be advantageous for larvae and newly settled juveniles. Consequently, these results suggest that levels of <span class="hlt">ocean</span> acidification likely to be experienced in the near future might not, in isolation, significantly disadvantage the growth and performance of larvae from benthic-spawning marine fishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5437290','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5437290"><span>Charcoal evidence that rising atmospheric oxygen terminated <span class="hlt">Early</span> Jurassic <span class="hlt">ocean</span> anoxia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Baker, Sarah J.; Hesselbo, Stephen P.; Lenton, Timothy M.; Duarte, Luís V.; Belcher, Claire M.</p> <p>2017-01-01</p> <p>The Toarcian <span class="hlt">Oceanic</span> Anoxic Event (T-OAE) was characterized by a major disturbance to the global carbon(C)-cycle, and depleted oxygen in Earth's <span class="hlt">oceans</span> resulting in marine mass extinction. Numerical models predict that increased organic carbon burial should drive a rise in atmospheric oxygen (pO2) leading to termination of an OAE after ∼1 Myr. Wildfire is highly responsive to changes in pO2 implying that fire-activity should vary across OAEs. Here we test this hypothesis by tracing variations in the abundance of fossil charcoal across the T-OAE. We report a sustained ∼800 kyr enhancement of fire-activity beginning ∼1 Myr after the onset of the T-OAE and peaking during its termination. This major enhancement of fire occurred across the timescale of predicted pO2 variations, and we argue this was primarily driven by increased pO2. Our study provides the first fossil-based evidence suggesting that fire-feedbacks to rising pO2 may have aided in terminating the T-OAE. PMID:28497785</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28497785','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28497785"><span>Charcoal evidence that rising atmospheric oxygen terminated <span class="hlt">Early</span> Jurassic <span class="hlt">ocean</span> anoxia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baker, Sarah J; Hesselbo, Stephen P; Lenton, Timothy M; Duarte, Luís V; Belcher, Claire M</p> <p>2017-05-12</p> <p>The Toarcian <span class="hlt">Oceanic</span> Anoxic Event (T-OAE) was characterized by a major disturbance to the global carbon(C)-cycle, and depleted oxygen in Earth's <span class="hlt">oceans</span> resulting in marine mass extinction. Numerical models predict that increased organic carbon burial should drive a rise in atmospheric oxygen (pO 2 ) leading to termination of an OAE after ∼1 Myr. Wildfire is highly responsive to changes in pO 2 implying that fire-activity should vary across OAEs. Here we test this hypothesis by tracing variations in the abundance of fossil charcoal across the T-OAE. We report a sustained ∼800 kyr enhancement of fire-activity beginning ∼1 Myr after the onset of the T-OAE and peaking during its termination. This major enhancement of fire occurred across the timescale of predicted pO 2 variations, and we argue this was primarily driven by increased pO 2 . Our study provides the first fossil-based evidence suggesting that fire-feedbacks to rising pO 2 may have aided in terminating the T-OAE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2817176','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2817176"><span>Effects of <span class="hlt">ocean</span> acidification on the <span class="hlt">early</span> life history of a tropical marine fish</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Munday, Philip L.; Donelson, Jennifer M.; Dixson, Danielle L.; Endo, Geoff G. K.</p> <p>2009-01-01</p> <p>Little is known about how fishes and other non-calcifying marine organisms will respond to the increased levels of dissolved CO2 and reduced sea water pH that are predicted to occur over the coming century. We reared eggs and larvae of the orange clownfish, Amphiprion percula, in sea water simulating a range of <span class="hlt">ocean</span> acidification scenarios for the next 50–100 years (current day, 550, 750 and 1030 ppm atmospheric CO2). CO2 acidification had no detectable effect on embryonic duration, egg survival and size at hatching. In contrast, CO2 acidification tended to increase the growth rate of larvae. By the time of settlement (11 days post-hatching), larvae from some parental pairs were 15 to 18 per cent longer and 47 to 52 per cent heavier in acidified water compared with controls. Larvae from other parents were unaffected by CO2 acidification. Elevated CO2 and reduced pH had no effect on the maximum swimming speed of settlement-stage larvae. There was, however, a weak positive relationship between length and swimming speed. Large size is usually considered to be advantageous for larvae and newly settled juveniles. Consequently, these results suggest that levels of <span class="hlt">ocean</span> acidification likely to be experienced in the near future might not, in isolation, significantly disadvantage the growth and performance of larvae from benthic-spawning marine fishes. PMID:19556256</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.5567P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.5567P"><span>Global <span class="hlt">Ocean</span> Data Quality Assessment of SARAL/AltiKa GDR <span class="hlt">products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Picot, Nicolas; Prandi, Pierre; desjonqueres, jean-damien</p> <p>2015-04-01</p> <p>The SARAL mission was successfully launched on February, 5th 2013 and cycle 1 started a few days later on March 14th. For more than 2 years, the Ka-band altimeter and dual frequency radiometer on board have been collecting high quality <span class="hlt">ocean</span> topography measurements. Within the first months of the mission, a first patch (P1) was developed to correct some small anomalies detected in the <span class="hlt">products</span> and to account for in-flight calibration data. At the beginning of year 2014, a second patch (P2) was produced (applied from cycle 10 pass 407 on OGDR data and from pass 566 on IGDR data) and the all GDR produced before this were reprocessed in order to deliver a consistent dataset to users. This new version of the <span class="hlt">products</span> provides, among other changes, important improvements regarding radiometer data processing, sea-state bias and wind speed. Since the beginning of the mission, data quality assessment of OGDR, IGDR and GDR data has been routinely performed at CNES and CLS (as part of the CNES SALP project). We will present the main results of the data quality assessment over <span class="hlt">ocean</span> based on SARAL/AltiKa GDR data reprocessed using the homogeneous P2 version. The main data quality metrics presented will include: Data availability and validity, Monitoring of the main altimeter and radiometer parameters and comparisons to other altimeter missions such as OSTM/Jason-2, Mission performance through mono-mission crossovers analysis, Investigation of inter-mission biases and large-scale regional differences from multi-mission crossovers between SARAL and Jason-2. Monitoring of the global mean SLA and comparison to Jason-2 Finally, we will present the new <span class="hlt">product</span> version standard that is currently under development on CNES side.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DSRII.127...93R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DSRII.127...93R"><span>The inhibition of N2O <span class="hlt">production</span> by <span class="hlt">ocean</span> acidification in cold temperate and polar waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rees, Andrew P.; Brown, Ian J.; Jayakumar, Amal; Ward, Bess B.</p> <p>2016-05-01</p> <p>The effects of <span class="hlt">ocean</span> acidification (OA) on nitrous oxide (N2O) <span class="hlt">production</span> and on the community composition of ammonium oxidizing archaea (AOA) were examined in the northern and southern sub-polar and polar Atlantic <span class="hlt">Ocean</span>. Two research cruises were performed during June 2012 between the North Sea and Arctic Greenland and Barent Seas, and in January-February 2013 to the Antarctic Scotia Sea. Seven stations were occupied in all during which shipboard experimental manipulations of the carbonate chemistry were performed through additions of NaHCO3-+HCl in order to examine the impact of short-term (48 h for N2O and between 96 and 168 h for AOA) exposure to control and elevated conditions of OA. During each experiment, triplicate incubations were performed at ambient conditions and at 3 lowered levels of pH which varied between 0.06 and 0.4 units according to the total scale and which were targeted at CO2 partial pressures of 500, 750 and 1000 μatm. The AOA assemblage in both Arctic and Antarctic regions was dominated by two major archetypes that represent the marine AOA clades most often detected in seawater. There were no significant changes in AOA assemblage composition between the beginning and end of the incubation experiments. N2O <span class="hlt">production</span> was sensitive to decreasing pHT at all stations and decreased by between 2.4% and 44% with reduced pHT values of between 0.06 and 0.4. The reduction in N2O yield from nitrification was directly related to a decrease of between 28% and 67% in available NH3 as a result of the pH driven shift in the NH3:NH4+ equilibrium. The maximum reduction in N2O <span class="hlt">production</span> at conditions projected for the end of the 21st century was estimated to be 0.82 Tg N y-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CliPa..11..473S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CliPa..11..473S"><span><span class="hlt">Early</span> Paleogene variations in the calcite compensation depth: new constraints using old borehole sediments from across Ninetyeast Ridge, central Indian <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>Slotnick, B. S.; Lauretano, V.; Backman, J.; Dickens, G. R.; Sluijs, A.; Lourens, L.</p> <p>2015-03-01</p> <p>Major variations in global carbon cycling occurred between 62 and 48 Ma, and these very likely related to changes in the total carbon inventory of the <span class="hlt">ocean</span>-atmosphere system. Based on carbon cycle theory, variations in the mass of the <span class="hlt">ocean</span> carbon should be reflected in contemporaneous global <span class="hlt">ocean</span> carbonate accumulation on the seafloor and, thereby, the depth of the calcite compensation depth (CCD). To better constrain the cause and magnitude of these changes, the community needs <span class="hlt">early</span> Paleogene carbon isotope and carbonate accumulation records from widely separated deep-sea sediment sections, especially including the Indian <span class="hlt">Ocean</span>. Several CCD reconstructions for this time interval have been generated using scientific drill sites in the Atlantic and Pacific <span class="hlt">oceans</span>; however, corresponding information from the Indian <span class="hlt">Ocean</span> has been extremely limited. To assess the depth of the CCD and the potential for renewed scientific drilling of Paleogene sequences in the Indian <span class="hlt">Ocean</span>, we examine lithologic, nannofossil, carbon isotope, and carbonate content records for late Paleocene - <span class="hlt">early</span> Eocene sediments recovered at three sites spanning Ninetyeast Ridge: Deep Sea Drilling Project (DSDP) Sites 213 (deep, east), 214 (shallow, central), and 215 (deep, west). The disturbed, discontinuous sediment sections are not ideal, because they were recovered in single holes using rotary coring methods, but remain the best Paleogene sediments available from the central Indian <span class="hlt">Ocean</span>. The δ13C records at Sites 213 and 215 are similar to those generated at several locations in the Atlantic and Pacific, including the prominent high in δ13C across the Paleocene carbon isotope maximum (PCIM) at Site 215, and the prominent low in δ13C across the <span class="hlt">early</span> Eocene Climatic Optimum (EECO) at both Site 213 and Site 215. The Paleocene-Eocene thermal maximum (PETM) and the K/X event are found at Site 213 but not at Site 215, presumably because of coring gaps. Carbonate content at both Sites 213 and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26903274','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26903274"><span>Isotopic disequilibrium in Globigerina bulloides and carbon isotope response to <span class="hlt">productivity</span> increase in 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>Prasanna, K; Ghosh, Prosenjit; Bhattacharya, S K; Mohan, K; Anilkumar, N</p> <p>2016-02-23</p> <p>Oxygen and carbon isotope ratios in planktonic foraminifera Globigerina bulloides collected from tow samples along a transect from the equatorial Indian <span class="hlt">ocean</span> to the Southern <span class="hlt">Ocean</span> (45°E and 80°E and 10°N to 53°S) were analysed and compared with the equilibrium δ(18)O and δ(13)C values of calcite calculated using the temperature and isotopic composition of the water column. The results agree within ~0.25‰ for the region between 10°N and 40°S and 75-200 m water depth which is considered to be the habitat of Globigerina bulloides. Further south (from 40°S to 55°S), however, the measured δ(18)O and δ(13)C values are higher than the expected values by ~2‰ and ~1‰ respectively. These enrichments can be attributed to either a 'vital effect' or a higher calcification rate. An interesting pattern of increase in the δ(13)C(DIC) value of the surface water with latitude is observed between 35°S and~ 60°S, with a peak at~ 42°S. This can be caused by increased organic matter <span class="hlt">production</span> and associated removal. A simple model accounting for the increase in the δ(13)C(DIC) values is proposed which fits well with the observed chlorophyll abundance as a function of latitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4763226','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4763226"><span>Isotopic disequilibrium in Globigerina bulloides and carbon isotope response to <span class="hlt">productivity</span> increase in Southern <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>Prasanna, K.; Ghosh, Prosenjit; Bhattacharya, S. K.; Mohan, K.; Anilkumar, N.</p> <p>2016-01-01</p> <p>Oxygen and carbon isotope ratios in planktonic foraminifera Globigerina bulloides collected from tow samples along a transect from the equatorial Indian <span class="hlt">ocean</span> to the Southern <span class="hlt">Ocean</span> (45°E and 80°E and 10°N to 53°S) were analysed and compared with the equilibrium δ18O and δ13C values of calcite calculated using the temperature and isotopic composition of the water column. The results agree within ~0.25‰ for the region between 10°N and 40°S and 75–200 m water depth which is considered to be the habitat of Globigerina bulloides. Further south (from 40°S to 55°S), however, the measured δ18O and δ13C values are higher than the expected values by ~2‰ and ~1‰ respectively. These enrichments can be attributed to either a ‘vital effect’ or a higher calcification rate. An interesting pattern of increase in the δ13C(DIC) value of the surface water with latitude is observed between 35°S and~ 60°S, with a peak at~ 42°S. This can be caused by increased organic matter <span class="hlt">production</span> and associated removal. A simple model accounting for the increase in the δ13C(DIC) values is proposed which fits well with the observed chlorophyll abundance as a function of latitude. PMID:26903274</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5652...89I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5652...89I"><span>Consistency of two global MODIS aerosol <span class="hlt">products</span> over <span class="hlt">ocean</span> on Terra and Aqua CERES SSF datasets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ignatov, Alexander; Minnis, Patrick; Wielicki, Bruce; Loeb, Norman G.; Remer, Lorraine A.; Kaufman, Yoram J.; Miller, Walter F.; Sun-Mack, Sunny; Laszlo, Istvan; Geier, Erika B.</p> <p>2004-12-01</p> <p>MODIS aerosol retrievals over <span class="hlt">ocean</span> from Terra and Aqua platforms are available from the Clouds and the Earth's Radiant Energy System (CERES) Single Scanner Footprint (SSF) datasets generated at NASA Langley Research Center (LaRC). Two aerosol <span class="hlt">products</span> are reported side by side. The primary M <span class="hlt">product</span> is generated by subsetting and remapping the multi-spectral (0.44 - 2.1 μm) MOD04 aerosols onto CERES footprints. MOD04 processing uses cloud screening and aerosol algorithms developed by the MODIS science team. The secondary (AVHRR-like) A <span class="hlt">product</span> is generated in only two MODIS bands: 1 and 6 on Terra, and ` and 7 on Aqua. The A processing uses NASA/LaRC cloud-screening and NOAA/NESDIS single channel aerosol algorthm. The M and A <span class="hlt">products</span> have been documented elsewhere and preliminarily compared using two weeks of global Terra CERES SSF (Edition 1A) data in December 2000 and June 2001. In this study, the M and A aerosol optical depths (AOD) in MODIS band 1 and (0.64 μm), τ1M and τ1A, are further checked for cross-platform consistency using 9 days of global Terra CERES SSF (Edition 2A) and Aqua CERES SSF (Edition 1A) data from 13 - 21 October 2002.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4299185','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4299185"><span>Climate change decouples <span class="hlt">oceanic</span> primary and export <span class="hlt">productivity</span> and organic carbon burial</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lopes, Cristina; Kucera, Michal; Mix, Alan C.</p> <p>2015-01-01</p> <p>Understanding responses of <span class="hlt">oceanic</span> primary <span class="hlt">productivity</span>, carbon export, and burial to climate change is essential for model-based projection of biological feedbacks in a high-CO2 world. Here we compare estimates of <span class="hlt">productivity</span> based on the composition of fossil diatom floras with organic carbon burial off Oregon in the Northeast Pacific across a large climatic transition at the last glacial termination. Although estimated primary <span class="hlt">productivity</span> was highest during the Last Glacial Maximum, carbon burial was lowest, reflecting reduced preservation linked to low sedimentation rates. A diatom size index further points to a glacial decrease (and deglacial increase) in the fraction of fixed carbon that was exported, inferred to reflect expansion, and contraction, of subpolar ecosystems that today favor smaller plankton. Thus, in contrast to models that link remineralization of carbon to temperature, in the Northeast Pacific, we find dominant ecosystem and sea floor control such that intervals of warming climate had more efficient carbon export and higher carbon burial despite falling primary <span class="hlt">productivity</span>. PMID:25453073</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/21419836','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21419836"><span>Bio-mining the microbial treasures of the <span class="hlt">ocean</span>: new natural <span class="hlt">products</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Imhoff, Johannes F; Labes, Antje; Wiese, Jutta</p> <p>2011-01-01</p> <p>The biological resources of the <span class="hlt">oceans</span> have been exploited since ancient human history, mainly by catching fish and harvesting algae. Research on natural <span class="hlt">products</span> with special emphasis on marine animals and also algae during the last decades of the 20th century has revealed the importance of marine organisms as producers of substances useful for the treatment of human diseases. Though a large number of bioactive substances have been identified, some many years ago, only recently the first drugs from the <span class="hlt">oceans</span> were approved. Quite astonishingly, the immense diversity of microbes in the marine environments and their almost untouched capacity to produce natural <span class="hlt">products</span> and therefore the importance of microbes for marine biotechnology was realized on a broad basis by the scientific communities only recently. This has strengthened worldwide research activities dealing with the exploration of marine microorganisms for biotechnological applications, which comprise the <span class="hlt">production</span> of bioactive compounds for pharmaceutical use, as well as the development of other valuable <span class="hlt">products</span>, such as enzymes, nutraceuticals and cosmetics. While the focus in these fields was mainly on marine bacteria, also marine fungi now receive growing attention. Although culture-dependent studies continue to provide interesting new chemical structures with biological activities at a high rate and represent highly promising approaches for the search of new drugs, exploration and use of genomic and metagenomic resources are considered to further increase this potential. Many efforts are made for the sustainable exploration of marine microbial resources. Large culture collections specifically of marine bacteria and marine fungi are available. Compound libraries of marine natural <span class="hlt">products</span>, even of highly purified substances, were established. The expectations into the commercial exploitation of marine microbial resources has given rise to numerous institutions worldwide, basic research facilities as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8068L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8068L"><span>Hidden biosphere in an oxygen-deficient Atlantic open <span class="hlt">ocean</span> eddy: future implications of <span class="hlt">ocean</span> deoxygenation on primary <span class="hlt">production</span> in the eastern tropical North Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loescher, Carolin; Fischer, Martin; Neulinger, Sven; Fiedler, Björn; Philippi, Miriam; Schütte, Florian; Singh, Arvind; Hauss, Helena; Karstensen, Johannes; Körtzinger, Arne; Schmitz, Ruth</p> <p>2016-04-01</p> <p>The eastern tropical North Atlantic (ETNA) is characterized by a highly <span class="hlt">productive</span> coastal upwelling system and a moderate oxygen minimum zone with lowest open <span class="hlt">ocean</span> oxygen (O2) concentrations of approximately 40 μmol kg-1. The recent discovery of re-occurring mesoscale eddies with close to anoxic O2 concentrations (<1 μmol kg-1) located just below the mixed layer has challenged our understanding of O2 distribution and biogeochemical processes in this area. Here, we present the first microbial community study from a deoxygenated anticyclonic modewater eddy in the open waters of the ETNA. In the eddy, we observed significantly lower bacterial diversity compared to surrounding waters, along with a significant community shift. We detected enhanced primary <span class="hlt">productivity</span> in the surface layer of the eddy indicated by elevated chlorophyll concentrations and carbon uptake rates of up to three times as high as in surrounding waters. Carbon uptake rates below the euphotic zone correlated to the presence of a specific high-light ecotype of Prochlorococcus, which is usually underrepresented in the ETNA. Our data indicate that high primary <span class="hlt">production</span> in the eddy fuels export <span class="hlt">production</span> and supports enhanced respiration in a specific microbial community at shallow depths, below the mixed layer base. The O2-depleted core waters eddy promoted transcription of the key gene for denitrification, nirS. This process is usually absent from the open ETNA waters. In light of future projected <span class="hlt">ocean</span> deoxygenation, our results show that even distinct events of anoxia have the potential to alter microbial community structure with critical impacts on primary <span class="hlt">productivity</span> and biogeochemical processes of <span class="hlt">oceanic</span> water bodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGD....1214175L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....1214175L"><span>Hidden biosphere in an oxygen-deficient Atlantic open <span class="hlt">ocean</span> eddy: future implications of <span class="hlt">ocean</span> deoxygenation on primary <span class="hlt">production</span> in the eastern tropical North Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Löscher, C. R.; Fischer, M. A.; Neulinger, S. C.; Fiedler, B.; Philippi, M.; Schütte, F.; Singh, A.; Hauss, H.; Karstensen, J.; Körtzinger, A.; Künzel, S.; Schmitz, R. A.</p> <p>2015-08-01</p> <p>The eastern tropical North Atlantic (ETNA) is characterized by a highly <span class="hlt">productive</span> coastal upwelling system and a moderate oxygen minimum zone with lowest open <span class="hlt">ocean</span> oxygen (O2) concentrations of around 40 μmol kg-1. Only recently, the discovery of re-occurring mesoscale eddies with sometimes close to anoxic O2 concentrations (<1 μmol kg-1) and located just below the mixed layer challenged our understanding of O2 distribution and biogeochemical processes in this area. Here, we present the first metagenomic dataset from a deoxygenated anticyclonic modewater eddy in the open waters of the ETNA. In the eddy, we observed a significantly lower bacterial diversity compared to surrounding waters, along with a significant community shift. We detected enhanced primary <span class="hlt">productivity</span> in the surface layer of the eddy indicated by elevated chlorophyll concentrations and increased carbon uptake rates up to three times as high as in surrounding waters. Carbon uptake below the euphotic zone correlated to the presence of a specific high-light ecotype of Prochlorococcus, which is usually underrepresented in the ETNA. Our combined data indicate that high primary <span class="hlt">production</span> in the eddy fuels export <span class="hlt">production</span> and the presence of a specific microbial community responsible for enhanced respiration at shallow depths, below the mixed layer base. Progressively decreasing O2 concentrations in the eddy were found to promote transcription of the key gene for denitrification, nirS, in the O2-depleted core waters. This process is usually absent from the open ETNA waters. In the light of future <span class="hlt">ocean</span> deoxygenation our results show exemplarily that even distinct events of anoxia have the potential to alter microbial community structures and with that critically impact primary <span class="hlt">productivity</span> and biogeochemical processes of <span class="hlt">oceanic</span> water bodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGeo...12.7467L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGeo...12.7467L"><span>Hidden biosphere in an oxygen-deficient Atlantic open-<span class="hlt">ocean</span> eddy: future implications of <span class="hlt">ocean</span> deoxygenation on primary <span class="hlt">production</span> in the eastern tropical North Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Löscher, C. R.; Fischer, M. A.; Neulinger, S. C.; Fiedler, B.; Philippi, M.; Schütte, F.; Singh, A.; Hauss, H.; Karstensen, J.; Körtzinger, A.; Künzel, S.; Schmitz, R. A.</p> <p>2015-12-01</p> <p>The eastern tropical North Atlantic (ETNA) is characterized by a highly <span class="hlt">productive</span> coastal upwelling system and a moderate oxygen minimum zone with lowest open-<span class="hlt">ocean</span> oxygen (O2) concentrations of approximately 40 μmol kg-1. The recent discovery of re-occurring mesoscale eddies with close to anoxic O2 concentrations (< 1 μmol kg-1) located just below the mixed layer has challenged our understanding of O2 distribution and biogeochemical processes in this area. Here, we present the first microbial community study from a deoxygenated anticyclonic modewater eddy in the open waters of the ETNA. In the eddy, we observed significantly lower bacterial diversity compared to surrounding waters, along with a significant community shift. We detected enhanced primary <span class="hlt">productivity</span> in the surface layer of the eddy indicated by elevated chlorophyll concentrations and carbon uptake rates of up to three times as high as in surrounding waters. Carbon uptake rates below the euphotic zone correlated to the presence of a specific high-light ecotype of Prochlorococcus, which is usually underrepresented in the ETNA. Our data indicate that high primary <span class="hlt">production</span> in the eddy fuels export <span class="hlt">production</span> and supports enhanced respiration in a specific microbial community at shallow depths, below the mixed-layer base. The transcription of the key functional marker gene for dentrification, nirS, further indicated a potential for nitrogen loss processes in O2-depleted core waters of the eddy. Dentrification is usually absent from the open ETNA waters. In light of future projected <span class="hlt">ocean</span> deoxygenation, our results show that even distinct events of anoxia have the potential to alter microbial community structure with critical impacts on primary <span class="hlt">productivity</span> and biogeochemical processes of <span class="hlt">oceanic</span> water bodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Litho.296..265L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Litho.296..265L"><span><span class="hlt">Early</span> Carboniferous adakite-like and I-type granites in central Qiangtang, northern Tibet: Implications for intra-<span class="hlt">oceanic</span> subduction and back-arc basin formation within the Paleo-Tethys <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>Liu, Jin-Heng; Xie, Chao-Ming; Li, Cai; Wang, Ming; Wu, Hao; Li, Xing-Kui; Liu, Yi-Ming; Zhang, Tian-Yu</p> <p>2018-01-01</p> <p>Recent studies have proposed that the Late Devonian ophiolites in the central Qiangtang region of northern Tibet were formed in an <span class="hlt">oceanic</span> back-arc basin setting, which has led to controversy over the subduction setting of the Longmucuo-Shuanghu-Lancangjiang Suture Zone (LSLSZ) during the Late Devonian to <span class="hlt">Early</span> Carboniferous. In this paper we present new data about a suite of granite plutons that intrude into ophiolite in central Qiangtang. Our aim was to identify the type of subduction and to clarify the existence of an intra-<span class="hlt">oceanic</span> back-arc basin in the LSLSZ during the Late Devonian to <span class="hlt">Early</span> Carboniferous. The suite of granites consists of monzogranites, syenogranites, and granodiorites. Our laser ablation-inductively coupled plasma-mass spectrometry zircon U-Pb data yielded <span class="hlt">Early</span> Carboniferous crystallization ages of 357.2 Ma, 357.4 Ma and 351.1 Ma. We subsequently investigated the petrogenesis and tectonic setting of these granites based on their geochemical and Hf isotopic characteristics. First, we divided the granites into high Sr/Y (HSG) and low Sr/Y granites (LSG). The HSG group contains monzogranites and granodiorites that have similar geochemical characteristics to adakites (i.e., high Sr/Y and La/Yb ratios, low MgO, Y, and Yb contents, and no pronounced negative Eu anomaly), although they have slightly lower Sr and Al2O3 contents, caused by crystal fractionation during late magmatic evolution. Therefore, we define the HSG group as adakite-like granites. The study of the HSG shows that they are adakite-like granites formed by partial melting of <span class="hlt">oceanic</span> crust and experience fractional crystallization process during late evolution. However, some differences between the monzogranites and granodiorites indicate that there are varying degree contributions of subducted sediments during diagenesis. The LSG group contains syenogranites that have distinct negative correlations between their P2O5 and SiO2 contents, and Y and Th contents have significant positive</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 global <span class="hlt">productivity</span> gradients</span></a></p> <p><a target="_blank" href=""></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 global 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 <span class="hlt">productivity</span> 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 <span class="hlt">productivity</span> 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> <span class="hlt">productivity</span> coeval with increased nutrient availability in shelf areas. <span class="hlt">Productivity</span> 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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JAtS...62.1008I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JAtS...62.1008I"><span>Two MODIS Aerosol <span class="hlt">Products</span> over <span class="hlt">Ocean</span> on the Terra and Aqua CERES SSF Datasets.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ignatov, Alexander; Minnis, Patrick; Loeb, Norman; Wielicki, Bruce; Miller, Walter; Sun-Mack, Sunny; Tanré, Didier; Remer, Lorraine; Laszlo, Istvan; Geier, Erika</p> <p>2005-04-01</p> <p>Understanding the impact of aerosols on the earth's radiation budget and the long-term climate record requires consistent measurements of aerosol properties and radiative fluxes. The Clouds and the Earth's Radiant Energy System (CERES) Science Team combines satellite-based retrievals of aerosols, clouds, and radiative fluxes into Single Scanner Footprint (SSF) datasets from the Terra and Aqua satellites. Over <span class="hlt">ocean</span>, two aerosol <span class="hlt">products</span> are derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) using different sampling and aerosol algorithms. The primary, or M, <span class="hlt">product</span> is taken from the standard multispectral aerosol <span class="hlt">product</span> developed by the MODIS aerosol group while a simpler, secondary [Advanced Very High Resolution Radiometer (AVHRR) like], or A, <span class="hlt">product</span> is derived by the CERES Science Team using a different cloud clearing method and a single-channel aerosol algorithm. Two aerosol optical depths (AOD), τA1 and τA2, are derived from MODIS bands 1 (0.644 μm) and 6 (1.632 μm) resembling the AVHRR/3 channels 1 and 3A, respectively. On Aqua the retrievals are made in band 7 (2.119 μm) because of poor quality data from band 6. The respective Ångström exponents can be derived from the values of τ. The A <span class="hlt">product</span> serves as a backup for the M <span class="hlt">product</span>. More importantly, the overlap of these aerosol <span class="hlt">products</span> is essential for placing the 20+ year heritage AVHRR aerosol record in the context of more advanced aerosol sensors and algorithms such as that used for the M <span class="hlt">product</span>.This study documents the M and A <span class="hlt">products</span>, highlighting their CERES SSF specifics. Based on 2 weeks of global Terra data, coincident M and A AODs are found to be strongly correlated in both bands. However, both domains in which the M and A aerosols are available, and the respective τ/α statistics significantly differ because of discrepancies in sampling due to differences in cloud and sun-glint screening. In both aerosol <span class="hlt">products</span>, correlation is observed between the retrieved</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6541F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6541F"><span>Optimal Geoid Modelling to determine the Mean <span class="hlt">Ocean</span> Circulation - Project Overview and <span class="hlt">early</span> Results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fecher, Thomas; Knudsen, Per; Bettadpur, Srinivas; Gruber, Thomas; Maximenko, Nikolai; Pie, Nadege; Siegismund, Frank; Stammer, Detlef</p> <p>2017-04-01</p> <p>The ESA project GOCE-OGMOC (Optimal Geoid Modelling based on GOCE and GRACE third-party mission data and merging with altimetric sea surface data to optimally determine <span class="hlt">Ocean</span> Circulation) examines the influence of the satellite missions GRACE and in particular GOCE in <span class="hlt">ocean</span> modelling applications. The project goal is an improved processing of satellite and ground data for the preparation and combination of gravity and altimetry data on the way to an optimal MDT solution. Explicitly, the two main objectives are (i) to enhance the GRACE error modelling and optimally combine GOCE and GRACE [and optionally terrestrial/altimetric data] and (ii) to integrate the optimal Earth gravity field model with MSS and drifter information to derive a state-of-the art MDT including an error assessment. The main work packages referring to (i) are the characterization of geoid model errors, the identification of GRACE error sources, the revision of GRACE error models, the optimization of weighting schemes for the participating data sets and finally the estimation of an optimally combined gravity field model. In this context, also the leakage of terrestrial data into coastal regions shall be investigated, as leakage is not only a problem for the gravity field model itself, but is also mirrored in a derived MDT solution. Related to (ii) the tasks are the revision of MSS error covariances, the assessment of the mean circulation using drifter data sets and the computation of an optimal geodetic MDT as well as a so called state-of-the-art MDT, which combines the geodetic MDT with drifter mean circulation data. This paper presents an overview over the project results with focus on the geodetic results part.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AdSpR..37..806U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AdSpR..37..806U"><span>Meteorological Research Institute multivariate <span class="hlt">ocean</span> variational estimation (MOVE) system: Some <span class="hlt">early</span> results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Usui, Norihisa; Ishizaki, Shiro; Fujii, Yosuke; Tsujino, Hiroyuki; Yasuda, Tamaki; Kamachi, Masafumi</p> <p></p> <p>The Meteorological Research Institute multivariate <span class="hlt">ocean</span> variational estimation (MOVE) System has been developed as the next-generation <span class="hlt">ocean</span> data assimilation system in Japan Meteorological Agency. A multivariate three-dimensional variational (3DVAR) analysis scheme with vertical coupled temperature salinity empirical orthogonal function modes is adopted. The MOVE system has two varieties, the global (MOVE-G) and North Pacific (MOVE-NP) systems. The equatorial Pacific and western North Pacific are analyzed with assimilation experiments using MOVE-G and -NP, respectively. In each system, the salinity and velocity fields are well reproduced, even in cases without salinity data. Changes in surface and subsurface zonal currents during the 1997/98 El Niño event are captured well, and their transports are reasonably consistent with in situ observations. For example, the eastward transport in the upper layer around the equator has 70 Sv in spring 1997 and weakens in spring 1998. With MOVE-NP, the Kuroshio transport has 25 Sv in the East China Sea, and 40 Sv crossing the ASUKA (Affiliated Surveys of the Kuroshio off Cape Ashizuri) line south of Japan. The variations in the Kuroshio transports crossing the ASUKA line agree well with observations. The Ryukyu Current System has a transport ranging from 6 Sv east of Taiwan to 17 Sv east of Amami. The Oyashio transport crossing the OICE (Oyashio Intensive observation line off Cape Erimo) line south of Hokkaido has 14 Sv southwestward (near shore) and 11 Sv northeastward (offshore). In the Kuroshio Oyashio transition area east of Japan, the eastward transport has 41 Sv (32 36°N) and 12 Sv (36 39°N) crossing the 145°E line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE31A..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE31A..03L"><span>An assessment of net primary <span class="hlt">productivity</span> estimates using coupled physical-biogeochemical/earth system models in the 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>Lee, Y. J.; Matrai, P.; Friedrichs, M. A.; Saba, V. S.</p> <p>2016-02-01</p> <p>Net primary <span class="hlt">production</span> (NPP) is the major source of energy for the Arctic <span class="hlt">Ocean</span> (AO) ecosystem, as in most ecosystems. Reproducing current patterns of NPP is essential to understand the physical and biogeochemical controls in the present and the future AO. The Primary <span class="hlt">Productivity</span> Algorithm Round Robin (PPARR) activity provides a framework to evaluate the skill and sensitivity of NPP as estimated by coupled global/regional climate models and earth system models in the AO. Here we compare results generated from 18 global/regional climate models and three earth system models with observations from a unique pan-Arctic data set (1959-2011) that includes in situ NPP (N=928 stations) and nitrate (N=678 stations). Models results showed a distribution similar to the in situ data distribution, except for the high values of integrated NPP data. Model skill of integrated NPP exhibited little difference as a function of sea ice condition (ice-free vs. ice-covered) and depth (shallow vs. deep), but performance of models varied significantly as a function of seasons. For example, simulated integrated NPP was underestimated in the beginning of the <span class="hlt">production</span> season (April-June) compared to mid-summer (July and August) and had the highest variability in late summer and <span class="hlt">early</span> fall (September-October). While models typically underestimated mean NPP, nitrate concentrations were overestimated. Overall, models performed better in reproducing nitrate than NPP in terms of differences in variability. The model performance was similar at all depths within the top 100 m, both in NPP and nitrate. Continual feedback, modification and improvement of the participating models and the resulting increase in model skill are the primary goals of the PPARR-5 AO exercise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989PrOce..22...47L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989PrOce..22...47L"><span>The biological pump: Profiles of plankton <span class="hlt">production</span> and consumption in the upper <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>Longhurst, Alan R.; Glen Harrison, W.</p> <p></p> <p>The ‘biological pump’ mediates flux of carbon to the interior of the <span class="hlt">ocean</span> by interctions between the components of the vertically-structured pelagic ecosystem of the photic zone. Chlorophyll profiles are not a simple indicator of autotrophic biomass or <span class="hlt">production</span>, because of non-linearities in the physiology of cells and preferential vertical distribution of taxa. Profiles of numbers or biomass of heterotrophs do not correspond with profiles of consumption, because of depth-selection (taxa, seasons) for reasons unconnected with feeding. Depths of highest plant biomass, chlorophyll and growth rate coincide when these depths are shallow, but become progressively separated in profiles where they are deeper - so that highest growth rate lies progressively shallower than the chloropyll maximum. It is still uncertain how plant biomass is distributed in deep profiles. Depths of greatest heterotroph biomass (mesozooplankton) are usually close to depths of fastest plant growth rate, and thus lie shallower than the chlorophyll maximum in profiles where this itself is deep. This correlation is functional, and relates to the role of heterotrophs in excreting metabolic wastes (especially ammonia), which may fuel a significant component of integrated algal <span class="hlt">production</span>, especially in the oligotrophic <span class="hlt">ocean</span>. Some, but not all faecal material from mesozooplankton of the photic zone appears in vertical flux below the pycnocine, depending on the size of the source organisms, and the degree of vertical mixing above the pycnocline. Diel, but probably not seasonal, vertical migration is significant in the vertical flux of dissolved nitrogen. Regional generalisations of the vertical relations of the main components of the ‘biological pump’ now appear within reach, and an approach is suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18988740','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18988740"><span><span class="hlt">Ocean</span> acidification causes bleaching and <span class="hlt">productivity</span> loss in coral reef builders.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anthony, K R N; Kline, D I; Diaz-Pulido, G; Dove, S; Hoegh-Guldberg, O</p> <p>2008-11-11</p> <p><span class="hlt">Ocean</span> acidification represents a key threat to coral reefs by reducing the calcification rate of framework builders. In addition, acidification is likely to affect the relationship between corals and their symbiotic dinoflagellates and the <span class="hlt">productivity</span> of this association. However, little is known about how acidification impacts on the physiology of reef builders and how acidification interacts with warming. Here, we report on an 8-week study that compared bleaching, <span class="hlt">productivity</span>, and calcification responses of crustose coralline algae (CCA) and branching (Acropora) and massive (Porites) coral species in response to acidification and warming. Using a 30-tank experimental system, we manipulated CO(2) levels to simulate doubling and three- to fourfold increases [Intergovernmental Panel on Climate Change (IPCC) projection categories IV and VI] relative to present-day levels under cool and warm scenarios. Results indicated that high CO(2) is a bleaching agent for corals and CCA under high irradiance, acting synergistically with warming to lower thermal bleaching thresholds. We propose that CO(2) induces bleaching via its impact on photoprotective mechanisms of the photosystems. Overall, acidification impacted more strongly on bleaching and <span class="hlt">productivity</span> than on calcification. Interestingly, the intermediate, warm CO(2) scenario led to a 30% increase in <span class="hlt">productivity</span> in Acropora, whereas high CO(2) lead to zero <span class="hlt">productivity</span> in both corals. CCA were most sensitive to acidification, with high CO(2) leading to negative <span class="hlt">productivity</span> and high rates of net dissolution. Our findings suggest that sensitive reef-building species such as CCA may be pushed beyond their thresholds for growth and survival within the next few decades whereas corals will show delayed and mixed responses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2580748','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2580748"><span><span class="hlt">Ocean</span> acidification causes bleaching and <span class="hlt">productivity</span> loss in coral reef builders</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Anthony, K. R. N.; Kline, D. I.; Diaz-Pulido, G.; Dove, S.; Hoegh-Guldberg, O.</p> <p>2008-01-01</p> <p><span class="hlt">Ocean</span> acidification represents a key threat to coral reefs by reducing the calcification rate of framework builders. In addition, acidification is likely to affect the relationship between corals and their symbiotic dinoflagellates and the <span class="hlt">productivity</span> of this association. However, little is known about how acidification impacts on the physiology of reef builders and how acidification interacts with warming. Here, we report on an 8-week study that compared bleaching, <span class="hlt">productivity</span>, and calcification responses of crustose coralline algae (CCA) and branching (Acropora) and massive (Porites) coral species in response to acidification and warming. Using a 30-tank experimental system, we manipulated CO2 levels to simulate doubling and three- to fourfold increases [Intergovernmental Panel on Climate Change (IPCC) projection categories IV and VI] relative to present-day levels under cool and warm scenarios. Results indicated that high CO2 is a bleaching agent for corals and CCA under high irradiance, acting synergistically with warming to lower thermal bleaching thresholds. We propose that CO2 induces bleaching via its impact on photoprotective mechanisms of the photosystems. Overall, acidification impacted more strongly on bleaching and <span class="hlt">productivity</span> than on calcification. Interestingly, the intermediate, warm CO2 scenario led to a 30% increase in <span class="hlt">productivity</span> in Acropora, whereas high CO2 lead to zero <span class="hlt">productivity</span> in both corals. CCA were most sensitive to acidification, with high CO2 leading to negative <span class="hlt">productivity</span> and high rates of net dissolution. Our findings suggest that sensitive reef-building species such as CCA may be pushed beyond their thresholds for growth and survival within the next few decades whereas corals will show delayed and mixed responses. PMID:18988740</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMS...180..191L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMS...180..191L"><span>Variability of Fe isotope compositions of hydrothermal sulfides and oxidation <span class="hlt">products</span> at mid-<span class="hlt">ocean</span> ridges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Xiaohu; Wang, Jianqiang; Chu, Fengyou; Wang, Hao; Li, Zhenggang; Yu, Xing; Bi, Dongwei; He, Yongsheng</p> <p>2018-04-01</p> <p>Significant Fe isotopic fractionation occurs during the precipitation and oxidative weathering of modern seafloor hydrothermal sulfides, which has an important impact on the cycling of Fe isotopes in the <span class="hlt">ocean</span>. This study reports the Fe-isotope compositions of whole-rock sulfides and single-mineral pyrite collected from hydrothermal fields at the South Mid-Atlantic Ridge (SMAR) and the East Pacific Rise (EPR) and discusses the impacts of precipitation and late-stage oxidative weathering of sulfide minerals on Fe isotopic fractionation. The results show large variation in the Fe-isotope compositions of the sulfides from the different hydrothermal fields on the mid-<span class="hlt">oceanic</span> ridges, indicating that relatively significant isotope fractionation occurs during the sulfide precipitation and oxidative weathering processes. The Fe-isotope compositions of the sulfides from the study area at the SMAR vary across a relatively small range, with an average value of 0.01‰. This Fe-isotope composition is similar to the Fe-isotope composition of mid-<span class="hlt">oceanic</span> ridge basalt, which suggests that Fe was mainly leached from basalt. In contrast, the Fe-isotope composition of the sulfides from the study area at the EPR are significantly enriched in light Fe isotopes (average value - 1.63‰), mainly due to the kinetic fractionation during the rapid precipitation process of hydrothermal sulfide. In addition, the pyrite from different hydrothermal fields is enriched in light Fe isotopes, which is consistent with the phenomenon in which light Fe isotopes are preferentially enriched during the precipitation of pyrite. The red oxides have the heaviest Fe-isotope compositions (up to 0.80‰), indicating that heavy Fe isotopes are preferentially enriched in the oxidation <span class="hlt">product</span> during the late-stage oxidation process. The data obtained from this study and previous studies show a significant difference between the Fe-isotope compositions of the sulfides from the SMAR and EPR. The relatively heavy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27381883','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27381883"><span>The rise of <span class="hlt">ocean</span> giants: maximum body size in Cenozoic marine mammals as an indicator for <span class="hlt">productivity</span> in the Pacific and Atlantic <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>Pyenson, Nicholas D; Vermeij, Geerat J</p> <p>2016-07-01</p> <p>Large consumers have ecological influence disproportionate to their abundance, although this influence in food webs depends directly on <span class="hlt">productivity</span>. Evolutionary patterns at geologic timescales inform expectations about the relationship between consumers and <span class="hlt">productivity</span>, but it is very difficult to track <span class="hlt">productivity</span> through time with direct, quantitative measures. Based on previous work that used the maximum body size of Cenozoic marine invertebrate assemblages as a proxy for benthic <span class="hlt">productivity</span>, we investigated how the maximum body size of Cenozoic marine mammals, in two feeding guilds, evolved over comparable temporal and geographical scales. First, maximal size in marine herbivores remains mostly stable and occupied by two different groups (desmostylians and sirenians) over separate timeframes in the North Pacific <span class="hlt">Ocean</span>, while sirenians exclusively dominated this ecological mode in the North Atlantic. Second, mysticete whales, which are the largest Cenozoic consumers in the filter-feeding guild, remained in the same size range until a Mio-Pliocene onset of cetacean gigantism. Both vertebrate guilds achieved very large size only recently, suggesting that different trophic mechanisms promoting gigantism in the <span class="hlt">oceans</span> have operated in the Cenozoic than in previous eras. © 2016 The Authors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920004395','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920004395"><span>Terrestrial <span class="hlt">production</span> vs. extraterrestrial delivery of prebiotic organics to the <span class="hlt">early</span> Earth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chyba, C. F.; Sagan, C.; Thomas, P. J.; Brookshaw, L.</p> <p>1991-01-01</p> <p>A comprehensive treatment of comet/asteroid interaction with the atmosphere, ensuring surface impact, and resulting organic pyrolysis is required to determine whether more than a negligible fraction of the organics in incident comets and asteroids actually survived collision with Earth. Results of such an investigation, using a smoothed particle hydrodynamic simulation of cometary and asteroidal impacts into both <span class="hlt">oceans</span> and rock, demonstrate that organics will not survive impacts at velocities approx. greater than 10 km s(exp -1), and that even comets and asteroids as small as 100m in radius cannot be aerobraked to below this velocity in 1 bar atmospheres. However, for plausible dense (10 bar CO2) <span class="hlt">early</span> atmospheres, there will be sufficient aerobraking during atmospheric passage for some organics to survive the ensuing impact. Combining these results with analytical fits to the lunar impact record shows that 4.5 Gyr ago Earth was accreting at least approx. 10(exp 6) kg yr(exp 1) of intact cometary organics, a flux which thereafter declined with a approx. 100 Myr half-life. The extent to which this influx was augmented by asteroid impacts, as well as the effect of more careful modelling of a variety of conservative approximations, is currently being quantified. These results may be placed in context by comparison with in situ organic <span class="hlt">production</span> from a variety of terrestrial energy sources, as well as organic delivery by interplanetary dust. Which source dominated the <span class="hlt">early</span> terrestrial prebiotic inventory is found to depend on the nature of the <span class="hlt">early</span> terrestrial atmosphere. However, there is an intriguing symmetry: it is exactly those dense CO2 atmospheres where in situ atmospheric <span class="hlt">production</span> of organic molecules should be the most difficult, in which intact cometary organics would be delivered in large amounts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8960L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8960L"><span>Major <span class="hlt">early</span> Eocene carbon cycle perturbations and changes in planktic foraminiferal assemblages from the southeast Atlantic <span class="hlt">Ocean</span> (ODP Site 1263)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luciani, Valeria; D'Onofrio, Roberta; Dickens, Gerald Roy; Wade, Bridget</p> <p>2017-04-01</p> <p>On a paleoclimatic perspective the <span class="hlt">early</span> Paleogene represents one of the most interesting and dynamic intervals of the Earth's history. Present record indicates that the Earth climate system reached its Cenozoic maximum peak of global warming and probably of pCO2 during the <span class="hlt">early</span> Eocene climatic optimum (EECO, 49-53 Ma). Superimposed to the general trend, our planet experienced short-term ( 40-200 kyr) repeated peaks in global temperatures and major changes in the carbon cycle, known as hyperthermals. Great scientific interest has been focused on the <span class="hlt">early</span> Paleogene hyperthermal events, given the assumed similarity with the current climatic scenario. Less attention has been dedicated to the EECO long lasting perturbation of extraordinary warming thus many characters of this interval still remain largely unconstrained, especially as for the biotic response. We present here results on <span class="hlt">early</span> Eocene planktic foraminiferal analysis from the southeast Atlantic <span class="hlt">Ocean</span> Drilling Program (ODP) Site 1263 (Walvis Ridge, Leg 208) to explore possible relationship between changes in assemblages and carbon cycle perturbation. The time interval is of particular interest for an abrupt switch occurred at low-latitude of the northern hemisphere between two important calcifiers of the tropical-subtropical <span class="hlt">early</span> Paleogene <span class="hlt">oceans</span>, the genera Morozovella and Acarinina at the carbon isotopic excursion known as J event, at the EECO onset. Precisely, the relative abundance of Morozovella permanently decreased by at least half, along with a progressive decrease in the number of species. Concomitantly, Acarinina almost doubled its abundance and diversified. Site 1263 was located during the <span class="hlt">early</span> Eocene at a latitude of 40° south therefore representing a temperate setting of southern hemisphere not yet explored for planktic foraminiferal changes. We document a permanent decrease in Morozovella abundance at the beginning of the EECO, although this decline is delayed by 165 kyr with respect to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950052579&hterms=Nitrate+water&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DNitrate%2Bwater','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950052579&hterms=Nitrate+water&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DNitrate%2Bwater"><span>New <span class="hlt">production</span> in the warm waters of the tropical Pacific <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>Pena, M. Angelica; Lewis, Marlon R.; Cullen, John J.</p> <p>1994-01-01</p> <p>The average depth-integrated rate of new <span class="hlt">production</span> in the tropical Pacific <span class="hlt">Ocean</span> was estimated from a calculation of horizontal and vertical nitrate balance over the region enclosed by the climatological 26 C isotherm. The net turbulent flux of nitrate into the region was computed in terms of the climatological net surface heat flux and the nitrate-temperature relationship at the base of the 26 C isotherm. The net advective transport of nitrate into the region was estimated using the mean nitrate distribution obtained from the analysis of historical data and previous results of a general circulation model of the tropical Pacific. The rate of new <span class="hlt">production</span> resulting from vertical turbulent fluxes of nitrate was found to be similar in magnitude to that due to advective transport. Most (about 75%) of the advective input of nitrate was due to the horizontal transport of nutrient-rich water from the eastern equatorial region rather than from equatorial upwelling. An average rate of new <span class="hlt">production</span> of 14.5 - 16 g C/sq m/yr was found for the warm waters of the tropical Pacific region. These values are in good agreement with previous estimates for this region and are almost five times less than is estimated for the eastern equatorial Pacific, where most of the nutrient upwelling occurs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A14A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A14A..04S"><span>Simultaneous aerosol/<span class="hlt">ocean</span> <span class="hlt">products</span> retrieved during the 2014 SABOR campaign using the NASA Research Scanning Polarimeter (RSP)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stamnes, S.; Hostetler, C. A.; Ferrare, R. A.; Hair, J. W.; Burton, S. P.; Liu, X.; Hu, Y.; Stamnes, K. H.; Chowdhary, J.; Brian, C.</p> <p>2017-12-01</p> <p>The SABOR (Ship-Aircraft Bio-Optical Research) campaign was conducted during the summer of 2014, in the Atlantic <span class="hlt">Ocean</span>, over the Chesapeake Bay and the eastern coastal region of the United States. The NASA GISS Research Scanning Polarimeter, a multi-angle, multi-spectral polarimeter measured the upwelling polarized radiances from a B200 aircraft. We present results from the new "MAPP" algorithm for RSP that is based on optimal estimation and that can retrieve simultaneous aerosol microphysical properties (including effective radius, single-scattering albedo, and real refractive index) and <span class="hlt">ocean</span> color <span class="hlt">products</span> using accurate radiative transfer and Mie calculations. The algorithm was applied to data collected during SABOR to retrieve aerosol microphysics and <span class="hlt">ocean</span> <span class="hlt">products</span> for all Aerosols-Above-<span class="hlt">Ocean</span> (AAO) scenes. The RSP MAPP <span class="hlt">products</span> are compared against collocated aerosol extinction and backscatter profiles collected by the NASA LaRC airborne High Spectral Resolution Lidar (HSRL-1), including lidar depth profiles of the <span class="hlt">ocean</span> diffuse attenuation coefficient and the hemispherical backscatter coefficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AsBio..16..245N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AsBio..16..245N"><span>Solar Irradiance Changes and Phytoplankton <span class="hlt">Productivity</span> in Earth's <span class="hlt">Ocean</span> Following Astrophysical Ionizing Radiation Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neale, Patrick J.; Thomas, Brian C.</p> <p>2016-04-01</p> <p>Two atmospheric responses to simulated astrophysical ionizing radiation events significant to life on Earth are <span class="hlt">production</span> of odd-nitrogen species, especially NO2, and subsequent depletion of stratospheric ozone. Ozone depletion increases incident short-wavelength ultraviolet radiation (UVB, 280-315 nm) and longer (>600 nm) wavelengths of photosynthetically available radiation (PAR, 400-700 nm). On the other hand, the NO2 haze decreases atmospheric transmission in the long-wavelength UVA (315-400 nm) and short-wavelength PAR. Here, we use the results of previous simulations of incident spectral irradiance following an ionizing radiation event to predict changes in terran <span class="hlt">productivity</span> focusing on photosynthesis of marine phytoplankton. The prediction is based on a spectral model of photosynthetic response, which was developed for the dominant genera in central regions of the <span class="hlt">ocean</span> (Synechococcus and Prochlorococcus), and on remote-sensing-based observations of spectral water transparency, temperature, wind speed, and mixed layer depth. Predicted <span class="hlt">productivity</span> declined after a simulated ionizing event, but the effect integrated over the water column was small. For integrations taking into account the full depth range of PAR transmission (down to 0.1% of utilizable PAR), the decrease was at most 2-3% (depending on strain), with larger effects (5-7%) for integrations just to the depth of the surface mixed layer. The deeper integrations were most affected by the decreased utilizable PAR at depth due to the NO2 haze, whereas shallower integrations were most affected by the increased surface UV. Several factors tended to dampen the magnitude of <span class="hlt">productivity</span> responses relative to increases in surface-damaging radiation, for example, most inhibition in the modeled strains is caused by UVA and PAR, and the greatest relative increase in damaging exposure is predicted to occur in the winter when UV and <span class="hlt">productivity</span> are low.</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('https://www.ncbi.nlm.nih.gov/pubmed/27027533','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27027533"><span>Solar Irradiance Changes and Phytoplankton <span class="hlt">Productivity</span> in Earth's <span class="hlt">Ocean</span> Following Astrophysical Ionizing Radiation Events.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neale, Patrick J; Thomas, Brian C</p> <p>2016-04-01</p> <p>Two atmospheric responses to simulated astrophysical ionizing radiation events significant to life on Earth are <span class="hlt">production</span> of odd-nitrogen species, especially NO2, and subsequent depletion of stratospheric ozone. Ozone depletion increases incident short-wavelength ultraviolet radiation (UVB, 280-315 nm) and longer (>600 nm) wavelengths of photosynthetically available radiation (PAR, 400-700 nm). On the other hand, the NO2 haze decreases atmospheric transmission in the long-wavelength UVA (315-400 nm) and short-wavelength PAR. Here, we use the results of previous simulations of incident spectral irradiance following an ionizing radiation event to predict changes in terran <span class="hlt">productivity</span> focusing on photosynthesis of marine phytoplankton. The prediction is based on a spectral model of photosynthetic response, which was developed for the dominant genera in central regions of the <span class="hlt">ocean</span> (Synechococcus and Prochlorococcus), and on remote-sensing-based observations of spectral water transparency, temperature, wind speed, and mixed layer depth. Predicted <span class="hlt">productivity</span> declined after a simulated ionizing event, but the effect integrated over the water column was small. For integrations taking into account the full depth range of PAR transmission (down to 0.1% of utilizable PAR), the decrease was at most 2-3% (depending on strain), with larger effects (5-7%) for integrations just to the depth of the surface mixed layer. The deeper integrations were most affected by the decreased utilizable PAR at depth due to the NO2 haze, whereas shallower integrations were most affected by the increased surface UV. Several factors tended to dampen the magnitude of <span class="hlt">productivity</span> responses relative to increases in surface-damaging radiation, for example, most inhibition in the modeled strains is caused by UVA and PAR, and the greatest relative increase in damaging exposure is predicted to occur in the winter when UV and <span class="hlt">productivity</span> are low.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAESc.154..187F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAESc.154..187F"><span><span class="hlt">Early</span> Cretaceous MORB-type basalt and A-type rhyolite in northern Tibet: Evidence for ridge subduction in the Bangong-Nujiang Tethyan <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>Fan, Jian-Jun; Li, Cai; Sun, Zhen-Ming; Xu, Wei; Wang, Ming; Xie, Chao-Ming</p> <p>2018-04-01</p> <p>New zircon U-Pb ages, major- and trace-element data, and Hf isotopic compositions are presented for bimodal volcanic rocks of the Zhaga Formation (ZF) in the western-middle segment of the Bangong-Nujiang suture zone (BNSZ), northern Tibet. The genesis of these rocks is described, and implications for late-stage evolution of the Bangong-Nujiang Tethyan <span class="hlt">Ocean</span> (BNTO) are considered. Detailed studies show that the ZF bimodal rocks, which occur as layers within a typical bathyal to abyssal flysch deposit, comprise MORB-type basalt that formed at a mid-<span class="hlt">ocean</span> ridge, and low-K calc-alkaline A-type rhyolite derived from juvenile crust. The combination of MORB-type basalt, calc-alkaline A-type rhyolite, and bathyal to abyssal flysch deposits in the ZF leads us to propose that they formed as a result of ridge subduction. The A-type ZF rhyolites yield LA-ICP-MS zircon U-Pb ages of 118-112 Ma, indicating formation during the <span class="hlt">Early</span> Cretaceous. Data from the present study, combined with regional geological data, indicate that the BNTO underwent conversion from <span class="hlt">ocean</span> opening to <span class="hlt">ocean</span> closure during the Late Jurassic-<span class="hlt">Early</span> Cretaceous. The eastern segment of the BNTO closed during this period, while the western and western-middle segments were still at least partially open and active during the <span class="hlt">Early</span> Cretaceous, accompanied by ridge subduction within the Bangong-Nujiang Tethyan <span class="hlt">Ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PrOce..72...84O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PrOce..72...84O"><span>The fate of <span class="hlt">production</span> in the central Arctic <span class="hlt">Ocean</span> - top-down regulation by zooplankton expatriates?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olli, Kalle; Wassmann, Paul; Reigstad, Marit; Ratkova, Tatjana N.; Arashkevich, Elena; Pasternak, Anna; Matrai, Patricia A.; Knulst, Johan; Tranvik, Lars; Klais, Riina; Jacobsen, A.</p> <p>2007-01-01</p> <p>We estimated primary and bacterial <span class="hlt">production</span>, mineral nutrients, suspended chlorophyll a (Chl), particulate organic carbon (POC) and nitrogen (PON), abundance of planktonic organisms, mesozooplankton fecal pellet <span class="hlt">production</span>, and the vertical flux of organic particles of the central Arctic <span class="hlt">Ocean</span> (Amundsen basin, 89-88° N) during a 3 week quasi-Lagrangian ice drift experiment at the peak of the <span class="hlt">productive</span> season (August 2001). A visual estimate of ≈15% ice-free surface, plus numerous melt ponds on ice sheets, supported a planktonic particulate primary <span class="hlt">production</span> of 50-150 mg C m -2 d -1 (mean 93 mg C m -2 d -1, n = 7), mostly confined to the upper 10 m of the nutrient replete water column. The surface mixed layer was separated from the rest of the water column by a strong halocline at 20 m depth. Phototrophic biomass was low, generally 0.03-0.3 mg Chl m -3 in the upper 20 m and <0.02 mg Chl m -3 below, dominated by various flagellates, dinoflagellates and diatoms. Bacterial abundance (typically 3.7-5.3 × 10 5, mean 4.1 × 10 5 cells ml -1 in the upper 20 m and 1.3-3.7 × 10 5, mean 1.9 × 10 5 cells ml -1 below) and Chl concentrations were closely correlated ( r = 0.75). Mineral nutrients (3 μmol NO 3 l -1, 0.45 μmol PO 4 l -1, 4-5 μmol SiO 4 l -1) were probably not limiting the primary <span class="hlt">production</span> in the upper layer. Suspended POC concentration was ∼30-105 (mean 53) mg C m -3 and PON ∼5.4-14.9 (mean 8.2) mg N m -3 with no clear vertical trend. The vertical flux of POC in the upper 30-100 m water column was ∼37-92 (mean 55) mg C m -2 d -1 without clear decrease with depth, and was quite similar at the six investigated stations. The mesozooplankton biomass (≈2 g DW m -2, mostly in the upper 50 m water column) was dominated by adult females of the large calanoid copepods Calanus hyperboreus and Calanus glacialis (≈1.6 g DW m -2). The grazing of these copepods (estimated via fecal pellet <span class="hlt">production</span> rates) was ≈15 mg C m -2 d -1, being on the order of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010374','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010374"><span>Underway Sampling of Marine Inherent Optical Properties on the Tara <span class="hlt">Oceans</span> Expedition as a Novel Resource for <span class="hlt">Ocean</span> Color Satellite Data <span class="hlt">Product</span> Validation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Werdell, P. Jeremy; Proctor, Christopher W.; Boss, Emmanuel; Leeuw, Thomas; Ouhssain, Mustapha</p> <p>2013-01-01</p> <p>Developing and validating data records from operational <span class="hlt">ocean</span> color satellite instruments requires substantial volumes of high quality in situ data. In the absence of broad, institutionally supported field programs, organizations such as the NASA <span class="hlt">Ocean</span> Biology Processing Group seek opportunistic datasets for use in their operational satellite calibration and validation activities. The publicly available, global biogeochemical dataset collected as part of the two and a half year Tara <span class="hlt">Oceans</span> expedition provides one such opportunity. We showed how the inline measurements of hyperspectral absorption and attenuation coefficients collected onboard the R/V Tara can be used to evaluate near-surface estimates of chlorophyll-a, spectral particulate backscattering coefficients, particulate organic carbon, and particle size classes derived from the NASA Moderate Resolution Imaging Spectroradiometer onboard Aqua (MODISA). The predominant strength of such flow-through measurements is their sampling rate-the 375 days of measurements resulted in 165 viable MODISA-to-in situ match-ups, compared to 13 from discrete water sampling. While the need to apply bio-optical models to estimate biogeochemical quantities of interest from spectroscopy remains a weakness, we demonstrated how discrete samples can be used in combination with flow-through measurements to create data records of sufficient quality to conduct first order evaluations of satellite-derived data <span class="hlt">products</span>. Given an emerging agency desire to rapidly evaluate new satellite missions, our results have significant implications on how calibration and validation teams for these missions will be constructed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1495123','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1495123"><span>Indicators of <span class="hlt">Early</span> Research <span class="hlt">Productivity</span> Among Primary Care Fellows</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Steiner, John F; Lanphear, Bruce P; Curtis, Peter; Vu, Kieu O</p> <p>2002-01-01</p> <p>OBJECTIVE Little is known about the impact of fellowship training in primary care on subsequent research <span class="hlt">productivity</span>. Our goal was to identify characteristics of research fellows and their training associated with subsequent publications and research funding. DESIGN Mail survey in 1998. SETTING AND PARTICIPANTS 1988–1997 graduates of 25 National Research Service Award primary care research fellowships in the United States. OUTCOME MEASURES 1) Publishing 1 or more papers per year since the beginning of fellowship, or 2) serving as principal investigator (PI) on a federal or non-federal grant. RESULTS One hundred forty-six of two hundred fifteen program graduates (68%) completed the survey. The median age was 38 years, and 51% were male. Thirty-two percent had published 1 or more papers per year, and 44% were PIs. Male gender (odds ratio [OR], 3.6; 95% confidence interval [95% CI], 1.4 to 9.2), self-reported allocation of 40% or more of fellowship time to research (OR, 4.4; 95% CI, 1.8 to 11.2), and having an influential mentor during fellowship (OR, 5.0; 95% CI, 1.5 to 17.2) were independently associated with publishing 1 or more papers per year. Fellows with funding as a PI were also more likely to have an influential mentor (OR, 3.0; 95% CI, 1.3 to 7.2). CONCLUSION Primary care fellows who had influential mentors were more <span class="hlt">productive</span> in research <span class="hlt">early</span> after fellowship. Awareness of the indicators of <span class="hlt">early</span> research success can inform the policies of agencies that fund research training and the curricula of training programs themselves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMPP34B..06M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMPP34B..06M"><span>Millennial-scale variability in dust deposition, marine export <span class="hlt">production</span>, and nutrient consumption in the glacial subantarctic <span class="hlt">ocean</span> (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinez-Garcia, A.; Sigman, D. M.; Anderson, R. F.; Ren, H. A.; Hodell, D. A.; Straub, M.; Jaccard, S.; Eglinton, T. I.; Haug, G. H.</p> <p>2013-12-01</p> <p>Based on the limitation of modern Southern <span class="hlt">Ocean</span> phytoplankton by iron and the evidence of higher iron-bearing dust fluxes to the <span class="hlt">ocean</span> during ice ages, it has been proposed that iron fertilization of Southern <span class="hlt">Ocean</span> phytoplankton contributed to the reduction in atmospheric CO2 during ice ages. In the Subantarctic zone of the Atlantic Southern <span class="hlt">Ocean</span>, glacial increases in dust flux and export <span class="hlt">production</span> have been documented, supporting the iron fertilization hypothesis. However, these observations could be interpreted alternatively as resulting from the equatorward migration of Southern <span class="hlt">Ocean</span> fronts during ice ages if the observed <span class="hlt">productivity</span> rise was not accompanied by an increase in major nutrient consumption. Here, new 230Th-normalized lithogenic and opal fluxes are combined with high-resolution biomarker measurements to reconstruct millennial-scale changes in dust deposition and marine export <span class="hlt">production</span> in the subantarctic Atlantic over the last glacial cycle. In the same record foraminifera-bound nitrogen isotopes are used to reconstruct ice age changes in surface nitrate utilization, providing a comprehensive test of the iron fertilization hypothesis. Elevation in foraminifera-bound δ15N, indicating more complete nitrate consumption, coincides with times of surface cooling and greater dust flux and export <span class="hlt">production</span>. These observations indicate that the ice age Subantarctic was characterized by iron fertilized phytoplankton growth. The resulting strengthening of the Southern <span class="hlt">Ocean</span>'s biological pump can explain the ~40 ppm lowering of CO2 that characterizes the transitions from mid-climate states to full ice age conditions as well as the millennial-scale atmospheric CO2 fluctuations observed within the last ice age</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NatGe..11..340G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NatGe..11..340G"><span>Deglacial upwelling, <span class="hlt">productivity</span> and CO2 outgassing in the North Pacific <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>Gray, William R.; Rae, James W. B.; Wills, Robert C. J.; Shevenell, Amelia E.; Taylor, Ben; Burke, Andrea; Foster, Gavin L.; Lear, Caroline H.</p> <p>2018-05-01</p> <p>The interplay between <span class="hlt">ocean</span> circulation and biological <span class="hlt">productivity</span> affects atmospheric CO2 levels and marine oxygen concentrations. During the warming of the last deglaciation, the North Pacific experienced a peak in <span class="hlt">productivity</span> and widespread hypoxia, with changes in circulation, iron supply and light limitation all proposed as potential drivers. Here we use the boron-isotope composition of planktic foraminifera from a sediment core in the western North Pacific to reconstruct pH and dissolved CO2 concentrations from 24,000 to 8,000 years ago. We find that the <span class="hlt">productivity</span> peak during the Bølling-Allerød warm interval, 14,700 to 12,900 years ago, was associated with a decrease in near-surface pH and an increase in pCO2, and must therefore have been driven by increased supply of nutrient- and CO2-rich waters. In a climate model ensemble (PMIP3), the presence of large ice sheets over North America results in high rates of wind-driven upwelling within the subpolar North Pacific. We suggest that this process, combined with collapse of North Pacific Intermediate Water formation at the onset of the Bølling-Allerød, led to high rates of upwelling of water rich in nutrients and CO2, and supported the peak in <span class="hlt">productivity</span>. The respiration of this organic matter, along with poor ventilation, probably caused the regional hypoxia. We suggest that CO2 outgassing from the North Pacific helped to maintain high atmospheric CO2 concentrations during the Bølling-Allerød and contributed to the deglacial CO2 rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GBioC..28..712M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GBioC..28..712M"><span>Western Pacific atmospheric nutrient deposition fluxes, their impact on surface <span class="hlt">ocean</span> <span class="hlt">productivity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martino, M.; Hamilton, D.; Baker, A. R.; Jickells, T. D.; Bromley, T.; Nojiri, Y.; Quack, B.; Boyd, P. W.</p> <p>2014-07-01</p> <p>The atmospheric deposition of both macronutrients and micronutrients plays an important role in driving primary <span class="hlt">productivity</span>, particularly in the low-latitude <span class="hlt">ocean</span>. We report aerosol major ion measurements for five ship-based sampling campaigns in the western Pacific from ~25°N to 20°S and compare the results with those from Atlantic meridional transects (~50°N to 50°S) with aerosols collected and analyzed in the same laboratory, allowing full incomparability. We discuss sources of the main nutrient species (nitrogen (N), phosphorus (P), and iron (Fe)) in the aerosols and their stoichiometry. Striking north-south gradients are evident over both basins with the Northern Hemisphere more impacted by terrestrial dust sources and anthropogenic emissions and the North Atlantic apparently more impacted than the North Pacific. We estimate the atmospheric supply rates of these nutrients and the potential impact of the atmospheric deposition on the tropical western Pacific. Our results suggest that the atmospheric deposition is P deficient relative to the needs of the resident phytoplankton. These findings suggest that atmospheric supply of N, Fe, and P increases primary <span class="hlt">productivity</span> utilizing some of the residual excess phosphorus (P*) in the surface waters to compensate for aerosol P deficiency. Regional primary <span class="hlt">productivity</span> is further enhanced via the stimulation of nitrogen fixation fuelled by the residual atmospheric iron and P*. Our stoichiometric calculations reveal that a P* of 0.1 µmol L-1 can offset the P deficiency in atmospheric supply for many months. This study suggests that atmospheric deposition may sustain ~10% of primary <span class="hlt">production</span> in both the western tropical Pacific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1014420','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1014420"><span><span class="hlt">Early</span> Student Support for SST Control by Subsurface Mixing during Indian <span class="hlt">Ocean</span> Monsoons</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-09-30</p> <p>Lee and Rainville), and NRL (Wijesekera). OBJECTIVES The objectives of this project are to: 1. use satellite-measured SSS , SST, and SSH to...forcing, and 5. synthesize the above information and <span class="hlt">products</span> to examine links and feedbacks between the SST and SSS of the SLD and local precipitation</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 <span class="hlt">Productivity</span>: a Global 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>), and Indian <span class="hlt">Ocean</span> (IOBioArgo). As examples, bio-optical sensors are identifying regional anomalies in light attenuation/scattering, with implications for <span class="hlt">ocean</span> <span class="hlt">productivity</span> and carbon export; SOCCOM floats show high CO2 outgassing in the Antarctic Circumpolar Current, due to previously unmeasured winter fluxes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004DSRI...51.1563L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004DSRI...51.1563L"><span>Net community <span class="hlt">production</span> and metabolic balance at the oligotrophic <span class="hlt">ocean</span> site, station ALOHA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>le B. Williams, Peter J.; Morris, Paul J.; Karl, David M.</p> <p>2004-11-01</p> <p>To test the hypothesis that in oligotrophic areas of the <span class="hlt">ocean</span> respiration exceeds <span class="hlt">production</span>, a 12-month study was undertaken of in vitro-determined net oxygen <span class="hlt">production</span> and consumption in the top 150 m of the water column at the extreme oligotrophic site, Station ALOHA, in the North Pacific subtropical gyre. Throughout the year the water column was observed to be in metabolic deficit, the calculated cumulative shortfall being 9±1.7 mol O2 m-2 a-1 (approximately 100 g C m-2 a-1), an amount equivalent to 40% of measured <span class="hlt">production</span> (annual estimated rates of <span class="hlt">production</span> and consumption were, respectively, 22 and 31 mol O2 m-2 a-1). We consider three possible explanations for the observed deficit: the in vitro oxygen rate measurements, in themselves, are fundamentally flawed and should be discounted, the observations are correct and the observed deficit is a true account of the balance of oxygen (and organic carbon) at Station ALOHA, or the observations are correct as they stand, but need not be interpreted as organic carbon imbalance for that ecosystem. We find no error unique to the oxygen rate measurements themselves. We find also no evidence that the associated organic carbon deficit can be sustained over the long-term by internal organic reserves or by external subsidy. Accordingly we accept the geochemical findings that calculated in situ oxygen flux requires the euphotic zone of the water column at this site to be slightly (circa 2 mol C m-2 a-1) autotrophic, in contrast to the simple analysis of our observations which gives a net heterotrophic water column. We discuss a number of processes that may give rise to the observed discrepancy. In part it may derive from the difficulty of reproducing the variations in the light field experienced by an algal cell due to vertical advection. It may also derive from the intermittency of <span class="hlt">production</span>. This latter effect would manifest itself in the following manner. Because of its universal distribution in the food web</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1250/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1250/"><span>Technical-Information <span class="hlt">Products</span> for a National Volcano <span class="hlt">Early</span> Warning System</span></a></p> <p><a target="_blank" href=""></a></p> <p>Guffanti, Marianne; Brantley, Steven R.; Cervelli, Peter F.; Nye, Christopher J.; Serafino, George N.; Siebert, Lee; Venezky, Dina Y.; Wald, Lisa</p> <p>2007-01-01</p> <p>Introduction Technical outreach - distinct from general-interest and K-12 educational outreach - for volcanic hazards is aimed at providing usable scientific information about potential or ongoing volcanic activity to public officials, businesses, and individuals in support of their response, preparedness, and mitigation efforts. Within the context of a National Volcano <span class="hlt">Early</span> Warning System (NVEWS) (Ewert et al., 2005), technical outreach is a critical process, transferring the benefits of enhanced monitoring and hazards research to key constituents who have to initiate actions or make policy decisions to lessen the hazardous impact of volcanic activity. This report discusses recommendations of the Technical-Information <span class="hlt">Products</span> Working Group convened in 2006 as part of the NVEWS planning process. The basic charge to the Working Group was to identify a web-based, volcanological '<span class="hlt">product</span> line' for NVEWS to meet the specific hazard-information needs of technical users. Members of the Working Group were: *Marianne Guffanti (Chair), USGS, Reston VA *Steve Brantley, USGS, Hawaiian Volcano Observatory HI *Peter Cervelli, USGS, Alaska Volcano Observatory, Anchorage AK *Chris Nye, Division of Geological and Geophysical Surveys and Alaska Volcano Observatory, Fairbanks AK *George Serafino, National <span class="hlt">Oceanic</span> and Atmospheric Administration, Camp Springs MD *Lee Siebert, Smithsonian Institution, Washington DC *Dina Venezky, USGS, Volcano Hazards Team, Menlo Park CA *Lisa Wald, USGS, Earthquake Hazards Program, Golden CO</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.3685K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.3685K"><span><span class="hlt">Early</span> to middle Miocene climate evolution: New insights from IODP Sites U1335, U1337 and U1338 (eastern equatorial Pacific <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>Kochhann, Karlos G. D.; Holbourn, Ann; Kuhnt, Wolfgang; Lyle, Mitch; Raffi, Isabella; Channell, James E.; Andersen, Nils</p> <p>2015-04-01</p> <p>The lower to middle Miocene (~20 to 13 Ma) carbonate-rich sedimentary successions recovered at Integrated <span class="hlt">Ocean</span> Drilling Program (IODP) Sites U1335, U1337 and U1338 allow unsurpassed resolution over the Climatic Optimum (16.9-14.7 Ma) and the transition into a colder climate mode after 13.9 Ma with re-establishment of permanent Antarctic ice sheets. High-resolution (1-10 kyr) stable carbon (δ13C) and oxygen (δ18O) isotopes of well-preserved epibenthic foraminifera (Cibicidoides mundulus and Planulina wuellerstorfi) from these three sites show that the Climatic Optimum was characterized by high-amplitude climate variations and intense perturbations of the carbon cycle. Episodes of peak warmth coincided with transient shoaling of the carbonate compensation depth and enhanced carbonate dissolution in the deep <span class="hlt">ocean</span>. The U1335 and U1337 records additionally reveal that the rapid global warming and/or polar ice melting event, marking the onset of the Climatic Optimum at ~16.9 Ma, was coupled to a massive increase in carbonate dissolution, indicated by sharp drops in carbonate percentages and accumulation rates and by the fragmentation or complete dissolution of planktonic foraminifers. After ~14.7 Ma, stepwise global cooling, culminating with extensive ice growth over Antarctica at ~13.8 Ma, coincide with enhanced opal and benthic foraminiferal accumulation rates, suggesting that increased siliceous <span class="hlt">productivity</span> and organic carbon burial may have contributed to CO2 drawdown. Integration of age models derived from orbitally-tuned, high-resolution isotopes, biostratigraphic data and magnetic reversals allows further constraints on the temporal sequence of events and helps unravel the drivers of <span class="hlt">early</span> to middle Miocene climate variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMPP11C2035H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMPP11C2035H"><span>Timing of the Toarcian <span class="hlt">Ocean</span> Anoxic Event (<span class="hlt">Early</span> Jurassic) from correlation of astronomically forced global stratigraphic sections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, C.; Hinnov, L. A.; Hesselbo, S. P.</p> <p>2012-12-01</p> <p>The <span class="hlt">Early</span> Toarcian <span class="hlt">Oceanic</span> Anoxic Event (OAE) in the <span class="hlt">Early</span> Jurassic Period is associated with a major negative carbon isotope excursion (CIE), mass extinction, marine transgression and global warming. The Toarcian OAE is thought to have been caused by flood basalt magmatism, and may have been a trigger for mass extinction. However, these proposed causes of the Toarcian OAE and associated biotic crisis are not adequately resolved by a precise chronology. The duration of the Toarcian OAE has been estimated to be anywhere from ~0.12 to ~0.9 Myr, most recently 0.74 to 3.26 Myr from U-Pb dating. The CIE associated with the Toarcian OAE has a similar pattern at numerous localities, and there is evidence for astronomical forcing of marine carbon isotopes. Here we estimate a duration of ~625 kyr for the main negative CIE, ~860 kyr for the polymorphum zone and >1.58 Myr for the levisoni zone based on 405-kyr astronomical eccentricity tuning of the marine section at Peniche (Portugal). This 405-kyr tuned series provides a ~2.5 Myr continuous high-resolution chronology through the <span class="hlt">Early</span> Toarcian. There are 6, or possibly 7 short eccentricity cycles in the main CIE interval at Peniche. To confirm this astronomically based estimate, we analyzed five other sections at Yorkshire (UK), Dotternhausen (Germany), Valdorbia (Italy), Mechowo (Poland) and Serrucho, Neuquén (Argentina), from marine and terrestrial carbon isotopic series. These six stratigraphic sections from <span class="hlt">Early</span> Jurassic western Tethys and eastern Panthalassa record the Toarcian OAE with ~6 prominent carbon isotope cycles in the CIE that provide us a 600 ± 100 kyr duration. The Peniche 405 kyr-tuned series indicates that the pre- and post-CIE intervals experienced strong precession-eccentricity-forced climate change, whereas the CIE interval is marked by dominant obliquity forcing. These dramatic and abrupt changes in astronomical response in the carbon isotopes point to fundamental shifting in the <span class="hlt">Early</span> Toarcian</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRC..123.2945A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRC..123.2945A"><span>Assessment of Export Efficiency Equations in the Southern <span class="hlt">Ocean</span> Applied to Satellite-Based Net Primary <span class="hlt">Production</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arteaga, Lionel; Haëntjens, Nils; Boss, Emmanuel; Johnson, Kenneth S.; Sarmiento, Jorge L.</p> <p>2018-04-01</p> <p>Carbon export efficiency (e-ratio) is defined as the fraction of organic carbon fixed through net primary <span class="hlt">production</span> (NPP) that is exported out of the surface <span class="hlt">productive</span> layer of the <span class="hlt">ocean</span>. Recent observations for the Southern <span class="hlt">Ocean</span> suggest a negative e-ratio versus NPP relationship, and a reduced dependency of export efficiency on temperature, different than in the global domain. In this study, we complement information from a passive satellite sensor with novel space-based lidar observations of <span class="hlt">ocean</span> particulate backscattering to infer NPP over the entire annual cycle, and estimate Southern <span class="hlt">Ocean</span> export rates from five different empirical models of export efficiency. Inferred Southern <span class="hlt">Ocean</span> NPP falls within the range of previous studies, with a mean estimate of 15.8 (± 3.9) Pg C yr-1 for the region south of 30°S during the 2005-2016 period. We find that an export efficiency model that accounts for silica(Si)-ballasting, which is constrained by observations with a negative e-ratio versus NPP relationship, shows the best agreement with in situ-based estimates of annual net community <span class="hlt">production</span> (annual export of 2.7 ± 0.6 Pg C yr-1 south of 30°S). By contrast, models based on the analysis of global observations with a positive e-ratio versus NPP relationship predict annually integrated export rates that are ˜ 33% higher than the Si-dependent model. Our results suggest that accounting for Si-induced ballasting is important for the estimation of carbon export in the Southern <span class="hlt">Ocean</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25895052','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25895052"><span>Seafood inclusion in commercial main meal <span class="hlt">early</span> years' food <span class="hlt">products</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carstairs, Sharon A; Marais, Debbi; Craig, Leone C A; Kiezebrink, Kirsty</p> <p>2016-10-01</p> <p>Seafood consumption is recommended as part of a healthy, balanced diet. Under-exposure to seafood during <span class="hlt">early</span> years feeding, when taste and food acceptance is developed, may impact on the future development of a varied diet. This study aimed to investigate the availability and nutritional content of seafood in commercial infant meals compared to the other food types. A survey was conducted of all commercial infant main meal <span class="hlt">products</span> available for purchase in supermarkets, high street retailers and online stores within the United Kingdom. The primary food type (seafood, poultry, meat and vegetables) within each <span class="hlt">product</span>, nutritional composition per 100 g, and ingredient contribution were assessed. Of the original 341 main meal <span class="hlt">products</span> seafood (n = 13; 3.8%) was underrepresented compared to poultry (103; 30.2%), meat (121; 35.5%) and vegetables (104; 30.5%). The number of the seafood meals increased three years later (n = 20; 6.3%) vegetable meals remained the largest contributor to the market (115; 36.4%) with meat (99; 31.3%) and poultry (82; 26.0%) both contributing slightly less than previously. Seafood-based meals provided significantly higher energy (83.0 kcal), protein (4.6 g), and total fat (3.2 g) than vegetable (68 kcal, 2.7 g, 1.9 g), meat (66 kcal, 3.0 g, 2.1 g) and poultry-based meals (66 kcal, 3.0 g, 2.1 g) and higher saturated fat (1.3 g) than poultry (0.4 g) and vegetable-based (0.6 g) meals (all per 100 g) which may be attributed to additional dairy ingredients. Parents who predominantly use commercial <span class="hlt">products</span> to wean their infant may face challenges in sourcing a range of seafood <span class="hlt">products</span> to enable the introduction of this food into the diet of their infant. © 2015 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080030961','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080030961"><span>Heavy Isotope Composition of Oxygen in Zircon from Soil Sample 14163: Lunar Perspective of an <span class="hlt">Early</span> <span class="hlt">Ocean</span> on the Earth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nemchin, A. A.; Whitehouse, M. J.; Pidgeon, R. T.; Meyer, C.</p> <p>2006-01-01</p> <p>Thirty oxygen analyses of a large (sub-millimetre) zircon grain from the lunar soil sample 14163 have been determined using CAMECA 1270 ion microprobe. The sample 14163 was returned form the Fra Mauro region by Apollo 14 mission. Zircon grain of 0.6-0.8 mm in size extracted from the sample was imaged using CL detector fitted to the Philips Electron Microscope in order to reveal internal structure. Oxygen isotopes have been analysed during two sessions. The first set of data was collected using the original mount where the grain was set in the resin attached to the glass slide. This resulted in the two complications: (i) standard zircon has to be analysed from the separate mount and (ii) the lunar zircon grain was rased in the holder compared to the standard. In order to investigate, if the elevated oxygen compositions observed during this session could have resulted from this difference in geometric configuration during the standard and sample analyses, the lunar zircon was extracted from the original mount, remounted with the standard chip in the new resin disk and reanalysed during the second session. All analyses made during the first session show delta O-18 values heavier than 6.0%. The second set of data has a wider spread of delta O-18 values with some values as low as 5.6%. Nevertheless, a half of observed delta O-18 values in this set is also higher than 6.0%. Slightly lighter oxygen compositions observed during the second session indicate possible dependence of measured delta O-18 values on the geometry of analysed samples. Presence of zircons with similar heavy oxygen isotope compositions on the Moon, which neither had liquid water or felic crust similar to that on the Earth nor ever developed regime similar to plate tectonics, suggests that other mechanisms can be responsible for elevated delta O-18 values in zircons. This implies that there is no support for the presence of an <span class="hlt">ocean</span> on the surface of the <span class="hlt">early</span> Earth and as the <span class="hlt">ocean</span> appears to be an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26507275','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26507275"><span><span class="hlt">Early</span> Pliocene onset of modern Nordic Seas circulation related to <span class="hlt">ocean</span> gateway changes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Schepper, Stijn; Schreck, Michael; Beck, Kristina Marie; Matthiessen, Jens; Fahl, Kirsten; Mangerud, Gunn</p> <p>2015-10-28</p> <p>The globally warm climate of the <span class="hlt">early</span> Pliocene gradually cooled from 4 million years ago, synchronous with decreasing atmospheric CO2 concentrations. In contrast, palaeoceanographic records indicate that the Nordic Seas cooled during the earliest Pliocene, before global cooling. However, a lack of knowledge regarding the precise timing of Nordic Seas cooling has limited our understanding of the governing mechanisms. Here, using marine palynology, we show that cooling in the Nordic Seas was coincident with the first trans-Arctic migration of cool-water Pacific mollusks around 4.5 million years ago, and followed by the development of a modern-like Nordic Seas surface circulation. Nordic Seas cooling precedes global cooling by 500,000 years; as such, we propose that reconfiguration of the Bering Strait and Central American Seaway triggered the development of a modern circulation in the Nordic Seas, which is essential for North Atlantic Deep Water formation and a precursor for more widespread Greenland glaciation in the late Pliocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18.5861S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18.5861S"><span>Gradient flux measurements of sea-air DMS transfer during the Surface <span class="hlt">Ocean</span> Aerosol <span class="hlt">Production</span> (SOAP) experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, Murray J.; Walker, Carolyn F.; Bell, Thomas G.; Harvey, Mike J.; Saltzman, Eric S.; Law, Cliff S.</p> <p>2018-04-01</p> <p>Direct measurements of marine dimethylsulfide (DMS) fluxes are sparse, particularly in the Southern <span class="hlt">Ocean</span>. The Surface <span class="hlt">Ocean</span> Aerosol <span class="hlt">Production</span> (SOAP) voyage in February-March 2012 examined the distribution and flux of DMS in a biologically active frontal system in the southwest Pacific <span class="hlt">Ocean</span>. Three distinct phytoplankton blooms were studied with <span class="hlt">oceanic</span> DMS concentrations as high as 25 nmol L-1. Measurements of DMS fluxes were made using two independent methods: the eddy covariance (EC) technique using atmospheric pressure chemical ionization-mass spectrometry (API-CIMS) and the gradient flux (GF) technique from an autonomous catamaran platform. Catamaran flux measurements are relatively unaffected by airflow distortion and are made close to the water surface, where gas gradients are largest. Flux measurements were complemented by near-surface hydrographic measurements to elucidate physical factors influencing DMS emission. Individual DMS fluxes derived by EC showed significant scatter and, at times, consistent departures from the Coupled <span class="hlt">Ocean</span>-Atmosphere Response Experiment gas transfer algorithm (COAREG). A direct comparison between the two flux methods was carried out to separate instrumental effects from environmental effects and showed good agreement with a regression slope of 0.96 (r2 = 0.89). A period of abnormal downward atmospheric heat flux enhanced near-surface <span class="hlt">ocean</span> stratification and reduced turbulent exchange, during which GF and EC transfer velocities showed good agreement but modelled COAREG values were significantly higher. The transfer velocity derived from near-surface <span class="hlt">ocean</span> turbulence measurements on a spar buoy compared well with the COAREG model in general but showed less variation. This first direct comparison between EC and GF fluxes of DMS provides confidence in compilation of flux estimates from both techniques, as well as in the stable periods when the observations are not well predicted by the COAREG model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005GeoRL..3210610P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005GeoRL..3210610P"><span>Radionuclide and biomarker proxies of past <span class="hlt">ocean</span> circulation and <span class="hlt">productivity</span> in the Arabian Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pourmand, A.; Marcantonio, F.; Bianchi, T. S.; Canuel, E. A.; Waterson, E. J.</p> <p>2005-05-01</p> <p>We present new excess 231Pa/230Th activity ratios and lipid biomarker results from northeastern Arabian Sea sediments (core 93KL) spanning the past 50 ka in an effort to constrain further the relationship between climate at low and high latitudes. 231Pa/230Th activity ratios are maintained at values significantly higher than the water-column <span class="hlt">production</span> ratio of 0.093. Average 231Pa/230Th activity ratios are lower during the last glacial period than during the Holocene. The lowest 231Pa/230Th activity ratios coincide with the timing of Heinrich Events 1-5. Profiles of lipid biomarker fluxes and 231Pa/230Th activity ratios from 32 to 12 ka show similar patterns, suggesting that 231Pa is more efficiently scavenged relative to 230Th at times when diatoms make up a proportionally larger part of the primary biomass signal. In the Holocene, high 231Pa/230Th activity ratios may indicate enhanced 231Pa export from the southern to the northern Indian <span class="hlt">Ocean</span> via intensified thermohaline circulation.</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('http://adsabs.harvard.edu/abs/2016AGUOSED33A..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSED33A..08C"><span>Broader Impact Guidance for Florida <span class="hlt">Ocean</span> Scientists: Process, <span class="hlt">Products</span> and Outcomes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cook, S.</p> <p>2016-02-01</p> <p>In response to the 2011 National Science Board report National Science Foundation's Merit Review Criteria: Review and Revision, in 2012 significant changes were made to the portions of the National Science Foundation's (NSF's) Grant Proposal Guide that describe the Foundation's expectations with respect to the Broader Impacts (BI) criterion and what reviewers should look for in assessing the quality of the required BI components of proposals. Over the past 5 years, COSEE Florida (the Florida Center for <span class="hlt">Ocean</span> Sciences Education Excellence) has provided individualized content and editorial `coaching' on Broader Impacts for Florida scientists and educators submitting proposals to NSF. As of September 2015, 32% of the plans prepared with our guidance have been associated with projects that have received support. This presentation will review 1) the current BI guidance provided by NSF in the 2012 and subsequent editions of the Grant Proposal Guide, 2) the administrative process used by COSEE Florida to identify and assist scientists in understanding these changes and preparing fundable BI plans, 3) the characteristics of submitted plans in terms of type of plan, PI career stage and demographics 4) `lessons learned' about plan strengths and weaknesses and 5) the <span class="hlt">products</span> developed (or currently under development) as COSEE Florida legacy documents to guide current and future scientists in addressing the Broader Impacts criterion. Resources developed by other Centers in the national COSEE network and the new National Alliance for Broader Impacts (NABI) will also be described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatGe...8..126S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatGe...8..126S"><span>Modulation of oxygen <span class="hlt">production</span> in Archaean <span class="hlt">oceans</span> by episodes of Fe(II) toxicity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swanner, Elizabeth D.; Mloszewska, Aleksandra M.; Cirpka, Olaf A.; Schoenberg, Ronny; Konhauser, Kurt O.; Kappler, Andreas</p> <p>2015-02-01</p> <p>Oxygen accumulated in the surface waters of the Earth's <span class="hlt">oceans</span> and atmosphere several hundred million years before the Great Oxidation Event between 2.4 and 2.3 billion years ago. Before the Great Oxidation Event, periods of enhanced submarine volcanism associated with mantle plume events supplied Fe(II) to sea water. These periods generally coincide with the disappearance of indicators of the presence of molecular oxygen in Archaean sedimentary records. The presence of Fe(II) in the water column can lead to oxidative stress in some organisms as a result of reactions between Fe(II) and oxygen that produce reactive oxygen species. Here we test the hypothesis that the upwelling of Fe(II)-rich, anoxic water into the photic zone during the late Archaean subjected oxygenic phototrophic bacteria to Fe(II) toxicity. In laboratory experiments, we found that supplying Fe(II) to the anoxic growth medium housing a common species of planktonic cyanobacteria decreased both the efficiency of oxygenic photosynthesis and their growth rates. We suggest that this occurs because of increasing intracellular concentrations of reactive oxygen species. We use geochemical modelling to show that Fe(II) toxicity in conditions found in the late Archaean photic zone could have substantially inhibited water column oxygen <span class="hlt">production</span>, thus decreasing fluxes of oxygen to the atmosphere. We therefore propose that the timing of atmospheric oxygenation was controlled by the timing of submarine, plume-type volcanism, with Fe(II) toxicity as the modulating factor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160014493&hterms=improvement+products&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dimprovement%2Bproducts','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160014493&hterms=improvement+products&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dimprovement%2Bproducts"><span>Identifying and Analyzing Uncertainty Structures in the TRMM Microwave Imager Precipitation <span class="hlt">Product</span> over Tropical <span class="hlt">Ocean</span> Basins</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liu, Jianbo; Kummerow, Christian D.; Elsaesser, Gregory S.</p> <p>2016-01-01</p> <p>Despite continuous improvements in microwave sensors and retrieval algorithms, our understanding of precipitation uncertainty is quite limited, due primarily to inconsistent findings in studies that compare satellite estimates to in situ observations over different parts of the world. This study seeks to characterize the temporal and spatial properties of uncertainty in the Tropical Rainfall Measuring Mission Microwave Imager surface rainfall <span class="hlt">product</span> over tropical <span class="hlt">ocean</span> basins. Two uncertainty analysis frameworks are introduced to qualitatively evaluate the properties of uncertainty under a hierarchy of spatiotemporal data resolutions. The first framework (i.e. 'climate method') demonstrates that, apart from random errors and regionally dependent biases, a large component of the overall precipitation uncertainty is manifested in cyclical patterns that are closely related to large-scale atmospheric modes of variability. By estimating the magnitudes of major uncertainty sources independently, the climate method is able to explain 45-88% of the monthly uncertainty variability. The percentage is largely resolution dependent (with the lowest percentage explained associated with a 1 deg x 1 deg spatial/1 month temporal resolution, and highest associated with a 3 deg x 3 deg spatial/3 month temporal resolution). The second framework (i.e. 'weather method') explains regional mean precipitation uncertainty as a summation of uncertainties associated with individual precipitation systems. By further assuming that self-similar recurring precipitation systems yield qualitatively comparable precipitation uncertainties, the weather method can consistently resolve about 50 % of the daily uncertainty variability, with only limited dependence on the regions of interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGD....10.9179S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGD....10.9179S"><span>On the role of mesoscale eddies for the biological <span class="hlt">productivity</span> and biogeochemistry in the eastern tropical Pacific <span class="hlt">Ocean</span> off Peru</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stramma, L.; Bange, H. W.; Czeschel, R.; Lorenzo, A.; Frank, M.</p> <p>2013-06-01</p> <p>Mesoscale eddies seem to play an important role for both the hydrography and biogeochemistry of the eastern tropical Pacific <span class="hlt">Ocean</span> (ETSP) off Peru. However, detailed surveys of these eddies are not available, which has so far hampered an in depth understanding of their implications for nutrient distribution and biological <span class="hlt">productivity</span>. In this study three eddies along a section at 16°45' S have been surveyed intensively during R/V Meteor cruise M90 in November 2012. A coastal mode water eddy, an open <span class="hlt">ocean</span> mode water eddy and an open <span class="hlt">ocean</span> cyclonic eddy have been identified and sampled in order to determine both their hydrographic properties and their influence on the biogeochemical setting of the ETSP. In the thermocline the temperature of the coastal anticyclonic eddy was up to 2 °C warmer, 0.2 more saline and the swirl velocity was up to 35 cm s-1. The observed temperature and salinity anomalies, as well as swirl velocities of both types of eddies were about twice as large as had been described for the mean eddies in the ETSP and the observed heat and salt anomalies (AHA, ASA) show a much larger variability than the mean AHA and ASA. We found that the eddies contributed significantly to <span class="hlt">productivity</span> by maintaining pronounced subsurface maxima of chlorophyll. Based on a comparison of the coastal (young) mode water eddy and the open <span class="hlt">ocean</span> (old) mode water eddy we conclude that the aging of eddies when they detach from the coast and move westward to the open <span class="hlt">ocean</span> considerably influences the eddies' properties: chlorophyll maxima are weaker and nutrients are subducted. The coastal mode water eddy was found to be a hotspot of nitrogen loss in the OMZ, whereas, the open <span class="hlt">ocean</span> cyclonic eddy was of negligible importance for nitrogen loss. Our results show that the important role the eddies play in the ETSP can only be fully deciphered and understood through dedicated high spatial and temporal resolution oceanographic/biogeochemical surveys.</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 <span class="hlt">Production</span>, Food Quality, and Carbon Uptake in the Global <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 <span class="hlt">production</span>, 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 global net primary <span class="hlt">production</span> decline (7.7%) to current generation fixed stoichiometry models. Global 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('https://www.ncbi.nlm.nih.gov/pubmed/26301371','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26301371"><span>Estimating <span class="hlt">Oceanic</span> Primary <span class="hlt">Production</span> Using Vertical Irradiance and Chlorophyll Profiles from <span class="hlt">Ocean</span> Gliders in the North Atlantic.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hemsley, Victoria S; Smyth, Timothy J; Martin, Adrian P; Frajka-Williams, Eleanor; Thompson, Andrew F; Damerell, Gillian; Painter, Stuart C</p> <p>2015-10-06</p> <p>An autonomous underwater vehicle (Seaglider) has been used to estimate marine primary <span class="hlt">production</span> (PP) using a combination of irradiance and fluorescence vertical profiles. This method provides estimates for depth-resolved and temporally evolving PP on fine spatial scales in the absence of ship-based calibrations. We describe techniques to correct for known issues associated with long autonomous deployments such as sensor calibration drift and fluorescence quenching. Comparisons were made between the Seaglider, stable isotope ((13)C), and satellite estimates of PP. The Seaglider-based PP estimates were comparable to both satellite estimates and stable isotope measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24132201','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24132201"><span>Impacts of light shading and nutrient enrichment geo-engineering approaches on the <span class="hlt">productivity</span> of a stratified, oligotrophic <span class="hlt">ocean</span> ecosystem.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hardman-Mountford, Nick J; Polimene, Luca; Hirata, Takafumi; Brewin, Robert J W; Aiken, Jim</p> <p>2013-12-06</p> <p>Geo-engineering proposals to mitigate global warming have focused either on methods of carbon dioxide removal, particularly nutrient fertilization of plant growth, or on cooling the Earth's surface by reducing incoming solar radiation (shading). Marine phytoplankton contribute half the Earth's biological carbon fixation and carbon export in the <span class="hlt">ocean</span> is modulated by the actions of microbes and grazing communities in recycling nutrients. Both nutrients and light are essential for photosynthesis, so understanding the relative influence of both these geo-engineering approaches on <span class="hlt">ocean</span> ecosystem <span class="hlt">production</span> and processes is critical to the evaluation of their effectiveness. In this paper, we investigate the relationship between light and nutrient availability on <span class="hlt">productivity</span> in a stratified, oligotrophic subtropical <span class="hlt">ocean</span> ecosystem using a one-dimensional water column model coupled to a multi-plankton ecosystem model, with the goal of elucidating potential impacts of these geo-engineering approaches on ecosystem <span class="hlt">production</span>. We find that solar shading approaches can redistribute <span class="hlt">productivity</span> in the water column but do not change total <span class="hlt">production</span>. Macronutrient enrichment is able to enhance the export of carbon, although heterotrophic recycling reduces the efficiency of carbon export substantially over time. Our results highlight the requirement for a fuller consideration of marine ecosystem interactions and feedbacks, beyond simply the stimulation of surface blooms, in the evaluation of putative geo-engineering approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3808547','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3808547"><span>Impacts of light shading and nutrient enrichment geo-engineering approaches on the <span class="hlt">productivity</span> of a stratified, oligotrophic <span class="hlt">ocean</span> ecosystem</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hardman-Mountford, Nick J.; Polimene, Luca; Hirata, Takafumi; Brewin, Robert J. W.; Aiken, Jim</p> <p>2013-01-01</p> <p>Geo-engineering proposals to mitigate global warming have focused either on methods of carbon dioxide removal, particularly nutrient fertilization of plant growth, or on cooling the Earth's surface by reducing incoming solar radiation (shading). Marine phytoplankton contribute half the Earth's biological carbon fixation and carbon export in the <span class="hlt">ocean</span> is modulated by the actions of microbes and grazing communities in recycling nutrients. Both nutrients and light are essential for photosynthesis, so understanding the relative influence of both these geo-engineering approaches on <span class="hlt">ocean</span> ecosystem <span class="hlt">production</span> and processes is critical to the evaluation of their effectiveness. In this paper, we investigate the relationship between light and nutrient availability on <span class="hlt">productivity</span> in a stratified, oligotrophic subtropical <span class="hlt">ocean</span> ecosystem using a one-dimensional water column model coupled to a multi-plankton ecosystem model, with the goal of elucidating potential impacts of these geo-engineering approaches on ecosystem <span class="hlt">production</span>. We find that solar shading approaches can redistribute <span class="hlt">productivity</span> in the water column but do not change total <span class="hlt">production</span>. Macronutrient enrichment is able to enhance the export of carbon, although heterotrophic recycling reduces the efficiency of carbon export substantially over time. Our results highlight the requirement for a fuller consideration of marine ecosystem interactions and feedbacks, beyond simply the stimulation of surface blooms, in the evaluation of putative geo-engineering approaches. PMID:24132201</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRG..122.1385G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRG..122.1385G"><span>Approach for estimating the dynamic physical thresholds of phytoplankton <span class="hlt">production</span> and biomass in the tropical-subtropical Pacific <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>Gómez-Ocampo, E.; Gaxiola-Castro, G.; Durazo, Reginaldo</p> <p>2017-06-01</p> <p>Threshold is defined as the point where small changes in an environmental driver produce large responses in the ecosystem. Generalized additive models (GAMs) were used to estimate the thresholds and contribution of key dynamic physical variables in terms of phytoplankton <span class="hlt">production</span> and variations in biomass in the tropical-subtropical Pacific <span class="hlt">Ocean</span> off Mexico. The statistical approach used here showed that thresholds were shallower for primary <span class="hlt">production</span> than for phytoplankton biomass (pycnocline < 68 m and mixed layer < 30 m versus pycnocline < 45 m and mixed layer < 80 m) but were similar for absolute dynamic topography and Ekman pumping (ADT < 59 cm and EkP > 0 cm d-1 versus ADT < 60 cm and EkP > 4 cm d-1). The relatively high <span class="hlt">productivity</span> on seasonal (spring) and interannual (La Niña 2008) scales was linked to low ADT (45-60 cm) and shallow pycnocline depth (9-68 m) and mixed layer (8-40 m). Statistical estimations from satellite data indicated that the contributions of <span class="hlt">ocean</span> circulation to phytoplankton variability were 18% (for phytoplankton biomass) and 46% (for phytoplankton <span class="hlt">production</span>). Although the statistical contribution of models constructed with in situ integrated chlorophyll a and primary <span class="hlt">production</span> data was lower than the one obtained with satellite data (11%), the fits were better for the former, based on the residual distribution. The results reported here suggest that estimated thresholds may reliably explain the spatial-temporal variations of phytoplankton in the tropical-subtropical Pacific <span class="hlt">Ocean</span> off the coast of Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GPC...158..119L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GPC...158..119L"><span>Planktic foraminiferal response to <span class="hlt">early</span> Eocene carbon cycle perturbations in the southeast Atlantic <span class="hlt">Ocean</span> (ODP Site 1263)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luciani, Valeria; D'Onofrio, Roberta; Dickens, Gerald R.; Wade, Bridget S.</p> <p>2017-11-01</p> <p>At low latitude locations in the northern hemisphere, striking changes in the relative abundances and diversity of the two dominant planktic foraminifera genera, Morozovella and Acarinina, are known to have occurred close to the <span class="hlt">Early</span> Eocene Climatic Optimum (EECO; 49-53 Ma). Lower Eocene carbonate-rich sediments at <span class="hlt">Ocean</span> Drilling Program (ODP) Site 1263 were deposited on a bathymetric high (Walvis Ridge) at 40° S, and afford an opportunity to examine such planktic foraminiferal assemblage changes in a temperate southern hemisphere setting. We present here quantified counts of <span class="hlt">early</span> Eocene planktic foraminiferal assemblages from Hole 1263B, along with bulk sediment stable isotope analyses and proxy measurements for carbonate dissolution. The bulk sediment δ13C record at Site 1263 resembles similar records generated elsewhere, such that known and inferred hyperthermal events can be readily identified. Although some carbonate dissolution has occurred, the well-preserved planktic foraminiferal assemblages mostly represent primary changes in environmental conditions. Our results document the permanent decrease in Morozovella abundance and increase in Acarinina abundance at the beginning of the EECO, although this switch occurred 165 kyr after that at low-latitude northern hemisphere locations. This suggests that unfavourable environmental conditions for morozovellids at the start of the EECO, such as sustained passage of a temperature threshold or other changes in surface waters, occurred at lower latitudes first. The remarkable turnover from Morozovella to Acarinina was widely geographically widespread, although the causal mechanism remains elusive. In addition, at Site 1263, we document the virtual disappearance within the EECO of the biserial chiloguembelinids, commonly considered as inhabiting intermediate water depths, and a reduction in abundance of the thermocline-dwelling subbotinids. We interpret these changes as signals of subsurface water properties</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24603709','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24603709"><span>Relationships between meiofaunal biodiversity and prokaryotic heterotrophic <span class="hlt">production</span> in different tropical habitats and <span class="hlt">oceanic</span> regions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pusceddu, Antonio; Gambi, Cristina; Corinaldesi, Cinzia; Scopa, Mariaspina; Danovaro, Roberto</p> <p>2014-01-01</p> <p>Tropical marine ecosystems are among the most diverse of the world <span class="hlt">oceans</span>, so that assessing the linkages between biodiversity and ecosystem functions (BEF) is a crucial step to predict consequences of biodiversity loss. Most BEF studies in marine ecosystems have been carried out on macrobenthic diversity, whereas the influence of the meiofauna on ecosystem functioning has received much less attention. We compared meiofaunal and nematode biodiversity and prokaryotic heterotrophic <span class="hlt">production</span> across seagrass, mangrove and reef sediments in the Caribbean, Celebes and Red Seas. For all variables we report the presence of differences among habitats within the same region, and among regions within the same habitat. In all regions, the richness of meiofaunal taxa in reef and seagrass sediments is higher than in mangrove sediments. The sediments of the Celebes Sea show the highest meiofaunal biodiversity. The composition of meiofaunal assemblages varies significantly among habitats in the same region. The nematode beta diversity among habitats within the same region is higher than the beta diversity among regions. Although one site per habitat was considered in each region, these results suggest that the composition of meiofaunal assemblages varies primarily among biogeographic regions, whereas the composition of nematode assemblages varies more considerably among habitats. Meiofauna and nematode biodiversity and prokaryotic heterotrophic <span class="hlt">production</span>, even after the removal of covariate effects linked with longitude and the quantity and nutritional quality of organic matter, are positively and linearly linked both across regions and within each habitat type. Our results confirm that meiofauna and nematode biodiversity may influence benthic prokaryotic activity, which, in turn, implies that diversity loss could have negative impacts on ecosystem functioning in these systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5342202','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5342202"><span>Effects of <span class="hlt">ocean</span> acidification on primary <span class="hlt">production</span> in a coastal North Sea phytoplankton community</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Eberlein, Tim; Wohlrab, Sylke; Rost, Björn; John, Uwe; Bach, Lennart T.; Riebesell, Ulf; Van de Waal, Dedmer B.</p> <p>2017-01-01</p> <p>We studied the effect of <span class="hlt">ocean</span> acidification (OA) on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study). From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar Fjord, Sweden. CO2 concentrations were enriched in five mesocosms to reach average CO2 partial pressures (pCO2) of 760 μatm. The remaining five mesocosms were used as control at ambient pCO2 of 380 μatm. Our paper is part of a PLOS collection on this long-term mesocosm experiment. Here, we here tested the effect of OA on total primary <span class="hlt">production</span> (PPT) by performing 14C-based bottle incubations for 24 h. Furthermore, photoacclimation was assessed by conducting 14C-based photosynthesis-irradiance response (P/I) curves. Changes in chlorophyll a concentrations over time were reflected in the development of PPT, and showed higher phytoplankton biomass build-up under OA. We observed two subsequent phytoplankton blooms in all mesocosms, with peaks in PPT around day 33 and day 56. OA had no significant effect on PPT, except for a marginal increase during the second phytoplankton bloom when inorganic nutrients were already depleted. Maximum light use efficiencies and light saturation indices calculated from the P/I curves changed simultaneously in all mesocosms, and suggest that OA did not alter phytoplankton photoacclimation. Despite large variability in time-integrated <span class="hlt">productivity</span> estimates among replicates, our overall results indicate that coastal phytoplankton communities can be affected by OA at certain times of the seasonal succession with potential consequences for ecosystem functioning. PMID:28273107</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29714221','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29714221"><span>Simultaneous polarimeter retrievals of microphysical aerosol and <span class="hlt">ocean</span> color parameters from the "MAPP" algorithm with comparison to high-spectral-resolution lidar aerosol and <span class="hlt">ocean</span> <span class="hlt">products</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stamnes, S; Hostetler, C; Ferrare, R; Burton, S; Liu, X; Hair, J; Hu, Y; Wasilewski, A; Martin, W; van Diedenhoven, B; Chowdhary, J; Cetinić, I; Berg, L K; Stamnes, K; Cairns, B</p> <p>2018-04-01</p> <p>We present an optimal-estimation-based retrieval framework, the microphysical aerosol properties from polarimetry (MAPP) algorithm, designed for simultaneous retrieval of aerosol microphysical properties and <span class="hlt">ocean</span> color bio-optical parameters using multi-angular total and polarized radiances. Polarimetric measurements from the airborne NASA Research Scanning Polarimeter (RSP) were inverted by MAPP to produce atmosphere and <span class="hlt">ocean</span> <span class="hlt">products</span>. The RSP MAPP results are compared with co-incident lidar measurements made by the NASA High-Spectral-Resolution Lidar HSRL-1 and HSRL-2 instruments. Comparisons are made of the aerosol optical depth (AOD) at 355 and 532 nm, lidar column-averaged measurements of the aerosol lidar ratio and Ångstrøm exponent, and lidar <span class="hlt">ocean</span> measurements of the particulate hemispherical backscatter coefficient and the diffuse attenuation coefficient. The measurements were collected during the 2012 Two-Column Aerosol Project (TCAP) campaign and the 2014 Ship-Aircraft Bio-Optical Research (SABOR) campaign. For the SABOR campaign, 73% RSP MAPP retrievals fall within ±0.04 AOD at 532 nm as measured by HSRL-1, with an R value of 0.933 and root-mean-square deviation of 0.0372. For the TCAP campaign, 53% of RSP MAPP retrievals are within 0.04 AOD as measured by HSRL-2, with an R value of 0.927 and root-mean-square deviation of 0.0673. Comparisons with HSRL-2 AOD at 355 nm during TCAP result in an R value of 0.959 and a root-mean-square deviation of 0.0694. The RSP retrievals using the MAPP optimal estimation framework represent a key milestone on the path to a combined lidar + polarimeter retrieval using both HSRL and RSP measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1455298-simultaneous-polarimeter-retrievals-microphysical-aerosol-ocean-color-parameters-from-mapp-algorithm-comparison-high-spectral-resolution-lidar-aerosol-ocean-products','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1455298-simultaneous-polarimeter-retrievals-microphysical-aerosol-ocean-color-parameters-from-mapp-algorithm-comparison-high-spectral-resolution-lidar-aerosol-ocean-products"><span>Simultaneous polarimeter retrievals of microphysical aerosol and <span class="hlt">ocean</span> color parameters from the “MAPP” algorithm with comparison to high-spectral-resolution lidar aerosol and <span class="hlt">ocean</span> <span class="hlt">products</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciT</a></p> <p>Stamnes, S.; Hostetler, C.; Ferrare, R.</p> <p></p> <p>We present an optimal estimation based retrieval framework, the Microphysical Aerosol Properties from Polarimetry (MAPP) algorithm, designed for simultaneous retrieval of aerosol microphysical properties and <span class="hlt">ocean</span> color bio-optical parameters using multi-angular polarized radiances. Polarimetric measurements from the airborne NASA Research Scanning Polarimeter (RSP) were inverted by MAPP to produce atmosphere and <span class="hlt">ocean</span> <span class="hlt">products</span>. The RSP MAPP results are compared with co-incident lidar measurements made by the NASA High Spectral Resolution Lidar HSRL-1 and HSRL-2 instruments. Comparisons are made of the aerosol optical depth (AOD) at 355, 532, and 1064 nm, lidar column-averaged measurements of the aerosol lidar ratio and Ã…ngstrømmore » exponent, and lidar <span class="hlt">ocean</span> measurements of the particulate hemispherical backscatter coefficient and the diffuse attenuation coefficient. The measurements were collected during the 2012 Two-Column Aerosol Project (TCAP) campaign and the 2014 Ship-Aircraft Bio- Optical Research (SABOR) campaign. For the SABOR campaign, 71% RSP MAPP retrievals fall within 0.04 AOD at 532 nm as measured by HSRL-1, with an R value of 0.925 and root-mean-square deviation of 0.04. For the TCAP campaign, 55% of RSP MAPP retrievals are within 0.04 AOD as measured by HSRL-2, with an R value of 0.925 and root-mean-square deviation of 0.07. Comparisons with HSRL-2 AOD at 355 nm during TCAP result in an R value of 0.96 and a root-mean-square deviation of also 0.07. The RSP retrievals using the MAPP optimal estimation framework represent a key milestone on the path to a combined lidar+polarimeter retrieval using both HSRL and RSP measurements.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSAH54A0111S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSAH54A0111S"><span>Impact of bacterial DMS <span class="hlt">production</span> on [DMS/P] under <span class="hlt">ocean</span> acidification (KOSMOS_2.0): insights from the subtropics.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suffrian, K.; Posman, K.; Matrai, P.; Countway, P. D.; Archer, S. D.</p> <p>2016-02-01</p> <p>Marine dimethyl sulfide (DMS), a ubiquitous atmospheric trace gas, comprises the largest source of sulphur to the atmosphere. So far, temperate and high-latitude <span class="hlt">ocean</span> acidification (OA) mesocosm experiments point to a decrease of this precursor for cloud condensation nuclei, leading to fewer clouds, and resulting in an increased radiative force. To our knowledge no experiments have yet been carried out which address multiple forcings (temperature and pCO2) in the subtropics. We thus joined the 55-day KOSMOS large mesocosm experiment on Gran Canaria to investigate if the observed decrease could be global. As subtropical and tropical <span class="hlt">oceans</span> comprise a large proportion of the world's <span class="hlt">oceans</span>, we were i.a. interested if 1) increasing <span class="hlt">ocean</span> acidification in a subtropical environment would also decrease [DMS], and if 2) bacterial DMS <span class="hlt">production</span> could explain a large part of potential decreases. Here we focus on the first phase (day 1-23), showing the impact of OA on [DMS] and [DMSP] (dimethylsulfoniopropionate). Bacteria are thought to be the main DMS producers, so we used 35S-DMSP as a tracer to investigate the impact of bacterial DMS <span class="hlt">production</span> on observed [DMS] decreases correlated with increasing OA. [DMS] showed a strong inverse correlation with [H+] (-50% vs. ambient control). [DMSPp] (-37%) and [DMSPd] (-20%) also decreased with increasing [H+]. Our results support findings from higher latitude mesocosm experiments, thus suggesting the effect might be global. Bacterial DMS <span class="hlt">production</span> rates, their rate constants, and yields during the peak in [DMS] were negatively correlated with [H+] on single days, while gross DMS-<span class="hlt">production</span> was high enough to support observed [DMS] increases. Bacterial DMSP uptake rates and DMS <span class="hlt">production</span> rates were not correlated with [H+] on any other day. Bacterial effects alone are thus not enough to explain observed changes in standing stocks. We will further explore the results by normalizing to bacterial protein <span class="hlt">production</span>, cell abundance</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24358240','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24358240"><span>Impacts of <span class="hlt">ocean</span> acidification on <span class="hlt">early</span> life-history stages and settlement of the coral-eating sea star Acanthaster planci.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Uthicke, Sven; Pecorino, Danilo; Albright, Rebecca; Negri, Andrew Peter; Cantin, Neal; Liddy, Michelle; Dworjanyn, Symon; Kamya, Pamela; Byrne, Maria; Lamare, Miles</p> <p>2013-01-01</p> <p>Coral reefs are marine biodiversity hotspots, but their existence is threatened by global change and local pressures such as land-runoff and overfishing. Population explosions of coral-eating crown of thorns sea stars (COTS) are a major contributor to recent decline in coral cover on the Great Barrier Reef. Here, we investigate how projected near-future <span class="hlt">ocean</span> acidification (OA) conditions can affect <span class="hlt">early</span> life history stages of COTS, by investigating important milestones including sperm motility, fertilisation rates, and larval development and settlement. OA (increased pCO2 to 900-1200 µatm pCO2) significantly reduced sperm motility and, to a lesser extent, velocity, which strongly reduced fertilization rates at environmentally relevant sperm concentrations. Normal development of 10 d old larvae was significantly lower under elevated pCO2 but larval size was not significantly different between treatments. Settlement of COTS larvae was significantly reduced on crustose coralline algae (known settlement inducers of COTS) that had been exposed to OA conditions for 85 d prior to settlement assays. Effect size analyses illustrated that reduced settlement may be the largest bottleneck for overall juvenile <span class="hlt">production</span>. Results indicate that reductions in fertilisation and settlement success alone would reduce COTS population replenishment by over 50%. However, it is unlikely that this effect is sufficient to provide respite for corals from other negative anthropogenic impacts and direct stress from OA and warming on corals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.481..162I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.481..162I"><span>Sedimentary evidence for enhanced hydrological cycling in response to rapid carbon release during the <span class="hlt">early</span> Toarcian <span class="hlt">oceanic</span> anoxic event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Izumi, Kentaro; Kemp, David B.; Itamiya, Shoma; Inui, Mutsuko</p> <p>2018-01-01</p> <p>A pronounced excursion in the carbon-isotope composition of biospheric carbon and coeval seawater warming during the <span class="hlt">early</span> Toarcian (∼183 Ma) has been linked to the large-scale transfer of 12C-enriched carbon to the <span class="hlt">oceans</span> and atmosphere. A European bias in the distribution of available data means that the precise pattern, tempo and global expression of this carbon cycle perturbation, and the associated environmental responses, remain uncertain. Here, we present a new cm-scale terrestrial-dominated carbon-isotope record through an expanded lower Toarcian section from Japan that displays a negative excursion pattern similar to marine and terrestrial carbon-isotope records documented from Europe. These new data suggest that 12C-enriched carbon was added to the biosphere in at least one rapid, millennial-scale pulse. Sedimentological analysis indicates a close association between the carbon-isotope excursion and high-energy sediment transport and enhanced fluvial discharge. Together, these data support the hypothesis that a sudden strengthening of the global hydrological cycle occurred in direct and immediate response to rapid carbon release and atmospheric warming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4664409','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4664409"><span>The Gondwana Breakup and the History of the Atlantic and Indian <span class="hlt">Oceans</span> Unveils Two New Clades for <span class="hlt">Early</span> Neobatrachian Diversification</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Frazão, Annelise; da Silva, Hélio Ricardo; Russo, Claudia Augusta de Moraes</p> <p>2015-01-01</p> <p>The largest anuran diversity belongs to the Neobatrachia, which harbor more than five thousand extant species. Here, we propose a new hypothesis for the historical aspects of the neobatrachian evolution with a formal biogeographical analysis. We selected 12 genes for 144 neobatrachian genera and four archaeobatrachian outgroups and performed a phylogenetic analysis using a maximum likelihood algorithm with the rapid bootstrap test. We also estimated divergence times for major lineages using a relaxed uncorrelated clock method. According to our time scale, the diversification of crown Neobatrachia began around the end of the <span class="hlt">Early</span> Cretaceous. Our phylogenetic tree suggests that the first split of Neobatrachia is related to the geological events in the Atlantic and Indian <span class="hlt">Oceans</span>. Hence, we propose names for these clades that indicate this connection, i.e., Atlanticanura and Indianura. The Atlanticanura is composed of three major neobatrachian lineages: Heleophrynidae, Australobatrachia and Nobleobatrachia. On the other hand, the Indianura consists of two major lineages: Sooglossoidea and Ranoides. The biogeographical analysis indicates that many neobatrachian splits occurred as a result of geological events such as the separation between South America and Africa, between India and the Seychelles, and between Australia and South America. PMID:26618546</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28618153','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28618153"><span>Cascading influence of inorganic nitrogen sources on DOM <span class="hlt">production</span>, composition, lability and microbial community structure in the open <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>Goldberg, S J; Nelson, C E; Viviani, D A; Shulse, C N; Church, M J</p> <p>2017-09-01</p> <p>Nitrogen frequently limits <span class="hlt">oceanic</span> photosynthesis and the availability of inorganic nitrogen sources in the surface <span class="hlt">oceans</span> is shifting with global change. We evaluated the potential for abrupt increases in inorganic N sources to induce cascading effects on dissolved organic matter (DOM) and microbial communities in the surface <span class="hlt">ocean</span>. We collected water from 5 m depth in the central North Pacific and amended duplicate 20 liter polycarbonate carboys with nitrate or ammonium, tracking planktonic carbon fixation, DOM <span class="hlt">production</span>, DOM composition and microbial community structure responses over 1 week relative to controls. Both nitrogen sources stimulated bulk phytoplankton, bacterial and DOM <span class="hlt">production</span> and enriched Synechococcus and Flavobacteriaceae; ammonium enriched for oligotrophic Actinobacteria OM1 and Gammaproteobacteria KI89A clades while nitrate enriched Gammaproteobacteria SAR86, SAR92 and OM60 clades. DOM resulting from both N enrichments was more labile and stimulated growth of copiotrophic Gammaproteobacteria (Alteromonadaceae and Oceanospirillaceae) and Alphaproteobacteria (Rhodobacteraceae and Hyphomonadaceae) in weeklong dark incubations relative to controls. Our study illustrates how nitrogen pulses may have direct and cascading effects on DOM composition and microbial community dynamics in the open <span class="hlt">ocean</span>. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP52B..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP52B..07L"><span>The PETM in the coastal <span class="hlt">ocean</span>: changes in redox, <span class="hlt">productivity</span>, and organic matter sources recorded in mid-Atlantic sediments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lyons, S. L.; Baczynski, A. A.; Vornlocher, J.; Freeman, K. H.</p> <p>2016-12-01</p> <p>Climate events in the geologic record reveal the broad array of Earth's responses to carbon cycle perturbations, and provide valuable insights to the predicted impacts of future anthropogenic climate change. The Paleocene-Eocene Thermal Maximum (PETM) hyperthermal was linked to a rapid injection of isotopically light carbon into Earth's <span class="hlt">ocean</span>-atmosphere system, and this event serves as the best-known analogue for anthropogenic climate change. The addition of 4500 Gt CO2 over < 20,000 years, estimated based on carbon isotope excursions of 3-5‰ in marine and terrestrial records, was accompanied by abrupt global warming of 5-9 oC. Changes in <span class="hlt">ocean</span> redox chemistry, <span class="hlt">productivity</span>, sediment accumulation, and organic matter sourcing often accompany climate and carbon cycle perturbations and have been implicated in PETM off-shore <span class="hlt">ocean</span> records. Yet, despite numerous studies of biomarkers and organic matter in terrestrial and marine PETM records, we lack organic records from truly coastal environments, leaving a gap in our understanding of the land-<span class="hlt">ocean</span> interface and how the shallow marine environments changed during the PETM. To better understand the effects of climate change on coastal sites and the marine sedimentary records during the PETM, we investigated the role of redox, <span class="hlt">productivity</span>, and organic matter sourcing using recently collected cores from the paleo-Atlantic shelf. These new coastal PETM records provide needed datasets to understand biogeochemical changes in the shallow marine environment. Here, we present lipid biomarkers (pristane, phytane, n-alkanes, hopanoids, steranes, GDGTs) and compound-specific carbon isotope data along a transect from proximal coastal to more distal inner shelf. These molecular records help detail the intensity of water column stratification, <span class="hlt">productivity</span>, and carbon source changes, as well as shifting terrestrial and marine inputs. Constraining the marine carbon isotope excursion, organic matter sourcing, and water column</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://adsabs.harvard.edu/abs/2010EGUGA..1214696N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1214696N"><span>Open <span class="hlt">oceanic</span> <span class="hlt">productivity</span> changes at mid-latitudes during interglacials and its relation to the Atlantic Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nave, Silvia; Lebreiro, S.; Kissel, C.; Guihou, A.; Figueiredo, M. O.; Silva, T. P.; Michel, E.; Cortijo, E.; Labeyrie, L.; Voelker, A.</p> <p>2010-05-01</p> <p>Variations in the interactions between marine ecosystems, thermohaline circulation, external forcing and atmospheric greenhouse gases concentrations are not yet fully represented in detailed models of the glacial-interglacial transitions. Most of the research on past <span class="hlt">productivity</span> changes has been focused so far on high-<span class="hlt">productivity</span> areas such as upwelling areas (i.e. equatorial or coastal upwelling areas) even though those regions appraise only a little part of the <span class="hlt">ocean</span>. Accordingly, the importance of <span class="hlt">oceanic</span> <span class="hlt">productivity</span> changes over glacial/interglacial cycles should be better known, as it may also play an important role on the loss of photosynthetically generated carbon as a central mechanism in the global carbon cycle. Its understanding will help quantifying the parameters needed to run comprehensive climate models, and subsequently help to better predict climate change for the near future. A high-resolution study of <span class="hlt">oceanic</span> <span class="hlt">productivity</span>, bottom water flow speed, surface and deep-water mass, bottom water ventilation, and terrestrial input changes during two interglacials (Holocene and Marine Isotope Stage [MIS] 5), at an open <span class="hlt">ocean</span> site approximately 300 km west off Portugal [IMAGES core MD01-2446: 39°03'N, 12°37'W, 3547 m water depth] was conducted within the AMOCINT project (ESF-EUROCORES programme, 06-EuroMARC-FP-008). Even though siliceous <span class="hlt">productivity</span> is expectedly low for <span class="hlt">oceanic</span> regions, it shows a robust and consistent pattern with increased values during cold phases of MIS 5, and during the glacial stages 4 and 6 suggesting higher nutrient availability, during these periods. The same pattern is observed for MIS2 and the last deglaciation. The opal record is fully supported by the organic carbon content and to the estimated <span class="hlt">productivity</span> using foraminifera based FA20 and SIMMAX.28 transfer functions for a near location. The benthic δ13C record suggests less North Atlantic Deep Water (NADW) coincident with periods of higher <span class="hlt">productivity</span>. The grain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1006106','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1006106"><span>Annual Growth of Contract Costs for Major Programs in Development and <span class="hlt">Early</span> <span class="hlt">Production</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-03-21</p> <p>changes, we can identify some underlying drivers and rule out others. Development and <span class="hlt">Early</span> <span class="hlt">Production</span> Differences BBP-era drops are driven by dropping...Annual Growth of Contract Costs for Major Programs in Development and <span class="hlt">Early</span> <span class="hlt">Production</span> Dan Davis and Philip S...Growth of Contract Costs for Major Programs in Development and <span class="hlt">Early</span> <span class="hlt">Production</span> Dan Davis and Philip S. Antón March 21, 2016 SUMMARY Cost is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.1934D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.1934D"><span><span class="hlt">Ocean</span> modelling and <span class="hlt">Early</span>-Warning System for the Gulf of Thailand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Lima Rego, Joao; Yan, Kun; Sisomphon, Piyamarn; Thanathanphon, Watin; Twigt, Daniel; Irazoqui Apecechea, Maialen</p> <p>2017-04-01</p> <p> illustrate the system's development and main features, with a focus on decision-support <span class="hlt">products</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004DSRII..51..897W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004DSRII..51..897W"><span><span class="hlt">Early</span> <span class="hlt">ocean</span> survival and marine movements of hatchery and wild steelhead trout ( Oncorhynchus mykiss) determined by an acoustic array: Queen Charlotte Strait, British Columbia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Welch, David W.; Ward, Bruce R.; Batten, Sonia D.</p> <p>2004-03-01</p> <p><span class="hlt">Early</span> <span class="hlt">ocean</span> movements, residency, and survival of steelhead (Oncorhynchus mykiss) were examined in Queen Charlotte Strait, a large (20×100 km2) marine area separating Vancouver Island from the mainland. The results provide the first detailed data on the <span class="hlt">ocean</span> biology of hatchery and wild steelhead smolts. Initial <span class="hlt">ocean</span> movements were not strongly directed, with most smolts swimming in the range of 0.2-0.5 body length (BL) s-1. The majority (78%) vacated Queen Charlotte Strait within 1 week of release in freshwater. Relative marine survival of hatchery smolts surgically implanted 1 month prior to release was identical to that of wild smolts implanted on the day of release; survival of hatchery smolts transported to the study site, implanted, and released all on the same day was significantly lower. The results suggest that the <span class="hlt">early</span> marine survival of hatchery and wild smolts may be fundamentally similar, but that the cumulative stress of transportation and surgery may reduce post-surgery survival. Hatchery smolts moved at higher average swimming speeds than wild smolts, but the difference was not statistically significant. <span class="hlt">Early</span> marine survival within the study region appears to be relatively high (⩾55%), contradicting assumptions that the <span class="hlt">early</span> marine phase is the critical period for determining salmon recruitment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=340130&Lab=NERL&keyword=One+AND+case+AND+study+AND+approach&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=340130&Lab=NERL&keyword=One+AND+case+AND+study+AND+approach&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>Performance metrics for the assessment of satellite data <span class="hlt">products</span>: an <span class="hlt">ocean</span> color case study</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>Performance assessment of <span class="hlt">ocean</span> color satellite data has generally relied on statistical metrics chosen for their common usage and the rationale for selecting certain metrics is infrequently explained. Commonly reported statistics based on mean squared errors, such as the coeffic...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26PSL.441...38J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26PSL.441...38J"><span>A highly redox-heterogeneous <span class="hlt">ocean</span> in South China during the <span class="hlt">early</span> Cambrian (˜529-514 Ma): Implications for biota-environment co-evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Chengsheng; Li, Chao; Algeo, Thomas J.; Planavsky, Noah J.; Cui, Hao; Yang, Xinglian; Zhao, Yuanlong; Zhang, Xingliang; Xie, Shucheng</p> <p>2016-05-01</p> <p>The ;Cambrian Explosion; is known for rapid increases in the morphological disparity and taxonomic diversity of metazoans. It has been widely proposed that this biological event was a consequence of oxygenation of the global <span class="hlt">ocean</span>, but this hypothesis is still under debate. Here, we present high-resolution Fe-S-C-Al-trace element geochemical records from the Jinsha (outer shelf) and Weng'an (outer shelf) sections of the <span class="hlt">early</span> Cambrian Yangtze Platform, integrating these results with previously published data from six correlative sections representing a range of water depths (Xiaotan, Shatan, Dingtai, Yangjiaping, Songtao, and Longbizui). The integrated iron chemistry and redox-sensitive trace element data suggest that euxinic mid-depth waters dynamically coexisted with oxic surface waters and ferruginous deep waters during the earliest Cambrian, but that stepwise expansion of oxic waters commenced during Cambrian Stage 3 (∼ 521- 514 Ma). Combined with data from lower Cambrian sections elsewhere, including Oman, Iran and Canada, we infer that the global <span class="hlt">ocean</span> exhibited a high degree of redox heterogeneity during the <span class="hlt">early</span> Cambrian, consistent with low atmospheric oxygen levels (∼ 10- 40% of present atmospheric level, or PAL). A large spatial gradient in pyrite sulfur isotopic compositions (δ34Spy), which vary from a mean of - 12.0 ‰ in nearshore areas to + 22.5 ‰ in distal deepwater sections in lower Cambrian marine units of South China imply low concentrations and spatial heterogeneity of seawater sulfate, which is consistent with a limited <span class="hlt">oceanic</span> sulfate reservoir globally. By comparing our reconstructed redox chemistry with fossil records from the lower Cambrian of South China, we infer that a stepwise oxygenation of shelf and slope environments occurred concurrently with a gradual increase in ecosystem complexity. However, deep waters remained anoxic and ferruginous even as macrozooplankton and suspension-feeding mesozooplankton appeared during</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5014238','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5014238"><span>An assessment of phytoplankton primary <span class="hlt">productivity</span> in the Arctic <span class="hlt">Ocean</span> from satellite <span class="hlt">ocean</span> color/in situ chlorophyll‐a based models</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Matrai, Patricia A.; Friedrichs, Marjorie A. M.; Saba, Vincent S.; Antoine, David; Ardyna, Mathieu; Asanuma, Ichio; Babin, Marcel; Bélanger, Simon; Benoît‐Gagné, Maxime; Devred, Emmanuel; Fernández‐Méndez, Mar; Gentili, Bernard; Hirawake, Toru; Kang, Sung‐Ho; Kameda, Takahiko; Katlein, Christian; Lee, Sang H.; Lee, Zhongping; Mélin, Frédéric; Scardi, Michele; Smyth, Tim J.; Tang, Shilin; Turpie, Kevin R.; Waters, Kirk J.; Westberry, Toby K.</p> <p>2015-01-01</p> <p>Abstract We investigated 32 net primary <span class="hlt">productivity</span> (NPP) models by assessing skills to reproduce integrated NPP in the Arctic <span class="hlt">Ocean</span>. The models were provided with two sources each of surface chlorophyll‐a concentration (chlorophyll), photosynthetically available radiation (PAR), sea surface temperature (SST), and mixed‐layer depth (MLD). The models were most sensitive to uncertainties in surface chlorophyll, generally performing better with in situ chlorophyll than with satellite‐derived values. They were much less sensitive to uncertainties in PAR, SST, and MLD, possibly due to relatively narrow ranges of input data and/or relatively little difference between input data sources. Regardless of type or complexity, most of the models were not able to fully reproduce the variability of in situ NPP, whereas some of them exhibited almost no bias (i.e., reproduced the mean of in situ NPP). The models performed relatively well in low‐<span class="hlt">productivity</span> seasons as well as in sea ice‐covered/deep‐water regions. Depth‐resolved models correlated more with in situ NPP than other model types, but had a greater tendency to overestimate mean NPP whereas absorption‐based models exhibited the lowest bias associated with weaker correlation. The models performed better when a subsurface chlorophyll‐a maximum (SCM) was absent. As a group, the models overestimated mean NPP, however this was partly offset by some models underestimating NPP when a SCM was present. Our study suggests that NPP models need to be carefully tuned for the Arctic <span class="hlt">Ocean</span> because most of the models performing relatively well were those that used Arctic‐relevant parameters. PMID:27668139</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Litho.308..104D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Litho.308..104D"><span>Magmatic record of Late Devonian arc-continent collision in the northern Qiangtang, Tibet: Implications for the <span class="hlt">early</span> evolution of East Paleo-Tethys <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>Dan, Wei; Wang, Qiang; Zhang, Xiu-Zheng; Zhang, Chunfu; Tang, Gong-Jian; Wang, Jun; Ou, Quan; Hao, Lu-Lu; Qi, Yue</p> <p>2018-05-01</p> <p>Recognizing the <span class="hlt">early</span>-developed intra-<span class="hlt">oceanic</span> arc is important in revealing the <span class="hlt">early</span> evolution of East Paleo-Tethys <span class="hlt">Ocean</span>. In this study, new SIMS zircon U-Pb dating, O-Hf isotopes, and whole-rock geochemical data are reported for the newly-discovered Late Devonian-<span class="hlt">Early</span> Carboniferous arc in Qiangtang, central Tibet. New dating results reveal that the eastern Riwanchaka volcanic rocks were formed at 370-365 Ma and were intruded by the 360 Ma Gangma Co alkali feldspar granites. The volcanic rocks consist of basalts, andesites, dacites, and rhyodacites, whose geochemistry is similar to that typical of subduction-related volcanism. The basalts and andesites were generated by partial melting of the fluid and sediment-melt metasomatized mantle, respectively. The rhyodacites and dacites were probably derived from the fractional crystallization of andesites and from partial melting of the juvenile underplated mafic rocks, respectively. The Gangma Co alkali feldspar granites are A-type granites, and were possibly derived by partial melting of juvenile underplated mafic rocks in a post-collisional setting. The 370-365 Ma volcanic arc was characterized by basalts with <span class="hlt">oceanic</span> arc-like Ce/Yb ratios and by rhyodacites with mantle-like or slightly higher zircon δ18O values, and it was associated with the contemporary ophiolites. Thus, we propose that it is the earliest intra-<span class="hlt">oceanic</span> arc in the East Paleo-Tethys <span class="hlt">Ocean</span>, and was accreted to the Northern Qiangtang Terrane during 365-360 Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP51D2349A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP51D2349A"><span>A Holocene record of <span class="hlt">ocean</span> <span class="hlt">productivity</span> and upwelling from the northern California continental slope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Addison, J. A.; Barron, J. A.; Finney, B.; Kusler, J. E.; Bukry, D.; Heusser, L. E.; Alexander, C. R., Jr.</p> <p>2016-12-01</p> <p>The Holocene upwelling history of the northern California continental slope is examined using a 7-m-long marine sediment core (TN062-O550; 40.9°N, 124.6°W, 550 m water depth) collected offshore from Eureka, CA, that spans the last 7,400 calibrated years before present (cal yrs BP). A combination of biogenic sediment concentrations (opal, total organic C, and total N), stable isotopes (organic matter δ13C and bulk sedimentary δ15N), and key microfossil indicators of upwelling were used to test the hypothesis that marine <span class="hlt">productivity</span> in the California Current System (CCS) driven by coastal upwelling has co-varied with global Holocene millennial-scale warm intervals. Results show biogenic sediment accumulation in TN062-O550 varied considerably during the Holocene, despite being located within 50 km of the mouth of the Eel River, one of the largest sources of terrigenous sediment to the Northeast Pacific <span class="hlt">Ocean</span> margin. A key time interval beginning at 2900 cal yr BP indicates the onset of modern upwelling in the CCS, and that this period also corresponds to the most intense period of upwelling in the last 7,400 years. When these results are placed into a regional CCS context during the Holocene, it was found that the timing of upwelling intensification as recorded in TN062-O550 corresponds closely to that seen at nearby ODP Site 1019 as well as in the Santa Barbara Basin of southern California. Other CCS records with less high-quality age control show similar results, which suggest late Holocene upwelling intensification may be synchronous throughout the CCS. Based on the strong correspondence between the alkenone-derived sea surface temperature record at ODP Site 1019 and the onset of late Holocene upwelling in northern California, we tentatively suggest that regional CCS warming may be conducive to upwelling intensification in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME51B..04V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME51B..04V"><span>Phytoplankton Functional Diversity and New <span class="hlt">Production</span> during Spring and Summer Blooms in the Subarctic Atlantic <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>Van Oostende, N.; Fawcett, S. E.; Ji, Q.; Marconi, D.; Lueders-Dumont, J.; Sigman, D. M.; Ward, B. B.</p> <p>2016-02-01</p> <p>In the subarctic Atlantic <span class="hlt">Ocean</span>, strong seasonal cycles in heat flux drive water column stratification, which governs the supply of nutrients to the euphotic zone that fuels the biological pump. The export efficiency of this pump is largely determined by the degree of phytoplankton nitrate (NO3-) assimilation and phytoplankton community size structure. We investigated nitrogen assimilation and phytoplankton community diversity and size structure on spring and summer cruises to 50-60°N, by using a combination of stable isotope tracer incubations, flow cytometry, microscopy, size-fractionated algal pigments, and nitrogen stable isotope measurements. As expected in springtime, the phytoplankton community was dominated by large (>20 µm) cells while in late summer these constituted only a minor fraction of the assemblage. The weaker density stratification of the water column in the spring compared to the summer allowed for surface nutrient concentrations that were not limiting phytoplankton growth (e.g., [NO3-] >5 µM). Despite stronger water column stratification in the summer, partial consumption of subsurface NO3-, which had recently been supplied to surface waters, allowed for total chlorophyll and particulate nitrogen (PN) to attain similar levels during both seasons. High 15N/14N of NO3- and PN in surface waters is consistent with NO3- utilization. In springtime, however, the phytoplankton community consumed NO3- at PN-normalized rates up to fivefold higher than in summer, despite having comparable uptake rates for ammonium and inorganic carbon. This observation implies that the large phytoplankton species that are abundant in spring, mostly diatoms, contribute disproportionally more to new <span class="hlt">production</span> than summer phytoplankton communities that are devoid of these large species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70194250','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70194250"><span>A Holocene record of <span class="hlt">ocean</span> <span class="hlt">productivity</span> and upwelling from the northern California continental slope</span></a></p> <p><a target="_blank" href=""></a></p> <p>Addison, Jason A.; Barron, John A.; Finney, Bruce P.; Kusler, Jennifer E.; Bukry, David; Heusser, Linda E.; Alexander, Clark R.</p> <p>2018-01-01</p> <p>The Holocene upwelling history of the northern California continental slope is examined using the high-resolution record of TN062-O550 (40.9°N, 124.6°W, 550 m water depth). This 7-m-long marine sediment core spans the last ∼7500 years, and we use it to test the hypothesis that marine <span class="hlt">productivity</span> in the California Current System (CCS) driven by coastal upwelling has co-varied with Holocene millennial-scale warm intervals. A combination of biogenic sediment concentrations (opal, total organic C, and total N), stable isotopes (organic matter δ13C and bulk sedimentary δ15N), and key microfossil indicators of upwelling were used to test this hypothesis. The record of biogenic accumulation in TN062-O550 shows considerable Holocene variability despite being located within 50 km of the mouth of the Eel River, which is one of the largest sources of terrigenous sediment to the Northeast Pacific <span class="hlt">Ocean</span> margin. A key time interval beginning at ∼2900 calibrated years before present (cal yr BP) indicates the onset of modern upwelling in the CCS, and this period also corresponds to the most intense period of upwelling in the last 7500 years. When these results are placed into a regional CCS context during the Holocene, it was found that the timing of upwelling intensification at TN062-O550 corresponds closely to that seen at nearby ODP Site 1019, as well as in the Santa Barbara Basin of southern California. Other CCS records with less refined age control show similar results, which suggest late Holocene upwelling intensification may be synchronous throughout the CCS. Based on the strong correspondence between the alkenone sea surface temperature record at ODP Site 1019 and the onset of late Holocene upwelling in northern California, we suggest that CCS warming may be conducive to upwelling intensification, though future changes are unclear as the mechanisms forcing SST variability may differ.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GBioC..30..859P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GBioC..30..859P"><span>Net community <span class="hlt">production</span> at <span class="hlt">Ocean</span> Station Papa observed with nitrate and oxygen sensors on profiling floats</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plant, Joshua N.; Johnson, Kenneth S.; Sakamoto, Carole M.; Jannasch, Hans W.; Coletti, Luke J.; Riser, Stephen C.; Swift, Dana D.</p> <p>2016-06-01</p> <p>Six profiling floats equipped with nitrate and oxygen sensors were deployed at <span class="hlt">Ocean</span> Station P in the Gulf of Alaska. The resulting six calendar years and 10 float years of nitrate and oxygen data were used to determine an average annual cycle for net community <span class="hlt">production</span> (NCP) in the top 35 m of the water column. NCP became positive in February as soon as the mixing activity in the surface layer began to weaken, but nearly 3 months before the traditionally defined mixed layer began to shoal from its winter time maximum. NCP displayed two maxima, one toward the end of May and another in August with a summertime minimum in June corresponding to the historical peak in mesozooplankton biomass. The average annual NCP was determined to be 1.5 ± 0.6 mol C m-2 yr-1 using nitrate and 1.5 ± 0.7 mol C m-2 yr-1 using oxygen. The results from oxygen data proved to be quite sensitive to the gas exchange model used as well as the accuracy of the oxygen measurement. Gas exchange models optimized for carbon dioxide flux generally ignore transport due to gas exchange through the injection of bubbles, and these models yield NCP values that are two to three time higher than the nitrate-based estimates. If nitrate and oxygen NCP rates are assumed to be related by the Redfield model, we show that the oxygen gas exchange model can be optimized by tuning the exchange terms to reproduce the nitrate NCP annual cycle.</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 <span class="hlt">Products</span> at the Global 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) <span class="hlt">products</span>. Two different strategies can be implemented: direct validation of satellite OC <span class="hlt">products</span> 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 global bio-optical relationships. Divergences of the ratio between Kd values at 380 nm and those at 490 nm from global 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://adsabs.harvard.edu/abs/2017JGRC..122..745D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122..745D"><span>Community <span class="hlt">production</span> modulates coral reef pH and the sensitivity of ecosystem calcification to <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>DeCarlo, Thomas M.; Cohen, Anne L.; Wong, George T. F.; Shiah, Fuh-Kwo; Lentz, Steven J.; Davis, Kristen A.; Shamberger, Kathryn E. F.; Lohmann, Pat</p> <p>2017-01-01</p> <p>Coral reefs are built of calcium carbonate (CaCO3) produced biogenically by a diversity of calcifying plants, animals, and microbes. As the <span class="hlt">ocean</span> warms and acidifies, there is mounting concern that declining calcification rates could shift coral reef CaCO3 budgets from net accretion to net dissolution. We quantified net ecosystem calcification (NEC) and <span class="hlt">production</span> (NEP) on Dongsha Atoll, northern South China Sea, over a 2 week period that included a transient bleaching event. Peak daytime pH on the wide, shallow reef flat during the nonbleaching period was ˜8.5, significantly elevated above that of the surrounding open <span class="hlt">ocean</span> (˜8.0-8.1) as a consequence of daytime NEP (up to 112 mmol C m-2 h-1). Diurnal-averaged NEC was 390 ± 90 mmol CaCO3 m-2 d-1, higher than any other coral reef studied to date despite comparable calcifier cover (25%) and relatively high fleshy algal cover (19%). Coral bleaching linked to elevated temperatures significantly reduced daytime NEP by 29 mmol C m-2 h-1. pH on the reef flat declined by 0.2 units, causing a 40% reduction in NEC in the absence of pH changes in the surrounding open <span class="hlt">ocean</span>. Our findings highlight the interactive relationship between carbonate chemistry of coral reef ecosystems and ecosystem <span class="hlt">production</span> and calcification rates, which are in turn impacted by <span class="hlt">ocean</span> warming. As open-<span class="hlt">ocean</span> waters bathing coral reefs warm and acidify over the 21st century, the health and composition of reef benthic communities will play a major role in determining on-reef conditions that will in turn dictate the ecosystem response to climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PNAS..114.1806Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PNAS..114.1806Z"><span>Redox chemistry changes in the Panthalassic <span class="hlt">Ocean</span> linked to the end-Permian mass extinction and delayed <span class="hlt">Early</span> Triassic biotic recovery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Guijie; Zhang, Xiaolin; Hu, Dongping; Li, Dandan; Algeo, Thomas J.; Farquhar, James; Henderson, Charles M.; Qin, Liping; Shen, Megan; Shen, Danielle; Schoepfer, Shane D.; Chen, Kefan; Shen, Yanan</p> <p>2017-02-01</p> <p>The end-Permian mass extinction represents the most severe biotic crisis for the last 540 million years, and the marine ecosystem recovery from this extinction was protracted, spanning the entirety of the <span class="hlt">Early</span> Triassic and possibly longer. Numerous studies from the low-latitude Paleotethys and high-latitude Boreal <span class="hlt">oceans</span> have examined the possible link between <span class="hlt">ocean</span> chemistry changes and the end-Permian mass extinction. However, redox chemistry changes in the Panthalassic <span class="hlt">Ocean</span>, comprising ˜85-90% of the global <span class="hlt">ocean</span> area, remain under debate. Here, we report multiple S-isotopic data of pyrite from Upper Permian-Lower Triassic deep-sea sediments of the Panthalassic <span class="hlt">Ocean</span>, now present in outcrops of western Canada and Japan. We find a sulfur isotope signal of negative Δ33S with either positive δ34S or negative δ34S that implies mixing of sulfide sulfur with different δ34S before, during, and after the end-Permian mass extinction. The precise coincidence of the negative Δ33S anomaly with the extinction horizon in western Canada suggests that shoaling of H2S-rich waters may have driven the end-Permian mass extinction. Our data also imply episodic euxinia and oscillations between sulfidic and oxic conditions during the earliest Triassic, providing evidence of a causal link between incursion of sulfidic waters and the delayed recovery of the marine ecosystem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GPC...164....1J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GPC...164....1J"><span>On the relationship between the <span class="hlt">early</span> spring Indian <span class="hlt">Ocean</span>'s sea surface temperature (SST) and the Tibetan Plateau atmospheric heat source in summer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Chenxu; Zhang, Yuanzhi; Cheng, Qiuming; Li, Yu; Jiang, Tingchen; San Liang, X.</p> <p>2018-05-01</p> <p>In this study, we evaluated the effects of springtime Indian <span class="hlt">Ocean</span>'s sea surface temperature (SST) on the Tibetan Plateau's role as atmospheric heat source (AHS) in summer. The SST data of the National <span class="hlt">Oceanic</span> and Atmospheric Administration (NOAA), European Centre for Medium-Range Weather Forecasts (ECMWF) and the Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) and the reanalysis data of the National Center for Environmental Prediction (NCEP) and National Center for Atmospheric Research (NCAR) for 33 years (from 1979 to 2011) were used to analyze the relationship between the Indian <span class="hlt">Ocean</span> SST and the Tibetan Plateau's AHS in summer, using the approaches that include correlation analysis, and lead-lag analysis. Our results show that some certain strong <span class="hlt">oceanic</span> SSTs affect the summer plateau heat, specially finding that the <span class="hlt">early</span> spring SSTs of the Indian <span class="hlt">Ocean</span> significantly affect the plateau's ability to serve as a heat source in summer. Moreover, the anomalous atmospheric circulation and transport of water vapor are related to the Plateau heat variation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917579V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917579V"><span>ARMOR3D: A 3D multi-observations T,S,U,V <span class="hlt">product</span> of 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>Verbrugge, Nathalie; Mulet, Sandrine; Guinehut, Stéphanie; Buongiorno-Nardelli, Bruno</p> <p>2017-04-01</p> <p>To have a synoptic view of the 3D <span class="hlt">ocean</span> to pursue <span class="hlt">oceanic</span> studies, an observed gridded <span class="hlt">product</span> can be often useful instead of using raw observations which can be irregularly distributed in space and time as the in situ profiles for instance or which offer only a surface view of the <span class="hlt">ocean</span> as satellite data. The originality of the ARMOR3D observation based <span class="hlt">product</span> is to take advantage of the strengths of these 2 types of data by combining satellite SLA, SST, SSS datasets with in situ T, S vertical profiles in order to build a global 3D weekly temperature, salinity and geostrophic velocities fields at a spatial 1/4° resolution. The mesoscale content of the satellite data and the vertical sampling of the in situ profiles are complementary in this statistical approach. ARMOR3D is part of the CMEMS project through the GLO-OBS component. A full reprocessing from 1993 to 2016 and near-real-time fields from 1/1/2014 to present are available through the CMEMS web portal. The range of applications of this <span class="hlt">product</span> is wide: OSE studies have been already conducted to evaluate the ARGO network and in 2017, OSE and OSSE will be performed in the western Tropical Pacific as part of the TPOS2020 project (Tropical Pacific Observing System for 2020 Pacific). The <span class="hlt">product</span> is useful also to study mesoscale eddies characteristics as well as links with the biogeochemical processes. For example, in 2015, ARMOR3D fields have been used as inputs of a micronekton model within the framework of the ESA OSMOSIS Project. Furthermore, ARMOR3D also contributes to the annual CMEMS <span class="hlt">Ocean</span> State Report.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-10-14/pdf/2010-25850.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-10-14/pdf/2010-25850.pdf"><span>75 FR 63188 - Draft Guidance for Industry: <span class="hlt">Early</span> Clinical Trials With Live Biotherapeutic <span class="hlt">Products</span>: Chemistry...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-10-14</p> <p>...] Draft Guidance for Industry: <span class="hlt">Early</span> Clinical Trials With Live Biotherapeutic <span class="hlt">Products</span>: Chemistry...: Chemistry, Manufacturing, and Control Information'' dated September 2010. The draft guidance provides... <span class="hlt">Products</span>: Chemistry, Manufacturing, and Control Information'' dated September 2010. The draft guidance...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMGP13B..01C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMGP13B..01C"><span>Closure of the Mongol-Okhotsk <span class="hlt">Ocean</span> as Constrained by Late Permian to <span class="hlt">Early</span> Cretaceous Paleomagnetic Data from the Suture Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cogne, J.; Kravchinsky, V.; Gilder, S.; Hankard, F.</p> <p>2005-12-01</p> <p>The Paleozoic Mongol-Okhotsk <span class="hlt">Ocean</span> separated the Siberian craton to the north from a landmass composed of Amuria, Tarim, Qaidam, Tibet and the North and South China blocks to the south. Based on a comparison of paleomagnetic data from the NCB with the Eurasian apparent polar wander path, this <span class="hlt">ocean</span> closed by the beginning of the Cretaceous. We present here a review of recent paleomagnetic studies of Late Permian to <span class="hlt">Early</span> Cretaceous formations from the Transbaikal area of south Siberia, coming from localities situated on both sides of the Mongol-Okhotsk suture zone. The main conclusions that we draw from these studies are as follows. (1) A Late Permian ~4500 km latitude difference indeed existed between Amuria and the Siberia blocks at 110°E longitude. (2) In Middle-Late Jurassic times, a 1700 to 2700 km paleolatitudinal gap still existed between the two blocks. This contradicts geological interpretations of a Middle Jurassic closure of the <span class="hlt">ocean</span> at this longitude. (3) Consistency of <span class="hlt">Early</span> Cretaceous paleolatitudes from both sides of the suture demonstrates the closure of the <span class="hlt">ocean</span> at that time. Altogether, these suggest a quite fast closure between the Middle Jurassic and the <span class="hlt">Early</span> Cretaceous, at about 15±11 cm/yr. Finally, all pre-Late Cretaceous paleomagnetic poles appear to be distributed along small-circles centered on site localities. We think this is due to continued deformation acting in the Mongol-Okhotsk suture region related to suturing. Conversely, the post-<span class="hlt">Early</span> Cretaceous rotations may be related to Tertiary deformation under the effect of the India-Asia collision.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110011892','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110011892"><span>Observations of Recent Arctic Sea Ice Volume Loss and Its Impact on <span class="hlt">Ocean</span>-Atmosphere Energy Exchange and Ice <span class="hlt">Production</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kurtz, N. T.; Markus, T.; Farrell, S. L.; Worthen, D. L.; Boisvert, L. N.</p> <p>2011-01-01</p> <p>Using recently developed techniques we estimate snow and sea ice thickness distributions for the Arctic basin through the combination of freeboard data from the Ice, Cloud, and land Elevation Satellite (ICESat) and a snow depth model. These data are used with meteorological data and a thermodynamic sea ice model to calculate <span class="hlt">ocean</span>-atmosphere heat exchange and ice volume <span class="hlt">production</span> during the 2003-2008 fall and winter seasons. The calculated heat fluxes and ice growth rates are in agreement with previous observations over multiyear ice. In this study, we calculate heat fluxes and ice growth rates for the full distribution of ice thicknesses covering the Arctic basin and determine the impact of ice thickness change on the calculated values. Thinning of the sea ice is observed which greatly increases the 2005-2007 fall period <span class="hlt">ocean</span>-atmosphere heat fluxes compared to those observed in 2003. Although there was also a decline in sea ice thickness for the winter periods, the winter time heat flux was found to be less impacted by the observed changes in ice thickness. A large increase in the net Arctic <span class="hlt">ocean</span>-atmosphere heat output is also observed in the fall periods due to changes in the areal coverage of sea ice. The anomalously low sea ice coverage in 2007 led to a net <span class="hlt">ocean</span>-atmosphere heat output approximately 3 times greater than was observed in previous years and suggests that sea ice losses are now playing a role in increasing surface air temperatures in the Arctic.</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/2014AGUFM.A43F3331F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A43F3331F"><span>Climate Change Response of <span class="hlt">Ocean</span> Net Primary <span class="hlt">Production</span> (NPP) and Export <span class="hlt">Production</span> (EP) Regulated by Stratification Increases in The CMIP5 models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, W.; Randerson, J. T.; Moore, J. K.</p> <p>2014-12-01</p> <p><span class="hlt">Ocean</span> warming due to rising atmospheric CO2 has increasing impacts on <span class="hlt">ocean</span> ecosystems by modifying the ecophysiology and distribution of marine organisms, and by altering <span class="hlt">ocean</span> circulation and stratification. We explore <span class="hlt">ocean</span> NPP and EP changes at the global scale with simulations performed in the framework of the fifth Coupled Model Inter-comparison Project (CMIP5). Global NPP and EP are reduced considerably by the end of the century for the representative concentration pathway (RCP) 8.5 scenario, although models differ in their significantly in their direct temperature impacts on <span class="hlt">production</span> and remineralization. The Earth system models used here project similar NPP trends albeit the magnitudes vary substantially. In general, projected changes in the 2090s for NPP range between -2.3 to -16.2% while export <span class="hlt">production</span> reach -7 to -18% relative to 1990s. This is accompanied by increased stratification by 17-30%. Results indicate that globally reduced NPP is closely related to increased <span class="hlt">ocean</span> stratification (R2=0.78). This is especially the case for global export <span class="hlt">production</span>, that seems to be mostly controlled by the increased stratification (R2=0.95). We also identify phytoplankton community impacts on these patterns, that vary across the models. The negative response of NPP to climate change may be through bottom-up control, leading to a reduced capacity of <span class="hlt">oceans</span> to regulate climate through the biological carbon pump. There are large disagreements among the CMIP5 models in terms of simulated nutrient and oxygen concentrations for the 1990s, and their trends over time with climate change. In addition, potentially important marine biogeochemical feedbacks on the climate system were not well represented in the CMIP5 models, including important feedbacks with aerosol deposition and the marine iron cycle, and feedbacks involving the oxygen minimum zones and the marine nitrogen cycle. Thus, these substantial reductions in primary <span class="hlt">productivity</span> and export <span class="hlt">production</span> over</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14.3129H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14.3129H"><span>Implications of sea-ice biogeochemistry for <span class="hlt">oceanic</span> <span class="hlt">production</span> and emissions of dimethyl sulfide in the Arctic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayashida, Hakase; Steiner, Nadja; Monahan, Adam; Galindo, Virginie; Lizotte, Martine; Levasseur, Maurice</p> <p>2017-06-01</p> <p>Sea ice represents an additional <span class="hlt">oceanic</span> source of the climatically active gas dimethyl sulfide (DMS) for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of field measurements. In this study, we developed a coupled sea ice-<span class="hlt">ocean</span> ecosystem-sulfur cycle model to investigate the potential impact of bottom-ice DMS and its precursor dimethylsulfoniopropionate (DMSP) on the <span class="hlt">oceanic</span> <span class="hlt">production</span> and emissions of DMS in the Arctic. The results of the 1-D model simulation were compared with field data collected during May and June of 2010 in Resolute Passage. Our results reproduced the accumulation of DMS and DMSP in the bottom ice during the development of an ice algal bloom. The release of these sulfur species took place predominantly during the earlier phase of the melt period, resulting in an increase of DMS and DMSP in the underlying water column prior to the onset of an under-ice phytoplankton bloom. <span class="hlt">Production</span> and removal rates of processes considered in the model are analyzed to identify the processes dominating the budgets of DMS and DMSP both in the bottom ice and the underlying water column. When openings in the ice were taken into account, the simulated sea-air DMS flux during the melt period was dominated by episodic spikes of up to 8.1 µmol m-2 d-1. Further model simulations were conducted to assess the effects of the incorporation of sea-ice biogeochemistry on DMS <span class="hlt">production</span> and emissions, as well as the sensitivity of our results to changes of uncertain model parameters of the sea-ice sulfur cycle. The results highlight the importance of taking into account both the sea-ice sulfur cycle and ecosystem in the flux estimates of <span class="hlt">oceanic</span> DMS near the ice margins and identify key uncertainties in processes and rates that should be better constrained by new observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdSpR..61.2801S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdSpR..61.2801S"><span>A novel method for destriping of OCM-2 data and radiometric performance analysis for improved <span class="hlt">ocean</span> color data <span class="hlt">products</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Rakesh Kumar; Shanmugam, Palanisamy</p> <p>2018-06-01</p> <p>Despite the capability of <span class="hlt">Ocean</span> Color Monitor aboard Oceansat-2 satellite to provide frequent, high-spatial resolution, visible and near-infrared images for scientific research on coastal zones and climate data records over the global <span class="hlt">ocean</span>, the generation of science quality <span class="hlt">ocean</span> color <span class="hlt">products</span> from OCM-2 data has been hampered by serious vertical striping artifacts and poor calibration of detectors. These along-track stripes are the results of variations in the relative response of the individual detectors of the OCM-2 CCD array. The random unsystematic stripes and bandings on the scene edges affect both visual interpretation and radiometric integrity of remotely sensed data, contribute to confusion in the aerosol correction process, and multiply and propagate into higher level <span class="hlt">ocean</span> color <span class="hlt">products</span> generated by atmospheric correction and bio-optical algorithms. Despite a number of destriping algorithms reported in the literature, complete removal of stripes without residual effects and signal distortion in both low- and high-level <span class="hlt">products</span> is still challenging. Here, a new operational algorithm has been developed that employs an inverted gaussian function to estimate error fraction parameters, which are uncorrelated and vary in spatial, spectral and temporal domains. The algorithm is tested on a large number of OCM-2 scenes from Arabian Sea and Bay of Bengal waters contaminated with severe stripes. The destriping effectiveness of this approach is then evaluated by means of various qualitative and quantitative analyses, and by comparison with the results of the previously reported method. Clearly, the present method is more effective in terms of removing the stripe noise while preserving the radiometric integrity of the destriped OCM-2 data. Furthermore, a preliminary time-dependent calibration of the OCM-2 sensor is performed with several match-up in-situ data to evaluate its radiometric performance for <span class="hlt">ocean</span> color applications. OCM-2 derived water</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010014160','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010014160"><span>Modeling <span class="hlt">Oceanic</span> Primary <span class="hlt">Production</span>: Photoacclimation and Nutrient Effects on Light-saturated Photosynthesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Behrenfeld, Michael J.; Maranon, Emilio; Siegel, David A.; Hooker, Stanford B.</p> <p>2000-01-01</p> <p>In this report, we describe a new model (the 'PhotoAcc' model) for estimating changes in the light-saturated rate of chlorophyll-normalized phytoplankton carbon fixation (Pbmax). The model is based on measurements conducted during the Atlantic Meridional Transect studies and the Bermuda Time Series program. The PhotoAcc model explained 64% to 82% of the observed variability in Pbmax for our data set, whereas none of the previously published Pbmax models described over the past 44 years explained any of the variance. The significance of this result is that a primary limiting factor for extracting <span class="hlt">ocean</span> carbon fixation rates from satellite measurements of near surface chlorophyll has been errors in the estimate of Pbmax. Our new model should thus result in much improved calculations of <span class="hlt">oceanic</span> photosynthesis and thus the role of the <span class="hlt">oceans</span> in the global carbon cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CliPa...8..171F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CliPa...8..171F"><span>Bridging the Faraoni and Selli <span class="hlt">oceanic</span> anoxic events: late Hauterivian to <span class="hlt">early</span> Aptian dysaerobic to anaerobic phases in the Tethys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Föllmi, K. B.; Bôle, M.; Jammet, N.; Froidevaux, P.; Godet, A.; Bodin, S.; Adatte, T.; Matera, V.; Fleitmann, D.; Spangenberg, J. E.</p> <p>2012-01-01</p> <p>A detailed geochemical analysis was performed on the upper part of the Maiolica Formation in the Breggia (southern Switzerland) and Capriolo sections (northern Italy). The analysed sediments consist of well-bedded, partly siliceous, pelagic carbonate, which lodges numerous thin, dark and organic-rich layers. Stable-isotope, phosphorus, organic-carbon and a suite of redox-sensitive trace-element contents (RSTE: Mo, U, Co, V and As) were measured. The RSTE pattern and Corg:Ptot ratios indicate that most organic-rich layers were deposited under dysaerobic rather than anaerobic conditions and that latter conditions were likely restricted to short intervals in the latest Hauterivian, the <span class="hlt">early</span> Barremian and the pre-Selli <span class="hlt">early</span> Aptian. Correlations are both possible with organic-rich intervals in central Italy (the Gorgo a Cerbara section) and the Boreal Lower Saxony Basin, as well as with the facies and drowning pattern in the Helvetic segment of the northern Tethyan carbonate platform. Our data and correlations suggest that the latest Hauterivian witnessed the progressive installation of dysaerobic conditions in the Tethys, which went along with the onset in sediment condensation, phosphogenesis and platform drowning on the northern Tethyan margin, and which culminated in the Faraoni anoxic episode. This episode is followed by further episodes of dysaerobic conditions in the Tethys and the Lower Saxony Basin, which became more frequent and progressively stronger in the late <span class="hlt">early</span> Barremian. Platform drowning persisted and did not halt before the latest <span class="hlt">early</span> Barremian. The late Barremian witnessed diminishing frequencies and intensities in dysaerobic conditions, which went along with the progressive installation of the Urgonian carbonate platform. Near the Barremian-Aptian boundary, the increasing density in dysaerobic episodes in the Tethyan and Lower Saxony Basins is paralleled by a change towards heterozoan carbonate <span class="hlt">production</span> on the northern Tethyan shelf. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGeo...91...51V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGeo...91...51V"><span><span class="hlt">Production</span> of mildly alkaline basalts at complex <span class="hlt">ocean</span> ridge settings: Perspectives from basalts emitted during the 2010 eruption at the Eyjafjallajökull volcano, Iceland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viccaro, Marco; Nicotra, Eugenio; Urso, Salvatore</p> <p>2015-11-01</p> <p>The <span class="hlt">early</span> phase of the 2010 eruption at the Eyjafjallajökull volcano (Iceland) produced poorly evolved mildly alkaline basalts that have a signature more enriched with respect to the typically depleted basalts emitted at <span class="hlt">ocean</span> ridges. The whole rock geochemistry of these basaltic magmas offers a great opportunity to investigate the mantle source characteristics and reasons leading to this enriched fingerprint in proximity of the <span class="hlt">ocean</span> ridge system. Some basaltic <span class="hlt">products</span> of Katla volcano, ∼25 km east of Eyjafjallajökull, have been chosen from the literature, as they display a similar mildly alkaline signature and can be therefore useful to explore the same target. Major and trace element variations of the whole rock suggest a very limited evolutionary degree for the 2010 Eyjafjallajökull <span class="hlt">products</span> and the selected Katla magmas, highlighting the minor role played by differentiation processes such as fractional crystallization. Nevertheless, effects of the limited fractionation have been erased through re-equilibration of the major and trace element abundances at primary conditions. Concentrations of Th after re-equilibration have been assumed as indexes of the partial melting degree, given the high incompatibility of the element, and enrichment ratios calculated for each trace element. Especially for LILE (Rb, Ba, K, Sr), the pattern of resulting enrichment ratios well matches that obtained from fractional melting of peridotite bearing hydrous phases (amphibole/phlogopite). This put forward the idea that magmas have been generated through partial melting of enriched mantle domains where hydrous minerals have been stabilized as a consequence of metasomatic processes. Refertilization of the mantle has been attributed to intrusion of hydrous silicate melts and fractional crystallization of hydrous cumulates. These refertilizing melts, inherited from an ancient subducted <span class="hlt">oceanic</span> crust, intruded into a depleted <span class="hlt">oceanic</span> lithosphere that remained stored for a long time</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 global biological <span class="hlt">production</span>. 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 <span class="hlt">early</span> 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 global biological <span class="hlt">production</span>. 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 <span class="hlt">production</span>, by increasing surface nutrient drawdown in an <span class="hlt">ocean</span> general circulation model. We demonstrate that atmospheric CO(2) and global biological export <span class="hlt">production</span> 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 global export <span class="hlt">production</span> 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://www.ncbi.nlm.nih.gov/pubmed/16346297','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16346297"><span>Bacterioplankton in antarctic <span class="hlt">ocean</span> waters during late austral winter: abundance, frequency of dividing cells, and estimates of <span class="hlt">production</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hanson, R B; Shafer, D; Ryan, T; Pope, D H; Lowery, H K</p> <p>1983-05-01</p> <p>Bacterioplankton <span class="hlt">productivity</span> in Antarctic waters of the eastern South Pacific <span class="hlt">Ocean</span> and Drake Passage was estimated by direct counts and frequency of dividing cells (FDC). Total bacterioplankton assemblages were enumerated by epifluorescent microscopy. The experimentally determined relationship between in situ FDC and the potential instantaneous growth rate constant (mu) is best described by the regression equation ln mu = 0.081 FDC - 3.73. In the eastern South Pacific <span class="hlt">Ocean</span>, bacterioplankton abundance (2 x 10 to 3.5 x 10 cells per ml) and FDC (11%) were highest at the Polar Front (Antarctic Convergence). North of the Subantarctic Front, abundance and FDC were between 1 x 10 to 2 x 10 cells per ml and 3 to 5%, respectively, and were vertically homogeneous to a depth of 600 m. In Drake Passage, abundance (10 x 10 cells per ml) and FDC (16%) were highest in waters south of the Polar Front and near the sea ice. Subantarctic waters in Drake Passage contained 4 x 10 cells per ml with 4 to 5% FDC. Instantaneous growth rate constants ranged between 0.029 and 0.088 h. Using estimates of potential mu and measured standing stocks, we estimated <span class="hlt">productivity</span> to range from 0.62 mug of C per liter . day in the eastern South Pacific <span class="hlt">Ocean</span> to 17.1 mug of C per liter . day in the Drake Passage near the sea ice.</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 global <span class="hlt">productivity</span>: 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 global 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 global teleconnections that mediate the response of the global <span class="hlt">ocean</span> ecosystem. We confirm previous findings from idealized studies that increased iron fertilization decreases biological <span class="hlt">production</span> in the subtropical gyres and we quantify the counterintuitive and asymmetric response of global <span class="hlt">productivity</span> to increases and decreases in the aeolian iron supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70000341','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70000341"><span>Trace-element budgets in the Ohio/Sunbury shales of Kentucky: Constraints on <span class="hlt">ocean</span> circulation and primary <span class="hlt">productivity</span> in the Devonian-Mississippian Appalachian Basin</span></a></p> <p><a target="_blank" href=""></a></p> <p>Perkins, R.B.; Piper, D.Z.; Mason, C.E.</p> <p>2008-01-01</p> <p>The hydrography of the Appalachian Basin in late Devonian-<span class="hlt">early</span> Mississippian time is modeled based on the geochemistry of black shales and constrained by others' paleogeographic reconstructions. The model supports a robust exchange of basin bottom water with the open <span class="hlt">ocean</span>, with residence times of less than forty years during deposition of the Cleveland Shale Member of the Ohio Shale. This is counter to previous interpretations of these carbon-rich units having accumulated under a stratified and stagnant water column, i.e., with a strongly restricted bottom bottom-water circulation. A robust circulation of bottom waters is further consistent with the palaeoclimatology, whereby eastern trade-winds drove upwelling and arid conditions limited terrestrial inputs of siliciclastic sediment, fresh waters, and riverine nutrients. The model suggests that primary <span class="hlt">productivity</span> was high (~ 2??g C m- 2 d- 1), although no higher than in select locations in the <span class="hlt">ocean</span> today. The flux of organic carbon settling through the water column and its deposition on the sea floor was similar to fluxes found in modern marine environments. Calculations based on the average accumulation rate of the marine fraction of Ni suggest the flux of organic carbon settling out of the water column was approximately 9% of primary <span class="hlt">productivity</span>, versus an accumulation rate (burial) of organic carbon of 0.5% of primary <span class="hlt">productivity</span>. Trace-element ratios of V:Mo and Cr:Mo in the marine sediment fraction indicate that bottom waters shifted from predominantly anoxic (sulfate reducing) during deposition of the Huron Shale Member of the Ohio Shale to predominantly suboxic (nitrate reducing) during deposition of the Cleveland Shale Member and the Sunbury Shale, but with anoxic conditions occurring intermittently throughout this period. ?? 2008 Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1093367','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1093367"><span>Assessment of Energy <span class="hlt">Production</span> Potential from <span class="hlt">Ocean</span> Currents along the United States Coastline</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciT</a></p> <p>Haas, Kevin</p> <p></p> <p>Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the <span class="hlt">ocean</span>. <span class="hlt">Ocean</span> currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General <span class="hlt">ocean</span> circulations exist in the form of large rotating <span class="hlt">ocean</span> gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic <span class="hlt">Ocean</span> that flows along the east coastline of the United States, and therefore is of particular interest as a potentialmore » energy resource for the United States. This project created a national database of <span class="hlt">ocean</span> current energy resources to help advance awareness and market penetration in <span class="hlt">ocean</span> current energy resource assessment. The database, consisting of joint velocity magnitude and direction probability histograms, was created from data created by seven years of numerical model simulations. The accuracy of the database was evaluated by ORNL?s independent validation effort documented in a separate report. Estimates of the total theoretical power resource contained in the <span class="hlt">ocean</span> currents were calculated utilizing two separate approaches. Firstly, the theoretical energy balance in the Gulf Stream system was examined using the two-dimensional <span class="hlt">ocean</span> circulation equations based on the assumptions of the Stommel model for subtropical gyres with the quasi-geostrophic balance between pressure gradient, Coriolis force, wind stress and friction driving the circulation. Parameters including water depth, natural dissipation rate and wind stress are calibrated in the model so that the model can reproduce reasonable flow properties including volume flux and energy flux. To represent flow dissipation due to turbines additional turbine drag coefficient is formulated and included in the model. Secondly, to determine the reasonableness of the total power</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS13D1272H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS13D1272H"><span>Intra-seasonal Mixed Layer Process Variability from the ECCO <span class="hlt">Ocean</span> Data Assimilation <span class="hlt">Product</span>: Preliminary Analysis Relevant to DYNAMO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halkides, D. J.; Waliser, D. E.; Lee, T.; Lucas, L. E.; Murtugudde, R. G.</p> <p>2010-12-01</p> <p>The Madden Julian Oscillation (MJO), the dominant feature of 30-90 day variability in the tropical Indian (IO) and Pacific (PO) <span class="hlt">Oceans</span>, plays an important role in air-sea interactions and affects multi-scale phenomena ranging from hurricanes to ENSO. Understanding the MJO requires knowledge of <span class="hlt">ocean</span> mixed layer (ML) heat budgets. As part of a model-data intercomparison planned for 2011-13 to support the Dynamics of the MJO (DYNAMO) project (a US branch of the CINDY2011 international field program), we perform ML heat budget calculations using a heat-conserving assimilation <span class="hlt">product</span> from the Estimating the Circulation and Climate of the <span class="hlt">Ocean</span> (ECCO) project to study the onset and evolution of MJO scale anomalies in the tropics. For the IO, we focus on the western equatorial basin and the southwest IO thermocline ridge. Here, upwelling processes are very important, indicating a slab or 1-D <span class="hlt">ocean</span> model is insufficient for accurate MJO simulation. We also examine several locations across the equatorial PO. For example, in the eastern PO, we compare results from ECCO to prior studies with different findings: one based on incomplete mooring data indicating vertical processes dominate, another based on model output that indicates meridional advection dominates in the same area. In ECCO, subsurface process and horizontal advection terms are both important, but their relationships to the net tendency vary spatially. This work has implications for understanding MJO onset and development, associated air-sea interactions, ramifications for multi-scale cross-equatorial heat transport (especially in the IO), and, it is likely to be important in constructing a predictive index for MJO onset. We present budgets in terms of variability of the atmospheric and <span class="hlt">oceanic</span> circulations, as well as mixed layer and barrier layer depths, and we address DYNAMO’s third hypothesis: “The barrier-layer, wind and shear driven mixing, shallow thermocline, and mixing-layer entrainment all play</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010114461','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010114461"><span>Modeling UV-B Effects on Primary <span class="hlt">Production</span> Throughout the Southern <span class="hlt">Ocean</span> Using Multi-Sensor Satellite Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lubin, Dan</p> <p>2001-01-01</p> <p>This study has used a combination of <span class="hlt">ocean</span> color, backscattered ultraviolet, and passive microwave satellite data to investigate the impact of the springtime Antarctic ozone depletion on the base of the Antarctic marine food web - primary <span class="hlt">production</span> by phytoplankton. Spectral ultraviolet (UV) radiation fields derived from the satellite data are propagated into the water column where they force physiologically-based numerical models of phytoplankton growth. This large-scale study has been divided into two components: (1) the use of Total Ozone Mapping Spectrometer (TOMS) and Special Sensor Microwave Imager (SSM/I) data in conjunction with radiative transfer theory to derive the surface spectral UV irradiance throughout the Southern <span class="hlt">Ocean</span>; and (2) the merging of these UV irradiances with the climatology of chlorophyll derived from SeaWiFS data to specify the input data for the physiological models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.7293S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.7293S"><span>On the role of mesoscale eddies for the biological <span class="hlt">productivity</span> and biogeochemistry in the eastern tropical Pacific <span class="hlt">Ocean</span> off Peru</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stramma, L.; Bange, H. W.; Czeschel, R.; Lorenzo, A.; Frank, M.</p> <p>2013-11-01</p> <p>Mesoscale eddies seem to play an important role for both the hydrography and biogeochemistry of the eastern tropical Pacific <span class="hlt">Ocean</span> (ETSP) off Peru. However, detailed surveys of these eddies are not available, which has so far hampered an in depth understanding of their implications for nutrient distribution and biological <span class="hlt">productivity</span>. In this study, three eddies along a section at 16°45´ S have been surveyed intensively during R/V Meteor cruise M90 in November 2012. A coastal mode water eddy, an open <span class="hlt">ocean</span> mode water eddy and an open <span class="hlt">ocean</span> cyclonic eddy have been identified and sampled in order to determine both their hydrographic properties and their influence on the biogeochemical setting of the ETSP. In the thermocline the temperature of the coastal anticyclonic eddy was up to 2 °C warmer, 0.2 more saline and the swirl velocity was up to 35 cm s-1. The observed temperature and salinity anomalies, as well as swirl velocities of both types of eddies were about twice as large as had been described for the mean eddies in the ETSP. The observed heat and salt anomalies (AHA, ASA) of the anticyclonic eddy near the shelf-break of 17.7 × 1018 J and 36.6 × 1010 kg are more than twice as large as the mean AHA and ASA for the ETSP. We found that the eddies contributed to the <span class="hlt">productivity</span> by maintaining pronounced subsurface maxima of chlorophyll of up to 6 μg L-1. Based on a comparison of the coastal (young) mode water eddy and the open <span class="hlt">ocean</span> (old) mode water eddy we suggest that the ageing of eddies when they detach from the shelf-break and move westward to the open <span class="hlt">ocean</span> influences the eddies' properties: chlorophyll maxima are reduced to about half (2.5-3 μg L-1) and nutrients are subducted. However, different settings at the time of formation may also contribute to the observed differences between the young and old mode water eddies. The coastal mode water eddy was found to be a site of nitrogen (N) loss in the OMZ with a maximum ΔNO3- anomaly (i.e. N loss) of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC52C..07R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC52C..07R"><span>"Supergreen" Renewables: Integration of Mineral Weathering Into Renewable Energy <span class="hlt">Production</span> for Air CO2 Removal and Storage as <span class="hlt">Ocean</span> Alkalinity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rau, G. H.; Carroll, S.; Ren, Z. J.</p> <p>2015-12-01</p> <p>Excess planetary CO2 and accompanying <span class="hlt">ocean</span> acidification are naturally mitigated on geologic time scales via mineral weathering. Here, CO2 acidifies the hydrosphere, which then slowly reacts with silicate and carbonate minerals to produce dissolved bicarbonates that are ultimately delivered to the <span class="hlt">ocean</span>. This alkalinity not only provides long-term sequestration of the excess atmospheric carbon, but it also chemically counters the effects of <span class="hlt">ocean</span> acidification by stabilizing or raising pH and carbonate saturation state, thus helping rebalance <span class="hlt">ocean</span> chemistry and preserving marine ecosystems. Recent research has demonstrated ways of greatly accelerating this process by its integration into energy systems. Specifically, it has been shown (1) that some 80% of the CO2 in a waste gas stream can be spontaneously converted to stable, seawater mineral bicarbonate in the presence of a common carbonate mineral - limestone. This can allow removal of CO2 from biomass combustion and bio-energy <span class="hlt">production</span> while generating beneficial <span class="hlt">ocean</span> alkalinity, providing a potentially cheaper and more environmentally friendly negative-CO2-emissions alternative to BECCS. It has also been demonstrated that strong acids anodically produced in a standard saline water electrolysis cell in the formation of H2 can be reacted with carbonate or silicate minerals to generate strong base solutions. These solutions are highly absorptive of air CO2, converting it to mineral bicarbonate in solution. When such electrochemical cells are powered by non-fossil energy (e.g. electricity from wind, solar, tidal, biomass, geothermal, etc. energy sources), the system generates H2 that is strongly CO2-emissions-negative, while producing beneficial marine alkalinity (2-4). The preceding systems therefore point the way toward renewable energy <span class="hlt">production</span> that, when tightly coupled to geochemical mitigation of CO2 and formation of natural <span class="hlt">ocean</span> "antacids", forms a high capacity, negative-CO2-emissions, "supergreen</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910878A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910878A"><span>In situ observations of <span class="hlt">ocean</span> <span class="hlt">productivity</span> using the SeaCycler mooring in the central Labrador Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Atamanchuk, Dariia; Koelling, Jannes; Devred, Emmanuel; Siddall, Greg; Send, Uwe; Wallace, Douglas</p> <p>2017-04-01</p> <p>The Central Labrador Sea is a major deep-convection region in the NW Atlantic which is the most intense sink for anthropogenic carbon in the global <span class="hlt">ocean</span> (de Vries et al, 2013). CO2 enters the <span class="hlt">ocean</span> by air-sea exchange and is transported into the <span class="hlt">ocean</span>'s interior mainly though the biological pump (Longhurst et al., 1989). Despite its important role for CO2 uptake and high natural variability, the Labrador Sea is undersampled due to rough conditions and an overall lack of volunteer observing ship (VOS) transits. The SeaCycler moored profiler is currently providing year-round data from the central Labrador Sea and resolves daily changes of inorganic carbon and related properties from the upper 150m of the water column. SeaCycler's sensor float is equipped with 13 physical, chemical and biooptical sensors which measure temperature, salinity, dissolved gases, nutrients and optical properties of seawater. A combination of Pro-CV (Pro-Oceanus Inc, Canada) and CO2 optode (Aanderaa, Norway) sensors in profiling mode provides a detailed description of Dissolved Inorganic Carbon (DIC) dynamics in the upper 150m over the <span class="hlt">productive</span> season. This allows, for the first time, high-resolution carbon-based estimates of <span class="hlt">ocean</span> <span class="hlt">productivity</span> from throughout the euphotic zone over an annual cycle which can be compared to estimates derived from simultaneous oxygen and nitrate (Deep SUNA, Satlantic LP, Canada) profiles. These in situ carbon, nitrogen and oxygen-based estimates of using in-situ data are further compared with remotely-sensed estimates from MODIS satellite data. The SeaCycler data allow estimation of the annual cycle of the air-sea CO2 flux and carbon export. Concurrently recorded in-situ bio-optical data allow direct comparison of optical measurements of biomass change and reveal key patterns in the seasonal succession of phytoplankton groups responsible for carbon drawdown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS41B..02I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS41B..02I"><span>Multi-model Ensemble of <span class="hlt">Ocean</span> Data Assimilation <span class="hlt">Products</span> in The Northwestern Pacific and Their Quality Assessment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Isoguchi, O.; Matsui, K.; Kamachi, M.; Usui, N.; Miyazawa, Y.; Ishikawa, Y.; Hirose, N.</p> <p>2017-12-01</p> <p>Several operational <span class="hlt">ocean</span> assimilation models are currently available for the Northwestern Pacific and surrounding marginal seas. One of the main targets is predicting the Kuroshio/Kuroshio Extension, which have an impact not only on social activities, such as fishery and ship routing, but also on local weather. There is a demand to assess their quality comprehensively and make the best out the available <span class="hlt">products</span>. In the present study, several <span class="hlt">ocean</span> data assimilation <span class="hlt">products</span> and their multi-ensemble <span class="hlt">product</span> were assessed by comparing with satellite-derived sea surface temperature (SST), sea surface height (SSH), and in-situ hydrographic sections. The Kuroshio axes were also computed from the surface currents of these <span class="hlt">products</span> and were compared with the Kuroshio Axis data produced analyzing satellite-SST, SSH, and in-situ observations by Marine Information Research Center (MIRC). The multi-model ensemble <span class="hlt">products</span> generally showed the best accuracy in terms of the comparisons with the satellite-derived SST and SSH. On the other hand, the ensemble <span class="hlt">products</span> didn't result in the best one in the comparison with the hydrographic sections. It is thus suggested that the multi-model ensemble works efficiently for the horizontally 2D parameters for which each assimilation <span class="hlt">product</span> tends to have random errors while it does not work well for the vertical 2D comparisons for which it tends to have bias errors with respect to in-situ data. In the assessment with the Kuroshio Axis Data, some <span class="hlt">products</span> showed more energetic behavior than the Kuroshio Axis data, resulting in the large path errors which are defined as a ratio between an area surrounded by the reference and model-derived ones and a path length. It is however not determined which are real, because in-situ observations are still lacking to resolve energetic Kuroshio behavior even though the Kuroshio is one of the strongest current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036615','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036615"><span>Regional estimates of reef carbonate dynamics and <span class="hlt">productivity</span> Using Landsat 7 ETM+, and potential impacts from <span class="hlt">ocean</span> acidification</span></a></p> <p><a target="_blank" href=""></a></p> <p>Moses, C.S.; Andrefouet, S.; Kranenburg, C.; Muller-Karger, F. E.</p> <p>2009-01-01</p> <p>Using imagery at 30 m spatial resolution from the most recent Landsat satellite, the Landsat 7 Enhanced Thematic Mapper Plus (ETM+), we scale up reef metabolic <span class="hlt">productivity</span> and calcification from local habitat-scale (10 -1 to 100 km2) measurements to regional scales (103 to 104 km2). Distribution and spatial extent of the North Florida Reef Tract (NFRT) habitats come from supervised classification of the Landsat imagery within independent Landsat-derived Millennium Coral Reef Map geomorphologic classes. This system minimizes the depth range and variability of benthic habitat characteristics found in the area of supervised classification and limits misclassification. Classification of Landsat imagery into 5 biotopes (sand, dense live cover, sparse live cover, seagrass, and sparse seagrass) by geomorphologic class is >73% accurate at regional scales. Based on recently