Horizontal variability of the marine boundary layer structure upwind of San Nicolas Island during FIRE, 1987

NASA Technical Reports Server (NTRS)

Jensen, Douglas R.

1990-01-01

During the months of June and July 1987, the Marine Stratocumulus Intensive Field Observation Experiment of First ISCCP Regional Experiment (FIRE) was conducted in the Southern California offshore area in the vicinity of San Nicolas Island (SNI). The Naval Ocean Systems Center (NOSC) airborne platform was utilized during FIRE to investigate the upwind low level horizontal variability of the marine boundary layer structure to determine the representativeness of SNI-based measurements to upwind open ocean conditions. The NOSC airborne meteorological platform made three flights during FIRE, two during clear sky conditions (19 and 23 July), and one during two stratus conditions (15 July). The boundary layer structure variations associated with the stratus clouds of 15 July 1987 are discussed. Profiles of air temperature (AT) and relative humidity (RH) taken 'at' and 'upwind' of SNI do show differences between the so-called open ocean conditions and those taken near the island. However, the observed difference cannot be uniquely identified to island effects, especially since the upwind fluctuations of AT and RH bound the SNI measurements. Total optical depths measures at SNI do not appear to be greatly affected by any surface based aerosol effects created by the island and could therefore realistically represent open ocean conditions. However, if one were to use the SNI aerosol measurements to predict ship to ship EO propagation conditions, significant errors could be introduced due to the increased number of surface aerosols observed near SNI which may not be, and were not, characteristic of open ocean conditions. Sea surface temperature measurements taken at the island will not, in general, represent those upwind open ocean conditions. Also, since CTT's varied appreciably along the upwind radials, measurements of CTT over the island may not be representative of actual open ocean CTT's.

Formation and maintenance of nocturnal low-level stratus over the southern West African monsoon region during AMMA 2006

NASA Astrophysics Data System (ADS)

Schuster, Robert; Fink, Andreas; Knippertz, Peter

2013-04-01

The southern parts of West Africa, from the coast to about 9°N, are frequently covered by an extensive deck of shallow, low (200 - 400 m above ground) stratus or stratocumulus clouds during the summer monsoon season as shown by recent studies based on ground observations and new satellite products. These clouds usually form at night in association with a nocturnal low-level jet (NLLJ) and can persist into the early afternoon hours until they are dissipated or replaced by fair-weather cumuli. Recent work suggests that the stratus deck and its effect on the surface radiation balance are unsatisfactorily represented in standard satellite retrievals and simulations by state-of-the-art climate models. Here we use high-resolution regional simulations with the Weather Research and Forecast (WRF) model and observations from the African Monsoon Multidisciplinary Analysis (AMMA) 2006 campaign to investigate (a) the spatiotemporal distribution, (b) the influence on the radiation balance, and (c) the detailed formation and maintenance mechanisms of the stratiform clouds. The model configuration used for this study has been determined following an extensive sensitivity study. The main conclusions are: (a) At least some configurations of WRF satisfactorily reproduce the diurnal cycle of the low cloud evolution. (b) The simulated stratus deck forms after sunset along the coast, spreads inland in the course of the night, and dissipates in the early afternoon. (c) The average surface net radiation balance in stratus-dominated regions is 35 W m-2 lower than in those with less clouds. (d) The cloud formation is related to a subtle balance between "stratogenic" upward (downward) fluxes of latent (sensible) heat caused by shear-driven turbulence below the NLLJ, cold advection from the ocean, forced lifting at the windward side of orography, and radiative cooling on one hand, and "stratolytic" dry advection and latent heating on the other hand. Future work should focus on the influence of the stratus on energy and moisture budgets and on the West African monsoon system as a whole.

Comparison of Sea-Air CO2 Flux Estimates Using Satellite-Based Versus Mooring Wind Speed Data

NASA Astrophysics Data System (ADS)

Sutton, A. J.; Sabine, C. L.; Feely, R. A.; Wanninkhof, R. H.

2016-12-01

The global ocean is a major sink of anthropogenic CO2, absorbing approximately 27% of CO2 emissions since the beginning of the industrial revolution. Any variation or change in the ocean CO2 sink has implications for future climate. Observations of sea-air CO2 flux have relied primarily on ship-based underway measurements of partial pressure of CO2 (pCO2) combined with satellite, model, or multi-platform wind products. Direct measurements of ΔpCO2 (seawater - air pCO2) and wind speed from moored platforms now allow for high-resolution CO2 flux time series. Here we present a comparison of CO2 flux calculated from moored ΔpCO2 measured on four moorings in different biomes of the Pacific Ocean in combination with: 1) Cross-Calibrated Multi-Platform (CCMP) winds or 2) wind speed measurements made on ocean reference moorings excluded from the CCMP dataset. Preliminary results show using CCMP winds overestimates CO2 flux on average by 5% at the Kuroshio Extension Observatory, Ocean Station Papa, WHOI Hawaii Ocean Timeseries Station, and Stratus. In general, CO2 flux seasonality follows patterns of seawater pCO2 and SST with periods of CO2 outgassing during summer and CO2 uptake during winter at these locations. Any offsets or seasonal biases in CCMP winds could impact global ocean sink estimates using this data product. Here we present patterns and trends between the two CO2 flux estimates and discuss the potential implications for tracking variability and change in global ocean CO2 uptake.

Daytime sea fog retrieval based on GOCI data: a case study over the Yellow Sea.

PubMed

Yuan, Yibo; Qiu, Zhongfeng; Sun, Deyong; Wang, Shengqiang; Yue, Xiaoyuan

2016-01-25

In this paper, a new daytime sea fog detection algorithm has been developed by using Geostationary Ocean Color Imager (GOCI) data. Based on spectral analysis, differences in spectral characteristics were found over different underlying surfaces, which include land, sea, middle/high level clouds, stratus clouds and sea fog. Statistical analysis showed that the Rrc (412 nm) (Rayleigh Corrected Reflectance) of sea fog pixels is approximately 0.1-0.6. Similarly, various band combinations could be used to separate different surfaces. Therefore, three indices (SLDI, MCDI and BSI) were set to discern land/sea, middle/high level clouds and fog/stratus clouds, respectively, from which it was generally easy to extract fog pixels. The remote sensing algorithm was verified using coastal sounding data, which demonstrated that the algorithm had the ability to detect sea fog. The algorithm was then used to monitor an 8-hour sea fog event and the results were consistent with observational data from buoys data deployed near the Sheyang coast (121°E, 34°N). The goal of this study was to establish a daytime sea fog detection algorithm based on GOCI data, which shows promise for detecting fog separately from stratus.

Aircraft Measurements of Total Mercury and Monomethyl Mercury in Summertime Marine Stratus Cloudwater from Coastal California, USA.

PubMed

Weiss-Penzias, Peter; Sorooshian, Armin; Coale, Kenneth; Heim, Wesley; Crosbie, Ewan; Dadashazar, Hossein; MacDonald, Alexander B; Wang, Zhen; Jonsson, Haflidi

2018-03-06

Water samples from marine stratus clouds were collected during 16 aircraft flights above the Pacific Ocean near the Central California coast during the summer of 2016. These samples were analyzed for total mercury (THg), monomethyl mercury (MMHg), and 32 other chemical species in addition to aerosol physical parameters. The mean concentrations of THg and MMHg in the cloudwater samples were 9.2 ± 6.0 ng L -1 (2.3-33.8 ng L -1 ) ( N = 97) and 0.87 ± 0.66 ng L -1 (0.17-2.9 ng L -1 ) ( N = 22), respectively. This corresponds to 9.5% (3-21%) MMHg as a fraction of THg. Low and high nonsea salt calcium ion (nss-Ca 2+ ) concentrations in cloudwater were used to classify flights as "marine" and "continental", respectively. Mean [MMHg] marine was significantly higher ( p < 0.05) than [MMHg] continental consistent with an ocean source of dimethyl Hg (DMHg) to the atmosphere. Mean THg in cloudwater was not significantly different between the two categories, indicating multiple emissions sources. Mean [THg] continental was correlated with pH, CO, NO 3 - , NH 4 + , and other trace metals, whereas [THg] marine was correlated with MMHg and Na + . THg concentrations were negatively correlated with altitude, consistent with ocean and land emissions, coupled with removal at the cloud-top due to drizzle formation.

Statistical Analyses of Satellite Cloud Object Data From CERES. Part 4; Boundary-layer Cloud Objects During 1998 El Nino

NASA Technical Reports Server (NTRS)

Xu, Kuan-Man; Wong, Takmeng; Wielicki, Bruce A.; Parker, Lindsay

2006-01-01

Three boundary-layer cloud object types, stratus, stratocumulus and cumulus, that occurred over the Pacific Ocean during January-August 1998, are identified from the CERES (Clouds and the Earth s Radiant Energy System) single scanner footprint (SSF) data from the TRMM (Tropical Rainfall Measuring Mission) satellite. This study emphasizes the differences and similarities in the characteristics of each cloud-object type between the tropical and subtropical regions and among different size categories and among small geographic areas. Both the frequencies of occurrence and statistical distributions of cloud physical properties are analyzed. In terms of frequencies of occurrence, stratocumulus clouds dominate the entire boundary layer cloud population in all regions and among all size categories. Stratus clouds are more prevalent in the subtropics and near the coastal regions, while cumulus clouds are relatively prevalent over open ocean and the equatorial regions, particularly, within the small size categories. The largest size category of stratus cloud objects occurs more frequently in the subtropics than in the tropics and has much larger average size than its cumulus and stratocumulus counterparts. Each of the three cloud object types exhibits small differences in statistical distributions of cloud optical depth, liquid water path, TOA albedo and perhaps cloud-top height, but large differences in those of cloud-top temperature and OLR between the tropics and subtropics. Differences in the sea surface temperature (SST) distributions between the tropics and subtropics influence some of the cloud macrophysical properties, but cloud microphysical properties and albedo for each cloud object type are likely determined by (local) boundary-layer dynamics and structures. Systematic variations of cloud optical depth, TOA albedo, cloud-top height, OLR and SST with cloud object sizes are pronounced for the stratocumulus and stratus types, which are related to systematic variations of the strength of inversion with cloud object sizes, produced by large-scale subsidence. The differences in cloud macrophysical properties over small regions are significantly larger than those of cloud microphysical properties and TOA albedo, suggesting a greater control of (local) large-scale dynamics and other factors on cloud object properties. When the three cloud object types are combined, the relative population among the three types is the most important factor for determining the cloud object properties in a Pacific transect where the transition of boundary-layer cloud types takes place.

Representing the Seasonal Variation of Marine Stratus and Stratocumulus near the Western Coast of Continents

NASA Astrophysics Data System (ADS)

He, Y.; Dickinson, R.

2005-12-01

The seasonal variation of marine stratus and stratocumulus (MSC) plays a significant role in ocean- atmosphere-land interaction during the seasonal transition of basic climate in the Eastern Pacific. A key factor in parameterization of MSC cloud cover is atmospheric stability. In this study, we examine the importance of lower troposphere stability for Marine Stratus and Stratocumulus (MSC) cloud cover variations over subtropical oceans on monthly and seasonal timescales. Our approach is to consider a two-layer conceptual model with moist denser boundary layer air topped by dry lighter free air beneath a trade wind inversion at around 700 mb.The vertical integrated dry static energy is of central importance in the lower troposphere. The variation of dry static energy transport and latent heat release leads to the variation of cloud top radiative forcing, which is a function of low cloud cover. A diagnostic cloud cover scheme derived from the model is a nonlinear function of lower troposphere stability and large-scale subsidence. Use ERA-40 and ISCCP-FD data as input, the scheme reproduces well the seasonal variation of low cloud cover in four MSC regions near the western coast of continents. NCAR CAM linear empirical cloud cover scheme could explain 16% of the observed ISCCP monthly covariance in the southeast subtropical Pacific during 1990 to 2000 period; while the new cloud cover scheme could explain 50% of the total covariance. When implementing new scheme into NCAR CAM3.1, it is found that the seasonal phase of MSC is better simulated near the Peruvian region, but the seasonal amplitudes of MSC cloud cover in four MSC regions using both schemes have systematic problems. Possible causes for model cloud biases are investigated through numerical experiments. The importance of MSC cloud cover in the eastern Pacific on local mean climate is also discussed.

Reproducibility of Spectral Domain Optical Coherence Tomography Retinal Thickness Measurements and Conversion to Equivalent Time Domain Metrics in Diabetic Macular Edema

PubMed Central

Bressler, Susan B.; Edwards, Allison R.; Chalam, Kakarla V.; Bressler, Neil M.; Glassman, Adam R.; Jaffe, Glenn J.; Melia, Michele; Saggau, David D.; Plous, Oren Z.

2014-01-01

Importance Advances in retinal imaging have led to the development of optical coherence tomography (OCT) instruments that incorporate spectral domain (SD) technology. Understanding measurement variability and relationships between retinal thickness measurements obtained on different machines is critical for proper use in clinical trials and clinical settings. Objectives Evaluate reproducibility of retinal thickness measurements from OCT images obtained by time domain (TD) (Zeiss Stratus) and SD (Zeiss Cirrus and Heidelberg Spectralis) instruments and formulate equations to convert retinal thickness measurements from SD-OCT to equivalent values on TD-OCT. Design Cross-sectional observational study. Each study eye underwent two replicate Stratus scans followed by two replicate Cirrus or Spectralis (real time image registration utilized) scans centered on the fovea. Setting Private and institutional practices Participants Diabetic persons with at least one eye with central-involved diabetic macular edema (DME), defined as Stratus central subfield thickness (CST)≥250μm. An additional normative cohort, individuals with diabetes but without DME, was enrolled. Main Outcome Measure(s) OCT CST and macular volume Results The Bland-Altman coefficient of repeatability for relative change in CST (the degree of change that could be expected from measurement variability) was lower on Spectralis compared with Stratus and Cirrus scans (7%, 12–15%, and 14%, respectively). For each cohort, the initial Stratus CST was within 10% of the replicate Stratus measurement 92% of the time; the conversion equations predicted a Stratus CST within 10% of the observed thickness 86% and 89% of the time for Stratus/Cirrus and Stratus/Spectralis groups, respectively. The Bland-Altman limits of agreement for relative change in CST between machines (the degree of change that could be expected from measurement variability, combined within and between instrument variability) were 21% for Cirrus and 19% for Spectralis, comparing predicted versus actual Stratus measurement. Conclusions and Relevance Reproducibility appears better on Spectralis than Cirrus and Stratus. Conversion equations to transform Cirrus or Spectralis measurements to Stratus-equivalent values, within 10% of the observed Stratus thickness values, appear feasible. CST changes beyond 10% when using the same machine or 20% when switching machines, after conversion to Stratus equivalents, are likely due to a change in retinal thickness and not measurement error. PMID:25058482

Physical Processes within the Nocturnal Stratus-Topped Boundary Layer. Revision

DTIC Science & Technology

1992-01-01

applied to PBL parameter- ization by Chatfield and Brost (1987), Randall (1987), Wang and Albrecht (1990), and Randall et al. (1992). One of the closures...mecha- nism. Acknowledgments We thank Joost Businger, Don Lenschow, figa Paluch, Steve Siems, Steve Stage, Roland Stull, and George Young for helpful...Oncley, 1990: Flux measurement with conditional sampling. At- mos. Oceanic Tech., 7, 349-352. Chatfield, R. B., and R. A. Brost , 1987: A two-stream model

Low Cloud Type over the Ocean from Surface Observations. Part III: Relationship to Vertical Motion and the Regional Surface Synoptic Environment.

NASA Astrophysics Data System (ADS)

Norris, Joel R.; Klein, Stephen A.

2000-01-01

Composite large-scale dynamical fields contemporaneous with low cloud types observed at midlatitude Ocean Weather Station (OWS) C and eastern subtropical OWS N are used to establish representative relationships between low cloud type and the synoptic environment. The composites are constructed by averaging meteorological observations of surface wind and sea level pressure from volunteering observing ships (VOS) and analyses of sea level pressure, 1000-mb wind, and 700-mb pressure vertical velocity from the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) reanalysis project on those dates and times of day when a particular low cloud type was reported at the OWS.VOS and NCEP results for OWS C during summer show that bad-weather stratus occurs with strong convergence and ascent slightly ahead of a surface low center and trough. Cumulus-under-stratocumulus and moderate and large cumulus occur with divergence and subsidence in the cold sector of an extratropical cyclone. Both sky-obscuring fog and no-low-cloud typically occur with southwesterly flow from regions of warmer sea surface temperature and differ primarily according to slight surface convergence and stronger warm advection in the case of sky-obscuring fog or surface divergence and weaker warm advection in the case of no-low-cloud. Fair-weather stratus and ordinary stratocumulus are associated with a mixture of meteorological conditions, but differ with respect to vertical motion in the environment. Fair-weather stratus occurs most commonly in the presence of slight convergence and ascent, while stratocumulus often occurs in the presence of divergence and subsidence.Surface divergence and estimated subsidence at the top of the boundary layer are calculated from VOS observations. At both OWS C and OWS N during summer and winter these values are large for ordinary stratocumulus, less for cumulus-under-stratocumulus, and least (and sometimes slightly negative) for moderate and large cumulus. Subsidence interpolated from NCEP analyses to the top of the boundary layer does not exhibit such variation, but the discrepancy may be due to deficiencies in the analysis procedure or the boundary layer parameterization of the NCEP model. The VOS results suggest that decreasing divergence and subsidence in addition to increasing sea surface temperature may promote the transition from stratocumulus to trade cumulus observed over low-latitude oceans.

Integrating Cloud Processes in the Community Atmosphere Model, Version 5.

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

Park, S.; Bretherton, Christopher S.; Rasch, Philip J.

2014-09-15

This paper provides a description on the parameterizations of global cloud system in CAM5. Compared to the previous versions, CAM5 cloud parameterization has the following unique characteristics: (1) a transparent cloud macrophysical structure that has horizontally non-overlapped deep cumulus, shallow cumulus and stratus in each grid layer, each of which has own cloud fraction, mass and number concentrations of cloud liquid droplets and ice crystals, (2) stratus-radiation-turbulence interaction that allows CAM5 to simulate marine stratocumulus solely from grid-mean RH without relying on the stability-based empirical empty stratus, (3) prognostic treatment of the number concentrations of stratus liquid droplets and icemore » crystals with activated aerosols and detrained in-cumulus condensates as the main sources and evaporation-sedimentation-precipitation of stratus condensate as the main sinks, and (4) radiatively active cumulus. By imposing consistency between diagnosed stratus fraction and prognosed stratus condensate, CAM5 is free from empty or highly-dense stratus at the end of stratus macrophysics. CAM5 also prognoses mass and number concentrations of various aerosol species. Thanks to the aerosol activation and the parameterizations of the radiation and stratiform precipitation production as a function of the droplet size, CAM5 simulates various aerosol indirect effects associated with stratus as well as direct effects, i.e., aerosol controls both the radiative and hydrological budgets. Detailed analysis of various simulations revealed that CAM5 is much better than CAM3/4 in the global performance as well as the physical formulation. However, several problems were also identifed, which can be attributed to inappropriate regional tuning, inconsistency between various physics parameterizations, and incomplete model physics. Continuous efforts are going on to further improve CAM5.« less

Climatology and dynamics of nocturnal low-level stratus over the southern West African monsoon region

NASA Astrophysics Data System (ADS)

Fink, A. H.; Schuster, R.; Knippertz, P.; van der Linden, R.

2013-12-01

The southern parts of West Africa, from the coast to about 10°N, are frequently covered by an extensive deck of shallow, low (200 - 400 m above ground) stratus or stratocumulus clouds during the summer monsoon season. These clouds usually form at night in association with a nocturnal low-level jet (NLLJ) and can persist into the early afternoon hours until they are dissipated or replaced by fair-weather cumuli. Recent work suggests that the stratus deck and its effect on the surface radiation balance are unsatisfactorily represented in standard satellite retrievals and simulations by state-of-the-art climate models. We will present the first ever climatology of the diurnal cycle of the low cloud deck based on surface observations and satellite products. In addition, we use high-resolution regional simulations with the Weather Research and Forecast (WRF) model and observations from the African Monsoon Multidisciplinary Analysis (AMMA) 2006 campaign to investigate (a) the spatiotemporal distribution, (b) the influence on the radiation balance, and (c) the detailed formation and maintenance mechanisms of the stratiform clouds as simulated by the model. The model configuration used for this study has been determined following an extensive sensitivity study, which has shown that at least some configurations of WRF satisfactorily reproduce the diurnal cycle of the low cloud evolution. The main conclusions are: (a) The observed stratus deck forms after sunset along the coast, spreads inland in the course of the night, reaches maximum poleward extent at about 10°N around 09-10 local time and dissipates in the early afternoon. (b) The average surface net radiation balance in stratus-dominated regions is 35 W m-2 lower than in those with less clouds. (c) The cloud formation is related to a subtle balance between 'stratogenic' upward (downward) fluxes of latent (sensible) heat caused by shear-driven turbulence below the NLLJ, cold advection from the ocean, forced lifting at the windward side of orography, and radiative cooling on one hand, and 'stratolytic' dry advection and latent heating on the other hand. Future work will focus on the influence of the stratus on the energy and moisture budget and on the West African monsoon system as a whole. Schematic illustration of the cloud formation process for (a) conditions close to the coast and (b) farther inland. Abbreviations are ADV: advection, E: latent heat flux, H: sensible heat flux, EV: evaporation, and NLLJ: nighttime low-level jet. Typical values for the contribution from each process are given. The effect of lifting was estimated by the difference in height and the assumption of a vertical temperature gradient of 0.65K/100 m (Fig. 12 in Schuster et al. 2013, J. Atmos. Sci, 70 (8), 2337-2355.

Improved Point Analysis Model (IPAM) (Users Guide)

DTIC Science & Technology

1991-02-01

Descriptions 7 Stratus fractus of bad weather* or Cumulus fractus of bad weather, or both ( pannus ), usually below Altostratus or Nimbostratus. 8...Cumulonimbus without anvil or fibrous upper part, Cumulus, Stratocumulus, Stratus or pannus . / Stratocumulus, Stratus, Cumulus and Cumulonimbus invisible owing

A Heuristic Parameterization for the Integrated Vertical Overlap of Cumulus and Stratus

NASA Astrophysics Data System (ADS)

Park, Sungsu

2017-10-01

The author developed a heuristic parameterization to handle the contrasting vertical overlap structures of cumulus and stratus in an integrated way. The parameterization assumes that cumulus is maximum-randomly overlapped with adjacent cumulus; stratus is maximum-randomly overlapped with adjacent stratus; and radiation and precipitation areas at each model interface are grouped into four categories, that is, convective, stratiform, mixed, and clear areas. For simplicity, thermodynamic scalars within individual portions of cloud, radiation, and precipitation areas are assumed to be internally homogeneous. The parameterization was implemented into the Seoul National University Atmosphere Model version 0 (SAM0) in an offline mode and tested over the globe. The offline control simulation reasonably reproduces the online surface precipitation flux and longwave cloud radiative forcing (LWCF). Although the cumulus fraction is much smaller than the stratus fraction, cumulus dominantly contributes to precipitation production in the tropics. For radiation, however, stratus is dominant. Compared with the maximum overlap, the random overlap of stratus produces stronger LWCF and, surprisingly, more precipitation flux due to less evaporation of convective precipitation. Compared with the maximum overlap, the random overlap of cumulus simulates stronger LWCF and weaker precipitation flux. Compared with the control simulation with separate cumulus and stratus, the simulation with a single-merged cloud substantially enhances the LWCF in the tropical deep convection and midlatitude storm track regions. The process-splitting treatment of convective and stratiform precipitation with an independent precipitation approximation (IPA) simulates weaker surface precipitation flux than the control simulation in the tropical region.

78 FR 52975 - Amended Certification Regarding Eligibility To Apply for Worker Adjustment Assistance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-27

... Servicing, Inc., Power Reo Management Services, Inc., and Stratus Asset Management Coppell, Texas; Homeward... Servicing, Inc., Power Reo Management Services, Inc., and Stratus Asset Management Addison, Texas; Homeward... Servicing, Inc., Power Reo Management Services, Inc., and Stratus Asset Management Jacksonville, Florida In...

Relativistic radiative transfer in a moving stratus irradiated by a luminous flat source

NASA Astrophysics Data System (ADS)

Fukue, Jun

2015-06-01

Relativistic radiative transfer in a geometrically thin stratus (sheet-like gaseous cloud with finite optical depth), which is moving at a relativistic speed around a luminous flat source, such as accretion disks, and is irradiated by the source, is examined under the special relativistic treatment. Incident radiation is aberrated and Doppler-shifted when it is received by the stratus, and emitted radiation is also aberrated and Doppler-shifted when it leaves the stratus. Considering these relativistic effects, we analytically obtain the emergent intensity as well as other radiative quantities in the purely scattering case for both infinite and finite strati. We mainly consider the frequency-integrated case, but also briefly show the frequency-dependent one. We also solve the relativistic radiative transfer equation numerically, and compare the results with the analytical solutions. In the infinite stratus, the mean intensity in the comoving and inertial frames decreases and becomes constant, as the stratus speed increases. The flux in the comoving frame decreases exponentially with the optical depth. The emergent intensity decreases as the speed increases, since the incident photons are redshifted at the bottom-side of the stratus. In the finite stratus, the mean intensity in the comoving and inertial frames quickly increases in the top-side region due to the aberrated photons. The flux in the comoving frame is positive in the range of 0 < β ≤ 0.4, while it becomes negative for β ≳ 0.5. The behavior of the emergent intensity is similar to that of the infinite case, although there is an irradiation effect caused by the aberrated photons.

On the Global Character of Overlap Between Low and High Clouds

NASA Technical Reports Server (NTRS)

Yuan, Tianle; Oreopoulos, Lazaros

2013-01-01

The global character of overlap between low and high clouds is examined using active satellite sensors. Low-cloud fraction has a strong land-ocean contrast with oceanic values double those over land. Major low-cloud regimes include not only the eastern ocean boundary stratocumulus and shallow cumulus but also those associated with cold air outbreaks downwind of wintertime continents and land stratus over particular geographic areas. Globally, about 30% of low clouds are overlapped by high clouds. The overlap rate exhibits strong spatial variability ranging from higher than 90% in the tropics to less than 5% in subsidence areas and is anticorrelated with subsidence rate and low-cloud fraction. The zonal mean of vertical separation between cloud layers is never smaller than 5 km and its zonal variation closely follows that of tropopause height, implying a tight connection with tropopause dynamics. Possible impacts of cloud overlap on low clouds are discussed.

Eddington limit for a gaseous stratus with finite optical depth

NASA Astrophysics Data System (ADS)

Fukue, Jun

2015-06-01

The Eddington luminosity of a spherical source is usually defined for a uniformly extending normal plasma. We usually suppose that the gas can accrete to the central object at the sub-Eddington luminosity, while it would be blown off from the central luminous source in the super-Eddington case. We reconsider this central dogma of the Eddington limit under the radiative transfer effect for the purely scattering case, using analytical and numerical methods. For the translucent isolated gas cloud (stratus) with finite optical depth, the concept of the Eddington luminosity is drastically changed. In an heuristic way, we find that the critical condition is approximately expressed as Γ = (1 + μ* + τc)/2, where Γ (=L/LE) is the central luminosity L normalized by the Eddington luminosity LE, τc is the optical depth of the stratus, and μ* (=√{1-R_*^2/R^2}) is the direction cosine of the central object, R* being the radius of the central object, and R the distance from the central object. When the optical depth of the stratus is around unity, the classical Eddington limit roughly holds for the stratus; Γ ˜ 1. However, when the optical depth is greater than unity, the critical condition becomes roughly Γ ˜ τc/2, and the stratus would infall on to the central source even at the highly super-Eddington luminosity. When the optical depth is less than unity, on the other hand, the critical condition reduces to Γ ≳ (1 + μ*)/2, and the stratus could be blown off in some limited ranges, depending on μ*. This new concept of the Eddington limit for the isolated stratus could drastically change the accretion and outflow physics of highly inhomegeneous plasmas, with relevance for astrophysical jets and winds and supermassive black hole formation.

An Economical Analytical Equation for the Integrated Vertical Overlap of Cumulus and Stratus

NASA Astrophysics Data System (ADS)

Park, Sungsu

2018-03-01

By extending the previously proposed heuristic parameterization, the author derived an analytical equation computing the overlap areas between the precipitation (or radiation) areas and the cloud areas in a cloud system consisting of cumulus and stratus. The new analytical equation is accurate and much more efficient than the previous heuristic equation, which suffers from the truncation error in association with the digitalization of the overlap areas. Global test simulations with the new analytical formula in an offline mode showed that the maximum cumulus overlap simulates more surface precipitation flux than the random cumulus overlap. On the other hand, the maximum stratus overlap simulates less surface precipitation flux than random stratus overlap, which is due to the increase in the evaporation rate of convective precipitation from the random to maximum stratus overlap. The independent precipitation approximation (IPA) marginally decreases the surface precipitation flux, implying that IPA works well with other parameterizations. In contrast to the net production rate of precipitation and surface precipitation flux that increase when the cumulus and stratus are maximally and randomly overlapped, respectively, the global mean net radiative cooling and longwave cloud radiative forcing (LWCF) increase when the cumulus and stratus are randomly overlapped. On the global average, the vertical cloud overlap exerts larger impacts on the precipitation flux than on the radiation flux. The radiation scheme taking the subgrid variability of water vapor between the cloud and clear portions into account substantially increases the global mean LWCF in tropical deep convection and midlatitude storm track regions.

CGILS: Results from the First Phase of an International Project to Understand the Physical Mechanisms of Low Cloud Feedbacks in Single Column Models

NASA Technical Reports Server (NTRS)

Zhang, Minghua; Bretherton, Christopher S.; Blossey, Peter N.; Austin, Phillip H.; Bacmeister, Julio T.; Bony, Sandrine; Brient, Florent; Cheedela, Suvarchal K.; Cheng, Anning; DelGenio, Anthony;

The Impact of Sea Surface Temperature Front on Stratus-Sea Fog over the Yellow and East China Seas

NASA Astrophysics Data System (ADS)

Zhang, S.; Li, M.; Liu, F.

2013-12-01

A stratus-sea fog event occurred on 3 June 2011 over the Yellow and East China Seas (as shown in figure) is investigated observationally and numerically. Emphasis is put on the influences of the sea surface temperature front (SSTF) and of the synoptic circulations on the transition of stratus to sea fog. The southerly winds from a synoptic high pressure transport water vapor from the East China Sea to the Yellow Sea, while the subsidence induced by the high contributes to the formation of the temperature inversion on the top of the stratus or stratocumulus that appears mainly over the warm flank of a sea surface temperature front in the East China Sea. Forced by the SSTF, there is a secondary cell within the atmospheric boundary layer (ABL), with a sinking branch on the cold flank and a rising one on the warm flank of the SSTF. This sinking branch, in phase with the synoptic subsidence, forces the stratus or stratocumulus to lower in the elevation getting close to the sea surface as these clouds move northward driven by the southerly winds. The cloud droplets can either reach to the sea surface directly or evaporate into water vapor that may condense again when coming close to the cold sea surface to form fog. In this later case, the stratus and fog may separate. The cooling effect of cold sea surface counteracts the adiabatic heating induced by the subsidence and thus helps the transition of stratus to sea fog in the southern Yellow Sea. By smoothing the SSTF in the numerical experiment, the secondary cell weakens and the sea fog patches shrink obviously over the cold flank of the SSTF though the synoptic subsidence and moist advection still exist. A conceptual model is suggested for the transition of stratus to sea fog in the Yellow and East China Seas, which is helpful for the forecast of sea fog over these areas. The satellite visible image of the stratus-fog event. The fog appears in the Yellow Sea and the stratocumulus in the East China Sea.

Homogenizing Surface and Satellite Observations of Cloud. Aspects of Bias in Surface Data.

DTIC Science & Technology

1987-11-10

both ( pannus ), usually below fractus of bad weather, or both ( pannus ), usu- Altostratus or Nimbostratus ally below Altostratus or Nimbostratus 8 Cumulus...Stratocumulus, Stratus of an anvil; either accompanied or not by Cu- or pannus mulonimbus without anvil or fibrous upper part, by Cumulus, Stratocumulus...Stratus or pannus CL clouds invisible owing to darkness, fog, / Stratocumulus, Stratus, Cumulus and Cu- blowing dust or sand, or other similar mulonimbus

Equilibrium configuration of a stratus floating above accretion disks: Full-disk calculation

NASA Astrophysics Data System (ADS)

Itanishi, Yusuke; Fukue, Jun

2017-06-01

We examine floating strati above a luminous accretion disk, supported by the radiative force from the entire disk, and calculate the equilibrium locus, which depends on the disk luminosity and the optical depth of the stratus. Due to the radiative transfer effect (albedo effect), the floating height of the stratus with a finite optical depth generally becomes high, compared with the particle case. In contrast to the case of the near-disk approximation, moreover, the floating height becomes yet higher in the present full-disk calculation, since the intense radiation from the inner disk is taken into account. As a result, when the disk luminosity normalized by the Eddington luminosity is ˜0.3 and the stratus optical depth is around unity, the stable configuration disappears at around r ˜ 50 rg, rg being the Schwarzschild radius, and the stratus would be blown off as a cloudy wind consisting of many strati with appropriate conditions. This luminosity is sufficiently smaller than the Eddington one, and the present results suggest that the radiation-driven cloudy wind can be easily blown off from the sub-Eddington disk, and this can explain various outflows observed in ultra-fast outflow objects as well as in broad-absorption-line quasars.

Roles of drizzle in a one-dimensional third-order turbulence closure model of the nocturnal stratus-topped marine boundary layer

NASA Technical Reports Server (NTRS)

Wang, Shouping; Wang, Qing

1994-01-01

This study focuses on the effects of drizzle in a one-dimensional third-order turbulence closure model of the nocturnal stratus-topped marine boundary layer. When the simulated drizzle rate is relatively small (maximum approximately equal to 0.6 mm/day), steady-state solutions are obtained. The boundary layer stabilizes essentially because drizzle causes evaporative cooling of the subcloud layer. This stabilization considerably reduces the buoyancy flux and turbulence kinetic energy below the stratus cloud. Thus, drizzle tends to decouple the cloud from the subcloud layer in the model, as suggested by many observational studies. In addition, the evaporation of drizzle in the subcloud layer creates small scattered clouds, which are likely to represent cumulus clouds, below the solid stratus cloud in the model. The sensitivity experiments show that these scattered clouds help maintain a coupled boundary layer. When the drizzle rate is relatively large (maximum approximately equal to 0.9 mm/day), the response of the model becomes transient with bursts in turbulent fluxes. This phenomenon is related to the formation of the scattered cloud layer below the solid stratus cloud. It appears that the model is inadequate to represent the heat and moisture transport by strong updrafts covering a small fractional area in cumulus convection.

Evolution of the atmospheric boundary layer in southern West Africa - an overview from the DACCIWA field campaign

NASA Astrophysics Data System (ADS)

Kalthoff, Norbert; Lohou, Fabienne; Brooks, Barbara; Jegede, Gbenga; Adler, Bianca; Ajao, Adewale; Ayoola, Muritala; Babić, Karmen; Bessardon, Geoffrey; Delon, Claire; Dione, Cheikh; Handwerker, Jan; Jambert, Corinne; Kohler, Martin; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier; Smith, Victoria; Sunmonu, Lukman; Wieser, Andreas

2017-04-01

In southern West Africa, extended low-level stratus clouds form very frequently during night-time and persist long into the following day influencing the diurnal cycle of the atmospheric boundary layer (ABL). During the course of the day, a transition from nocturnal low-level stratus to stratocumulus, cumulus, and sometimes congestus and possibly cumulonimbus clouds is observed. In June and July 2016, a ground-based field campaign took place in southern West Africa within the framework of the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project with the aim to identify the meteorological controls on the stratus and the evolution of the ABL. During the measurement period, extensive remote sensing and in-situ measurements were performed at three supersites in Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). We give an overview of the atmospheric conditions during the whole measurement period focusing on the vertical and temporal distribution of the stratus and relevant related atmospheric features.

Increased-resolution OCT thickness mapping of the human macula: a statistically based registration.

PubMed

Bernardes, Rui; Santos, Torcato; Cunha-Vaz, José

2008-05-01

To describe the development of a technique that enhances spatial resolution of retinal thickness maps of the Stratus OCT (Carl Zeiss Meditec, Inc., Dublin, CA). A retinal thickness atlas (RT-atlas) template was calculated, and a macular coordinate system was established, to pursue this objective. The RT-atlas was developed from principal component analysis of retinal thickness analyzer (RTA) maps acquired from healthy volunteers. The Stratus OCT radial thickness measurements were registered on the RT-atlas, from which an improved macular thickness map was calculated. Thereafter, Stratus OCT circular scans were registered on the previously calculated map to enhance spatial resolution. The developed technique was applied to Stratus OCT thickness data from healthy volunteers and from patients with diabetic retinopathy (DR) or age-related macular degeneration (AMD). Results showed that for normal, or close to normal, macular thickness maps from healthy volunteers and patients with DR, this technique can be an important aid in determining retinal thickness. Efforts are under way to improve the registration of retinal thickness data in patients with AMD. The developed technique enhances the evaluation of data acquired by the Stratus OCT, helping the detection of early retinal thickness abnormalities. Moreover, a normative database of retinal thickness measurements gained from this technique, as referenced to the macular coordinate system, can be created without errors induced by missed fixation and eye tilt.

Retinal thickness on Stratus optical coherence tomography in people with diabetes and minimal or no diabetic retinopathy.

PubMed

Bressler, Neil M; Edwards, Allison R; Antoszyk, Andrew N; Beck, Roy W; Browning, David J; Ciardella, Antonio P; Danis, Ronald P; Elman, Michael J; Friedman, Scott M; Glassman, Adam R; Gross, Jeffrey G; Li, Helen K; Murtha, Timothy J; Stone, Thomas W; Sun, Jennifer K

2008-05-01

To evaluate optical coherence tomography (OCT) thickness of the macula in people with diabetes but minimal or no retinopathy and to compare these findings with published normative data in the literature from subjects reported to have no retinal disease. Cross-sectional study. In a multicenter community- and university-based practices setting, 97 subjects with diabetes with no or minimal diabetic retinopathy and no central retinal thickening on clinical examination and a center point thickness of 225 microm or less on OCT (Stratus OCT; Carl Zeiss Meditec, Dublin, California, USA) were recruited. Electronic Early Treatment of Diabetic Retinopathy Study best-corrected visual acuity, seven-field stereoscopic color fundus photographs, and Stratus OCT fast macular scan were noted. Main outcome measures were central subfield (CSF) thickness measured on Stratus OCT. On average, CSF thickness was 201 +/- 22 microm. CSF thickness was significantly greater in retinas from men than retinas from women (mean +/- standard deviation, 209 +/- 18 microm vs 194 +/- 23 microm; P < .001). After adjusting for gender, no additional factors were found to be associated significantly with CSF thickness (P > .10). CSF thicknesses on Stratus OCT in people with diabetes and minimal or no retinopathy are similar to thicknesses reported from a normative database of people without diabetes. CSF thickness is greater in men than in women, consistent with many, but not all, previous reports. Studies involving comparisons of retinal thickness with expected norms should consider different mean values for women and men.

Optical coherence tomography-based decision making in exudative age-related macular degeneration: comparison of time- vs spectral-domain devices.

PubMed

Cukras, C; Wang, Y D; Meyerle, C B; Forooghian, F; Chew, E Y; Wong, W T

2010-05-01

To determine whether optical coherence tomography (OCT) device-type influences clinical grading of OCT imaging in the context of exudative age-related macular degeneration (AMD). Ninety-six paired OCT scans from 49 patients with active exudative AMD were obtained on both the time-domain Stratus OCT system and the spectral-domain Cirrus OCT system at the same visit. Three independent graders judged each scan for the presence of intraretinal fluid (IRF) or subretinal fluid (SRF). The degree of grader consensus was evaluated and the ability of the systems to detect the presence of disease activity was analysed. Cirrus OCT generated a higher degree of inter-grader consensus than Stratus OCT with higher intraclass correlation coefficients for all parameters analysed. A pair-wise comparison of Cirrus OCT with Stratus OCT systems revealed that Cirrus-based gradings more frequently reported the presence of SRF and IRF and detected overall neovascular activity at a higher rate (P<0.05) compared with Stratus-based gradings. The choice of time-domain (Stratus) vs spectra-domain (Cirrus) OCT systems has a measurable impact on clinical decision making in exudative AMD. Spectral-domain OCT systems may be able to generate more consensus in clinical interpretation and, in particular cases, detect disease activity not detected by time-domain systems. Clinical trials using OCT-based clinical evaluations of exudative AMD may need to account for these inter-system differences in planning and analysis.

76 FR 70520 - Rovac Corp., RS Group of Companies, Inc., Rymer Foods, Inc. Stratus Services Group, Inc., Sun Cal...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

...., Rymer Foods, Inc. Stratus Services Group, Inc., Sun Cal Energy, Inc., Sun Motor International, Inc... current and accurate information concerning the securities of Sun Cal Energy, Inc. because it has not... Sun Motor International, Inc. because it has not filed any periodic reports since the period ended...

Spatial and temporal patterns of cloud cover and fog inundation in coastal California: Ecological implications

USGS Publications Warehouse

Rastogi, Bharat; Williams, A. Park; Fischer, Douglas T.; Iacobellis, Sam F.; McEachern, A. Kathryn; Carvalho, Leila; Jones, Charles Leslie; Baguskas, Sara A.; Still, Christopher J.

2016-01-01

The presence of low-lying stratocumulus clouds and fog has been known to modify biophysical and ecological properties in coastal California where forests are frequently shaded by low-lying clouds or immersed in fog during otherwise warm and dry summer months. Summer fog and stratus can ameliorate summer drought stress and enhance soil water budgets, and often have different spatial and temporal patterns. Here we use remote sensing datasets to characterize the spatial and temporal patterns of cloud cover over California’s northern Channel Islands. We found marine stratus to be persistent from May through September across the years 2001-2012. Stratus clouds were both most frequent and had the greatest spatial extent in July. Clouds typically formed in the evening, and dissipated by the following early afternoon. We present a novel method to downscale satellite imagery using atmospheric observations and discriminate patterns of fog from those of stratus and help explain patterns of fog deposition previously studied on the islands. The outcomes of this study contribute significantly to our ability to quantify the occurrence of coastal fog at biologically meaningful spatial and temporal scales that can improve our understanding of cloud-ecosystem interactions, species distributions and coastal ecohydrology.

Simulation of the modern arctic climate by the NCAR CCM1

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

Bromwich, D.H.; Tzeng, R.Y.; Parish, T.R.

The NCAR CCM1's simulation of the modern arctic climate is evaluated by comparing a five-year seasonal cycle simulation with the ECMWF global analyses. The sea level pressure (SLP), storm tracks, vertical cross section of height, 500-hPa height, total energy budget, and moisture budget are analyzed to investigate the biases in the simulated arctic climate. The results show that the model simulates anomalously low SLP, too much activity, and anomalously strong baroclinicity to the west of Greenland and vice versa to the east of Greenland. This bias is mainly attributed to the model's topographic representation of Greenland. First, the broadened Greenlandmore » topography in the model distorts the path of cyclone waves over the North Atlantic Ocean. Second, the model oversimulates the ridge over Greenland, which intensifies its blocking effect and steers the cyclone waves clockwise around it and hence produces an artificial [open quotes]circum-Greenland[close quotes] trough. These biases are significantly alleviated when the horizontal resolution increases to T42. Over the Arctic basin, the modal simulates large amounts of low-level (stratus) clouds in winter and almost no stratus in summer, which is opposite to the observations. This bias is mainly due to the location of the simulated SLP features and the negative anomaly of storm activity, which prevent the transport of moisture into this region during summer but favor this transport in winter. 26 refs., 14 figs., 42 tabs.« less

Cloud Processed CCN Suppress Stratus Cloud Drizzle

NASA Astrophysics Data System (ADS)

Hudson, J. G.; Noble, S. R., Jr.

2017-12-01

Conversion of sulfur dioxide to sulfate within cloud droplets increases the sizes and decreases the critical supersaturation, Sc, of cloud residual particles that had nucleated the droplets. Since other particles remain at the same sizes and Sc a size and Sc gap is often observed. Hudson et al. (2015) showed higher cloud droplet concentrations (Nc) in stratus clouds associated with bimodal high-resolution CCN spectra from the DRI CCN spectrometer compared to clouds associated with unimodal CCN spectra (not cloud processed). Here we show that CCN spectral shape (bimodal or unimodal) affects all aspects of stratus cloud microphysics and drizzle. Panel A shows mean differential cloud droplet spectra that have been divided according to traditional slopes, k, of the 131 measured CCN spectra in the Marine Stratus/Stratocumulus Experiment (MASE) off the Central California coast. K is generally high within the supersaturation, S, range of stratus clouds (< 0.5%). Because cloud processing decreases Sc of some particles, it reduces k. Panel A shows higher concentrations of small cloud droplets apparently grown on lower k CCN than clouds grown on higher k CCN. At small droplet sizes the concentrations follow the k order of the legend, black, red, green, blue (lowest to highest k). Above 13 µm diameter the lines cross and the hierarchy reverses so that blue (highest k) has the highest concentrations followed by green, red and black (lowest k). This reversed hierarchy continues into the drizzle size range (panel B) where the most drizzle drops, Nd, are in clouds grown on the least cloud-processed CCN (blue), while clouds grown on the most processed CCN (black) have the lowest Nd. Suppression of stratus cloud drizzle by cloud processing is an additional 2nd indirect aerosol effect (IAE) that along with the enhancement of 1st IAE by higher Nc (panel A) are above and beyond original IAE. However, further similar analysis is needed in other cloud regimes to determine if MASE was typical. Hudson, J.G., S. Noble, and S. Tabor, 2015: J. Geophys. Res., Atmos., 120, 3436-3452, doi:10.1002/2014JD022669.

Stratus Cloud Radiative Effects from Cloud Processed Bimodal CCN Distributions

NASA Astrophysics Data System (ADS)

Noble, S. R., Jr.; Hudson, J. G.

2016-12-01

Inability to understand cloud processes is a large component of climate uncertainty. Increases in cloud condensation nuclei (CCN) concentrations are known to increase cloud droplet number concentrations (Nc). This aerosol-cloud interaction (ACI) produces greater Nc at smaller sizes, which brightens clouds. A lesser understood ACI is cloud processing of CCN. This improves CCN that then more easily activate at lower cloud supersaturations (S). Bimodal CCN distributions thus ensue from these evaporated cloud droplets. Hudson et al. (2015) related CCN bimodality to Nc. In stratus clouds, bimodal CCN created greater Nc whereas in cumulus less Nc. Thus, CCN distribution shape influences cloud properties; microphysics and radiative properties. Measured uni- and bimodal CCN distributions were input into an adiabatic droplet growth model using various specified vertical wind speeds (W). Bimodal CCN produced greater Nc (Fig. 1a) and smaller mean diameters (MD; Fig. 1b) at lower W typical of stratus clouds (<70 cm/s). Improved CCN (low critical S) were more easily activated at the lower S of stratus from low W, thus, creating greater Nc. Competition for condensate thus reduced MD and drizzle. At greater W, typical of cumulus clouds (>70 cm/s), bimodal CCN made lower Nc with larger MD thus enhancing drizzle whereas unimodal CCN made greater Nc with smaller MD, thus reducing drizzle. Thus, theoretical predictions of Nc and MD for uni- and bimodal CCN agree with the sense of the observations. Radiative effects were determined using a cloud grown to a 250-meter thickness. Bimodal CCN at low W reduced cloud effective radius (re), made greater cloud optical thickness (COT), and made greater cloud albedo (Fig. 1c). At very low W changes were as much as +9% for albedo, +17% for COT, and -12% for re. Stratus clouds typically have low W and cover large areas. Thus, these changes in cloud radiative properties at low W impact climate. Stratus cloud susceptibility to CCN distribution thus requires further investigation to determine their impact on ACI. Hudson et al. (2015), JGRA, 120, 3436-3452.

Interannual variability in stratiform cloudiness and sea surface temperature

NASA Technical Reports Server (NTRS)

Norris, Joel R.; Leovy, Conway B.

1994-01-01

Marine stratiform cloudiness (MSC)(stratus, stratocumulus, and fog) is widespread over subtropical oceans west of the continents and over midlatitude oceans during summer, the season when MSC has maximum influence on surface downward radiation and is most influenced by boundary-layer processes. Long-term datasets of cloudiness and sea surface teperature (SST) from surface observations from 1952 to 1981 are used to examine interannual variations in MSC and SST. Linear correlations of anomalies in seasonal MSC amount with seasonal SST anomalies are negative and significant in midlatitude and eastern subtropical oceans, especially during summer. Significant negative correlations between SST and nimbostratus and nonprecipitating midlevel cloudiness are also observed at midlatitudes during summer, suggesting that summer storm tracks shift from year to year following year-to-year meridional shifts in the SST gradient. Over the 30-yr period, there are significant upward trends in MSC amount over the northern midlatitude oceans and a significant downward trend off the coast of California. The highest correlations and trends occur where gradients in MSC and SST are strongest. During summer, correlations between SST and MSC anomalies peak at zero lag in midlatitudes where warm advection prevails, but SST lags MSC in subtropical regions where cold advection predominates. This difference is attributed to a tendency for anomalies in latent heat flux to compensate anomalies in surface downward radiation in warm advection regions but not in cold advection regions.

Cloud-Scale Numerical Modeling of the Arctic Boundary Layer

NASA Technical Reports Server (NTRS)

Krueger, Steven K.

1998-01-01

The interactions between sea ice, open ocean, atmospheric radiation, and clouds over the Arctic Ocean exert a strong influence on global climate. Uncertainties in the formulation of interactive air-sea-ice processes in global climate models (GCMs) result in large differences between the Arctic, and global, climates simulated by different models. Arctic stratus clouds are not well-simulated by GCMs, yet exert a strong influence on the surface energy budget of the Arctic. Leads (channels of open water in sea ice) have significant impacts on the large-scale budgets during the Arctic winter, when they contribute about 50 percent of the surface fluxes over the Arctic Ocean, but cover only 1 to 2 percent of its area. Convective plumes generated by wide leads may penetrate the surface inversion and produce condensate that spreads up to 250 km downwind of the lead, and may significantly affect the longwave radiative fluxes at the surface and thereby the sea ice thickness. The effects of leads and boundary layer clouds must be accurately represented in climate models to allow possible feedbacks between them and the sea ice thickness. The FIRE III Arctic boundary layer clouds field program, in conjunction with the SHEBA ice camp and the ARM North Slope of Alaska and Adjacent Arctic Ocean site, will offer an unprecedented opportunity to greatly improve our ability to parameterize the important effects of leads and boundary layer clouds in GCMs.

Evaluation of time domain and spectral domain optical coherence tomography in the measurement of diabetic macular edema.

PubMed

Forooghian, Farzin; Cukras, Catherine; Meyerle, Catherine B; Chew, Emily Y; Wong, Wai T

2008-10-01

To evaluate macular thickness and volume measurements and their intrasession repeatability in two optical coherence tomography (OCT) systems: the Stratus OCT, a time domain system, and the Cirrus HD-OCT, a spectral domain system (both by Carl Zeiss Meditec, Inc., Dublin, CA), in the context of diabetic macular edema (DME). Thirty-three eyes of 33 diabetic patients with clinically significant macular edema (CSME) were scanned in a single session by a single operator on both OCT systems. Macular thickness measurements of nine standard macular subfields and total macular volume were obtained and analyzed. Bland-Altman plots were constructed to assess agreement in macular measurements. Intraclass correlation coefficients (ICCs), coefficients of repeatability (CR(W)), and coefficients of variation (CV(W)) were used to assess intrasession repeatability. Macular thickness in nine retinal subfields and macular volume were significantly higher in the Cirrus HD-OCT system compared with the Stratus OCT system. Subfield thickness and total volume measurements, respectively, were 30 to 55 microm and 3.2 mm(3) greater for the Cirrus HD-OCT system compared with the Stratus OCT system. Both Stratus OCT and Cirrus HD-OCT systems demonstrated high intrasession repeatability, with overlapping ranges for CR(W), CV(W), and ICC. Repeatability measures (CR(W) and CV(W)) differed significantly between systems in only one of nine subfields (outer temporal subfield). Absolute measures of macular thickness and volume in patients with DME differed significantly in magnitude between the Stratus OCT and Cirrus HD-OCT systems. However, both OCT systems demonstrated high intrasessional repeatability. Although the two systems may not be used interchangeably, they appear equally reliable in generating macular measurements for clinical practice and research.

The variability of California summertime marine stratus: impacts on surface air temperatures

USGS Publications Warehouse

Iacobellis, Sam F.; Cayan, Daniel R.

2013-01-01

This study investigates the variability of clouds, primarily marine stratus clouds, and how they are associated with surface temperature anomalies over California, especially along the coastal margin. We focus on the summer months of June to September when marine stratus are the dominant cloud type. Data used include satellite cloud reflectivity (cloud albedo) measurements, hourly surface observations of cloud cover and air temperature at coastal airports, and observed values of daily surface temperature at stations throughout California and Nevada. Much of the anomalous variability of summer clouds is organized over regional patterns that affect considerable portions of the coast, often extend hundreds of kilometers to the west and southwest over the North Pacific, and are bounded to the east by coastal mountains. The occurrence of marine stratus is positively correlated with both the strength and height of the thermal inversion that caps the marine boundary layer, with inversion base height being a key factor in determining their inland penetration. Cloud cover is strongly associated with surface temperature variations. In general, increased presence of cloud (higher cloud albedo) produces cooler daytime temperatures and warmer nighttime temperatures. Summer daytime temperature fluctuations associated with cloud cover variations typically exceed 1°C. The inversion-cloud albedo-temperature associations that occur at daily timescales are also found at seasonal timescales.

Earth observations taken from orbiter Discovery during STS-85 mission

NASA Image and Video Library

1997-08-11

STS085-716-081 (7-19 August 1997) --- This photograph provides a southerly view from Vancouver, B. C. in the foreground, to Portland, Oregon near the top. Coastal stratus, a common occurrence, hugs the Pacific coastline and laps into Puget sound. The silty Fraser River cuts through Vancouver and empties into Puget Sound with a large, milky plume of sediment (bottom). Near the top of the image, the Columbia River runs across the Cascades (between Mt. Adams and Mt. Hood) and the Coast Ranges to the Pacific Ocean. Snow caps the highest peaks of the Olympic Mountains (near center), and the Cascade volcanoes of Rainier (closest to Seattle), Adams and Hood (top). The smaller, gray mountain just south (above and right) of Rainier is Mt. St. Helens.

A model to determine open or closed cellular convection

NASA Technical Reports Server (NTRS)

Helfand, H. M.; Kalnay, E.

1981-01-01

A simple mechanism is proposed to explain the observed presence in the atmosphere of open or closed cellular convection. If convection is produced by cooling concentrated near the top of the cloud layer, as in radiative cooling of stratus clouds, it develops strong descending currents which are compensated by weak ascent over most of the horizontal area, and closed cells result. Conversely, heating concentrated near the bottom of a layer, as when an air mass is heated by warm water, results in strong ascending currents compensated by weak descent over most of the area, or open cells. This mechanism is similar to the one suggested by Stommel (1962) to explain the smallness of the oceans' sinking regions. The mechanism is studied numerically by means of a two-dimensional, nonlinear Boussinesq model.

Marine Layer Stratus Study

NASA Astrophysics Data System (ADS)

Wells, Leonard A.

2007-06-01

The intent of this study is to develop a better understanding of the behavior of late spring through early fall marine layer stratus and fog at Vandenberg Air Force Base, which accounts for a majority of aviation forecasting difficulties. The main objective was to use Leipper (1995) study as a starting point to evaluate synoptic and mesoscale processes involved, and identify specific meteorological parameters that affected the behavior of marine layer stratus and fog. After identifying those parameters, the study evaluates how well the various weather models forecast them. The main conclusion of this study is that weak upper-air dynamic features work with boundary layer motions to influence marine layer behavior. It highlights the importance of correctly forecasting the surface temperature by showing how it ties directly to the wind field. That wind field, modified by the local terrain, establishes the low-level convergence and divergence pattern and the resulting marine layer cloud thicknesses and visibilities.

The Continuation of Cloud Statistics for NASA Climate Change Studies

NASA Technical Reports Server (NTRS)

Wylie, Donald P.

2001-01-01

The weather systems, cyclones, and anticyclones, along with air trajectories and cloud forms, are compared to past studies of the Arctic to assess compatibility of the four month study of the Arctic Cloud Experiment flights of the First ISCCP Regional Experiment (FIRE/ACE) with past climatologies. The frequency and movement of cyclones (lows) and anticyclones (highs) followed the general eastward and northeastward directions indicated by past studies. Most cyclones (lows) came from eastern Siberia and the Bering Sea to the south and moved north across the Bering Straight or Alaska into the Arctic Ocean. They generally weakened in central pressure as they moved poleward. Anticyclones (highs) were most common in the eastern Beaufort Sea near Canada in June and July as predicted from previous studies. However, many cyclones and anticyclones moved in westward directions which is rare in other latitudes. Erratic changes in shape and intensity on a daily basis also were observed. The National Center for Environmental Prediction (NCEP) analysis generally reflected the Surface Heat Budget in the Arctic (SHEBA) Ship World Meteorological Organization (WMO) observations which it used. However, NCEP temperatures were biased warm by 1.0 to 1.5 C in April and early May. In July when the surface temperature were at the freezing/thawing point, the NCEP analysis changed to a cold bias of -1.0 C. Dew points had smaller biases except for July where they were biased cold by -1.4 C. Wind speeds had a -2 m/s low bias for the six windiest days. Surface barometric pressures had consistently low biases from -1.2 to -2.8 hPa in all four months. Air parcel historical trajectories were mainly from the south or from local anticyclonic gyres in the Beaufort Sea. Most air came to the SHEBA Ship from the north Pacific Ocean or from Alaska and Canada and occasionally from eastern Siberia. Very few trajectories traced back across the pole to Europe and Central Asia. Cloud cover was high, as expected, from 69-86% of the time. Satellite data also indicate frequent stratus, altostratus, and cirrus clouds (occurring 61% of the time) above the expected boundary layer fog and Arctic stratus clouds.

Contributions of the atmosphere-land and ocean-sea ice model components to the tropical Atlantic SST bias in CESM1

NASA Astrophysics Data System (ADS)

Song, Z.; Lee, S. K.; Wang, C.; Kirtman, B. P.; Qiao, F.

2016-02-01

In order to identify and quantify intrinsic errors in the atmosphere-land and ocean-sea ice model components of the Community Earth System Model version 1 (CESM1) and their contributions to the tropical Atlantic sea surface temperature (SST) bias in CESM1, we propose a new method of diagnosis and apply it to a set of CESM1 simulations. Our analyses of the model simulations indicate that both the atmosphere-land and ocean-sea ice model components of CESM1 contain large errors in the tropical Atlantic. When the two model components are fully coupled, the intrinsic errors in the two components emerge quickly within a year with strong seasonality in their growth rates. In particular, the ocean-sea ice model contributes significantly in forcing the eastern equatorial Atlantic warm SST bias in early boreal summer. Further analysis shows that the upper thermocline water underneath the eastern equatorial Atlantic surface mixed layer is too warm in a stand-alone ocean-sea ice simulation of CESM1 forced with observed surface flux fields, suggesting that the mixed layer cooling associated with the entrainment of upper thermocline water is too weak in early boreal summer. Therefore, although we acknowledge the potential importance of the westerly wind bias in the western equatorial Atlantic and the low-level stratus cloud bias in the southeastern tropical Atlantic, both of which originate from the atmosphere-land model, we emphasize here that solving those problems in the atmosphere-land model alone does not resolve the equatorial Atlantic warm bias in CESM1.

Improved Visualization of Glaucomatous Retinal Damage Using High-speed Ultrahigh-Resolution Optical Coherence Tomography

PubMed Central

Mumcuoglu, Tarkan; Wollstein, Gadi; Wojtkowski, Maciej; Kagemann, Larry; Ishikawa, Hiroshi; Gabriele, Michelle L.; Srinivasan, Vivek; Fujimoto, James G.; Duker, Jay S.; Schuman, Joel S.

2009-01-01

Purpose To test if improving optical coherence tomography (OCT) resolution and scanning speed improves the visualization of glaucomatous structural changes as compared with conventional OCT. Design Prospective observational case series. Participants Healthy and glaucomatous subjects in various stages of disease. Methods Subjects were scanned at a single visit with commercially available OCT (StratusOCT) and high-speed ultrahigh-resolution (hsUHR) OCT. The prototype hsUHR OCT had an axial resolution of 3.4 μm (3 times higher than StratusOCT), with an A-scan rate of 24 000 hertz (60 times faster than StratusOCT). The fast scanning rate allowed the acquisition of novel scanning patterns such as raster scanning, which provided dense coverage of the retina and optic nerve head. Main Outcome Measures Discrimination of retinal tissue layers and detailed visualization of retinal structures. Results High-speed UHR OCT provided a marked improvement in tissue visualization as compared with StratusOCT. This allowed the identification of numerous retinal layers, including the ganglion cell layer, which is specifically prone to glaucomatous damage. Fast scanning and the enhanced A-scan registration properties of hsUHR OCT provided maps of the macula and optic nerve head with unprecedented detail, including en face OCT fundus images and retinal nerve fiber layer thickness maps. Conclusion High-speed UHR OCT improves visualization of the tissues relevant to the detection and management of glaucoma. PMID:17884170

High-resolution Fourier-Domain Optical Coherence Tomography and Microperimetric Findings After Macula-off Retinal Detachment Repair

PubMed Central

Smith, Allison J.; Telander, David G.; Zawadzki, Robert J.; Choi, Stacey S.; Morse, Lawrence S.; Werner, John S.; Park, Susanna S.

2009-01-01

Objective To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1). Design Prospective observational case series. Participants Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy. Methods FD OCT with axial and transverse resolution of 4.5 μm and 10 to 15 μm, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function. Main Outcome Measures Stratus OCT scans, FD OCT scans, and MP-1 data. Results Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (P<0.001, χ2). Both imaging modalities revealed persistent subretinal fluid in 2 eyes (12%) and lamellar hole in 1 eye. Among 7 subjects who had reliable MP-1 data, areas of abnormal function corresponded to areas of photoreceptor layer disruptions or persistent subretinal fluid in 5 subjects (71%); one subject had normal FD OCT and MP-1. Conclusions Photoreceptor disruption after macula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair. PMID:18672289

Fog Bank, Namib Desert, Namibia, Africa

NASA Image and Video Library

1991-12-01

Fog is the only source of moisture for desert dwelling animals and plants living in the Namib Desert sand dune field, Namibia (23.5N, 15.0E). Coastal stratus clouds provide most of the life supporting moisture as fog droplets in this arid land where the usual annual rainfall is less than a quarter of an inch for decades at a time. In this view, the stratus clouds over the coast conform to the dune pattern proving that the fog is in ground contact.

Fog Bank, Namib Desert, Namibia, Africa

NASA Technical Reports Server (NTRS)

1991-01-01

Fog is the only source of moisture for desert dwelling animals and plants living in the Namib Desert sand dune field, Namibia (23.5N, 15.0E). Coastal stratus clouds provide most of the life supporting moisture as fog droplets in this arid land where the usual annual rainfall is less than a quarter of an inch for decades at a time. In this view, the stratus clouds over the coast conform to the dune pattern proving that the fog is in ground contact.

Impact of Arctic sea-ice retreat on the recent change in cloud-base height during autumn

NASA Astrophysics Data System (ADS)

Sato, K.; Inoue, J.; Kodama, Y.; Overland, J. E.

2012-12-01

Cloud-base observations over the ice-free Chukchi and Beaufort Seas in autumn were conducted using a shipboard ceilometer and radiosondes during the 1999-2010 cruises of the Japanese R/V Mirai. To understand the recent change in cloud base height over the Arctic Ocean, these cloud-base height data were compared with the observation data under ice-covered situation during SHEBA (the Surface Heat Budget of the Arctic Ocean project in 1998). Our ice-free results showed a 30 % decrease (increase) in the frequency of low clouds with a ceiling below (above) 500 m. Temperature profiles revealed that the boundary layer was well developed over the ice-free ocean in the 2000s, whereas a stable layer dominated during the ice-covered period in 1998. The change in surface boundary conditions likely resulted in the difference in cloud-base height, although it had little impact on air temperatures in the mid- and upper troposphere. Data from the 2010 R/V Mirai cruise were investigated in detail in terms of air-sea temperature difference. This suggests that stratus cloud over the sea ice has been replaced as stratocumulus clouds with low cloud fraction due to the decrease in static stability induced by the sea-ice retreat. The relationship between cloud-base height and air-sea temperature difference (SST-Ts) was analyzed in detail using special section data during 2010 cruise data. Stratus clouds near the sea surface were predominant under a warm advection situation, whereas stratocumulus clouds with a cloud-free layer were significant under a cold advection situation. The threshold temperature difference between sea surface and air temperatures for distinguishing the dominant cloud types was 3 K. Anomalous upward turbulent heat fluxes associated with the sea-ice retreat have likely contributed to warming of the lower troposphere. Frequency distribution of the cloud-base height (km) detected by a ceilometer/lidar (black bars) and radiosondes (gray bars), and profiles of potential temperature (K) for (a) ice-free cases (R/V Mirai during September) and (b) ice-covered case (SHEBA during September 1998). (c) Vertical profiles of air temperature from 1000 hPa to 150 hPa (solid lines: observations north of 75°N, and dashed lines: the ERA-Interim reanalysis over 75-82.5°N, 150-170°W). Green, blue, and red lines denote profiles derived from observations by NP stations (the 1980s), SHEBA (1998), and the R/V Mirai (the 2000s), respectively. (d) Temperature trend calculated by the ERA-Interim reanalysis over the area.

Comparison of retinal thickness by Fourier-domain optical coherence tomography and OCT retinal image analysis software segmentation analysis derived from Stratus optical coherence tomography images

NASA Astrophysics Data System (ADS)

Tátrai, Erika; Ranganathan, Sudarshan; Ferencz, Mária; Debuc, Delia Cabrera; Somfai, Gábor Márk

2011-05-01

Purpose: To compare thickness measurements between Fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT images analyzed with a custom-built OCT retinal image analysis software (OCTRIMA). Methods: Macular mapping (MM) by StratusOCT and MM5 and MM6 scanning protocols by an RTVue-100 FD-OCT device are performed on 11 subjects with no retinal pathology. Retinal thickness (RT) and the thickness of the ganglion cell complex (GCC) obtained with the MM6 protocol are compared for each early treatment diabetic retinopathy study (ETDRS)-like region with corresponding results obtained with OCTRIMA. RT results are compared by analysis of variance with Dunnett post hoc test, while GCC results are compared by paired t-test. Results: A high correlation is obtained for the RT between OCTRIMA and MM5 and MM6 protocols. In all regions, the StratusOCT provide the lowest RT values (mean difference 43 +/- 8 μm compared to OCTRIMA, and 42 +/- 14 μm compared to RTVue MM6). All RTVue GCC measurements were significantly thicker (mean difference between 6 and 12 μm) than the GCC measurements of OCTRIMA. Conclusion: High correspondence of RT measurements is obtained not only for RT but also for the segmentation of intraretinal layers between FD-OCT and StratusOCT-derived OCTRIMA analysis. However, a correction factor is required to compensate for OCT-specific differences to make measurements more comparable to any available OCT device.

The Strength of Cloud Feedbacks and the Structure of Tropical Climate Change - A CESM Sensitivity Study

NASA Astrophysics Data System (ADS)

Erfani, E.; Burls, N.

2017-12-01

The nature of local coupled ocean-atmosphere interactions within the tropics is determined by background conditions such as the depth of the equatorial thermocline, the water vapor content of the tropical atmosphere, and the radiative forcing of tropical clouds. These factors are set not only by the coupled tropical variability itself but also by extra-tropical conditions. For example, the strength of the cold tongue is ultimately controlled by the temperature of waters subducted in the extra-tropics and transported to the equator by the ocean subtropical cells (STCs). Similarly, inter-hemispheric asymmetries in extra-tropical atmospheric heating are communicated to the tropics affecting cross-equatorial heat transport and ITCZ position. Acknowledging from a fully coupled perspective the influence of both tropical and extra-tropical conditions, we are performing a suite of CESM experiments across which we systematically alter the strength of convective and stratus cloud feedbacks. By systematically exploring the sensitivity of the tropical coupled system to imposed changes in the strength of tropical and extra-tropical cloud feedbacks to CO2-induced warming this work aims to formalize our understanding of cloud controls on tropical climate.

Estimates for the Probabilities of Surface-to-Air Cloud-Free Lines-of-Sight and Low Cloud Statistics from Ship Observations. Part 1. Fifteen Marine Locations.

DTIC Science & Technology

1980-11-24

time before and after) or cumulus fractus of bad weath’er, or both ( pannus ), usually below altostratus or nimbostratus. 8 = Cumulus and stratocumulus...vibrous upper part by cumulus, stratocumulus, stratus or pannus . + . from Surface Marine Observations Tape Deck TDF-11 *Fog All clouds in the 0-50...Fractus of bad weather, cr V both ( pannus ), usually below Alto- stratus or N~imbostratus. The term "bad weather* denotes the conditions which coenerally

Physical feedbacks on stratus cloud amount resolve the Faint Young Sun Paradox

NASA Astrophysics Data System (ADS)

Goldblatt, C.; McCusker, K. E.; McDonald, V.

2017-12-01

Geological evidence suggests that Earth was mostly warm and not glaciated during the Archean, despite Earth receiving only around 80% of the present day amount of sunlight. 1-D models require higher abundances of greenhouse gases than geochemical proxies permit, whereas some 3-D models permit lower greenhouse gas inventories, but for reasons which are somewhat opaque. Here, we show that physically motivated changes to low cloud (stratus) amount likely played a large role in resolving the FYSP. The amount of stratus cloud is strongly linked to lower tropospheric stability [Slingo 1987; Woods and Bretherton 2006], with a stronger inversion at the planetary boundary layer trapping moisture and giving a higher stratus cloud fraction. By hypothesis, an Archean situation where the surface is heated less by sunlight and the atmosphere is heated more by absorption of thermal radiation with a stronger greenhouse, should feature a weaker inversion and less stable lower troposphere. Hence, with a weaker sun but stronger greenhouse, we expect less stratus clouds. To test this hypothesis, we run a set of carefully controlled General Circulation Model experiments using the Community Atmosphere Model. We change only the solar constant and CO2 mixing ratio, increasing CO2 and decreasing the solar constant so that the global mean surface temperature remains the same. We do not change anything else, so as to focus directly on a single hypothesis, and to keep the model as near to known conditions as possible. We find that at 80% of modern solar constant: (1) only 30,000 ppmv CO2 is required to maintain modern surface temperatures, versus the expectation of 80,000 ppmv from radiative forcing calculations. (2) The dominant change is to low cloud fraction, decreasing from 34% to 25%, with an associated reduction in short-wave cloud forcing of 20W/m/m. This can be set in the context of a 50W/m/m radiative deficit due to the weaker sun, so the cloud feedback contributes two-fifths of the required warming. (3) There is a reduced meridional temperature gradient such that the poles are 4 to 8 K warmer than present, which will further contributes to the avoidance of glaciation.

Improving image segmentation performance and quantitative analysis via a computer-aided grading methodology for optical coherence tomography retinal image analysis.

PubMed

Debuc, Delia Cabrera; Salinas, Harry M; Ranganathan, Sudarshan; Tátrai, Erika; Gao, Wei; Shen, Meixiao; Wang, Jianhua; Somfai, Gábor M; Puliafito, Carmen A

2010-01-01

We demonstrate quantitative analysis and error correction of optical coherence tomography (OCT) retinal images by using a custom-built, computer-aided grading methodology. A total of 60 Stratus OCT (Carl Zeiss Meditec, Dublin, California) B-scans collected from ten normal healthy eyes are analyzed by two independent graders. The average retinal thickness per macular region is compared with the automated Stratus OCT results. Intergrader and intragrader reproducibility is calculated by Bland-Altman plots of the mean difference between both gradings and by Pearson correlation coefficients. In addition, the correlation between Stratus OCT and our methodology-derived thickness is also presented. The mean thickness difference between Stratus OCT and our methodology is 6.53 microm and 26.71 microm when using the inner segment/outer segment (IS/OS) junction and outer segment/retinal pigment epithelium (OS/RPE) junction as the outer retinal border, respectively. Overall, the median of the thickness differences as a percentage of the mean thickness is less than 1% and 2% for the intragrader and intergrader reproducibility test, respectively. The measurement accuracy range of the OCT retinal image analysis (OCTRIMA) algorithm is between 0.27 and 1.47 microm and 0.6 and 1.76 microm for the intragrader and intergrader reproducibility tests, respectively. Pearson correlation coefficients demonstrate R(2)>0.98 for all Early Treatment Diabetic Retinopathy Study (ETDRS) regions. Our methodology facilitates a more robust and localized quantification of the retinal structure in normal healthy controls and patients with clinically significant intraretinal features.

Improving image segmentation performance and quantitative analysis via a computer-aided grading methodology for optical coherence tomography retinal image analysis

NASA Astrophysics Data System (ADS)

Cabrera Debuc, Delia; Salinas, Harry M.; Ranganathan, Sudarshan; Tátrai, Erika; Gao, Wei; Shen, Meixiao; Wang, Jianhua; Somfai, Gábor M.; Puliafito, Carmen A.

2010-07-01

We demonstrate quantitative analysis and error correction of optical coherence tomography (OCT) retinal images by using a custom-built, computer-aided grading methodology. A total of 60 Stratus OCT (Carl Zeiss Meditec, Dublin, California) B-scans collected from ten normal healthy eyes are analyzed by two independent graders. The average retinal thickness per macular region is compared with the automated Stratus OCT results. Intergrader and intragrader reproducibility is calculated by Bland-Altman plots of the mean difference between both gradings and by Pearson correlation coefficients. In addition, the correlation between Stratus OCT and our methodology-derived thickness is also presented. The mean thickness difference between Stratus OCT and our methodology is 6.53 μm and 26.71 μm when using the inner segment/outer segment (IS/OS) junction and outer segment/retinal pigment epithelium (OS/RPE) junction as the outer retinal border, respectively. Overall, the median of the thickness differences as a percentage of the mean thickness is less than 1% and 2% for the intragrader and intergrader reproducibility test, respectively. The measurement accuracy range of the OCT retinal image analysis (OCTRIMA) algorithm is between 0.27 and 1.47 μm and 0.6 and 1.76 μm for the intragrader and intergrader reproducibility tests, respectively. Pearson correlation coefficients demonstrate R2>0.98 for all Early Treatment Diabetic Retinopathy Study (ETDRS) regions. Our methodology facilitates a more robust and localized quantification of the retinal structure in normal healthy controls and patients with clinically significant intraretinal features.

In vivo visualization of robotically implemented synthetic tracked aperture ultrasound (STRATUS) imaging system using curvilinear array

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Aalamifar, Fereshteh; Boctor, Emad M.

2016-04-01

Synthetic aperture for ultrasound is a technique utilizing a wide aperture in both transmit and receive to enhance the ultrasound image quality. The limitation of synthetic aperture is the maximum available aperture size limit determined by the physical size of ultrasound probe. We propose Synthetic-Tracked Aperture Ultrasound (STRATUS) imaging system to overcome the limitation by extending the beamforming aperture size through ultrasound probe tracking. With a setup involving a robotic arm, the ultrasound probe is moved using the robotic arm, while the positions on a scanning trajectory are tracked in real-time. Data from each pose are synthesized to construct a high resolution image. In previous studies, we have demonstrated the feasibility through phantom experiments. However, various additional factors such as real-time data collection or motion artifacts should be taken into account when the in vivo target becomes the subject. In this work, we build a robot-based STRATUS imaging system with continuous data collection capability considering the practical implementation. A curvilinear array is used instead of a linear array to benefit from its wider capture angle. We scanned human forearms under two scenarios: one submerged the arm in the water tank under 10 cm depth, and the other directly scanned the arm from the surface. The image contrast improved 5.51 dB, and 9.96 dB for the underwater scan and the direct scan, respectively. The result indicates the practical feasibility of STRATUS imaging system, and the technique can be potentially applied to the wide range of human body.

Structure-function correlations in glaucoma using matrix and standard automated perimetry versus time-domain and spectral-domain OCT devices.

PubMed

Pinto, Luciano Moreira; Costa, Elaine Fiod; Melo, Luiz Alberto S; Gross, Paula Blasco; Sato, Eduardo Toshio; Almeida, Andrea Pereira; Maia, Andre; Paranhos, Augusto

2014-04-10

We examined the structure-function relationship between two perimetric tests, the frequency doubling technology (FDT) matrix and standard automated perimetry (SAP), and two optical coherence tomography (OCT) devices (time-domain and spectral-domain). This cross-sectional study included 97 eyes from 29 healthy individuals, and 68 individuals with early, moderate, or advanced primary open-angle glaucoma. The correlations between overall and sectorial parameters of retinal nerve fiber layer thickness (RNFL) measured with Stratus and Spectralis OCT, and the visual field sensitivity obtained with FDT matrix and SAP were assessed. The relationship also was evaluated using a previously described linear model. The correlation coefficients for the threshold sensitivity measured with SAP and Stratus OCT ranged from 0.44 to 0.79, and those for Spectralis OCT ranged from 0.30 to 0.75. Regarding FDT matrix, the correlation ranged from 0.40 to 0.79 with Stratus OCT and from 0.39 to 0.79 with Spectralis OCT. Stronger correlations were found in the overall measurements and the arcuate sectors for both visual fields and OCT devices. A linear relationship was observed between FDT matrix sensitivity and the OCT devices. The previously described linear model fit the data from SAP and the OCT devices well, particularly in the inferotemporal sector. The FDT matrix and SAP visual sensitivities were related strongly to the RNFL thickness measured with the Stratus and Spectralis OCT devices, particularly in the overall and arcuate sectors. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Optical coherence tomography in anterior segment imaging

PubMed Central

Kalev-Landoy, Maya; Day, Alexander C.; Cordeiro, M. Francesca; Migdal, Clive

2008-01-01

Purpose To evaluate the ability of optical coherence tomography (OCT), designed primarily to image the posterior segment, to visualize the anterior chamber angle (ACA) in patients with different angle configurations. Methods In a prospective observational study, the anterior segments of 26 eyes of 26 patients were imaged using the Zeiss Stratus OCT, model 3000. Imaging of the anterior segment was achieved by adjusting the focusing control on the Stratus OCT. A total of 16 patients had abnormal angle configurations including narrow or closed angles and plateau irides, and 10 had normal angle configurations as determined by prior full ophthalmic examination, including slit-lamp biomicroscopy and gonioscopy. Results In all cases, OCT provided high-resolution information regarding iris configuration. The ACA itself was clearly visualized in patients with narrow or closed angles, but not in patients with open angles. Conclusions Stratus OCT offers a non-contact, convenient and rapid method of assessing the configuration of the anterior chamber. Despite its limitations, it may be of help during the routine clinical assessment and treatment of patients with glaucoma, particularly when gonioscopy is not possible or difficult to interpret. PMID:17355288

The Open-Ocean Sensible Heat Flux and Its Significance for Arctic Boundary Layer Mixing During Early Fall

NASA Technical Reports Server (NTRS)

Ganeshan, Manisha; Wu, Dongliang

2016-01-01

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-ocean sensible heat flux, a crucial mechanism of excessive ocean 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 Ocean to characterize the surface sensible heat flux (SSHF) during early 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 ocean-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 ocean 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 predicting the dynamic nature of the Arctic climate.

Meta-analysis of stratus OCT glaucoma diagnostic accuracy.

PubMed

Chen, Hsin-Yi; Chang, Yue-Cune

2014-09-01

To evaluate the diagnostic accuracy of glaucoma in different stages, different types of glaucoma, and different ethnic groups using Stratus optical coherence tomography (OCT). We searched MEDLINE to identify available articles on diagnostic accuracy of glaucoma published between January 2004 and December 2011. A PubMed (National Center for Biotechnology Information) search using medical subject headings and keywords was executed using the following terms: "diagnostic accuracy" or "receiver operator characteristic" or "area under curve" or "AUC" and "Stratus OCT" and "glaucoma." The search was subsequently limited to publications in English. The area under a receiver operator characteristic (AUC) curve was used to measure the diagnostic performance. A random-effects model was used to estimate the pooled AUC value of the 17 parameters (average retinal nerve fiber layer thickness, temporal quadrant, superior quadrant, nasal quadrant, inferior quadrant, and 1 to 12 o'clock). Meta-regression analysis was used to check the significance of some important factors: (1) glaucoma severity (five stages), (2) glaucoma types (four types), and (3) ethnicity (four categories). The orders of accuracy among those parameters were as follows: average > inferior > superior > 7 o'clock > 6 o'clock > 11 o'clock > 12 o'clock > 1 o'clock > 5 o'clock > nasal > temporal > 2 o'clock > 10 o'clock > 8 o'clock > 9 o'clock > 4 o'clock > 3 o'clock. After adjusting for the effects of age, glaucoma severity, glaucoma types, and ethnicity, the average retinal nerve fiber layer thickness provided highest accuracy compared with the other parameters of OCT. The diagnostic accuracy in Asian populations was significantly lower than that in whites and the other two ethnic types. Stratus OCT demonstrated good diagnostic capability in differentiating glaucomatous from normal eyes. However, we should be more cautious in applying this instrument in Asian groups in glaucoma management.

Preliminary Results from the First Deployment of a Tethered-Balloon Cloud Particle Imager Instrument Package in Arctic Stratus Clouds at Ny-Alesund

NASA Astrophysics Data System (ADS)

Lawson, P.; Stamnes, K.; Stamnes, J.; Zmarzly, P.; O'Connor, D.; Koskulics, J.; Hamre, B.

2008-12-01

A tethered balloon system specifically designed to collect microphysical data in mixed-phase clouds was deployed in Arctic stratus clouds during May 2008 near Ny-Alesund, Svalbard, at 79 degrees North Latitude. This is the first time a tethered balloon system with a cloud particle imager (CPI) that records high-resolution digital images of cloud drops and ice particles has been operated in cloud. The custom tether supplies electrical power to the instrument package, which in addition to the CPI houses a 4-pi short-wavelength radiometer and a met package that measures temperature, humidity, pressure, GPS position, wind speed and direction. The instrument package was profiled vertically through cloud up to altitudes of 1.6 km. Since power was supplied to the instrument package from the ground, it was possible to keep the balloon package aloft for extended periods of time, up to 9 hours at Ny- Ålesund, which was limited only by crew fatigue. CPI images of cloud drops and the sizes, shapes and degree of riming of ice particles are shown throughout vertical profiles of Arctic stratus clouds. The images show large regions of mixed-phase cloud from -8 to -2 C. The predominant ice crystal habits in these regions are needles and aggregates of needles. The amount of ice in the mixed-phase clouds varied considerably and did not appear to be a function of temperature. On some occasions, ice was observed near cloud base at -2 C with supercooled cloud above to - 8 C that was devoid of ice. Measurements of shortwave radiation are also presented. Correlations between particle distributions and radiative measurements will be analyzed to determine the effect of these Arctic stratus clouds on radiative forcing.

A comprehensive tool for measuring mammographic density changes over time.

PubMed

Eriksson, Mikael; Li, Jingmei; Leifland, Karin; Czene, Kamila; Hall, Per

2018-06-01

Mammographic density is a marker of breast cancer risk and diagnostics accuracy. Density change over time is a strong proxy for response to endocrine treatment and potentially a stronger predictor of breast cancer incidence. We developed STRATUS to analyse digital and analogue images and enable automated measurements of density changes over time. Raw and processed images from the same mammogram were randomly sampled from 41,353 healthy women. Measurements from raw images (using FDA approved software iCAD) were used as templates for STRATUS to measure density on processed images through machine learning. A similar two-step design was used to train density measures in analogue images. Relative risks of breast cancer were estimated in three unique datasets. An alignment protocol was developed using images from 11,409 women to reduce non-biological variability in density change. The protocol was evaluated in 55,073 women having two regular mammography screens. Differences and variances in densities were compared before and after image alignment. The average relative risk of breast cancer in the three datasets was 1.6 [95% confidence interval (CI) 1.3-1.8] per standard deviation of percent mammographic density. The discrimination was AUC 0.62 (CI 0.60-0.64). The type of image did not significantly influence the risk associations. Alignment decreased the non-biological variability in density change and re-estimated the yearly overall percent density decrease from 1.5 to 0.9%, p < 0.001. The quality of STRATUS density measures was not influenced by mammogram type. The alignment protocol reduced the non-biological variability between images over time. STRATUS has the potential to become a useful tool for epidemiological studies and clinical follow-up.

Frequencies and Characteristics of Global Oceanic Precipitation from Shipboard Present-Weather Reports

NASA Technical Reports Server (NTRS)

Petty, Grant W.

1995-01-01

Ship reports of present weather obtained from the Comprehensive Ocean-Atmosphere Data Set are analyzed for the period 1958-91 in order to elucidate regional and seasonal variations in the climatological frequency, phase, intensity, and character of oceanic precipitation. Specific findings of note include the following: 1) The frequency of thunderstorm reports, relative to all precipitation reports, is a strong function of location, with thunderstorm activity being favored within 1000-3000 km of major tropical and subtropical land masses, while being quite rare at other locations, even within the intertropical convergence zone. 2) The latitudinal frequency of precipitation over the southern oceans increases steadily toward the Antarctic continent and shows relatively little seasonal variation. The frequency of convective activity, however, shows considerable seasonal variability, with sharp winter maxima occurring near 38 deg. latitude in both hemispheres. 3) Drizzle is the preferred form of precipitation in a number of regions, most of which coincide with known regions of persistent marine stratus and stratocumulus in the subtropical highs. Less well documented is the high relative frequency of drizzle in the vicinity of the equatorial sea surface temperature front in the eastern Pacific. 4) Regional differences in the temporal scale of precipitation events (e.g., transient showers versus steady precipitation) are clearly depicted by way of the ratio of the frequency of precipitation at the observation time to the frequency of all precipitation reports, including precipitation during the previous hour. The results of this study suggest that many current satellite rainfall estimation techniques may substantially underestimate the fractional coverage or frequency of precipitation poleward of 50 deg. latitude and in the subtropical dry zones. They also draw attention to the need to carefully account for regional differences in the physical and spatial properties of rainfall when developing calibration relationships for satellite algorithms.

Annual Cycle of Cloud Forcing of Surface Radiation Budget

NASA Technical Reports Server (NTRS)

Wilber, Anne C.; Smith, G. Louis; Stackhouse, Paul W., Jr.; Gupta, Shashi K.

2006-01-01

The climate of the Earth is determined by its balance of radiation. The incoming and outgoing radiation fluxes are strongly modulated by clouds, which are not well understood. The Earth Radiation Budget Experiment (Barkstrom and Smith, 1986) provided data from which the effects of clouds on radiation at the top of the atmosphere (TOA) could be computed (Ramanathan, 1987). At TOA, clouds increase the reflected solar radiation, tending to cool the planet, and decrease the OLR, causing the planet to retain its heat (Ramanathan et al., 1989; Harrison et al., 1990). The effects of clouds on radiation fluxes are denoted cloud forcing. These shortwave and longwave forcings counter each other to various degrees, so that in the tropics the result is a near balance. Over mid and polar latitude oceans, cloud forcing at TOA results in large net loss of radiation. Here, there are large areas of stratus clouds and cloud systems associated with storms. These systems are sensitive to surface temperatures and vary strongly with the annual cycle. During winter, anticyclones form over the continents and move to the oceans during summer. This movement of major cloud systems causes large changes of surface radiation, which in turn drives the surface temperature and sensible and latent heat released to the atmosphere.

Spectral Cloud-Filtering of AIRS Data: Non-Polar Ocean

NASA Technical Reports Server (NTRS)

Aumann, Hartmut H.; Gregorich, David; Barron, Diana

2004-01-01

The Atmospheric Infrared Sounder (AIRS) is a grating array spectrometer which covers the thermal infrared spectral range between 640 and 1700/cm. In order to retain the maximum radiometric accuracy of the AIRS data, the effects of cloud contamination have to be minimized. We discuss cloud filtering which uses the high spectral resolution of AIRS to identify about 100,000 of 500,000 non-polar ocean spectra per day as relatively "cloud-free". Based on the comparison of surface channels with the NCEP provided global real time sst (rtg.sst), AIRS surface sensitive channels have a cold bias ranging from O.5K during the day to 0.8K during the night. Day and night spatial coherence tests show that the cold bias is due to cloud contamination. During the day the cloud contamination is due to a 2-3% broken cloud cover at the 1-2 km altitude, characteristic of low stratus clouds. The cloud-contamination effects surface sensitive channels only. Cloud contamination can be reduced to 0.2K by combining the spectral filter with a spatial coherence threshold, but the yield drops to 16,000 spectra per day. AIRS was launched in May 2002 on the Earth Observing System (EOS) Aqua satellite. Since September 2002 it has returned 4 million spectra of the globe each day.

Overview of the CERES Edition-4 Multilayer Cloud Property Datasets

NASA Astrophysics Data System (ADS)

Chang, F. L.; Minnis, P.; Sun-Mack, S.; Chen, Y.; Smith, R. A.; Brown, R. R.

2014-12-01

Knowledge of the cloud vertical distribution is important for understanding the role of clouds on earth's radiation budget and climate change. Since high-level cirrus clouds with low emission temperatures and small optical depths can provide a positive feedback to a climate system and low-level stratus clouds with high emission temperatures and large optical depths can provide a negative feedback effect, the retrieval of multilayer cloud properties using satellite observations, like Terra and Aqua MODIS, is critically important for a variety of cloud and climate applications. For the objective of the Clouds and the Earth's Radiant Energy System (CERES), new algorithms have been developed using Terra and Aqua MODIS data to allow separate retrievals of cirrus and stratus cloud properties when the two dominant cloud types are simultaneously present in a multilayer system. In this paper, we will present an overview of the new CERES Edition-4 multilayer cloud property datasets derived from Terra as well as Aqua. Assessment of the new CERES multilayer cloud datasets will include high-level cirrus and low-level stratus cloud heights, pressures, and temperatures as well as their optical depths, emissivities, and microphysical properties.

Optic Nerve Head Measurements With Optical Coherence Tomography: A Phantom-Based Study Reveals Differences Among Clinical Devices

PubMed Central

Agrawal, Anant; Baxi, Jigesh; Calhoun, William; Chen, Chieh-Li; Ishikawa, Hiroshi; Schuman, Joel S.; Wollstein, Gadi; Hammer, Daniel X.

2016-01-01

Purpose Optical coherence tomography (OCT) can monitor for glaucoma by measuring dimensions of the optic nerve head (ONH) cup and disc. Multiple clinical studies have shown that different OCT devices yield different estimates of retinal dimensions. We developed phantoms mimicking ONH morphology as a new way to compare ONH measurements from different clinical OCT devices. Methods Three phantoms were fabricated to model the ONH: One normal and two with glaucomatous anatomies. Phantoms were scanned with Stratus, RTVue, and Cirrus clinical devices, and with a laboratory OCT system as a reference. We analyzed device-reported ONH measurements of cup-to-disc ratio (CDR) and cup volume and compared them with offline measurements done manually and with a custom software algorithm, respectively. Results The mean absolute difference between clinical devices with device-reported measurements versus offline measurements was 0.082 vs. 0.013 for CDR and 0.044 mm3 vs. 0.019 mm3 for cup volume. Statistically significant differences between devices were present for 16 of 18 comparisons of device-reported measurements from the phantoms. Offline Cirrus measurements tended to be significantly different from those from Stratus and RTVue. Conclusions The interdevice differences in CDR and cup volume are primarily caused by the devices' proprietary ONH analysis algorithms. The three devices yield more similar ONH measurements when a consistent offline analysis technique is applied. Scan pattern on the ONH also may be a factor in the measurement differences. This phantom-based study has provided unique insights into characteristics of OCT measurements of the ONH. PMID:27409500

Derivation of Cloud Heating Rate Profiles using observations of Mixed-Phase Arctic Clouds: Impacts of Solar Zenith Angle

NASA Astrophysics Data System (ADS)

Zhang, G.; McFarquhar, G.; Poellot, M.; Verlinde, J.; Heymsfield, A.; Kok, G.

2005-12-01

Arctic stratus clouds play an important role in the energy balance of the Arctic region. Previous studies have suggested that Arctic stratus persist due to a balance among cloud top radiation cooling, latent heating, ice crystal fall out and large scale forcing. In this study, radiative heating profiles through Arctic stratus are computed using cloud, surface and thermodynamic observations obtained during the Mixed-Phase Arctic Cloud Experiment (M-PACE) as input to the radiative transfer model STREAMER. In particular, microphysical and macrophycial cloud properties such as phase, water content, effective particle size, particle shape, cloud height and cloud thickness were derived using data collected by in-situ sensors on the University of North Dakota (UND) Citation and ground-based remote sensors at Barrow and Oliktok Point. Temperature profiles were derived from radiosonde launches and a fresh snow surface was assumed. One series of sensitivity studies explored the dependence of the heating profile on the solar zenith angle. For smaller solar zenith angles, more incoming solar radiation is received at cloud top acting to counterbalance infrared cooling. As solar zenith angle in the Arctic is large compared to low latitudes, a large solar zenith angle may contribute to the longevity of these clouds.

An intercomparison of artificial intelligence approaches for polar scene identification

NASA Technical Reports Server (NTRS)

Tovinkere, V. R.; Penaloza, M.; Logar, A.; Lee, J.; Weger, R. C.; Berendes, T. A.; Welch, R. M.

1993-01-01

The following six different artificial-intelligence (AI) approaches to polar scene identification are examined: (1) a feed forward back propagation neural network, (2) a probabilistic neural network, (3) a hybrid neural network, (4) a 'don't care' feed forward perception model, (5) a 'don't care' feed forward back propagation neural network, and (6) a fuzzy logic based expert system. The ten classes into which six AVHRR local-coverage arctic scenes were classified were: water, solid sea ice, broken sea ice, snow-covered mountains, land, stratus over ice, stratus over water, cirrus over water, cumulus over water, and multilayer cloudiness. It was found that 'don't care' back propagation neural network produced the highest accuracies. This approach has also low CPU requirement.

Distinct Impacts of Aerosols on an Evolving Continental Cloud Complex during the RACORO Field Campaign

DOE PAGES

Lin, Yun; Wang, Yuan; Pan, Bowen; ...

2016-08-26

In this study, a continental cloud complex, consisting of shallow cumuli, a deep convective cloud (DCC), and stratus, is simulated by a cloud-resolving Weather Research and Forecasting Model to investigate the aerosol microphysical effect (AME) and aerosol radiative effect (ARE) on the various cloud regimes and their transitions during the Department of Energy Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) campaign. Under an elevated aerosol loading with AME only, a reduced cloudiness for the shallow cumuli and stratus resulted from more droplet evaporation competing with suppressed precipitation, but an enhanced cloudinessmore » for the DCC is attributed to more condensation. With the inclusion of ARE, the shallow cumuli are suppressed owing to the thermodynamic effects of light-absorbing aerosols. The responses of DCC and stratus to aerosols are monotonic with AME only but nonmonotonic with both AME and ARE. The DCC is invigorated because of favorable convection and moisture conditions at night induced by daytime ARE, via the so-called aerosol-enhanced conditional instability mechanism. Finally, the results reveal that the overall aerosol effects on the cloud complex are distinct from the individual cloud types, highlighting that the aerosol–cloud interactions for diverse cloud regimes and their transitions need to be evaluated to assess the regional and global climatic impacts.« less

Vertical-velocity skewness in the marine stratus-topped boundary layer

NASA Technical Reports Server (NTRS)

Moeng, Chin-Hoh; Rotunno, Richard; Paluch, Ilga R.

1990-01-01

Vertical-velocity skewness, S(sub w), in a turbulent flow is important in several regards. S(sub w) is indicative of the structure of the motion when it is positive, updrafts are narrower and stronger than surrounding downdrafts, and vice versa. Aircraft measurements often suggest cool, narrow downdrafts at some distance below the stratus cloud top, indicating a negative S(sub w) (Nicholls and Leighton, 1986). This seems natural as the turbulence within the stratus-topped boundary layer (CTBL) is driven mainly by the radiative cooling at the cloud top (although sometimes surface heating can also play a major role). One expects intuitively (e.g., Nicolls, 1984) that, in the situations where cloud-top cooling and surface heating coexist, the turbulence statistics in the upper part of the CTBL are influenced more by the cloud-top cooling, while those in the lower part, more by the surface heating. Thus one expects negative S(sub w) in the upper part, and positive in the lower part, in this case. In contradistinction, large-eddy simulations (LES) of the CTBL show just the opposite: the S(sub w) is positive in the upper part and negative in the lower part of the layer. To understand the nature of vertical-velocity skewness, the simplest type of buoyancy-driven turbulence (turbulent Rayleigh-Benard convection) is studied through direct numerical simulation.

Arctic Clouds

Atmospheric Science Data Center

2013-04-19

...     View Larger Image Stratus clouds are common in the Arctic during the summer months, ... (Acro Service Corporation/Jet Propulsion Laboratory), David J. Diner (Jet Propulsion Laboratory). Other formats available at JPL ...

WRF Model Simulations of Terrain-Driven Atmospheric Eddies in Marine Stratocumulus Clouds

NASA Astrophysics Data System (ADS)

Muller, B. M.; Herbster, C. G.; Mosher, F. R.

2014-12-01

It is not unusual to observe atmospheric eddies in satellite imagery of the marine stratus and stratocumulus clouds that characterize the summertime weather of the California coastal region and near-shore oceanic environment. The winds of the marine atmospheric boundary layer (MABL) over the ocean interact with the high terrain of prominent headlands and islands to create order-10 km scale areas of swirling air that can contain a cloud-free eye, 180-degree wind reversals at the surface over a period of minutes, and may be associated with mixing and turbulence between the high-humidity air of the MABL and the much warmer and drier inversion layer air above. However, synoptic and even subsynoptic surface weather measurements, and the synoptic upper-air observing network are inadequate, or in some cases, completely unable, to detect and characterize the formation, movement, and even the existence of the eddies. They can literally slip between land-based surface observation locations, or stay over the near-shore ocean environment where there may be no surface meteorological measurements. This study presents Weather Research and Forecasting (WRF) Model simulations of these small-scale, terrain-driven, atmospheric features in the MABL from cases detected in GOES satellite imagery. The purpose is to use model output to diagnose the formation mechanisms, sources of vorticity, and the air flow in and around the eddies. Satellite imagery is compared to simulated atmospheric variables to validate features generated within the model atmosphere, and model output is employed as a surrogate atmosphere to better understand the atmospheric characteristics of the eddies. Model air parcel trajectories are estimated to trace the movement and sources of the air contained in and around these often-observed, but seldom-measured features.

The Chemical Composition of Fogs and Clouds in Southern California.

NASA Astrophysics Data System (ADS)

Munger, James William

Fog and clouds are frequent occurrences in Southern California. Their chemical composition is of interest due to their potential role in the transformation of sulfur and nitrogen oxides to sulfuric and nitric acid and in the subsequent deposition of those acids. In addition, cloud and fog droplets may be involved in the chemistry of low-molecular-weight carboxylic acids and carbonyl compounds. The major inorganic species in cloud and fogwater samples were NH_4^+, H ^+, NO_3^-, and SO_4^{2-}. Concentrations in fogwater samples were 1-10 times 10^ {-3} M; pH values ranged from ~eq2 to 6. Nitrate usually exceeded sulfate. Acidity depended on the availability of of NH_3 from agricultural operations. Stratus cloudwater had somewhat lower concentrations; pH values were in the range 3-4. The major factors accounting for variation in fog- or cloudwater composition were the preexisting aerosol and gas concentrations and variations in liquid water content. Deposition and entrainment or advection of different air masses were also important during extended cloud or fog episodes. The droplet size dependence of cloudwater composition was investigated on one occasion in an intercepted coastal stratus clouds. The observations were consistent with the hypothesis that small droplets form on small secondary aerosol composed of H_2SO _4, HNO_3, and their NH_4^+ salts, while large droplets form on large sea-salt and soil-dust aerosol. Species that can exist in the gas phase, such as HCl and HNO _3, may be found in either droplet-size fraction. Concentrations of S(IV) and CH_2 O in the range 100-1000 μm were observed in fogwater from urban sites in Southern California. Lower concentrations were observed in stratus clouds. The high levels of S(IV) and CH_2 O were attributed to the formation of hydroxymethanesulfonate (HMSA), the S(IV) adduct of CH_2O. Direct measurement of HMSA in fogwater samples from Bakersfield, CA were made by ion-pairing chromatography. Glyoxal and methylglyoxal were observed at concentrations comparable to CH_2O in fogwater samples from Riverside, CA and in stratus cloudwater samples from sites along the Santa Barbara Channel.

Aerosol and Cloud Microphysical Characteristics of Rifts and Gradients in Maritime Stratocumulus Clouds

NASA Technical Reports Server (NTRS)

Sharon, Tarah M.; Albrecht, Bruce A.; Jonsson, Haflidi H.; Minnis, Patrick; Khaiyer, Mandana M.; Van Reken, Timothy; Seinfeld, John; Flagan, Rick

2008-01-01

A cloud rift is characterized as a large-scale, persistent area of broken, low reflectivity stratocumulus clouds usually surrounded by a solid deck of stratocumulus. A rift observed off the coast of Monterey Bay, California on 16 July 1999 was studied to compare the aerosol and cloud microphysical properties in the rift with those of the surrounding solid stratus deck. Variables measured from an instrumented aircraft included temperature, water vapor, and cloud liquid water. These measurements characterized the thermodynamic properties of the solid deck and rift areas. Microphysical measurements made included aerosol, cloud drop and drizzle drop concentrations and cloud condensation nuclei (CCN) concentrations. The microphysical characteristics in a solid stratus deck differ substantially from those of a broken, cellular rift where cloud droplet concentrations are a factor of 2 lower than those in the solid cloud. Further, CCN concentrations were found to be about 3 times greater in the solid cloud area compared with those in the rift and aerosol concentrations showed a similar difference as well. Although drizzle was observed near cloud top in parts of the solid stratus cloud, the largest drizzle rates were associated with the broken clouds within the rift area. In addition to marked differences in particle concentrations, evidence of a mesoscale circulation near the solid cloud rift boundary is presented. This mesoscale circulation provides a mechanism for maintaining a rift, but further study is required to understand the initiation of a rift and the conditions that may cause it to fill.

Examining Influence of Fog and Stratus Clouds on Bishop Pine Water Budgets, Channel Islands, CA

NASA Astrophysics Data System (ADS)

Fischer, D. T.; Still, C. J.; Williams, A. P.

2004-12-01

We present the first results from a project whose goal is to advance our basic understanding of the role that fog and persistent stratus clouds play in ecological processes in the California Channel Islands. Our work is focused on a population of Bishop Pines (Pinus muricata) on Santa Cruz Island (SCI), the largest, most topographically complex and most biologically diverse island along the California coast. This is the southernmost population (except for an outlier stand near San Vicente, Baja California), and tree growth appears to be water-limited in such a marginal habitat. We hypothesize that persistent fog and low stratus clouds enhance the water balance of these trees via direct water inputs (fog drip and foliar absorption) and reduced solar heating. To assess these possible effects, we have established weather stations and fog and rain collectors throughout the largest Bishop pine stand on SCI. Initial analysis of weather data shows dramatic differences in solar loading over short distances. We present data on the isotopic content (oxygen-18 and hydrogen-2) of water samples collected from winter 2003 to summer 2004. The samples we collected include fogwater, rainfall, water vapor, soil water, leaf and xylem water, and stream water. We also collected and analyzed leaf biomass and soil organic matter samples at periodic intervals for carbon-13 content. These latter data are evaluated in light of extensive leaf-level ecophysiological data collected in the field and as part of a parallel greenhouse study.

Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

NASA Technical Reports Server (NTRS)

Abshire, James B.; Ramanathan, Anand; Riris, Haris; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Weaver, Clark J.; Browell, Edward V.

2013-01-01

We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5-6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s) matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2-3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were <1.4 ppm for flight measurement altitudes >6 km.

Drivers of Intra-Summer Seasonality and Daily Variability of Coastal Low Cloudiness in California Subregions

NASA Astrophysics Data System (ADS)

Schwartz, R. E.; Iacobellis, S.; Gershunov, A.; Williams, P.; Cayan, D. R.

2014-12-01

Summertime low cloud intrusion into the terrestrial west coast of North America impacts human, ecological, and logistical systems. Over a broad region of the West Coast, summer (May - September) coastal low cloudiness (CLC) varies coherently on interannual to interdecadal timescales and has been found to be organized by North Pacific sea surface temperature. Broad-scale studies of low stratiform cloudiness over ocean basins also find that the season of maximum low stratus corresponds to the season of maximum lower tropospheric stability (LTS) or estimated inversion strength. We utilize a 18-summer record of CLC derived from NASA/NOAA Geostationary Operational Environmental Satellite (GOES) at 4km resolution over California (CA) to make a more nuanced spatial and temporal examination of intra-summer variability in CLC and its drivers. We find that uniform spatial coherency over CA is not apparent for intra-summer variability in CLC. On monthly to daily timescales, at least two distinct subregions of coastal California (CA) can be identified, where relationships between meteorology and stratus variability appear to change throughout summer in each subregion. While north of Point Conception and offshore the timing of maximum CLC is closely coincident with maximum LTS, in the Southern CA Bight and northern Baja region, maximum CLC occurs up to about a month before maximum LTS. It appears that summertime CLC in this southern region is not as strongly related as in the northern region to LTS. In particular, although the relationship is strong in May and June, starting in July the daily relationship between LTS and CLC in the south begins to deteriorate. Preliminary results indicate a moderate association between decreased CLC in the south and increased precipitable water content above 850 hPa on daily time scales beginning in July. Relationships between daily CLC variability and meteorological variables including winds, inland temperatures, relative humidity, and geopotential heights within and above the marine boundary layer are investigated and dissected by month, CA subregion, and cloud height. The rich spatial detail of the satellite derived CLC record is utilized to examine the propagation in time and space of CLC on synoptic scales within and among subregions.

Urbanization Causes Increased Cloud Base Height and Decreased Fog in Coastal Southern California

NASA Technical Reports Server (NTRS)

Williams, A. Park; Schwartz, Rachel E.; Iacobellis, Sam; Seager, Richard; Cook, Benjamin I.; Still, Christopher J.; Husak, Gregory; Michaelsen, Joel

2015-01-01

Subtropical marine stratus clouds regulate coastal and global climate, but future trends in these clouds are uncertain. In coastal Southern California (CSCA), interannual variations in summer stratus cloud occurrence are spatially coherent across 24 airfields and dictated by positive relationships with stability above the marine boundary layer (MBL) and MBL height. Trends, however, have been spatially variable since records began in the mid-1900s due to differences in nighttime warming. Among CSCA airfields, differences in nighttime warming, but not daytime warming, are strongly and positively related to fraction of nearby urban cover, consistent with an urban heat island effect. Nighttime warming raises the near-surface dew point depression, which lifts the altitude of condensation and cloud base height, thereby reducing fog frequency. Continued urban warming, rising cloud base heights, and associated effects on energy and water balance would profoundly impact ecological and human systems in highly populated and ecologically diverse CSCA.

Marine stratus initiative at San Francisco International Airport

DOT National Transportation Integrated Search

1996-06-25

San Francisco International Airport is one of the busiest airports in the United States and one of the highest delay airports in terms of total aircraft delay hours and number of imposed air traffic delay programs. May through September, weather fore...

Observational and Modeling Studies of Mixed-Phase Arctic Stratus: Results From M-PACE and Future Investigations as a Part of SEARCH

NASA Astrophysics Data System (ADS)

de Boer, G.; Eloranta, E. W.; Tripoli, G. J.; Hashino, T.

2005-12-01

A combination of unique observational and modeling tools is being utilized at the University of Wisconsin-Madison to investigate mixed-phase Arctic stratus formation and evolution, and aerosol influence on these processes. The combination of detailed measurements and advanced simulation techniques provides increased insight into processes governing the existence of these cloud structures. Simulations are completed using the Univ. of Wisconsin Non-Hydrostatic Modeling System (UW-NMS). The NMS is fully scalable, and currently being updated to include the Spectral Habitat Ice Prediction System (SHIPS). This new form of microphysics is built on interacting predictive systems for ice and liquid hydrometeors, and aerosols. The hydrometeor size spectra evolve through a modified spectral approach. No a-priori assumptions are made about ice characteristics such as habit, size and density. Instead, they evolve freely. The Univ. of Wisconsin Arctic High-Spectral Resolution Lidar (UW-AHSRL) was designed for long-term unattended Arctic operation and features unique measurement capabilities. Utilizing a molecular reference channel, the AHSRL provides absolutely calibrated measurements of aerosol backscatter cross-section, polarization, and optical depth, in addition to traditional lidar backscatter profiles. Algorithms utilizing AHSRL data in conjunction with millimeter radar data determine microphysical properties such as particle equivalent radius, and potentially liquid and ice water content. The AHSRL was deployed to Barrow, AK as part of M-PACE and is currently located in Eureka, Canada for the SEARCH campaign. Both of these locations host a NOAA Millimeter Wave Cloud Radar, aiding in the implementation of the above-mentioned algorithms. The AHSRL, combined with additional cloud and aerosol measurement instrumentation at these Arctic locations, provides an expansive source of mixed-phase cloud data to be used individually and as validation for UW-NMS simulations. We will outline current work being completed at the Univ. of Wisconsin, as well as present results from M-PACE simulations and data analysis and preliminary SEARCH measurements.

The cloud radiation impact from optics simulation and airborne observation

NASA Astrophysics Data System (ADS)

Melnikova, Irina; Kuznetsov, Anatoly; Gatebe, Charles

2017-02-01

The analytical approach of inverse asymptotic formulas of the radiative transfer theory is used for solving inverse problems of cloud optics. The method has advantages because it does not impose strict constraints, but it is tied to the desired solution. Observations are accomplished in extended stratus cloudiness, above a homogeneous ocean surface. Data from NASA`s Cloud Absorption Radiometer (CAR) during two airborne experiments (SAFARI-2000 and ARCTAS-2008) were analyzed. The analytical method of inverse asymptotic formulas was used to retrieve cloud optical parameters (optical thickness, single scattering albedo and asymmetry parameter of the phase function) and ground albedo in all 8 spectral channels independently. The method is free from a priori restrictions and there is no links to parameters, and it has been applied to data set of different origin and geometry of observations. Results obtained from different airborne, satellite and ground radiative experiments appeared consistence and showed common features of values of cloud parameters and its spectral dependence (Vasiluev, Melnikova, 2004; Gatebe et al., 2014). Optical parameters, retrieved here, are used for calculation of radiative divergence, reflected and transmitted irradiance and heating rates in cloudy atmosphere, that agree with previous observational data.

Understanding the tropical warm temperature bias simulated by climate models

NASA Astrophysics Data System (ADS)

Brient, Florent; Schneider, Tapio

2017-04-01

The state-of-the-art coupled general circulation models have difficulties in representing the observed spatial pattern of surface tempertaure. A majority of them suffers a warm bias in the tropical subsiding regions located over the eastern parts of oceans. These regions are usually covered by low-level clouds scattered from stratus along the coasts to more vertically developed shallow cumulus farther from them. Models usually fail to represent accurately this transition. Here we investigate physical drivers of this warm bias in CMIP5 models through a near-surface energy budget perspective. We show that overestimated solar insolation due to a lack of stratocumulus mostly explains the warm bias. This bias also arises partly from inter-model differences in surface fluxes that could be traced to differences in near-surface relative humidity and air-sea temperature gradient. We investigate the role of the atmosphere in driving surface biases by comparing historical and atmopsheric (AMIP) experiments. We show that some differences in boundary-layer characteristics, mostly those related to cloud fraction and relative humidity, are already present in AMIP experiments and may be the drivers of coupled biases. This gives insights in how models can be improved for better simulations of the tropical climate.

[Nutritional status in preschoolers attending a public day-care center in Valencia, Venezuela].

PubMed

Real, Sara Irene del; Jaeger, Armando Sánchez; Barón, María Adela; Díaz, Nayka; Solano, Liseti; Velásquez, Emma; López, Jesús

2007-09-01

With the purpose of evaluating nutritional status in a group of preschoolers attending a public day care center in Valencia, Venezuela (2002), a research was made for social stratus, anthropometric variables; weight, height and arm circumference, hemoglobin, seric retinol, presence of parasitosis and food consumption, as well as the mother's educational level. The program SPSS 11.0 and the t Student, ANOVA Post Hoc from Bonferroni and Fisher (p < 0.05) were used. A predominance of the female sex was presented (52%). According to the social stratus, 23.3% was located in the middleclass, and 76.8% on some level of poverty. 60% of the middleclass mothers had finished their high school education, while only 9.8% of the mothers in poverty had reached that level. According to the Z values (H/A, W/H and AC/H), high percentages under -1.00 were observed (27.3%, 25.6% and 24.5%, respectively). The W/H and AC/H of children of mothers studying in a university presented discrepancies when compared with children of mothers with a primary educational level. A 25.9% of anemia was presented, and there were differences between anemic and non-anemic groups for H/A and AC/H. Protozoaries were observed in 61.0%, helmintos in 16.9% and both in 22.1%. There was a 2.6 times higher risk of presenting nutritional deficiency for AC/H in the group found with parasites. An adequate consumption of energy and iron was found, with an excessive consumption of proteins and vitamin A. It is concluded that there exists a nutritional risk evaluated through hematologic parameters, the presence of parasitosis and social stratus.

Estimation of ice activation parameters within a particle tracking Lagrangian cloud model using the ensemble Kalman filter to match ISCDAC golden case observations

NASA Astrophysics Data System (ADS)

Reisner, J. M.; Dubey, M. K.

2010-12-01

To both quantify and reduce uncertainty in ice activation parameterizations for stratus clouds occurring in the temperature range between -5 to -10 C ensemble simulations of an ISDAC golden case have been conducted. To formulate the ensemble, three parameters found within an ice activation model have been sampled using a Latin hypercube technique over a parameter range that induces large variability in both number and mass of ice. The ice activation model is contained within a Lagrangian cloud model that simulates particle number as a function of radius for cloud ice, snow, graupel, cloud, and rain particles. A unique aspect of this model is that it produces very low levels of numerical diffusion that enable the model to accurately resolve the sharp cloud edges associated with the ISDAC stratus deck. Another important aspect of the model is that near the cloud edges the number of particles can be significantly increased to reduce sampling errors and accurately resolve physical processes such as collision-coalescence that occur in this region. Thus, given these relatively low numerical errors, as compared to traditional bin models, the sensitivity of a stratus deck to changes in parameters found within the activation model can be examined without fear of numerical contamination. Likewise, once the ensemble has been completed, ISDAC observations can be incorporated into a Kalman filter to optimally estimate the ice activation parameters and reduce overall model uncertainty. Hence, this work will highlight the ability of an ensemble Kalman filter system coupled to a highly accurate numerical model to estimate important parameters found within microphysical parameterizations containing high uncertainty.

Effect of pupillary dilatation on glaucoma assessments using optical coherence tomography

PubMed Central

Smith, Michael; Frost, Andrew; Graham, Christopher Mark; Shaw, Steven

2007-01-01

Aims To examine the effect of pupillary dilatation on the reliability of retinal nerve fibre layer (RNFL) and optic nerve head (ONH) assessments using Stratus OCT in a glaucoma clinic. Methods Observational study of 38 patients attending a glaucoma clinic. The “fast optic disc” and “fast RNFL thickness” programs on Stratus OCT were used to measure the RNFL thickness and ONH cup to disc ratio (CDR). Two scans were done before dilatation and two after dilatation with tropicamide 1% drops. The mean values and reproducibility before and after dilatation were compared, along with the quality of scans as indicated by the “signal strength” score. Results In nine patients (23.7%) no images were obtained undilated but after dilatation examination was possible in all patients. Inability to obtain an undilated scan was associated with smaller pupil size and increasing cataract. The scan quality, as judged by the signal strength score, was higher dilated than undilated for both RNFL thickness (p = 0.011) and ONH CDR (p = 0.007). Reproducibility was higher with dilated scans for RNFL thickness but not for ONH CDR. There were significant differences between the dilated and undilated examinations for three of the five RNFL thickness variables and two of the three ONH CDR categories. Conclusions Acquisition of high quality OCT images was not possible without pupillary dilatation in about 25% of the patients. The dilated scans were more reproducible and of higher quality than the undilated scans. The two methods of examination do not appear to be interchangeable, suggesting that in follow up examinations the pupil should be in the same condition as at baseline. Pupillary dilatation is recommended before glaucoma assessments using Stratus OCT. PMID:17556429

An Observational Case Study of Persistent Fog and Comparison with an Ensemble Forecast Model

NASA Astrophysics Data System (ADS)

Price, Jeremy; Porson, Aurore; Lock, Adrian

2015-05-01

We present a study of a persistent case of fog and use the observations to evaluate the UK Met Office ensemble model. The fog appeared to form initially in association with small patches of low-level stratus and spread rapidly across southern England during 11 December 2012, persisting for 24 h. The low visibility and occurrence of fog associated with the event was poorly forecast. Observations show that the surprisingly rapid spreading of the layer was due to a circulation at the fog edge, whereby cold cloudy air subsided into and mixed with warmer adjacent clear air. The resulting air was saturated, and hence the fog layer grew rapidly outwards from its edge. Measurements of fog-droplet deposition made overnight show that an average of 12 g m h was deposited but that the liquid water content remained almost constant, indicating that further liquid was condensing at a similar rate to the deposition, most likely due to the slow cooling. The circulation at the fog edge was also present during its dissipation, by which time the fog top had lowered by 150 m. During this period the continuing circulation at the fog edge, and increasing wind shear at fog top, acted to dissipate the fog by creating mixing with, by then, the drier adjacent and overlying air. Comparisons with a new, high resolution Met Office ensemble model show that this type of case remains challenging to simulate. Most ensemble members successfully simulated the formation and persistence of low stratus cloud in the region, but produced too much cloud initially overnight, which created a warm bias. During the daytime, ensemble predictions that had produced fog lifted it into low stratus, whilst in reality the fog remained present all day. Various aspects of the model performance are discussed further.

Correlation between retinal nerve fibre layer thickness and optic nerve head size: an optical coherence tomography study.

PubMed

Savini, G; Zanini, M; Carelli, V; Sadun, A A; Ross-Cisneros, F N; Barboni, P

2005-04-01

To investigate the correlation between retinal nerve fibre layer (RNFL) thickness and optic nerve head (ONH) size in normal white subjects by means of optical coherence tomography (OCT). 54 eyes of 54 healthy subjects aged between 15 and 54 underwent peripapillary RNFL thickness measurement by a series of three circular scans with a 3.4 mm diameter (Stratus OCT, RNFL Thickness 3.4 acquisition protocol). ONH analysis was performed by means of six radial scans centred on the optic disc (Stratus OCT, Fast Optic Disc acquisition protocol). The mean RNFL values were correlated with the data obtained by ONH analysis. The superior, nasal, and inferior quadrant RNFL thickness showed a significant correlation with the optic disc area (R = 0.3822, p = 0.0043), (R = 0.3024, p = 0.026), (R = 0.4048, p = 0.0024) and the horizontal disc diameter (R = 0.2971, p = 0.0291), (R = 0.2752, p = 0.044), (R = 0.3970, p = 0.003). The superior and inferior quadrant RNFL thickness was also positively correlated with the vertical disc diameter (R = 0.3774, p = 0.0049), (R = 0.2793, p = 0.0408). A significant correlation was observed between the 360 degrees average RNFL thickness and the optic disc area and the vertical and horizontal disc diameters of the ONH (R = 0.4985, p = 0.0001), (R = 0.4454, p = 0.0007), (R = 0.4301, p = 0.0012). RNFL thickness measurements obtained by Stratus OCT increased significantly with an increase in optic disc size. It is not clear if eyes with large ONHs show a thicker RNFL as a result of an increased amount of nerve fibres or to the shorter distance between the circular scan and the optic disc edge.

Validation of Satellite Derived Cloud Properties Over the Southeastern Pacific

NASA Astrophysics Data System (ADS)

Ayers, J.; Minnis, P.; Zuidema, P.; Sun-Mack, S.; Palikonda, R.; Nguyen, L.; Fairall, C.

2005-12-01

Satellite measurements of cloud properties and the radiation budget are essential for understanding meso- and large-scale processes that determine the variability in climate over the southeastern Pacific. Of particular interest in this region is the prevalent stratocumulus cloud deck. The stratocumulus albedos are directly related to cloud microphysical properties that need to be accurately characterized in Global Climate Models (GCMs) to properly estimate the Earth's radiation budget. Meteorological observations in this region are sparse causing large uncertainties in initialized model fields. Remote sensing from satellites can provide a wealth of information about the clouds in this region, but it is vital to validate the remotely sensed parameters and to understand their relationship to other parameters that are not directly observed by the satellites. The variety of measurements from the R/V Roger Revelle during the 2003 STRATUS cruise and from the R/V Ron Brown during EPIC 2001 and the 2004 STRATUS cruises are suitable for validating and improving the interpretation of the satellite derived cloud properties. In this study, satellite-derived cloud properties including coverage, height, optical depth, and liquid water path are compared with in situ measurements taken during the EPIC and STRATUS cruises. The remotely sensed values are derived from Geostationary Operational Environmental Satellite (GOES) imager data, Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra and Aqua satellites, and from the Visible and Infrared Scanner (VIRS) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite. The products from this study will include regional monthly cloud climatologies derived from the GOES data for the 2003 and 2004 cruises as well as micro and macro physical cloud property retrievals centered over the ship tracks from MODIS and VIRS.

Properties of CIRRUS Overlapping Clouds as Deduced from the GOES-12 Imagery Data

NASA Technical Reports Server (NTRS)

Chang, Fu-Lung; Minnis, Patrick; Lin, Bing; Sun-Mack, Sunny; Khaiyer, Mandana

2006-01-01

Understanding the impact of cirrus clouds on modifying both the solar reflected and terrestrial emitted radiations is crucial for climate studies. Unlike most boundary layer stratus and stratocumulus clouds that have a net cooling effect on the climate, high-level thin cirrus clouds can have a warming effect on our climate. Many research efforts have been devoted to retrieving cirrus cloud properties due to their ubiquitous presence. However, using satellite observations to detect and/or retrieve cirrus cloud properties faces two major challenges. First, they are often semitransparent at visible to infrared wavelengths; and secondly, they often occur over a lower cloud system. The overlapping of high-level cirrus and low-level stratus cloud poses a difficulty in determining the individual cloud top altitudes and optical properties, especially when the signals from cirrus clouds are overwhelmed by the signals of stratus clouds. Moreover, the operational satellite retrieval algorithms, which often assume only single layer cloud in the development of cloud retrieval techniques, cannot resolve the cloud overlapping situation properly. The new geostationary satellites, starting with the Twelfth Geostationary Operational Environmental Satellite (GOES-12), are providing a new suite of imager bands that have replaced the conventional 12-micron channel with a 13.3-micron CO2 absorption channel. The replacement of the 13.3-micron channel allows for the application of a CO2-slicing retrieval technique (Chahine et al. 1974; Smith and Platt 1978), which is one of the important passive satellite methods for remote sensing the altitudes of mid to high-level clouds. Using the CO2- slicing technique is more effective in detecting semitransparent cirrus clouds than using the conventional infrared-window method.

Cloud shading and fog drip influence the metabolism of a coastal pine ecosystem.

PubMed

Carbone, Mariah S; Park Williams, A; Ambrose, Anthony R; Boot, Claudia M; Bradley, Eliza S; Dawson, Todd E; Schaeffer, Sean M; Schimel, Joshua P; Still, Christopher J

2013-02-01

Assessing the ecological importance of clouds has substantial implications for our basic understanding of ecosystems and for predicting how they will respond to a changing climate. This study was conducted in a coastal Bishop pine forest ecosystem that experiences regular cycles of stratus cloud cover and inundation in summer. Our objective was to understand how these clouds impact ecosystem metabolism by contrasting two sites along a gradient of summer stratus cover. The site that was under cloud cover ~15% more of the summer daytime hours had lower air temperatures and evaporation rates, higher soil moisture content, and received more frequent fog drip inputs than the site with less cloud cover. These cloud-driven differences in environmental conditions translated into large differences in plant and microbial activity. Pine trees at the site with greater cloud cover exhibited less water stress in summer, larger basal area growth, and greater rates of sap velocity. The difference in basal area growth between the two sites was largely due to summer growth. Microbial metabolism was highly responsive to fog drip, illustrated by an observed ~3-fold increase in microbial biomass C with increasing summer fog drip. In addition, the site with more cloud cover had greater total soil respiration and a larger fractional contribution from heterotrophic sources. We conclude that clouds are important to the ecological functioning of these coastal forests, providing summer shading and cooling that relieve pine and microbial drought stress as well as regular moisture inputs that elevate plant and microbial metabolism. These findings are important for understanding how these and other seasonally dry coastal ecosystems will respond to predicted changes in stratus cover, rainfall, and temperature. © 2012 Blackwell Publishing Ltd.

Wet season water distribution in a tropical Andean cloud forest of Boyacá (Colombia) during the dry climate of El Niño

NASA Astrophysics Data System (ADS)

Garcia-Santos, G.; Berdugo, M. B.

2010-07-01

Fog has been demonstrated as the only source of moisture during the dry climate of El Niño in the tropical Andean cloud forest of Boyacá region in Colombia, yet its importance for the forest is virtually unknown. We assessed fog water distribution during the wet season inside the forest and outside in a practically deforested area. Water intercepted by plant was measured at different vertical stratus. Soil moisture in the first centimetres was also measured. During the anomalous drier wet season there was lack of rainfall and the total recorded cloud water was lower compared with the same period during the previous year. Our results indicated that the upper part of the forest mass intercepts most of the fog water compared with lower stratus when the fog event starts. However upper most stratus became rapidly drier after the event, which is explained because water is released to the atmosphere due to high heat atmosphere-leaves interface fluctuations caused by wind and solar radiation, flows towards a different water potential and drips from the leaves. Low amount of fog dripped from tree foliage into the soil, indicating a large water storage capacity of the epiphyte and bryophyte vegetation. Despite the small amount of throughfall, understory vegetation and litter remained wet, which might be explained by the water flowing through the epiphyte vegetation or the high capacity of the understory to absorb moisture from the air. Soil water did not infiltrate in depth, which underlines the importance of fog as water and cool source for seedling growth and shallow rooted understory species, especially during drier conditions.

Retinal Thickness Analysis by Race, Gender, and Age Using Stratus OCT™

PubMed Central

Kashani, Amir H.; Zimmer-Galler, Ingrid E.; Shah, Syed Mahmood; Dustin, Laurie; Do, Diana V.; Eliott, Dean; Haller, Julia A.; Nguyen, Quan Dong

2010-01-01

PURPOSE To detect differences in retinal thickness among patients of different race, gender and age using Stratus OCT™. DESIGN Cross-sectional study. METHODS In a multicenter, university-based study, 126 patients with no history of ocular disease were enrolled (78 diabetics without retinopathy and 48 nondiabetics). Optical coherence tomography measurements were performed using Stratus OCT™. Statistical comparisons of centerpoint foveal thickness and mean foveal thickness were made using generalized estimating equations adjusting for diabetic status, race, age, and gender. RESULTS The study population consisted of 36% males, 39% Caucasians, 33% African Americans, and 28% Hispanics. Mean foveal thickness was 191.6±2.7µm and 194.5±2.7µm for diabetics and nondiabetics, respectively (P=0.49). Mean foveal thickness in males was significantly larger than in females (201.8±2.7µm and 186.9±2.6µm, respectively; P<0.001). Mean foveal thickness was 200.2±2.7µm for Caucasians, 181.0±3.7µm for African Americans, and 194.7±3.9µm for Hispanics. Mean foveal thickness was significantly less for African Americans than Caucasians (P <0.0001) or Hispanics (P=0.005). Centerpoint foveal thickness and mean foveal thickness showed a significant increase with age. CONCLUSIONS There are statistically significant differences in retinal thickness between subjects of different race, gender, and age. When compared to Caucasians and Hispanics, African-American race is a predictor of decreased mean foveal thickness; and male sex (regardless of race) is a significant predictor of increased mean foveal thickness. Mean foveal thickness is similar among diabetics and nondiabetics when data are controlled for age, race, and sex. These results suggest that studies comparing OCT measurements should carefully control for age, race, and gender-based variations in retinal thickness. PMID:20042179

Meteorologial Techniques (Revision 21 Feb 2007)

DTIC Science & Technology

2003-06-13

Dissipation of Stratus Using Mixing Ratio and Temperature ------------------------- 2-12 Figure 2-27 Tropopause Method of Forecasting Cirrus...2-51 Figure 2-70 Bright Band Identification Using the WSR-88D...convective clouds using surface dew-point depressions --------------------- 2-11 Table 2-5 Aircraft category type

Sequoia: A fault-tolerant tightly coupled multiprocessor for transaction processing

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

Bernstein, P.A.

1988-02-01

The Sequoia computer is a tightly coupled multiprocessor, and thus attains the performance advantages of this style of architecture. It avoids most of the fault-tolerance disadvantages of tight coupling by using a new fault-tolerance design. The Sequoia architecture is similar to other multimicroprocessor architectures, such as those of Encore and Sequent, in that it gives dozens of microprocessors shared access to a large main memory. It resembles the Stratus architecture in its extensive use of hardware fault-detection techniques. It resembles Stratus and Auragen in its ability to quickly recover all processes after a single point failure, transparently to the user.more » However, Sequoia is unique in its combination of a large-scale tightly coupled architecture with a hardware approach to fault tolerance. This article gives an overview of how the hardware architecture and operating systems (OS) work together to provide a high degree of fault tolerance with good system performance.« less

Near-IR extinction and backscatter coefficient measurements in low- and mid-altitude clouds

NASA Technical Reports Server (NTRS)

Sztankay, Z. G.

1986-01-01

Knowledge of the attenuation and backscattering properties of clouds is required to high resolution for several types of optical sensing systems. Such data was obtained in about 15 hours of flights through clouds in the vicinity of Washington, D.C. The flights were mainly through stratocumulus, altocumulus, stratus, and stratus fractus clouds and covered an altitude and temperature range of 300 to 3200 m and -13 to 17 C. Two instruments were flown, each of which measured the backscatter from close range in two range bins to independently determine both the extinction and backscatter coefficients. The extinction and backscatter coefficients can be obtained from the signals in the two channels of each instrument, provided that the aerosol is uniform over the measurement region. When this assumptions holds, the extinction coefficient is derived basically from the ratio of the signal in the two channels; the backscatter coefficient can then be obtained from the signal in either channel.

Ultrahigh-Resolution Optical Coherence Tomography in Glaucoma

PubMed Central

Wollstein, Gadi; Paunescu, Leila A.; Ko, Tony H.; Fujimoto, James G.; Kowalevicz, Andrew; Hartl, Ingmar; Beaton, Siobahn; Ishikawa, Hiroshi; Mattox, Cynthia; Singh, Omah; Duker, Jay; Drexler, Wolfgang; Schuman, Joel S.

2007-01-01

Objective Optical coherence tomography (OCT) has been shown to be a valuable tool in glaucoma assessment. We investigated a new ultrahigh-resolution OCT (UHR-OCT) imaging system in glaucoma patients and compared the findings with those obtained by conventional-resolution OCT. Design Retrospective comparative case series. Participants A normal subject and 4 glaucoma patients representing various stages of glaucomatous damage. Testing All participants were scanned with StratusOCT (axial resolution of ~10 μm) and UHR-OCT (axial resolution of ~3 μm) at the same visit. Main Outcome Measure Comparison of OCT findings detected with StratusOCT and UHR-OCT. Results Ultrahigh-resolution OCT provides a detailed cross-sectional view of the scanned retinal area that allows differentiation between retinal layers. These UHR images were markedly better than those obtained by the conventional-resolution OCT. Conclusions Ultrahigh-resolution OCT provides high-resolution images of the ocular posterior segment, which improves the ability to detect retinal abnormalities due to glaucoma. PMID:15691556

A Climatology of Midlatitude Continental Clouds from the ARM SGP Site. Part I; Low-Level Cloud Macrophysical, Microphysical, and Radiative Properties

NASA Technical Reports Server (NTRS)

Dong, Xiquan; Minnis, Patrick; Xi, Baike

2005-01-01

A record of single-layer and overcast low cloud (stratus) properties has been generated using approximately 4000 hours of data collected from January 1997 to December 2002 at the Atmospheric Radiation Measurement (ARM) Southern Great Plains Central Facility (SCF). The cloud properties include liquid-phase and liquid-dominant, mixed-phase, low cloud macrophysical, microphysical, and radiative properties including cloud-base and -top heights and temperatures, and cloud physical thickness derived from a ground-based radar and lidar pair, and rawinsonde sounding; cloud liquid water path (LWP) and content (LWC), and cloud-droplet effective radius (r(sub e)) and number concentration (N) derived from the macrophysical properties and radiometer data; and cloud optical depth (tau), effective solar transmission (gamma), and cloud/top-of-atmosphere albedos (R(sub cldy)/R(sub TOA)) derived from Eppley precision spectral pyranometer measurements. The cloud properties were analyzed in terms of their seasonal, monthly, and hourly variations. In general, more stratus clouds occur during winter and spring than in summer. Cloud-layer altitudes and physical thicknesses were higher and greater in summer than in winter with averaged physical thicknesses of 0.85 km and 0.73 km for day and night, respectively. The seasonal variations of LWP, LWC, N. tau, R(sub cldy), and R(sub TOA) basically follow the same pattern with maxima and minima during winter and summer, respectively. There is no significant variation in mean r(sub e), however, despite a summertime peak in aerosol loading, Although a considerable degree of variability exists, the 6-yr average values of LWP, LWC, r(sub e), N, tau, gamma, R(sub cldy) and R(sub TOA) are 150 gm(exp -2) (138), 0.245 gm(exp -3) (0.268), 8.7 micrometers (8.5), 213 cm(exp -3) (238), 26.8 (24.8), 0.331, 0.672, 0.563 for daytime (nighttime). A new conceptual model of midlatitude continental low clouds at the ARM SGP site has been developed from this study. The low stratus cloud amount monotonically increases from midnight to early morning (0930 LT), and remains large until around local noon, then declines until 1930 LT when it levels off for the remainder of the night. In the morning, the stratus cloud layer is low, warm, and thick with less LWC, while in the afternoon it is high, cold, and thin with more LWC. Future parts of this series will consider other cloud types and cloud radiative forcing at the ARM SCF.

Simulation of the modern arctic climate by the NCAR CCM1

NASA Technical Reports Server (NTRS)

Bromwich, David H.; Tzeng, Ren-Yow; Parish, Thomas, R.

1994-01-01

The National Center of Atmospheric Research (NCAR) Community Climate Model Version 1 (CCM1's) simulation of the modern arctic climate is evaluated by comparing a five-year seasonal cycle simulation with the European Center for Medium-Range Weather Forecasts (ECMWF) global analyses. The sea level pressure (SLP), storm tracks, vertical cross section of height, 500-hPa height, total energy budget, and moisture budget are analyzed to investigate the biases in the simulated arctic climate. The results show that the model simulates anomalously low SLP, too much storm activity, and anomalously strong baroclinicity to the west of Greenland and vice versa to the east of Greenland. This bias is mainly attributed to the model's topographic representation of Greenland. First, the broadened Greenland topography in the model distorts the path of cyclone waves over the North Atlantic Ocean. Second, the model oversimulates the ridge over Greenland, which intensifies its blocking effect and steers the cyclone waves clockwise around it and hence produces an artificial circum-Greenland trough. These biases are significantly alleviated when the horizontal resolution increases to T42. Over the Arctic basin, the model simulates large amounts of low-level (stratus) clouds in winter and almost no stratus in summer, which is opposite to the observations. This bias is mainly due to the location of the simulated SLP features and the negative anomaly of storm activity, which prevent the transport of moisture into this region during summer but favor this transport in winter. The moisture budget analysis shows that the model's net annual precipitation (P-E) between 70 deg N and the North Pole is 6.6 times larger than the observations and the model transports six times more moisture into this region. The bias in the advection term is attributed to the positive moisture fixer scheme and the distorted flow pattern. However, the excessive moisture transport into the Arctic basin does not solely result from the advection term. The contribution by the moisture fixer is as large as from advection. By contrast, the semi-Lagrangian transport scheme used in the CCM2 significantly improves the moisture simulation for this region; however, globally the error is as serious as for the positive moisture fixer scheme. Finally, because the model has such serious problems in simulating the present arctic climate, its simulations of past and future climate change for this region are questionable.

Spring Regimes

DTIC Science & Technology

2003-04-15

of Albuquerque, New Mexico. . Since the system has “bottomed out” one could project a straight line northeastward (with little eastward movement of...in determining if forecast model guidance is “on track.” 14. 14. Subject Terms: CLOUDS, COMMA CLOUD, DRY LINE , GULF STRATUS, HEIGHT FALL CENTERS...4-40 Warm Fronts, Squall Lines and Mesocyclones

San Francisco and Bay Area, CA, USA

NASA Image and Video Library

1991-05-06

STS039-151-181A (28 April-6 May 1991) --- Large format (five-inch) frame of the San Francisco/Oakland Bay Area of northern California. Stratus clouds at 35,000 feet and cumulus clouds at about 15,000 feet are seen over the Pacific Coast, obscuring the Golden Gate Bridge.

Comparison of CERES-MODIS stratus cloud properties with ground-based measurements at the DOE ARM Southern Great Plains site

NASA Astrophysics Data System (ADS)

Dong, Xiquan; Minnis, Patrick; Xi, Baike; Sun-Mack, Sunny; Chen, Yan

2008-02-01

Overcast stratus cloud properties derived for the Clouds and the Earth's Radiant Energy System (CERES) project using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data are compared with observations taken at the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains site from March 2000 through December 2004. Retrievals from ARM surface-based data were averaged over a 1-h interval centered at the time of each satellite overpass, and the CERES-MODIS cloud properties were averaged within a 30 km × 30 km box centered on the ARM SGP site. Two data sets were analyzed: all of the data (ALL), which include multilayered, single-layered, and slightly broken stratus decks and a subset, single-layered unbroken decks (SL). The CERES-MODIS effective cloud heights were determined from effective cloud temperature using a lapse rate method with the surface temperature specified as the 24-h mean surface air temperature. For SL stratus, they are, on average, within the ARM radar-lidar estimated cloud boundaries and are 0.534 ± 0.542 km and 0.108 ± 0.480 km lower than the cloud physical tops and centers, respectively, and are comparable for day and night observations. The mean differences and standard deviations are slightly larger for ALL data, but not statistically different to those of SL data. The MODIS-derived effective cloud temperatures are 2.7 ± 2.4 K less than the surface-observed SL cloud center temperatures with very high correlations (0.86-0.97). Variations in the height differences are mainly caused by uncertainties in the surface air temperatures, lapse rates, and cloud top height variability. The biases are mainly the result of the differences between effective and physical cloud top, which are governed by cloud liquid water content and viewing zenith angle, and the selected lapse rate, -7.1 K km-1. On the basis of a total of 43 samples, the means and standard deviations of the differences between the daytime Terra and surface retrievals of effective radius re, optical depth, and liquid water path for SL stratus are 0.1 ± 1.9 μm (1.2 ± 23.5%), -1.3 ± 9.5 (-3.6 ± 26.2%), and 0.6 ± 49.9 gm-2 (0.3 ± 27%), respectively, while the corresponding correlation coefficients are 0.44, 0.87, and 0.89. For Aqua, they are 0.2 ± 1.9 μm (2.5 ± 23.4%), 2.5 ± 7.8 (7.8 ± 24.3%), and 28.1 ± 52.7 gm-2 (17.2 ± 32.2%), as well as 0.35, 0.96, and 0.93 from a total of 21 cases. The results for ALL cases are comparable. Although a bias in re was expected because the satellite retrieval of effective radius only represents the top of the cloud, the surface-based radar retrievals revealed that the vertical profile of re is highly variable with smaller droplets occurring at cloud top in some cases. The larger bias in optical depth and liquid water path for Aqua is due, at least partially, to differences in the Terra and Aqua MODIS visible channel calibrations. Methods for improving the cloud top height and microphysical property retrievals are suggested.

The role of simulated small-scale ocean variability in inverse computations for ocean acoustic tomography.

PubMed

Dushaw, Brian D; Sagen, Hanne

2017-12-01

Ocean acoustic tomography depends on a suitable reference ocean environment with which to set the basic parameters of the inverse problem. Some inverse problems may require a reference ocean that includes the small-scale variations from internal waves, small mesoscale, or spice. Tomographic inversions that employ data of stable shadow zone arrivals, such as those that have been observed in the North Pacific and Canary Basin, are an example. Estimating temperature from the unique acoustic data that have been obtained in Fram Strait is another example. The addition of small-scale variability to augment a smooth reference ocean is essential to understanding the acoustic forward problem in these cases. Rather than a hindrance, the stochastic influences of the small scale can be exploited to obtain accurate inverse estimates. Inverse solutions are readily obtained, and they give computed arrival patterns that matched the observations. The approach is not ad hoc, but universal, and it has allowed inverse estimates for ocean temperature variations in Fram Strait to be readily computed on several acoustic paths for which tomographic data were obtained.

Northern Chile and Andes Mountains seen from STS-61 Shuttle Endeavour

NASA Image and Video Library

1993-12-09

STS061-101-023 (8 Dec 1993) --- This color photograph is a spectacular, panoramic (southeastern view) shot that features the northern half of the country of Chile and the Andes Mountains of South America. The Atacama Desert, one of the driest regions on earth, is clearly visible along the northern Chilean coast. This desert extends from roughly Arica in the north to the city of Caldera in the south, a distance of six hundred miles. Some parts of this very arid region go for more than twenty years without measurable precipitation. It is an area of dramatic and abrupt elevation changes. For example, from the waters edge there is an escarpment of the coastal plateau that rises like an unbroken wall two or three thousand feet above the Pacific Ocean. From the coastal plateau, there is an even more dramatic increase in elevation -- from two thousand feet above sea level to an average elevation of thirteen thousand feet above sea level in the Bolivian Altiplano. This elevation change occurs within a one hundred to two hundred mile distance from the Pacific Ocean. The north-south trending spine of the Andes Mountains can be seen on this photograph. Several of the volcanic peaks in this mountain chain exceed 20,000 feet above sea level. Interspersed with these volcanic peaks, numerous dry lake beds (salars) can be seen as highly reflective surfaces. The largest of these salars (Salar de Uyuni) is visible at the edge of the Hubble Space Telescope (HST). Offshore, the cold Peruvian current produces low stratus clouds that can be found along this coastline at certain times of the year. This is the same type of meteorological phenomena that is found along the southern California coast and the Skeleton coast of southwestern Africa.

Earth Observations taken by Expedition 38 crewmember

NASA Image and Video Library

2014-01-28

ISS038-E-036501 (28 Jan. 2014) --- This wide field-of-view image photographed by an Expedition 38 crew member on the International Space Station shows an east-west swath of the southwestern Indian Ocean. Two remote islands, part of the French Southern and Antarctic Lands, appear in the center of the image. Possession Island (right center) and East Island (center) are both only 18 kilometers long. A smaller island, Ile aux Cochons (Pigs Island), lies 100 kilometers to the west. Each island has set up V-shaped trains of waves, like bow waves, as the air flows over the islands from the west (right to left). The bow-wave patterns are overlaid on the low regional stratus (blanket) cloud that is so common in the southern Indian Ocean at 50 degrees south latitude. This view was taken from more than 400 kilometers above the sea surface and reveals relationships that could not be readily understood by someone standing on one of the islands. For example, larger and higher islands produce larger waves. So the largest are being generated by Possession Island (934 meters above sea level at the highest point), and East Island, versus much smaller waves developed downwind of the tiny Ile de Pingouins (340 meters above sea level high, invisible below the cloud deck). Other patterns also can be detected. Waves in an upper layer can be seen casting shadows onto a lower layer (lower left). In the top half of the image the waves are making thicker and thinner zones in the clouds of the lower layer. Wave trains from Possession Island and Ile aux Cochons are interacting in a cross-hatch pattern (center).

Changes in the type of precipitation and associated cloud types in Eastern Romania (1961-2008)

NASA Astrophysics Data System (ADS)

Manea, Ancuta; Birsan, Marius-Victor; Tudorache, George; Cărbunaru, Felicia

2016-03-01

Recent climate change is characterized (among other things) by changes in the frequency of some meteorological phenomena. This paper deals with the long-term changes in various precipitation types, and the connection between their variability and cloud type frequencies, at 11 meteorological stations from Eastern Romania over 1961-2008. These stations were selected with respect to data record completeness for all considered variables (weather phenomena and cloud type). The meteorological variables involved in the present study are: monthly number of days with rain, snowfall, snow showers, rain and snow (sleet), sleet showers and monthly frequency of the Cumulonimbus, Nimbostratus and Stratus clouds. Our results show that all stations present statistically significant decreasing trends in the number of days with rain in the warm period of the year. Changes in the frequency of days for each precipitation type show statistically significant decreasing trends for non-convective (stratiform) precipitation - rain, drizzle, sleet and snowfall -, while the frequencies of rain shower and snow shower (convective precipitation) are increasing. Cloud types show decreasing trends for Nimbostratus and Stratus, and increasing trends for Cumulonimbus.

Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

NASA Technical Reports Server (NTRS)

Zhu, Jiang; Stevens, E.; Zhang, X.; Zavodsky, B. T.; Heinrichs, T.; Broderson, D.

2014-01-01

A case study and monthly statistical analysis using sounder data assimilation to improve the Alaska regional weather forecast model are presented. Weather forecast in Alaska faces challenges as well as opportunities. Alaska has a large land with multiple types of topography and coastal area. Weather forecast models must be finely tuned in order to accurately predict weather in Alaska. Being in the high-latitudes provides Alaska greater coverage of polar orbiting satellites for integration into forecasting models than the lower 48. Forecasting marine low stratus clouds is critical to the Alaska aviation and oil industry and is the current focus of the case study. NASA AIRS/CrIS sounder profiles data are used to do data assimilation for the Alaska regional weather forecast model to improve Arctic marine stratus clouds forecast. Choosing physical options for the WRF model is discussed. Preprocess of AIRS/CrIS sounder data for data assimilation is described. Local observation data, satellite data, and global data assimilation data are used to verify and/or evaluate the forecast results by the MET tools Model Evaluation Tools (MET).

Remote sensing data from CLARET: A prototype CART data set

NASA Technical Reports Server (NTRS)

Eberhard, Wynn L.; Uttal, Taneil; Clark, Kurt A.; Cupp, Richard E.; Dutton, Ellsworth G.; Fedor, Leonard, S.; Intrieri, Janet M.; Matrosov, Sergey Y.; Snider, Jack B.; Willis, Ron J.

1992-01-01

The data set containing radiation, meteorological , and cloud sensor observations is documented. It was prepared for use by the Department of Energy's Atmospheric Radiation Measurement (ARM) Program and other interested scientists. These data are a precursor of the types of data that ARM Cloud And Radiation Testbed (CART) sites will provide. The data are from the Cloud Lidar And Radar Exploratory Test (CLARET) conducted by the Wave Propagation Laboratory during autumn 1989 in the Denver-Boulder area of Colorado primarily for the purpose of developing new cloud-sensing techniques on cirrus. After becoming aware of the experiment, ARM scientists requested archival of subsets of the data to assist in the developing ARM program. Five CLARET cases were selected: two with cirrus, one with stratus, one with mixed-phase clouds, and one with clear skies. Satellite data from the stratus case and one cirrus case were analyzed for statistics on cloud cover and top height. The main body of the selected data are available on diskette from the Wave Propagation Laboratory or Los Alamos National Laboratory.

Arctic Stratus Cloud Properties and Their Effect on the Surface Radiation Budget: Selected Cases from FIRE ACE

NASA Technical Reports Server (NTRS)

Doug, Xiquan; Mace, Gerald G.; Minnis, Patrick; Young, David F.

2001-01-01

To study Arctic stratus cloud properties and their effect on the surface radiation balance during the spring transition season, analyses are performed using data taken during three cloudy and two clear days in May 1998 as part of the First ISCCP Regional Experiment (FIRE) Arctic Cloud Experiment (ACE). Radiative transfer models are used in conjunction with surface- and satellite-based measurements to retrieve the layer-averaged microphysical and shortwave radiative properties. The surface-retrieved cloud properties in Cases 1 and 2 agree well with the in situ and satellite retrievals. Discrepancies in Case 3 are due to spatial mismatches between the aircraft and the surface measurements in a highly variable cloud field. Also, the vertical structure in the cloud layer is not fully characterized by the aircraft measurements. Satellite data are critical for understanding some of the observed discrepancies. The satellite-derived particle sizes agree well with the coincident surface retrievals and with the aircraft data when they were collocated. Optical depths derived from visible-channel data over snow backgrounds were overestimated in all three cases, suggesting that methods currently used in satellite cloud climatologies derive optical depths that are too large. Use of a near-infrared channel with a solar infrared channel to simultaneously derive optical depth and particle size appears to alleviate this overestimation problem. Further study of the optical depth retrieval is needed. The surface-based radiometer data reveal that the Arctic stratus clouds produce a net warming of 20 W m(exp -2) in the surface layer during the transition season suggesting that these clouds may accelerate the spring time melting of the ice pack. This surface warming contrasts with the net cooling at the top of the atmosphere (TOA) during the same period. All analysis of the complete FIRE ACE data sets will be valuable for understanding the role of clouds during the entire melting and refreezing process that occurs annually in the Arctic.

Measurement Comparisons Towards Improving the Understanding of Aerosol-Cloud Processing

NASA Astrophysics Data System (ADS)

Noble, Stephen R.

Cloud processing of aerosol is an aerosol-cloud interaction that is not heavily researched but could have implications on climate. The three types of cloud processing are chemical processing, collision and coalescence processing, and Brownian capture of interstitial particles. All types improve cloud condensation nuclei (CCN) in size or hygroscopicity (kappa). These improved CCN affect subsequent clouds. This dissertation focuses on measurement comparisons to improve our observations and understanding of aerosol-cloud processing. Particle size distributions measured at the continental Southern Great Plains (SGP) site were compared with ground based measurements of cloud fraction (CF) and cloud base altitude (CBA). Particle size distributions were described by a new objective shape parameter to define bimodality rather than an old subjective one. Cloudy conditions at SGP were found to be correlated with lagged shape parameter. Horizontal wind speed and regional CF explained 42%+ of this lag time. Many of these surface particle size distributions were influenced by aerosol-cloud processing. Thus, cloud processing may be more widespread with more implications than previously thought. Particle size distributions measured during two aircraft field campaigns (MArine Stratus/stratocumulus Experiment; MASE; and Ice in Cloud Experiment-Tropical; ICE-T) were compared to CCN distributions. Tuning particle size to critical supersaturation revealed hygroscopicity expressed as ? when the distributions were overlain. Distributions near cumulus clouds (ICE-T) had a higher frequency of the same ?s (48% in ICE-T to 42% in MASE) between the accumulation (processed) and Aitken (unprocessed) modes. This suggested physical processing domination in ICE-T. More MASE (stratus cloud) kappa differences between modes pointed to chemical cloud processing. Chemistry measurements made in MASE showed increases in sulfates and nitrates with distributions that were more processed. This supported chemical cloud processing in MASE. This new method to determine kappa provides the needed information without interrupting ambient measurements. MODIS derived cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (re) were compared to the same in situ derived variables from cloud probe measurements of two stratus/stratocumulus cloud campaigns (MASE and Physics Of Stratocumulus Tops; POST). In situ data were from complete vertical cloud penetrations, while MODIS data were from pixels along the aircraft penetration path. Comparisons were well correlated except that MODIS LWP (14-36%) and re (20-30%) were biased high. The LWP bias was from re bias and was not improved by using the vertically stratified assumption. MODIS re bias was almost removed when compared to cloud top maximum in situ re, but, that does not describe re for the full depth of the cloud. COT is validated by in situ COT. High correlations suggest that MODIS variables are useful in self-comparisons such as gradient changes in stratus cloud re during aerosol-cloud processing.

Meteorological Techniques (Revision 26 Apr 2006)

DTIC Science & Technology

2003-06-13

OVV Graph ------------------------------------------------------------------------ 2-11 Figure 2-26 Dissipation of Stratus Using Mixing Ratio and...2-51 Figure 2-70 Bright Band Identification Using the WSR-88D. ------------------------------------------ 2-52 Figure 2-71 Example of Visible...R2, and R3 relative humidity values and cloud amounts ------------------------- 2-7 Table 2-4 Base of convective clouds using surface dew-point

Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign

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

Lee, Y. -N.; Springston, S.; Jayne, J.

2014-01-01

The chemical composition of aerosol particles ( D p ≤ 1.5 μm) was measured over the southeast Pacific Ocean during the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) between 16 October and 15 November 2008 using the US Department of Energy (DOE) G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and of how they interact with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL) aerosol mass was dominated bymore » non-sea-salt SO 4 2−, followed by Na +, Cl −, Org (total organics), NH 4 +, and NO 3 −, in decreasing order of importance; CH 3SO 3 − (MSA), Ca 2+, and K + rarely exceeded their limits of detection. Aerosols were strongly acidic with a NH 4 + to SO 4 2− equivalents ratio typically < 0.3. Sea-salt aerosol (SSA) particles, represented by NaCl, exhibited Cl − deficits caused by both HNO 3 and H 2SO 4, but for the most part were externally mixed with particles, mainly SO 4 2−. SSA contributed only a small fraction of the total accumulation mode particle number concentration. It was inferred that all aerosol species (except SSA) were of predominantly continental origin because of their strong land-to-sea concentration gradient. Comparison of relative changes in median values suggests that (1) an oceanic source of NH 3 is present between 72° W and 76° W, (2) additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31° S, with possible cloud processing, and (3) free tropospheric (FT) contributions to MBL gas and aerosol concentrations were negligible. Finally, the very low levels of CH 3SO 3 − observed as well as the correlation between SO 4 2− and NO 3 − (which is thought primarily anthropogenic) suggest a limited contribution of DMS to SO 4 2− aerosol production during VOCALS.« less

If Frisch is true - impacts of varying beam width, resolution, frequency combinations and beam overlap when retrieving liquid water content profiles

NASA Astrophysics Data System (ADS)

Küchler, N.; Kneifel, S.; Kollias, P.; Loehnert, U.

2017-12-01

Cumulus and stratocumulus clouds strongly affect the Earth's radiation budget and are a major uncertainty source in weather and climate prediction models. To improve and evaluate models, a comprehensive understanding of cloud processes is necessary and references are needed. Therefore active and passive microwave remote sensing of clouds can be used to derive cloud properties such as liquid water path and liquid water content (LWC), which can serve as a reference for model evaluation. However, both the measurements and the assumptions when retrieving physical quantities from the measurements involve uncertainty sources. Frisch et al. (1998) combined radar and radiometer observations to derive LWC profiles. Assuming their assumptions are correct, there will be still uncertainties regarding the measurement setup. We investigate how varying beam width, temporal and vertical resolutions, frequency combinations, and beam overlap of and between the two instruments influence the retrieval of LWC profiles. Especially, we discuss the benefit of combining vertically, high resolved radar and radiometer measurements using the same antenna, i.e. having ideal beam overlap. Frisch, A. S., G. Feingold, C. W. Fairall, T. Uttal, and J. B. Snider, 1998: On cloud radar and microwave radiometer measurements of stratus cloud liquid water profiles. J. Geophys. Res.: Atmos., 103 (18), 23 195-23 197, doi:0148-0227/98/98JD-01827509.00.

Using Bibliometrics to Demonstrate the Value of Library Journal Collections

ERIC Educational Resources Information Center

Belter, Christopher W.; Kaske, Neal K.

2016-01-01

Although cited reference studies are common in the library and information science literature, they are rarely performed in nonacademic institutions or in the atmospheric and oceanic sciences. In this paper, we analyze more than 400,000 cited references made by authors affiliated with the National Oceanic and Atmospheric Administration between…

The Ocean Gene Atlas: exploring the biogeography of plankton genes online.

PubMed

Villar, Emilie; Vannier, Thomas; Vernette, Caroline; Lescot, Magali; Cuenca, Miguelangel; Alexandre, Aurélien; Bachelerie, Paul; Rosnet, Thomas; Pelletier, Eric; Sunagawa, Shinichi; Hingamp, Pascal

2018-05-21

The Ocean Gene Atlas is a web service to explore the biogeography of genes from marine planktonic organisms. It allows users to query protein or nucleotide sequences against global ocean reference gene catalogs. With just one click, the abundance and location of target sequences are visualized on world maps as well as their taxonomic distribution. Interactive results panels allow for adjusting cutoffs for alignment quality and displaying the abundances of genes in the context of environmental features (temperature, nutrients, etc.) measured at the time of sampling. The ease of use enables non-bioinformaticians to explore quantitative and contextualized information on genes of interest in the global ocean ecosystem. Currently the Ocean Gene Atlas is deployed with (i) the Ocean Microbial Reference Gene Catalog (OM-RGC) comprising 40 million non-redundant mostly prokaryotic gene sequences associated with both Tara Oceans and Global Ocean Sampling (GOS) gene abundances and (ii) the Marine Atlas of Tara Ocean Unigenes (MATOU) composed of >116 million eukaryote unigenes. Additional datasets will be added upon availability of further marine environmental datasets that provide the required complement of sequence assemblies, raw reads and contextual environmental parameters. Ocean Gene Atlas is a freely-available web service at: http://tara-oceans.mio.osupytheas.fr/ocean-gene-atlas/.

Ocean state estimation for climate studies

NASA Technical Reports Server (NTRS)

Lee, T.

2002-01-01

Climate variabilities, which are of interest to CLIVAR, involve a broad range of spatial and temporal scales. Ocean state estimation (often referred to as ocean data assimilation), by optimally combining observations and models, becomes an important element of CLIVAR.

Meteorologial Techniques (Revision 13 Jun 2003)

DTIC Science & Technology

2003-06-13

RH and OVV Graph ------------------------------------------------------------------------ 2-11 Figure 2-26 Dissipation of Stratus Using Mixing Ratio...2-51 Figure 2-70 Bright Band Identification Using the WSR-88D. ------------------------------------------ 2-52 Figure 2-71 Example of...Table 2-3 R1, R2, and R3 relative humidity values and cloud amounts ------------------------- 2-7 Table 2-4 Base of convective clouds using surface dew

Trusted Silicon Stratus (TSS) Workshop

DTIC Science & Technology

2011-02-01

business case for a proposed Infrastructure-as-a- Service (IaaS)/ Software -as-a- Service ( SaaS ) cloud architecture. User desires for innovative pricing and...Public Physically Unclonable Function PUF Physically Unclonable Function SaaS Software -as-a- Service SIP Semiconductor Intellectual Property SNL...WORKSHOP NIMBIS SERVICES INCORPORATED FEBRUARY 2011 FINAL TECHNICAL REPORT  ROME, NY 13441 UNITED STATES AIR FORCE  AIR FORCE

The GOES-R/JPSS Approach for Identifying Hazardous Low Clouds: Overview and Operational Impacts

NASA Astrophysics Data System (ADS)

Calvert, Corey; Pavolonis, Michael; Lindstrom, Scott; Gravelle, Chad; Terborg, Amanda

2017-04-01

Low ceiling and visibility is a weather hazard that nearly every forecaster, in nearly every National Weather Service (NWS) Weather Forecast Office (WFO), must regularly address. In addition, national forecast centers such as the Aviation Weather Center (AWC), Alaska Aviation Weather Unit (AAWU) and the Ocean Prediction Center (OPC) are responsible for issuing low ceiling and visibility related products. As such, reliable methods for detecting and characterizing hazardous low clouds are needed. Traditionally, hazardous areas of Fog/Low Stratus (FLS) are identified using a simple stand-alone satellite product that is constructed by subtracting the 3.9 and 11 μm brightness temperatures. However, the 3.9-11 μm brightness temperature difference (BTD) has several major limitations. In an effort to address the limitations of the BTD product, the GOES-R Algorithm Working Group (AWG) developed an approach that fuses satellite, Numerical Weather Prediction (NWP) model, Sea Surface Temperature (SST) analyses, and other data sets (e.g. digital surface elevation maps, surface emissivity maps, and surface type maps) to determine the probability that hazardous low clouds are present using a naïve Bayesian classifier. In addition, recent research has focused on blending geostationary (e.g. GOES-R) and low earth orbit (e.g. JPSS) satellite data to further improve the products. The FLS algorithm has adopted an enterprise approach in that it can utilize satellite data from a variety of current and future operational sensors and NWP data from a variety of models. The FLS products are available in AWIPS/N-AWIPS/AWIPS-II and have been evaluated within NWS operations over the last four years as part of the Satellite Proving Ground. Forecaster feedback has been predominantly positive and references to these products within Area Forecast Discussions (AFD's) indicate that the products are influencing operational forecasts. At the request of the NWS, the FLS products are currently being transitioned to NOAA/NESDIS operations, which will ensure that users have long-term access to these products. This paper will provide an overview of the FLS products and illustrate how they are being used to improve transportation safety and efficiency.

Fourier-domain optical coherence tomography and adaptive optics reveal nerve fiber layer loss and photoreceptor changes in a patient with optic nerve drusen.

PubMed

Choi, Stacey S; Zawadzki, Robert J; Greiner, Mark A; Werner, John S; Keltner, John L

2008-06-01

New technology allows more precise definition of structural alterations of all retinal layers although it has not been used previously in cases of optic disc drusen. Using Stratus and Fourier domain (FD) optical coherence tomography (OCT) and adaptive optics (AO) through a flood-illuminated fundus camera, we studied the retinas of a patient with long-standing optic disc drusen and acute visual loss at high altitude attributed to ischemic optic neuropathy. Stratus OCT and FD-OCT confirmed severe thinning of the retinal nerve fiber layer (RNFL). FD-OCT revealed disturbances in the photoreceptor layer heretofore not described in optic disc drusen patients. AO confirmed the FD-OCT findings in the photoreceptor layer and also showed reduced cone density at retinal locations associated with reduced visual sensitivity. Based on this study, changes occur not only in the RNFL but also in the photoreceptor layer in optic nerve drusen complicated by ischemic optic neuropathy. This is the first reported application of FD-OCT and the AO to this condition. Such new imaging technology may in the future allow monitoring of disease progression more precisely and accurately.

Overview of the DACCIWA ground-based field campaign in southern West Africa

NASA Astrophysics Data System (ADS)

Lohou, Fabienne; Kalthoff, Norbert; Brooks, Barbara; Jegede, Gbenga; Adler, Bianca; Ajao, Adewale; Ayoola, Muritala; Babić, Karmen; Bessardon, Geoffrey; Delon, Claire; Dione, Cheikh; Handwerker, Jan; Jambert, Corinne; Kohler, Martin; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier; Smith, Victoria; Sunmonu, Lukman; Wieser, Andreas; Derrien, Solène

2017-04-01

During June and July 2016, a ground-based field campaign took place in southern West Africa within the framework of the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project. In the investigated region, extended low-level stratus clouds form very frequently during night-time and persist long into the following day influencing the diurnal cycle of the atmospheric boundary layer and, hence, the regional climate. The motivation for the measurements was to identify the meteorological controls on the whole process chain from the formation of nocturnal stratus clouds, via the daytime transition to convective clouds and the formation of deep precipitating clouds. During the measurement period, extensive remote sensing and in-situ measurements were performed at three supersites in Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). The gathered observations included the energy-balance components at the Earth's surface, the mean and turbulent conditions in the nocturnal and daytime ABL as well as the de- and entrainment processes between the ABL and the free troposphere. The meteorological measurements were supplemented by aerosol and air-chemistry observations. We will give an overview of the conducted measurements including instrument availability and strategy during intensive observation periods.

A regional analysis of cloudy mean spherical albedo over the marine stratocumulus region and the tropical Atlantic Ocean. M.S. Thesis

NASA Technical Reports Server (NTRS)

Ginger, Kathryn M.

1993-01-01

Since clouds are the largest variable in Earth's radiation budget, it is critical to determine both the spatial and temporal characteristics of their radiative properties. The relationships between cloud properties and cloud fraction are studied in order to supplement grid scale parameterizations. The satellite data used is from three hourly ISCCP (International Satellite Cloud Climatology Project) and monthly ERBE (Earth Radiation Budget Experiment) data on a 2.5 deg x 2.5 deg latitude-longitude grid. Mean cloud spherical albedo, the mean optical depth distribution, and cloud fraction are examined and compared off the coast of California and the mid-tropical Atlantic for July 1987 and 1988. Individual grid boxes and spatial averages over several grid boxes are correlated to Coakley's theory of reflection for uniform and broken layered cloud and to Kedem, et al.'s findings that rainfall volume and fractional area of rain in convective systems is linear. Kedem's hypothesis can be expressed in terms of cloud properties. That is, the total volume of liquid in a box is a linear function of cloud fraction. Results for the marine stratocumulus regime indicate that albedo is often invariant for cloud fractions of 20% to 80%. Coakley's satellite model of small and large clouds with cores (1 km) and edges (100 m) is consistent with this observation. The cores maintain high liquid water concentrations and large droplets while the edges contain low liquid water concentrations and small droplets. Large clouds are just a collection of cores. The mean optical depth (TAU) distributions support the above observation with TAU values of 3.55 to 9.38 favored across all cloud fractions. From these results, a method based upon Kedem, et al's theory is proposed to separate the cloud fraction and liquid water path (LWP) calculations in a general circulation model (GCM). In terms of spatial averaging, a linear relationship between albedo and cloud fraction is observed. For tropical locations outside the Intertropical Convergence Zone (ITCZ), results of cloud fraction and albedo spatial averaging followed that of the stratus boxes containing few overcast scenes. Both the ideas of Coakley and Kedem, et al. apply. Within the ITCZ, the grid boxes tended to have the same statistical properties as stratus boxes containing many overcast scenes. Because different dynamical forcing mechanisms are present, it is difficult to devise a method for determining subgrid scale variations. Neither of the theories proposed by Kedem, et al. or Coakley works well for the boxes with numerous overcast scenes.

A Regional Analysis of Cloudy Mean Spherical Albedo over the Marine Stratocumulus Region and the Tropical Atlantic Ocean

NASA Technical Reports Server (NTRS)

Ginger, Kathryn M.

1993-01-01

Since clouds are the largest variable in Earth's radiation budget, it is critical to determine both the spatial and temporal characteristics of their radiative properties. This study examines the relationships between cloud properties and cloud fraction in order to supplement grid scale parameterizations. The satellite data used in this study is from three hourly ISCCP (International Satellite Cloud Climatology Project) and monthly ERBE (Earth Radiation Budget Experiment) data on a 2.50 x 2.50 latitude-longitude grid. Mean cloud spherical albedo, the mean optical depth distribution and cloud fraction are examined and compared off the coast of California and the mid-tropical Atlantic for July 1987 and 1988. Individual grid boxes and spatial averages over several grid boxes are correlated to Coakleys (1991) theory of reflection for uniform and broken layered cloud and to Kedem, et al.(1990) findings that rainfall volume and fractional area of rain in convective systems is linear. Kedem's hypothesis can be expressed in terms of cloud properties. That is, the total volume of liquid in a box is a linear function of cloud fraction. Results for the marine stratocumulus regime indicate that albedo is often invariant for cloud fractions of 20% to 80%. Coakley's satellite model of small and large clouds with cores (1 km) and edges (100 in) is consistent with this observation. The cores maintain high liquid water concentrations and large droplets while the edges contain low liquid water concentrations and small droplets. Large clouds are just a collection of cores. The mean optical depth (TAU) distributions support the above observation with TAU values of 3.55 to 9.38 favored across all cloud fractions. From these results, a method based upon Kedem, et al. theory is proposed to separate the cloud fraction and liquid water path (LWP) calculations in a general circulation model (GCM). In terms of spatial averaging, a linear relationship between albedo and cloud fraction is observed. For tropical locations outside the Intertropical Convergence Zone (ITCZ), results of cloud fraction and albedo spatial averaging followed that of the stratus boxes containing few overcast scenes. Both the ideas of Coakley and Kedem, et al. apply. Within the ITCZ, the grid boxes tended to have the same statistical properties as stratus boxes containing many overcast scenes. Because different dynamical forcing mechanisms are present, it is difficult to devise a method for determining subgrid scale variations. Neither of the theories proposed by Kedem, et al. or Coakley works well for the boxes with numerous overcast scenes.

Institutional Change through Assessment: Contrasting Case Studies

ERIC Educational Resources Information Center

Deess, E. Pierre; Elliot, Norbert

2009-01-01

The framework for understanding the management difference is neatly captured by the "red ocean" and "blue ocean" strategies described by W. Chan Kim and Renee Mauborgne in "Blue Ocean Strategy" (Kim & Mauborgne, 2004). In the original, the terms refer to alternative market strategies. Red ocean means competition in a market defined by a zero sum…

User's Guide to OASIS, Oceanic and Atmospheric Scientific Information System. Key to Oceanic and Atmospheric Information Sources No. 1.

ERIC Educational Resources Information Center

National Oceanic and Atmospheric Administration (DOC), Washington, DC. Environmental Data Service.

OASIS (Oceanic and Atmospheric Scientific Information System) is an information retrieval service that furnishes ready reference to the technical literature and research efforts concerning the environmental sciences and marine and coastal resources. It provides computerized searches of both NOAA (National Oceanic and Atmospheric Administration)…

Exploring the functional side of the Ocean Sampling Day metagenomes

NASA Astrophysics Data System (ADS)

Antonio, F. G.; Kottmann, R.; Wallom, D.; Glöckner, F. O.

2016-02-01

The Ocean Sampling Day (OSD) is a simultaneous, collaborative, standardized, and global mega-sequencing campaign to analyze marine microbial community composition and functional traits. 150 metagenomes were sequenced from the first OSD in June 2014 including a rich set of environmental and oceanographic measurements. Unlike other ocean mega-surveys such as Global Ocean Sampling (GOS) or the TARA expedition that mostly sampled open ocean waters most of the OSD samples are from coastal sampling sites, an area not previously well studied in this regard. The result is that OSD adds more than three million new genes to the recently published Ocean Microbial-Reference Gene Catalog (Sunawaga et al., 2015). This allows us to significantly increase our knowledge of the ocean microbiome, identify hot-spots of novelty in terms of function and investigate the impact of human activities on oceans coastal areas where there is the largest interaction between dense human populations and the marine world. Additionally, these cumulative samples, related in time, space and environmental parameters, are providing insights into fundamental rules describing microbial diversity and function and contribute to the blue economy through the identification of novel ocean-derived biotechnologies. References: Sunagawa, Coelho, Chaffron, et al. (2015, May). Structure and function of the global ocean microbiome. Science, 348(6237), 126135.

Maintenance and Variations of Atmospheric Subsidence in the Southeast Pacific

NASA Astrophysics Data System (ADS)

Wang, C.; Lee, S.; Mechoso, C. R.; Enfield, D. B.

2010-12-01

The southeastern tropical Pacific (SEP) is characterized by large-scale subsidence, extensive and persistent stratocumulus cloud, and cold SST. The subtropical high in the South Pacific and subsidence over the SEP during the austral summer are related to the monsoonal heating over South America. Previous studies demonstrate that during the austral summer, Rossby wave response to heating associated with the South American monsoon system interacting with the midlatitude westerlies produces descending motion to the west of the South American heating, i.e., over the SEP. The Sverdrup balance demands the existence of equatorward flow beneath the region of descent, closing off the South Pacific subtropical anticyclone on its eastern flank. During seasons other than the austral summer, when convective activity over South America is weaker, other processes must be responsible for maintaining and varying the subsidence over the SEP. This paper shows that the Atlantic warm pool (AWP) is responsible for the subsidence in the SEP during the austral winter and spring. The AWP is a large body of warm water comprising the Gulf of Mexico, the Caribbean Sea, and the western tropical North Atlantic. AWP variability occurs on seasonal, interannual, and multidecadal timescales. The AWP reaches its maximum size in the boreal late summer and early fall, with large AWPs being almost three times larger than small ones. The warm pool alternates with South America as the seasonal heating source for the Hadley circulation in the Western Hemisphere. During the boreal summer and fall, a strong Hadley circulation emanates from the AWP and forks into the subsidence region of the SEP. The anomalous warm pool index is positively correlated with rainfall anomalies over the SEP where the drizzle under the stratus cloud deck appears. Large (small) warm pools strengthen (weaken) the summer Hadley circulation that emanates from the region of the warm pool into the SEP. This will change the subsidence over the SEP and thus the stratus cloud and drizzle. Atmospheric GCM and simple models are further used to demonstrate the remote and inter-hemispheric response of the AWP to the SEP; that is, the AWP contributes to sinking over the SEP and hence the stratus cloud in the region.

Comparative Efficacy of Daratumumab Monotherapy and Pomalidomide Plus Low-Dose Dexamethasone in the Treatment of Multiple Myeloma: A Matching Adjusted Indirect Comparison.

PubMed

Van Sanden, Suzy; Ito, Tetsuro; Diels, Joris; Vogel, Martin; Belch, Andrew; Oriol, Albert

2018-03-01

Daratumumab (a human CD38-directed monoclonal antibody) and pomalidomide (an immunomodulatory drug) plus dexamethasone are both relatively new treatment options for patients with heavily pretreated multiple myeloma. A matching adjusted indirect comparison (MAIC) was used to compare absolute treatment effects of daratumumab versus pomalidomide + low-dose dexamethasone (LoDex; 40 mg) on overall survival (OS), while adjusting for differences between the trial populations. The MAIC method reduces the risk of bias associated with naïve indirect comparisons. Data from 148 patients receiving daratumumab (16 mg/kg), pooled from the GEN501 and SIRIUS studies, were compared separately with data from patients receiving pomalidomide + LoDex in the MM-003 and STRATUS studies. The MAIC-adjusted hazard ratio (HR) for OS of daratumumab versus pomalidomide + LoDex was 0.56 (95% confidence interval [CI], 0.38-0.83; p  = .0041) for MM-003 and 0.51 (95% CI, 0.37-0.69; p  < .0001) for STRATUS. The treatment benefit was even more pronounced when the daratumumab population was restricted to pomalidomide-naïve patients (MM-003: HR, 0.33; 95% CI, 0.17-0.66; p  = .0017; STRATUS: HR, 0.41; 95% CI, 0.21-0.79; p  = .0082). An additional analysis indicated a consistent trend of the OS benefit across subgroups based on M-protein level reduction (≥50%, ≥25%, and <25%). The MAIC results suggest that daratumumab improves OS compared with pomalidomide + LoDex in patients with heavily pretreated multiple myeloma. This matching adjusted indirect comparison of clinical trial data from four studies analyzes the survival outcomes of patients with heavily pretreated, relapsed/refractory multiple myeloma who received either daratumumab monotherapy or pomalidomide plus low-dose dexamethasone. Using this method, daratumumab conferred a significant overall survival benefit compared with pomalidomide plus low-dose dexamethasone. In the absence of head-to-head trials, these indirect comparisons provide useful insights to clinicians and reimbursement authorities around the relative efficacy of treatments. © AlphaMed Press 2017.

Fog water collection under sea breeze conditions in the Western Mediterranean basin (Valencia region, Spain)

NASA Astrophysics Data System (ADS)

Azorin-Molina, C.; Corell, D.; Estrela, M. J.; Valiente, J. A.

2010-07-01

Orographic fog occurrences associated with sea breezes determine water collection potential over the mountain ranges near the Mediterranean coast of the Iberian Peninsula. Previous works have confirmed that the effect of sea breezes on cloud genera is to increase the frequency of low (Stratus) and convective (Cumulus) clouds. The primary impact of sea breeze flows corresponds to low stratiform clouds (Stratus, St, and Stratocumulus, Sc) formed in the convective internal boundary layer due to the inflow of moist sea air at lower levels. The formation of Sc clouds is caused by the rising and cooling of turbulent moist sea air over the highest slopes of the mountains at the end of the day. In the most Sc formation, we also observed dense fog banks of Stratus nebulosus (St neb) and dew during the early next morning, covering the inland topographical depressions. The aim of this study is to statistically analyze the impact of sea breezes on fog water collection in the convective internal boundary layer. The study area is located in the eastern of the Iberian Peninsula (Valencia region, Spain) and the survey corresponds to a 7-yr study period (2003-2009). This research is based upon a small network of eight passive fog water collectors distributed over 6 coastal- and 2 inland-mountain areas. A cylindrical fog water instrument (i.e. omnidirectional collection efficiency) based on the ASRC (Atmospheric Science Research Centre, State University of New York) string collector is used to sample fog water volumes on a daily basis. These stations also sampled temperature, humidity, wind speed and direction and precipitation measurements. The current study used these meteorological measurements to apply an automated and manual selection methodologies for identifying past sea breeze episodes. The dataset created by means of these selection techniques allows for the study of fog water volumes associated with sea breeze situations. A detailed statistical characterization of the orographic clouds episodes associated with sea breezes and other interesting aspects of this fog water collection study are presented here.

Effect of improper scan alignment on retinal nerve fiber layer thickness measurements using Stratus optical coherence tomograph.

PubMed

Vizzeri, Gianmarco; Bowd, Christopher; Medeiros, Felipe A; Weinreb, Robert N; Zangwill, Linda M

2008-08-01

Misalignment of the Stratus optical coherence tomograph scan circle placed by the operator around the optic nerve head (ONH) during each retinal nerve fiber layer (RNFL) examination can affect the instrument reproducibility and its theoretical ability to detect true structural changes in the RNFL thickness over time. We evaluated the effect of scan circle placement on RNFL measurements. Observational clinical study. Sixteen eyes of 8 normal participants were examined using the Stratus optical coherence tomograph Fast RNFL thickness acquisition protocol (software version 4.0.7; Carl Zeiss Meditec, Dublin, CA). Four consecutive images were taken by the same operator with the circular scan centered on the optic nerve head. Four images each with the scan displaced superiorly, inferiorly, temporally, and nasally were also acquired. Differences in average and sectoral RNFL thicknesses were determined. For the centered scans, the coefficients of variation (CV) and the intraclass correlation coefficient for the average RNFL thickness measured were calculated. When the average RNFL thickness of the centered scans was compared with the average RNFL thickness of the displaced scans individually using analysis of variance with post-hoc analysis, no difference was found between the average RNFL thickness of the nasally (105.2 microm), superiorly (106.2 microm), or inferiorly (104.1 microm) displaced scans and the centered scans (106.4 microm). However, a significant difference (analysis of variance with Dunnett's test: F=8.82, P<0.0001) was found between temporally displaced scans (115.8 microm) and centered scans. Significant differences in sectoral RNFL thickness measurements were found between centered and each displaced scan. The coefficient of variation for average RNFL thickness was 1.75% and intraclass correlation coefficient was 0.95. In normal eyes, average RNFL thickness measurements are robust and similar with significant superior, inferior, and nasal scan displacement, but average RNFL thickness is greater when scans are displaced temporally. Parapapillary scan misalignment produces significant changes in RNFL assessment characterized by an increase in measured RNFL thickness in the quadrant in which the scan is closer to the disc, and a significant decrease in RNFL thickness in the quadrant in which the scan is displaced further from the optic disc.

Multi-scale forcing and the formation of subtropical desert and monsoon

NASA Astrophysics Data System (ADS)

Wu, G. X.; Liu, Y.; Zhu, X.; Li, W.; Ren, R.; Duan, A.; Liang, X.

2009-09-01

This study investigates three types of atmospheric forcing across the summertime subtropics that are shown to contribute in various ways to the occurrence of dry and wet climates in the subtropics. To explain the formation of desert over the western parts of continents and monsoon over the eastern parts, we propose a new mechanism of positive feedback between diabatic heating and vorticity generation that occurs via meridional advection of planetary vorticity and temperature. Monsoon and desert are demonstrated to coexist as twin features of multi-scale forcing, as follows. First, continent-scale heating over land and cooling over ocean induce the ascent of air over the eastern parts of continents and western parts of oceans, and descent over eastern parts of oceans and western parts of continents. Second, local-scale sea-breeze forcing along coastal regions enhances air descent over eastern parts of oceans and ascent over eastern parts of continents. This leads to the formation of the well-defined summertime subtropical LOSECOD quadruplet-heating pattern across each continent and adjacent oceans, with long-wave radiative cooling (LO) over eastern parts of oceans, sensible heating (SE) over western parts of continents, condensation heating (CO) over eastern parts of continents, and double dominant heating (D: LO+CO) over western parts of oceans. Such a quadruplet heating pattern corresponds to a dry climate over the western parts of continents and a wet climate over eastern parts. Third, regional-scale orographic-uplift-heating generates poleward ascending flow to the east of orography and equatorward descending flow to the west. The Tibetan Plateau (TP) is located over the eastern Eurasian continent. The TP-forced circulation pattern is in phase with that produced by continental-scale forcing, and the strongest monsoon and largest deserts are formed over the Afro-Eurasian Continent. In contrast, the Rockies and the Andes are located over the western parts of their respective continents, and orography-induced ascent is separated from ascent due to continental-scale forcing. Accordingly, the deserts and monsoon climate over these continents are not as strongly developed as those over the Eurasian Continent. A new mechanism of positive feedback between diabatic heating and vorticity generation, which occurs via meridional transfer of heat and planetary vorticity, is proposed as a means of explaining the formation of subtropical desert and monsoon. Strong low-level longwave radiative cooling over eastern parts of oceans and strong surface sensible heating on western parts of continents generate negative vorticity that is balanced by positive planetary vorticity advection from high latitudes. The equatorward flow generated over eastern parts of oceans produces cold sea-surface temperature and stable stratification, leading in turn to the formation of low stratus clouds and the maintenance of strong in situ longwave radiative cooling. The equatorward flow over western parts of continents carries cold, dry air, thereby enhancing local sensible heating as well as moisture release from the underlying soil. These factors result in a dry desert climate. Over the eastern parts of continents, condensation heating generates positive vorticity in the lower troposphere, which is balanced by negative planetary vorticity advection of the meridional flow from low latitudes. The flow brings warm and moist air, thereby enhancing local convective instability and condensation heating associated with rainfall. These factors produce a wet monsoonal climate. Overall, our results demonstrate that subtropical desert and monsoon coexist as a consequence of multi-scale forcing along the subtropics.

Earth Observations taken by the Expedition 17 Crew

NASA Image and Video Library

2008-08-04

ISS017-E-012583 (4 Aug. 2008) --- Cape Farewell, Greenland is featured in this image photographed by an Expedition 17 crewmember on the International Space Station (ISS). This view illustrates the southernmost tip of Greenland, known as Kap Farvel in Danish and Nunap Isua in Inuit. The viewing direction is towards the northeast; the image was taken when the space station was located near its most northerly orbital latitude of 52 degrees, off the northern coast of the Island of Newfoundland approximately 1160 kilometers to the southwest. Greenland is the world's largest island with an area of over 2 million square kilometers; however much of the island is covered by an ice cap that can reach thicknesses of 3 kilometers. The image is highly oblique -- taken from an angle looking outwards from the ISS, rather than straight down towards the Earth -- and this provides a sense of topography along the southern edge of Greenland. The exposed dark grey bedrock along the southwestern coastline has been carved by glaciers into numerous fjords -- steep-sided valleys that drain directly into the ocean; the white cloud cover surrounding the island doubtless contains some sea ice and icebergs calved from glaciers. A band of high-altitude cirrus clouds (light grey) cast shadows on the lower stratus cloud deck in the lower third of the image. The thin blue layer of Earth's atmosphere is visible.

The Characterization of Deep Convective Clouds as an Invariant Calibration Target and as a Visible Calibration Technique

NASA Technical Reports Server (NTRS)

Doelling, David R.; Morstad, Daniel; Scarino, Benjamin R.; Bhatt, Rajendra; Gopalan, Arun

2012-01-01

Deep convective clouds (DCCs) are ideal visible calibration targets because they are bright nearly isotropic solar reflectors located over the tropics and they can be easily identified using a simple infrared threshold. Because all satellites view DCCs, DCCs provide the opportunity to uniformly monitor the stability of all operational sensors, both historical and present. A collective DCC anisotropically corrected radiance calibration approach is used to construct monthly probability distribution functions (PDFs) to monitor sensor stability. The DCC calibration targets were stable to within 0.5% and 0.3% per decade when the selection criteria were optimized based on Aqua MODerate Resolution Imaging Spectroradiometer 0.65-micrometer-band radiances. The Tropical Western Pacific (TWP), African, and South American regions were identified as the dominant DCC domains. For the 0.65-micrometer band, the PDF mode statistic is preferable, providing 0.3%regional consistency and 1%temporal uncertainty over land regions. It was found that the DCC within the TWP had the lowest radiometric response and DCC over land did not necessarily have the highest radiometric response. For wavelengths greater than 1 micrometer, the mean statistic is preferred, and land regions provided a regional variability of 0.7%with a temporal uncertainty of 1.1% where the DCC land response was higher than the response over ocean. Unlike stratus and cirrus clouds, the DCC spectra were not affected by water vapor absorption.

Satellite estimates of precipitation susceptibility in low-level marine stratiform clouds

DOE PAGES

Terai, C. R.; Wood, R.; Kubar, T. L.

2015-09-05

Quantifying the sensitivity of warm rain to aerosols is important for constraining climate model estimates of aerosol indirect effects. In this study, the precipitation sensitivity to cloud droplet number concentration (N d) in satellite retrievals is quantified by applying the precipitation susceptibility metric to a combined CloudSat/Moderate Resolution Imaging Spectroradiometer data set of stratus and stratocumulus clouds that cover the tropical and subtropical Pacific Ocean and Gulf of Mexico. We note that consistent with previous observational studies of marine stratocumulus, precipitation susceptibility decreases with increasing liquid water path (LWP), and the susceptibility of the mean precipitation rate R is nearlymore » equal to the sum of the susceptibilities of precipitation intensity and of probability of precipitation. Consistent with previous modeling studies, the satellite retrievals reveal that precipitation susceptibility varies not only with LWP but also with N d. Puzzlingly, negative values of precipitation susceptibility are found at low LWP and high N d. There is marked regional variation in precipitation susceptibility values that cannot simply be explained by regional variations in LWP and N d. This suggests other controls on precipitation apart from LWP and N d and that precipitation susceptibility will need to be quantified and understood at the regional scale when relating to its role in controlling possible aerosol-induced cloud lifetime effects.« less

The Atmospheric Boundary Layer

NASA Astrophysics Data System (ADS)

Garratt, J. R.

1994-05-01

A comprehensive and lucid account of the physics and dynamics of the lowest one to two kilometers of the Earth's atmosphere in direct contact with the Earth's surface, known as the atmospheric boundary layer (ABL). Dr. Garratt emphasizes the application of the ABL problems to numerical modeling of the climate, which makes this book unique among recent texts on the subject. He begins with a brief introduction to the ABL before leading to the development of mean and turbulence equations and the many scaling laws and theories that are the cornerstone of any serious ABL treatment. Modeling of the ABL is crucially dependent for its realism on the surface boundary conditions, so chapters four and five deal with aerodynamic and energy considerations, with attention given to both dry and wet land surfaces and the sea. The author next treats the structure of the clear-sky, thermally stratified ABL, including the convective and stable cases over homogeneous land, the marine ABL, and the internal boundary layer at the coastline. Chapter seven then extends this discussion to the cloudy ABL. This is particularly relevant to current research because the extensive stratocumulus regions over the subtropical oceans and stratus regions over the Arctic have been identified as key players in the climate system. In the final chapters, Dr. Garratt summarizes the book's material by discussing appropriate ABL and surface parameterization schemes in general circulation models of the atmosphere that are being used for climate stimulation.

Exploring the reversibility of marine climate change impacts in temperature overshoot scenarios

NASA Astrophysics Data System (ADS)

Zickfeld, K.; Li, X.; Tokarska, K.; Kohfeld, K. E.

2017-12-01

Artificial carbon dioxide removal (CDR) from the atmosphere has been proposed as a measure for mitigating climate change and restoring the climate system to a `safe' state after overshoot. Previous studies have demonstrated that the changes in surface air temperature due to anthropogenic CO2 emissions can be reversed through CDR, while some oceanic properties, for example thermosteric sea level rise, show a delay in their response to CDR. This research aims to investigate the reversibility of changes in ocean conditions after implementation of CDR with a focus on ocean biogeochemical properties. To achieve this, we analyze climate model simulations based on two sets of emission scenarios. We first use RCP2.6 and its extension until year 2300 as the reference scenario and design several temperature and cumulative CO2 emissions "overshoot" scenarios based on other RCPs, which represents cases with less ambitious mitigation policies in the near term that temporarily exceed the 2 °C target adopted by the Paris Agreement. In addition, we use a set of emission scenarios with a reference scenario limiting warming to 1.5°C in the long term and two overshoot scenarios. The University of Victoria Earth System Climate Model (UVic ESCM), a climate model of intermediate complexity, is forced with these emission scenarios. We compare the response of select ocean variables (seawater temperature, pH, dissolved oxygen) in the overshoot scenarios to that in the respective reference scenario at the time the same amount of cumulative emissions is achieved. Our results suggest that the overshoot and subsequent return to a reference CO2 cumulative emissions level would leave substantial impacts on the marine environment. Although the changes in global mean sea surface variables (temperature, pH and dissolved oxygen) are largely reversible, global mean ocean temperature, dissolved oxygen and pH differ significantly from those in the reference scenario. Large ocean areas exhibit temperature increase and pH and dissolved oxygen decrease relative to the reference scenario without cumulative CO2 emissions overshoot. Furthermore, our results show that the higher the level of overshoot, the lower the reversibility of changes in the marine environment.

The use of stellite scatterometer winds to drive a primitive equation model of the Indian Ocean: The impact of bandlike sampling

NASA Technical Reports Server (NTRS)

Barnier, Bernard; Capella, Jorge; O'Brien, James J.

1994-01-01

The aim of this study is to evaluate the impact of the bandlike sampling of spaceborne scatterometers on the ability of scatterometer winds to successfully force the mean flow and seasonal cycle of an ocean model in the context of equatorial and tropical dynamics. The equatorial ocean is simulated with a four-layer, primitive equation, reduced gravity model of the Indian Ocean. The variable wind stress used in this study is derived from one year (1988) of 6-hour analyses of the 10-m wind vector over the Indian Ocean performed at the European Centre for Medium-Range Weather Forecasts (ECMWF). It is applied as a forcing at every grid point of the model to drive a reference circulation. Scatterometer winds are simulated from ECMWF winds, using the nominal configurations and orbital parameters of the European Remote Sensing 1 (ERS-1) and NASA Scatterometer (NSCAT) missions. The model is forced in real time under swaths with the raw scatterometer winds of ERS-1 and NSCAT, with a persistence condition (i.e., the wind is kept constsnt until the next passage of the satellite provides a new value). The circulation obtained for each of the scatterometer experiments is compared with the reference circulation. The seasonal circulation of the Indian Ocean with NSCAT winds is very similar to the reference. The perturbations introduced by the bandlike sampling and the persistance condition have an impact similar to that of a small uncorrelated noise added to the reference forcing. The persistence condition for ERS-1 does not give results which are as good as those obtained for NSCAT.

Colors of the Daytime Overcast Sky

DTIC Science & Technology

2005-09-20

sunlight) spectra beneath overcast skies reveal an unexpectedly wide gamut of pastel colors. Analyses of these spectra indicate that at visible wavelengths...care, however, we also were able to acquire some data in drizzle, light rain, and snow. What kinds of chromaticity gamuts do such overcasts produce...noteworthy in Fig. 1. First, its chromaticity gamut for clear daylight is much less than for its two stratus and stratocumu- lus overcasts. Using the

Estimation of Cirrus and Stratus Cloud Heights Using Landsat Imagery

NASA Technical Reports Server (NTRS)

Inomata, Yasushi; Feind, R. E.; Welch, R. M.

1996-01-01

A new method based upon high-spatial-resolution imagery is presented that matches cloud and shadow regions to estimate cirrus and stratus cloud heights. The distance between the cloud and the matching shadow pattern is accomplished using the 2D cross-correlation function from which the cloud height is derived. The distance between the matching cloud-shadow patterns is verified manually. The derived heights also are validated through comparison with a temperature-based retrieval of cloud height. It is also demonstrated that an estimate of cloud thickness can be retrieved if both the sunside and anti-sunside of the cloud-shadow pair are apparent. The technique requires some intepretation to determine the cloud height level retrieved (i.e., the top, base, or mid-level). It is concluded that the method is accurate to within several pixels, equivalent to cloud height variations of about +/- 250 m. The results show that precise placement of the templates is unnecessary, so that the development of a semi-automated procedure is possible. Cloud templates of about 64 pixels on a side or larger produce consistent results. The procedure was repeated for imagery degraded to simulate lower spatial resolutions. The results suggest that spatial resolution of 150-200 m or better is necessary in order to obtain stable cloud height retrievals.

Three-dimensional image reconstruction of macula from stratus optical coherence tomography (OCT) for diagnosis of macular degeneration

NASA Astrophysics Data System (ADS)

Arinilhaq; Widita, R.

2016-03-01

Diagnosis of macular degeneration using a Stratus OCT with a fast macular thickness map (FMTM) method produced six B-scan images of macula from different angles. The images were converted into a retinal thickness chart to be evaluated by normal distribution percentile of data so that it can be classified as normal thickness of macula or as experiencing abnormality (e.g. thickening and thinning). Unfortunately, the diagnostic images only represent the retinal thickness in several areas of the macular region. Thus, this study is aims to obtain the entire retinal thickness in the macula area from Status OCT's output images. Basically, the volumetric image is obtained by combining each of the six images. Reconstruction consists of a series of processes such as pre-processing, segmentation, and interpolation. Linear interpolation techniques are used to fill the empty pixels in reconstruction matrix. Based on the results, this method is able to provide retinal thickness maps on the macula surface and the macula 3D image. Retinal thickness map can display the macula area which experienced abnormalities. The macula 3D image can show the layers of tissue in the macula that is abnormal. The system built cannot replace ophthalmologist in decision making in term of diagnosis.

Optical coherence tomography in retinitis pigmentosa: reproducibility and capacity to detect macular and retinal nerve fiber layer thickness alterations.

PubMed

Garcia-Martin, Elena; Pinilla, Isabel; Sancho, Eva; Almarcegui, Carmen; Dolz, Isabel; Rodriguez-Mena, Diego; Fuertes, Isabel; Cuenca, Nicolas

2012-09-01

To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitis pigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis). Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation. Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P < 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes. Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients.

The new version of the Institute of Numerical Mathematics Sigma Ocean Model (INMSOM) for simulation of Global Ocean circulation and its variability

NASA Astrophysics Data System (ADS)

Gusev, Anatoly; Fomin, Vladimir; Diansky, Nikolay; Korshenko, Evgeniya

2017-04-01

In this paper, we present the improved version of the ocean general circulation sigma-model developed in the Institute of Numerical Mathematics of the Russian Academy of Sciences (INM RAS). The previous version referred to as INMOM (Institute of Numerical Mathematics Ocean Model) is used as the oceanic component of the IPCC climate system model INMCM (Institute of Numerical Mathematics Climate Model (Volodin et al 2010,2013). Besides, INMOM as the only sigma-model was used for simulations according to CORE-II scenario (Danabasoglu et al. 2014,2016; Downes et al. 2015; Farneti et al. 2015). In general, INMOM results are comparable to ones of other OGCMs and were used for investigation of climatic variations in the North Atlantic (Gusev and Diansky 2014). However, detailed analysis of some CORE-II INMOM results revealed some disadvantages of the INMOM leading to considerable errors in reproducing some ocean characteristics. So, the mass transport in the Antarctic Circumpolar Current (ACC) was overestimated. As well, there were noticeable errors in reproducing thermohaline structure of the ocean. After analysing the previous results, the new version of the OGCM was developed. It was decided to entitle is INMSOM (Institute of Numerical Mathematics Sigma Ocean Model). The new title allows one to distingwish the new model, first, from its older version, and second, from another z-model developed in the INM RAS and referred to as INMIO (Institute of Numerical Mathematics and Institute of Oceanology ocean model) (Ushakov et al. 2016). There were numerous modifications in the model, some of them are as follows. 1) Formulation of the ocean circulation problem in terms of full free surface with taking into account water amount variation. 2) Using tensor form of lateral viscosity operator invariant to rotation. 3) Using isopycnal diffusion including Gent-McWilliams mixing. 4) Using atmospheric forcing computation according to NCAR methodology (Large and Yeager 2009). 5) Improvement river runoff algorithm accounting the total amount of discharged water. 6) Using explicit leapfrog time scheme for all lateral operators and implicit Euler scheme for vertical diffusion and viscosity. The INMSOM is tested by reproducing World Ocean circulation and thermohaline characteristics using the well-proved CORE dataset. The presentation is devoted to the analysis of new INMSOM simulation results, estimation of their quality and comparison to the ones previously obtained with the INMOM. The main aim of the INMSOM development is using it as the oceanic component of the next version of INMCM. The work was supported by the Russian Foundation for Basic Research (grants № 16-05-00534 and № 15-05-07539) References 1. Danabasoglu, G., Yeager S.G., Bailey D., et al., 2014: North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part I: Mean states. Ocean Modelling, 73, 76-107. 2. Danabasoglu, G., Yeager S.G., Kim W.M. et al., 2016: North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to decadal variability. Ocean Modelling, 97, 65-90. 3. Downes S.M., Farneti R., Uotila P. et al. An assessment of Southern Ocean water masses and sea ice during 1988-2007 in a suite of interannual CORE-II simulations. Ocean Modelling (2015), 94, 67-94. 4. Farneti R., Downes S.M., Griffies S.M. et al. An assessment of Antarctic Circumpolar Current and Southern Ocean Meridional Overturning Circulation during 1958-2007 in a suite of interannual CORE-II simulations, Ocean Modelling (2015), 93, 84-120. 5. Gusev A.V. and Diansky N.A. Numerical simulation of the World ocean circulation and its climatic variability for 1948-2007 using the INMOM. Izvestiya, Atmospheric and Oceanic Physics, 2014, V. 50, N. 1, P. 1-12 6. Large, W., Yeager, S., 2009. The global climatology of an interannually varying air-sea flux data set. Clim Dyn, V. 33, P. 341-364. 7. Ushakov K.V., Grankina T.B., Ibraev R.A. Modeling the water circulation in the North Atlantic in the scope of the CORE-II experiment. Izvestiya, Atmospheric and Oceanic Physics. 2016. V. 52, № 4, P. 365-375

Measurements of Ocean Surface Scattering Using an Airborne 94-GHz Cloud Radar: Implication for Calibration of Airborne and Spaceborne W-band Radars

NASA Technical Reports Server (NTRS)

Li, Li-Hua; Heymsfield, Gerald M.; Tian, Lin; Racette, Paul E.

2004-01-01

Scattering properties of the Ocean surface have been widely used as a calibration reference for airborne and spaceborne microwave sensors. However, at millimeter-wave frequencies, the ocean surface backscattering mechanism is still not well understood, in part, due to the lack of experimental measurements. During the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE), measurements of ocean surface backscattering were made using a 94-GHz (W-band) cloud radar onboard a NASA ER-2 high-altitude aircraft. The measurement set includes the normalized Ocean surface cross section over a range of the incidence angles under a variety of wind conditions. Analysis of the radar measurements shows good agreement with a quasi-specular scattering model. This unprecedented dataset enhances our knowledge about the Ocean surface scattering mechanism at 94 GHz. The results of this work support the proposition of using the Ocean surface as a calibration reference for airborne millimeter-wave cloud radars and for the ongoing NASA CloudSat mission, which will use a 94-GHz spaceborne cloud radar for global cloud measurements.

78 FR 42921 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Northwest...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-18

... Habitat for the Northwest Atlantic Ocean Distinct Population Segment of the Loggerhead Sea Turtle (Caretta... Northwest Atlantic Ocean Distinct Population Segment (DPS) of the Loggerhead Sea Turtle (Caretta caretta... Ocean DPS of the loggerhead sea turtle, its habitat, or previous Federal actions, refer to the proposed...

Surface Ship Infrared Signature Model Evaluation

DTIC Science & Technology

1994-04-01

measurement equipment. Thermal images were collected with an airborne AGA-780 imaging radiometer installed in a Piper Navajo aicraft. The integrated...apply to four large combatants (Ostrowski, 1993) and the R/V Point Sur. (The RV Point Sw’ is a 135-ft research 6 ship, owned by the National Science...system was mounted in a Piper Navajo aircraft that was flown at low altitudes within the proximity of the ship. Stratus clouds were present throughout

Low-Level Stratus Prediction Using Binary Statistical Regression: A Progress Report Using Moffett Field Data.

DTIC Science & Technology

1983-12-01

analysis; such work is not reported here. It seems pos- sible that a robust principle component analysis may he informa- tive (see Gnanadesikan (1977...Statistics in Atmospheric Sciences, American Meteorological Soc., Boston, Mass. (1979) pp. 46-48. a Gnanadesikan , R., Methods for Statistical Data...North Carolina Chapel Hill, NC 20742 Dr. R. Gnanadesikan Bell Telephone Lab Murray Hill, NJ 07733 -%.. *5%a: *1 *15 I ,, - . . , ,, ... . . . . . . NO

Aerosol and CCN over the Southern Ocean: Sources, Sinks and Processes

NASA Astrophysics Data System (ADS)

Clarke, A. D.; Freitag, S.; Howell, S. G.; Snider, J. R.; Kazil, J.; Feingold, G.; McNaughton, C. S.; Brekhovskikh, V.; Kapustin, V.; Campos, T. L.; Shank, L.

2013-12-01

Aerosol able to activate as cloud condensation nuclei (CCN) in marine stratus play an important role in cloud properties and processes. The 2008 VOCALS experiment (http://www.eol.ucar.edu/projects/vocals/) explored the aerosol cloud system over the South East Pacific (SEP). There, marine boundary layer (MBL) air from the Southern Ocean is directed north parallel to the South American coast and exposed to continental emissions. During this transport the initial clean MBL aerosol is modified in response to production, processing, entrainment, mixing, and removal. Here we discuss how the aerosol, the CCN and the clouds over the SEP are coupled by these processes. VOCALS data along 20S indicated cleanest air offshore and west of about 78W. However, some of the cleanest air (lowest CO concentrations) over the SEP were present in pockets of open cells (POC's). This suggests POC's are favored in places where remnants of Southern Ocean MBL air experienced the least mixing with higher CO sources during transport, either coastal or via entrainment of free troposphere air. Entrainment from the free troposphere (FT) was found to be an important source of marine boundary layer (MBL) aerosol in both near-shore and off-shore regions while direct advection of continental aerosol tended to influence aerosol and CCN closer to the coast. Entrainment from the FT included diverse sources from South America as well as long range transport from the western Pacific. Entrainment of FT aerosol can resupply the MBL with CCN and this process appears greatly enhanced when patchy 'rivers' of pollution lie directly above the inversion. This process was evident both offshore and near the coast. Production of CCN from sea spray aerosol (SSA) were found to increase with wind speed but atmospheric concentrations did not generally increase in the higher wind offshore regions because these regions had greater drizzle removal that compensated for increased production. Generally SSA larger than 60 nm were effective as marine cloud CCN but were only about 20% of the total. Elevated organic aerosol was usually associated with biomass burning sources and a natural marine organic aerosol source was weak. Although nucleation in clean scavenged air layers near the top of the boundary layer were observed under certain conditions, the resulting small aerosol sizes did not appear to provide an effective source of CCN sizes compared to other processes.

Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms

ERIC Educational Resources Information Center

Buth, Jeffrey M.

2016-01-01

Ocean acidification refers to the process by which seawater absorbs carbon dioxide from the atmosphere, producing aqueous carbonic acid. Acidic conditions increase the solubility of calcium carbonate, threatening corals and other calcareous organisms that depend on it for protective structures. The global nature of ocean acidification and the…

Using bibliometrics to demonstrate the value of library journal collections

PubMed Central

Belter, Christopher W; Kaske, Neal K

2016-01-01

Although cited reference studies are common in the library and information science literature, they are rarely performed in non-academic institutions or in the atmospheric and oceanic sciences. In this paper, we analyze over 400,000 cited references made by authors affiliated with the National Oceanic and Atmospheric Administration between 2009 and 2013. Our results suggest that these methods can be applied to research libraries in a variety of institutions, that the results of analyses performed at one institution may not be applicable to other institutions, and that cited reference analyses should be periodically updated to reflect changes in authors’ referencing behavior. PMID:27453584

Alterations of Cloud Microphysics Due to Cloud Processed CCN

NASA Astrophysics Data System (ADS)

Hudson, J. G.; Tabor, S. S.; Noble, S. R., Jr.

2015-12-01

High-resolution CCN spectra have revealed bimodality (Hudson et al. 2015) similar to aerosol size spectra (e.g., Hoppel et al. 1985). Bimodality is caused by chemical and physical cloud processes that increase mass or hygroscopicity of only CCN that produced activated cloud droplets. Bimodality is categorized by relative CCN concentrations (NCCN) within the two modes, Nu-Np; i.e., NCCN within the higher critical supersaturation, Sc, mode that did not undergo cloud processing minus NCCN within the lower Sc mode that was cloud processed. Lower, especially negative, Nu-Np designates greater processing. The table shows regressions between Nu-Np and characteristics of clouds nearest the CCN measurements. ICE-T MASE parameter R SL R SL Nc 0.17 93.24 -0.26 98.65 MD -0.31 99.69 0.33 99.78 σ -0.27 99.04 0.48 100.00 Ld -0.31 99.61 0.38 99.96 Table. Correlation coefficients, R, and one-tailed significance levels in percent, SL, for Nu-Np with microphysics of the clouds closest to each CCN measurement, 75 ICE-T and 74 MASE cases. Nc is cloud droplet concentration, MD is cloud droplet mean diameter, σ is standard deviation of cloud droplet spectra, Ldis drizzle drop LWC. Two aircraft field campaigns, Ice in Clouds Experiment-Tropical (ICE-T) and Marine Stratus/Stratocumulus Experiment (MASE) show opposite R signs because coalescence dominated cloud processing in low altitude ICE-T cumuli whereas chemical transformations predominated in MASE low altitude polluted stratus. Coalescence reduces Nc and NCCN, which thus increases MD, and σ, which promote Ld. Chemical transformations, e.g., SO2 to SO4, increase CCN hygroscopicity, thus reducing Sc, but not affecting Nc or NCCN. Lower Sc CCN are capable of producing greater Nc in subsequent cloud cycles, which leads to lower MD and σ which reduce Ld (figure). These observations are consistent with cloud droplet growth models for the higher vertical wind (W) of cumuli and lower W of stratus. Coalescence thus reduces the indirect aerosol effect (IAE) with a positive feedback that further enhances coalescence and drizzle. Chemical cloud processing enhances both components of IAE; 1st IAE by greater droplet surface area, 2ndIAE by suppressing drizzle and thus increasing cloudiness. Hoppel, Fitzgerald and Larson: JGR 90, 2365-79 Hudson, Noble and Tabor: JGRA 120, 3436-52

A Sediment Testing Reference Area Database for the San Francisco Deep Ocean Disposal Site (SF-DODS)

EPA Pesticide Factsheets

EPA established and maintains a SF-DODS reference area database of previously-collected sediment test data. Several sets of sediment test data have been successfully collected from the SF-DODS reference area.

The Roles of Convection Parameterization in the Formation of Double ITCZ Syndrome in the NCAR CESM: I. Atmospheric Processes

NASA Astrophysics Data System (ADS)

Song, Xiaoliang; Zhang, Guang J.

2018-03-01

Several improvements are implemented in the Zhang-McFarlane (ZM) convection scheme to investigate the roles of convection parameterization in the formation of double intertropical convergence zone (ITCZ) bias in the NCAR CESM1.2.1. It is shown that the prominent double ITCZ biases of precipitation, sea surface temperature (SST), and wind stress in the standard CESM1.2.1 are largely eliminated in all seasons with the use of these improvements in convection scheme. This study for the first time demonstrates that the modifications of convection scheme can eliminate the double ITCZ biases in all seasons, including boreal winter and spring. Further analysis shows that the elimination of the double ITCZ bias is achieved not by improving other possible contributors, such as stratus cloud bias off the west coast of South America and cloud/radiation biases over the Southern Ocean, but by modifying the convection scheme itself. This study demonstrates that convection scheme is the primary contributor to the double ITCZ bias in the CESM1.2.1, and provides a possible solution to the long-standing double ITCZ problem. The atmospheric model simulations forced by observed SST show that the original ZM convection scheme tends to produce double ITCZ bias in high SST scenario, while the modified convection scheme does not. The impact of changes in each core component of convection scheme on the double ITCZ bias in atmospheric model is identified and further investigated.

Final Report of Research Conducted For DE-AI02-08ER64546

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

Patrick Minnis

2012-03-28

Research was conducted for 3-4 years to use ARM data to validate satellite cloud retrievals and help the development of improved techniques for remotely sensing clouds and radiative fluxes from space to complement the ARM surface measurement program. This final report summarizes the results and publications during the last 2 years of the studies. Since our last report covering the 2009 period, we published four papers that were accepted during the previous reporting period and revised and published a fifth one. Our efforts to intercalibrate selected channels on several polar orbiting and geostationary satellite imagers, which are funded in partmore » by ASR, resulted in methods that were accepted as part of the international Global Space-based Intercalibration System (GSICS) calibration algorithms. We developed a new empirical method for correcting the spectral differences between comparable channels on various imagers that will be used to correct the calibrations of the satellite data used for ARM. We documented our cloud retrievals for the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex; ARM participated with an AAF contribution) in context of the entire experiment. We used our VOCALS satellite data along with the aircraft measurements to better understand the relationships between aerosols and liquid water path in marine stratus clouds. We continued or efforts to validate and improve the satellite cloud retrievals for ARM and using ARM data to validate retrievals for other purposes.« less

Brandburg Prominance, Namibia, Africa

NASA Technical Reports Server (NTRS)

1993-01-01

The Brandburg Prominance, Namibia (21.0S, 14.5E) is a round basaltic plug and is the highest feature (over 8,000 ft) in the country. Wind streaks on the surface of the coastal desert, aligned northeast to southwest, are the result of frequent sand storms. Coastal stratus clouds provide most of the life supporting moisture as fog droplets in this arid land where annual rainfall may be less than a quarter of an inch for decades at a time.

"I Think Autism Is Like Running on Windows While Everyone Else Is a Mac": Using a Participatory Action Research Approach with Students on the Autistic Spectrum to Rearticulate Autism and the Lived Experience of University

ERIC Educational Resources Information Center

Vincent, Jonathan; Potts, Megan; Fletcher, Daniel; Hodges, Simon; Howells, Jenny; Mitchell, Alex; Mallon, Brett; Ledger, Thomas

2017-01-01

This co-authored article outlines the research process and key findings from the Stratus Writers Project, a participatory action research project with a group of seven students on the autistic spectrum at a university in the North of England. The project explores their experiences of university through critical autobiographies and offers unique…

Tools and Techniques for Adding Fault Tolerance to Distributed and Parallel Programs

DTIC Science & Technology

1991-12-07

is rapidly approaching dimensions where fault tolerance can no longer be ignored. No matter how reliable the i .nd~ividual components May be, the...The scale of parallel computing systems is rapidly approaching dimensions where 41to’- erance can no longer be ignored. No matter how relitble the...those employed in the Tandem [71 and Stratus [35] systems, is clearly impractical. * No matter how reliable the individual components are, the sheer

Factors Controlling the Properties of Multi-Phase Arctic Stratocumulus Clouds

NASA Technical Reports Server (NTRS)

Fridlind, Ann; Ackerman, Andrew; Menon, Surabi

2005-01-01

The 2004 Multi-Phase Arctic Cloud Experiment (M-PACE) IOP at the ARM NSA site focused on measuring the properties of autumn transition-season arctic stratus and the environmental conditions controlling them, including concentrations of heterogeneous ice nuclei. Our work aims to use a large-eddy simulation (LES) code with embedded size-resolved aerosol and cloud microphysics to identify factors controlling multi-phase arctic stratus. Our preliminary simulations of autumn transition-season clouds observed during the 1994 Beaufort and Arctic Seas Experiment (BASE) indicated that low concentrations of ice nuclei, which were not measured, may have significantly lowered liquid water content and thereby stabilized cloud evolution. However, cloud drop concentrations appeared to be virtually immune to changes in liquid water content, indicating an active Bergeron process with little effect of collection on drop number concentration. We will compare these results with preliminary simulations from October 8-13 during MPACE. The sensitivity of cloud properties to uncertainty in other factors, such as large-scale forcings and aerosol profiles, will also be investigated. Based on the LES simulations with M-PACE data, preliminary results from the NASA GlSS single-column model (SCM) will be used to examine the sensitivity of predicted cloud properties to changing cloud drop number concentrations for multi-phase arctic clouds. Present parametrizations assumed fixed cloud droplet number concentrations and these will be modified using M-PACE data.

"Hi, R U There?" Adventures in Chat Reference Librarianship

ERIC Educational Resources Information Center

Dodge, Heather

2013-01-01

The ability to navigate the vast ocean of available information and perform reference services in digital environments is an essential component of the job for most of today's reference librarians, especially those working in academic libraries. Reference librarians face a challenge: they must be highly skilled at searching for, locating, and…

Fires in the Australian Capital Territory

NASA Technical Reports Server (NTRS)

2003-01-01

The height and extent of billowing smoke plumes from bushfires near Canberra, the Australian capital, are illustrated by these views from the Multi-angle Imaging SpectroRadiometer (MISR). The images were acquired on January 18, 2003. Never before had fires of this magnitude come so close to Australia's capital. Four people lost their lives and over 500 homes were destroyed, mostly in the southwestern suburbs. Australia's famous Mount Stromlo Observatory, located immediately west of the city, was also incinerated by the fires.

The top panel portrays a natural-color view from MISR's nadir camera, in which the eastern portion of the Australian Capital Territory is located south of a pale, ephemeral lake in the upper left-hand corner (Lake George). Several smoke plumes originate within the eastern part of the Australian Capital Territory, while the major plumes originate to the west of the image area. The Australian Capital Territory and much of New South Wales are completely obscured by the smoke, which is driven by fierce westerly winds and extends eastward to the coast and over the Pacific Ocean.

The lower panel provides a stereoscopically retrieved height field of the clouds and smoke plumes. The greenish areas indicate where smoke plumes extend several kilometers above a bank of patchy stratus clouds below. A few high clouds appear near the bottom of the image. Wind retrievals were excluded from this image in order to generate a smooth and continuous field. Although relative height variations are well-represented here, the inclusion of wind retrievals for this scene reduces the actual cloud height results by 1 to 2 kilometers. Areas where heights could not be retrieved are shown as dark gray.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuouslyand every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during Terra orbit 16421. The panels cover an area of 380 kilometers x 253 kilometers, and utilize data from blocks 118 to 120 within World Reference System-2 path 89.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Comparison of CERES-MODIS Stratus Cloud Properties with Ground-Based Measurements at the DOE ARM Southern Great Plains Site

NASA Technical Reports Server (NTRS)

Dong, Xiquan; Minnis Patrick; Xi, Baike; Sun-Mack, Sunny; Chen, Yan

2008-01-01

Overcast stratus cloud properties derived for the Clouds and the Earth's Radiant Energy system (CERES) Project using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data are compared with observations taken at the Atmospheric Radiation Measurement (ARM) Southern Great Plains site from March 2000 through December 2004. Retrievals from ARM surface-based data were averaged over a 1-hour interval centered at the time of each satellite overpass, and the CERES-MODIS cloud properties were averaged within a 30-km x 30 km box centered on the ARM SGP site. Two datasets were analyzed: all of the data (ALL) which include multilayered, single-layered, and slightly broken stratus decks and a subset, single-layered unbroken decks (SL). The CERES-MODIS effective cloud heights were determined from effective cloud temperature using a lapse rate method with the surface temperature specified as the 24-h mean surface air temperature. For SL stratus, they are, on average, within the ARM radar-lidar estimated cloud boundaries and are 0.534 +/- 0.542 km and 0.108 +/- 0.480 km lower than the cloud physical tops and centers, respectively, and are comparable for day and night observations. The mean differences and standard deviations are slightly larger for ALL data, but not statistically different to those of SL data. The MODIS-derived effective cloud temperatures are 2.7 +/- 2.4 K less than the surface-observed SL cloud center temperatures with very high correlations (0.86-0.97). Variations in the height differences are mainly caused by uncertainties in the surface air temperatures, lapse rates, and cloud-top height variability. The biases are mainly the result of the differences between effective and physical cloud top, which are governed by cloud liquid water content and viewing zenith angle, and the selected lapse rate, -7.1 K km(exp -1). Based on a total of 43 samples, the means and standard deviations of the differences between the daytime Terra and surface retrievals of effective radius r(sub e), optical depth, and liquid water path for SL stratu are 0.1 +/- 1.9 micrometers (1.2 +/- 23.5%), -1.3 +/- 9.5 (-3.6 +/-26.2%), and 0.6 +/- 49.9 gm (exp -2) (0.3 +/- 27%), respectively, while the corresponding correlation coefficients are 0.44, 0.87, and 0.89. For Aqua, they are 0.2 +/- 1.9 micrometers (2.5 +/- 23.4%), 2.5 +/- 7.8 (7.8 +/- 24.3%), and 28.1 +/- 52.7 gm (exp -2) (17.2 +/- 32.2%), as well as 0.35, 0.96, and 0.93 from a total of 21 cases. The results for ALL cases are comparable. Although a bias in R(sub e) was expected because the satellite retrieval of effective radius only represents the top of the cloud, the surface-based radar retrievals revealed that the vertical profile of r(sub e) is highly variable with smaller droplets occurring at cloud top in some cases. The larger bias in optical depth and liquid water path for Aqua is due, at least partially, to differences in the Terra and Aqua MODIS visible channel calibrations. methods for improving the cloud-top height and microphysical property retrievals are suggested.

New Insights Into the Origin and Evolution of the Hikurangi Oceanic Plateau

NASA Astrophysics Data System (ADS)

Hoernle, Kaj; Hauff, Folkmar; Werner, Reinhard; Mortimer, Nicholas

2004-10-01

Oceanic plateaus and continental flood basalts, collectively referred to as large igneous provinces (LIPs), represent the most voluminous volcanic events on Earth. In contrast to continental LIPs, relatively little is known about the surface and internal structure, range in age and chemical composition, origin, and evolution of oceanic plateaus, which occur throughout the world's oceans. One of the major goals of the R/V Sonne SO168 ZEALANDIA expedition (deport Wellington, 3 December 2002, return Christchurch, 15 January 2003) was to investigate the Hikurangi oceanic plateau off the east coast of New Zealand.

OSSE Assessment of Ocean Observing System Enhancements to Improve Coupled Tropical Cyclone Intensity Prediction

NASA Astrophysics Data System (ADS)

Halliwell, G. R., Jr.; Mehari, M. F.; Dong, J.; Kourafalou, V.; Atlas, R. M.; Kang, H.; Le Henaff, M.

2016-02-01

A new ocean OSSE system validated in the tropical/subtropical Atlantic Ocean is used to evaluate ocean observing strategies during the 2014 hurricane season with the goal of improving coupled tropical cyclone forecasts. Enhancements to the existing operational ocean observing system are evaluated prior to two storms, Edouard and Gonzalo, where ocean measurements were obtained during field experiments supported by the 2013 Disaster Relief Appropriation Act. For Gonzalo, a reference OSSE is performed to evaluate the impact of two ocean gliders deployed north and south of Puerto Rico and two Alamo profiling floats deployed in the same general region during most of the hurricane season. For Edouard, a reference OSSE is performed to evaluate impacts of the pre-storm ocean profile survey conducted by NOAA WP-3D aircraft. For both storms, additional OSSEs are then conducted to evaluate more extensive seasonal and pre-storm ocean observing strategies. These include (1) deploying a larger number of synthetic ocean gliders during the hurricane season, (2) deploying pre-storm synthetic thermistor chains or synthetic profiling floats along one or more "picket fence" lines that cross projected storm tracks, and (3) designing pre-storm airborne profiling surveys to have larger impacts than the actual pre-storm survey conducted for Edouard. Impacts are evaluated based on error reduction in ocean parameters important to SST cooling and hurricane intensity such as ocean heat content and the structure of the ocean eddy field. In all cases, ocean profiles that sample both temperature and salinity down to 1000m provide greater overall error reduction than shallower temperature profiles obtained from AXBTs and thermistor chains. Large spatial coverage with multiple instruments spanning a few degrees of longitude and latitude is necessary to sufficiently reduce ocean initialization errors over a region broad enough to significantly impact predicted surface enthalpy flux into the storm. Error reduction in hurricane intensity forecasts resulting from the additional ocean observations is then assessed by initializing the ocean component of the HYCOM-HWRF coupled prediction system with analyses produced by the OSSE system.

Geomagnetic field secular variation in Pacific Ocean: A Bayesian reference curve based on Holocene Hawaiian lava flows

NASA Astrophysics Data System (ADS)

Tema, E.; Herrero-Bervera, E.; Lanos, Ph.

2017-11-01

Hawaii is an ideal place for reconstructing the past variations of the Earth's magnetic field in the Pacific Ocean thanks to the almost continuous volcanic activity during the last 10 000 yrs. We present here an updated compilation of palaeomagnetic data from historic and radiocarbon dated Hawaiian lava flows available for the last ten millennia. A total of 278 directional and 66 intensity reference data have been used for the calculation of the first full geomagnetic field reference secular variation (SV) curves for central Pacific covering the last ten millennia. The obtained SV curves are calculated following recent advances on curve building based on the Bayesian statistics and are well constrained for the last five millennia while for older periods their error envelopes are wide due to the scarce number of reference data. The new Bayesian SV curves show three clear intensity maxima during the last 3000 yrs that are accompanied by sharp directional changes. Such short-term variations of the geomagnetic field could be interpreted as archaeomagnetic jerks and could be an interesting feature of the geomagnetic field variation in the Pacific Ocean that should be further explored by new data.

Estimation of mean sea surfaces in the north Atlantic, the Pacific and the Indian Ocean using GEOS-3 altimeter data

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Martin, T. V.; Mccarthy, J. J.; Chovitz, P. S.

1979-01-01

The mean surfaces of several regions of the world's oceans were estimated using GEOS-3 altimeter data. The northwest Atlantic, the northeast Pacific off the coast of California, the Indian Ocean, the southwest Pacific, and the Phillipine Sea are included. These surfaces have been oriented with respect to a common earth center-of-mass system by constraining the separate solutions to conform to precisely determined laser reference control orbits. The same reference orbits were used for all regions assuring continuity of the separate solutions. Radial accuracies of the control orbits were in the order of one meter. The altimeter measured sea surface height crossover differences were minimized by the adjustment of tilt and bias parameters for each pass with the exception of laser reference control passes. The tilt and bias adjustments removed long wavelength errors which were primarily due to orbit error. Ocean tides were evaluated. The resolution of the estimated sea surfaces varied from 0.25 degrees off the east coast of the United States to about 2 degrees in part of the Indian Ocean near Australia. The rms crossover discrepancy after adjustment varied from 30 cm to 70 cm depending upon geographic location. Comparisons of the altimeter derived mean sea surface in the North Atlantic with the 5 feet x 5 feet GEM-8 detailed gravimetric geoid indicated a relative consistency of better than a meter.

Phytoplankton off the Coast of Washington State

NASA Technical Reports Server (NTRS)

2002-01-01

Clear weather over the Pacific Northwest yesterday gave the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) a good view of this mountain region of the United States. Also, there are several phytoplankton blooms visible offshore. The white areas hugging the California coastline toward the bottom of the image are low-level stratus clouds. SeaWiFS acquired this true-color scene on October 3, 2001. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Why Cold-Wet Makes One Feel Chilled: A Literature Review

DTIC Science & Technology

1988-06-01

froid et mouill6. On examine aussi l’effet de la radiation solaire , l’interaction entre la peau at l’humidit6, entre la peau et la temp~rature de mgme...directions, including back out into space. Aerosols of water in clouds reflect incident solar energy . The upper surface of a stratus cloud cover can reflect...earth than under clear conditions. Albedo, the fraction of the incident energy which is reflected by a surface, varies considerably with the terrain

Using the Lagrangian Method to Track Trajectories of Fog And Mist in the Monterey Bay

DTIC Science & Technology

2017-12-01

inversions (Koračin et al. 2014). During these extensive research experiments (Pilié et al. 1979) the role of the Eastern Pacific High was the...the inversion , which then lifts and eventually erodes the marine layer (Koračin et al. 2005). 22 Figure 13. Trajectories from a thermal low lead... inversion characteristics support fog and stratus conditions. Figure 20. Annotation of “L” for June 1, which classifies “Local” wind conditions

Evaluation of Dredged Material Proposed for Ocean Disposal from Federal Projects in New York and New Jersey and the Military Ocean Terminal (MOTBY)

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

Barrows, E.S.; Antrim, L.D.; Pinza, M.R.

1996-08-01

The U.S. Army Corps of Engineers (USACE) is authorized by Section 103 of the Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA), Public Law 92-532, and by the Clean Water Act of 1972 (CWA) and Amendments of 1977 to permit, evaluate, and regulate the disposal of dredged material in ocean waters to minimize adverse environmental effects. Compliance with the regulations of the MPRSA calls for physical and biological testing of sediment proposed for dredging prior to its disposal in ocean waters. The testing required by the MPRSA criteria is conducted under a testing manual developed by the USACE andmore » the U.S. Environmental Protection Agency (EPA), Evaluation of Dredged Material Proposed for Ocean Disposal (Testing Manual), commonly referred to as the `Green Book.` Testing protocols in the Green Book include bulk sediment analysis, grain size analysis, elutriate testing, and biological testing. The biological testing includes bioassays for acute toxicity as well as analysis to determine bioaccumulation of certain contaminants by marine organisms. The objective of the USACE-NYD Federal Projects Program was to evaluate sediment proposed for dredging and unconfined ocean disposal at the Mud Dump Site. The results of analytical measurements and bioassays performed on the test sediments were compared with analyses of sediment from the Mud Dump Reference Site to determine whether the test sediments were acutely toxic to marine organisms or resulted in statistically significantly greater bioaccumulation of contaminants in marine organisms, relative to the reference sediment. Testing for the federal project areas was performed according to the requirements.« less

30 CFR 585.115 - Documents incorporated by reference.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Section 585.115 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE... authorized BOEM official. (d) You may inspect these documents at the Bureau of Ocean Energy Management, 381... Fixed Offshore Platforms—Working Stress Design; Twenty-first Edition, December 2000; Errata and...

30 CFR 585.115 - Documents incorporated by reference.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 585.115 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE... authorized BOEM official. (d) You may inspect these documents at the Bureau of Ocean Energy Management, 381... Fixed Offshore Platforms—Working Stress Design; Twenty-first Edition, December 2000; Errata and...

30 CFR 585.115 - Documents incorporated by reference.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 585.115 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE... authorized BOEM official. (d) You may inspect these documents at the Bureau of Ocean Energy Management, 381... Fixed Offshore Platforms—Working Stress Design; Twenty-first Edition, December 2000; Errata and...

77 FR 13604 - Notice of Agreements Filed

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

... Joint Services Agreement as party, and updates some of the service references in the agreement...: Crowley Latin America Services, LLC; Dole Ocean Cargo Express; King Ocean Services Limited; Seaboard... Latin American Services, LLC as a party to the Agreement. Agreement No.: 012067-006. Title: U.S...

Accuracy assessment of NOAA's daily reference evapotranspiration maps for the Texas High Plains

USDA-ARS?s Scientific Manuscript database

The National Oceanic and Atmospheric Administration (NOAA) provides daily reference ET for the continental U.S. using climatic data from North American Land Data Assimilation System (NLDAS). This data provides large scale spatial representation for reference ET, which is essential for regional scal...

Interpolation of the Radial Velocity Data from Coastal HF Radars

DTIC Science & Technology

2013-01-01

practical applications and may help to solve many environmental problems caused by human activity. References [1] Alvera -Azcarate A., A. Barth, M. Rixen...surface temperature, Ocean Modelling, 9,325-346. [2] Alvera -Azcarate, A., A. Barth,. J.-M. Beckers, and R. H. Weisber, 2007: Multivari- ate...predictions from the global Navy Coastal Ocean Model (NCOM) dur- ing 1998-2001,7. Atmos. Oceanic TechnoL, 21(12), 1876-1894. [4] Barth, A., Alvera

Combustion Aerosol over Marine Stratus: Long Range Transport, Subsidence and Aerosol-Cloud Interactions over the South East Pacific

NASA Astrophysics Data System (ADS)

Clarke, A. D.; Snider, J.; Freitag, S.; Feingold, G.; Campos, T. L.; Breckhovskikh, V.; Kazil, J.

2011-12-01

The worlds largest stratus deck over the South East Pacific (SEP) was a study target for the VOCALS (http://www.eol.ucar.edu/projects/vocals/) experiment in October 2008. Aerosol-cloud interactions were one major goal of several ship and aircraft studies including results from 14 flights of the NCAR C-130 aircraft reported here. Each flight covered about a 1000 km range with multiple profiles and legs below, in and above the Sc deck. Strong aerosol sources along the coast of Chile were expected and found to influence cloud condensation nuclei (CCN) in coastal clouds. However; "rivers" of elevated CO, black carbon (BC) associated with combustion aerosol effective as CCN at <0.3%S were also common in subsiding FT air overlying the extensive Sc deck for over 1000km offshore. This subsidence, linked to the Hadley circulation, brought in aerosol from sources over the western Pacific as well as South America. Observed entrainment of this aerosol appeared linked to cloud related turbulence. When present, this combustion aerosol increased available CCN and decreased effective radius compared to clouds in "clean" MBL air advected from the South Pacific. We hypothesize that this entrainment can help buffer MBL clouds over the SEP against depletion of CCN by drizzle. This may delay transition of closed cell to open cell convection, potentially leading to increased lifetimes of Sc clouds that entrain such aerosol.

Observational constraints on Arctic boundary-layer clouds, surface moisture and sensible heat fluxes

NASA Astrophysics Data System (ADS)

Wu, D. L.; Boisvert, L.; Klaus, D.; Dethloff, K.; Ganeshan, M.

2016-12-01

The dry, cold environment and dynamic surface variations make the Arctic a unique but difficult region for observations, especially in the atmospheric boundary layer (ABL). Spaceborne platforms have been the key vantage point to capture basin-scale changes during the recent Arctic warming. Using the AIRS temperature, moisture and surface data, we found that the Arctic surface moisture flux (SMF) had increased by 7% during 2003-2013 (18 W/m2 equivalent in latent heat), mostly in spring and fall near the Arctic coastal seas where large sea ice reduction and sea surface temperature (SST) increase were observed. The increase in Arctic SMF correlated well with the increases in total atmospheric column water vapor and low-level clouds, when compared to CALIPSO cloud observations. It has been challenging for climate models to reliably determine Arctic cloud radiative forcing (CRF). Using the regional climate model HIRHAM5 and assuming a more efficient Bergeron-Findeisen process with generalized subgrid-scale variability for total water content, we were able to produce a cloud distribution that is more consistent with the CloudSat/CALIPSO observations. More importantly, the modified schemes decrease (increase) the cloud water (ice) content in mixed-phase clouds, which help to improve the modeled CRF and energy budget at the surface, because of the dominant role of the liquid water in CRF. Yet, the coupling between Arctic low clouds and the surface is complex and has strong impacts on ABL. Studying GPS/COSMIC radio occultation (RO) refractivity profiles in the Arctic coldest and driest months, we successfully derived ABL inversion height and surface-based inversion (SBI) frequency, and they were anti-correlated over the Arctic Ocean. For the late summer and early fall season, we further analyzed Japanese R/V Mirai ship measurements and found that the open-ocean surface sensible heat flux (SSHF) can explain 10 % of the ABL height variability, whereas mechanisms such as cloud-driven turbulence appear to be dominant. Contrary to previous speculation, the efficiency of turbulent heat exchange is low. The SSHF contribution to ABL mixing is significant during the uplift (low-pressure) followed by the highly stable (stratus cloud) regime.

To authorize the Secretary of Commerce to convey real property, including improvements, of the National Oceanic and Atmospheric Administration in Ketchikan, Alaska, and for other purposes.

THOMAS, 112th Congress

Rep. Young, Don [R-AK-At Large

2011-07-25

House - 07/26/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

7 CFR 17.2 - Definition of terms.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... United States. The 50 States, the District of Columbia, and Puerto Rico. ... date shown on the ocean bill of lading. Destination country The foreign country to which the commodity... required to repay the funds to CCC. For example, this part refers to CCC “financing” both the ocean freight...

7 CFR 17.2 - Definition of terms.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... United States. The 50 States, the District of Columbia, and Puerto Rico. ... date shown on the ocean bill of lading. Destination country The foreign country to which the commodity... required to repay the funds to CCC. For example, this part refers to CCC “financing” both the ocean freight...

7 CFR 17.2 - Definition of terms.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... United States. The 50 States, the District of Columbia, and Puerto Rico. ... date shown on the ocean bill of lading. Destination country The foreign country to which the commodity... required to repay the funds to CCC. For example, this part refers to CCC “financing” both the ocean freight...

7 CFR 17.2 - Definition of terms.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... United States. The 50 States, the District of Columbia, and Puerto Rico. ... date shown on the ocean bill of lading. Destination country The foreign country to which the commodity... required to repay the funds to CCC. For example, this part refers to CCC “financing” both the ocean freight...

Biochemical Connections Between the Atmosphere and the Ocean

NASA Astrophysics Data System (ADS)

Liss, P. S.

INTRODUCTION THE CHEMICAL COMPOSITION OF THE EARTH'S ATMOSPHERE AIR-SEA EXCHANGE OF GASES OF IMPORTANCE Ozone Manmade Carbon Dioxide Dimethyl Sulphide Dimethyl Selenide Ammonia IMPACT OF ATMOSPHERIC DUST ON OCEAN BIOCHEMISTRY GLOBAL PERSPECTIVES ON BIOGEOCHEMICAL FLUXES ACROSS THE AIR-SEA INTERFACE DMS and the CLAW Hypothesis Iron REFERENCES

Area Handbook for the Indian Ocean Territories.

ERIC Educational Resources Information Center

Stoddard, Theodore L.; And Others

This volume, one of a series of handbooks on foreign culture, is intended as a reference tool for military and other personnel requiring an objective, comprehensive, and balanced description of the Indian Ocean Territories, namely, the two republics of Meldives and Mauritius, and the two European dependencies of Seychelles and Reunion. An…

How well can we quantify dust deposition to the ocean?

PubMed

Anderson, R F; Cheng, H; Edwards, R L; Fleisher, M Q; Hayes, C T; Huang, K-F; Kadko, D; Lam, P J; Landing, W M; Lao, Y; Lu, Y; Measures, C I; Moran, S B; Morton, P L; Ohnemus, D C; Robinson, L F; Shelley, R U

2016-11-28

Deposition of continental mineral aerosols (dust) in the Eastern Tropical North Atlantic Ocean, between the coast of Africa and the Mid-Atlantic Ridge, was estimated using several strategies based on the measurement of aerosols, trace metals dissolved in seawater, particulate material filtered from the water column, particles collected by sediment traps and sediments. Most of the data used in this synthesis involve samples collected during US GEOTRACES expeditions in 2010 and 2011, although some results from the literature are also used. Dust deposition generated by a global model serves as a reference against which the results from each observational strategy are compared. Observation-based dust fluxes disagree with one another by as much as two orders of magnitude, although most of the methods produce results that are consistent with the reference model to within a factor of 5. The large range of estimates indicates that further work is needed to reduce uncertainties associated with each method before it can be applied routinely to map dust deposition to the ocean. Calculated dust deposition using observational strategies thought to have the smallest uncertainties is lower than the reference model by a factor of 2-5, suggesting that the model may overestimate dust deposition in our study area.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'. © 2016 The Author(s).

How well can we quantify dust deposition to the ocean?

PubMed Central

Cheng, H.; Edwards, R. L.; Fleisher, M. Q.; Hayes, C. T.; Huang, K.-F.; Kadko, D.; Lam, P. J.; Landing, W. M.; Lao, Y.; Lu, Y.; Measures, C. I.; Moran, S. B.; Morton, P. L.; Ohnemus, D. C.; Robinson, L. F.; Shelley, R. U.

2016-01-01

Deposition of continental mineral aerosols (dust) in the Eastern Tropical North Atlantic Ocean, between the coast of Africa and the Mid-Atlantic Ridge, was estimated using several strategies based on the measurement of aerosols, trace metals dissolved in seawater, particulate material filtered from the water column, particles collected by sediment traps and sediments. Most of the data used in this synthesis involve samples collected during US GEOTRACES expeditions in 2010 and 2011, although some results from the literature are also used. Dust deposition generated by a global model serves as a reference against which the results from each observational strategy are compared. Observation-based dust fluxes disagree with one another by as much as two orders of magnitude, although most of the methods produce results that are consistent with the reference model to within a factor of 5. The large range of estimates indicates that further work is needed to reduce uncertainties associated with each method before it can be applied routinely to map dust deposition to the ocean. Calculated dust deposition using observational strategies thought to have the smallest uncertainties is lower than the reference model by a factor of 2–5, suggesting that the model may overestimate dust deposition in our study area. This article is part of the themed issue ‘Biological and climatic impacts of ocean trace element chemistry’. PMID:29035251

Chair of U. S. Ocean Policy Commission Urges Law of the Sea Ratification

NASA Astrophysics Data System (ADS)

Showstack, Randy

2004-06-01

The chair of the Congressionally-mandated U.S. Commission on Ocean Policy has urged the Senate to ratify the United Nations Convention on the Law of the Sea this year. Speaking at the Capitol Hill Oceans Week 2004 conference in Washington, D.C. on 10 June, James Watkins told the audience to help ``break the hold that a couple of senators have on that bill.'' Ratification of the treaty is among the key recommendations of the commission's interim report, which was issued on 20 April. The commission has referred to the convention as a ``constitution'' for the oceans.

Individual Aerosol Particles from Biomass Burning in Southern Africa. 1; Compositions and Size Distributions of Carbonaceous Particles

NASA Technical Reports Server (NTRS)

Posfai, Mihaly; Simonics, Renata; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.

2003-01-01

Individual aerosol particles in smoke plumes from biomass fires and in regional hazes in southern Africa were studied using analytical transmission electron microscopy (TEM), which allowed detailed characterization of carbonaceous particle types in smoke and determination of changes in particle properties and concentrations during smoke aging. Based on composition, morphology, and microstructure, three distinct types of carbonaceous particles were present in the smoke: organic particles with inorganic (K-salt) inclusions, tar ball particles, and soot. The relative number concentrations of organic particles were largest in young smoke, whereas tar balls were dominant in a slightly aged (1 hour) smoke from a smoldering fire. Flaming fires emitted relatively more soot particles than smoldering fires, but soot was a minor constituent of all studied plumes. Further aging caused the accumulation of sulfate on organic and soot particles, as indicated by the large number of internally mixed organic/sulfate and soot/sulfate particles in the regional haze. Externally mixed ammonium sulfate particles dominated in the boundary layer hazes, whereas organic/sulfate particles were the most abundant type in the upper hazes. Apparently, elevated haze layers were more strongly affected by biomass smoke than those within the boundary layer. Based on size distributions and the observed patterns of internal mixing, we hypothesize that organic and soot particles are the cloud-nucleating constituents of biomass smoke aerosols. Sea-salt particles dominated in the samples taken in stratus clouds over the Atlantic Ocean, off the coast of Namibia, whereas a distinct haze layer above the clouds consisted of aged biomass smoke particles.

Theoretical Studies of Microphysics of Marine Boundary-Layer Clouds

NASA Technical Reports Server (NTRS)

Toon, Owen B.

2002-01-01

This project is aimed at better understanding the role that aerosols play in altering the properties of stratus clouds. This interaction, termed the indirect effect of aerosols on climate, is a major subject a of study since the radiative forcing involved may rival that of greenhouse gases, but may be of the opposite sign. Our goal was to create numerical models of the phenomena, test them with data, and thereby gain insight into the physical processes occurring. Below we list the papers that we have produced during this grant. We then discuss these papers.

Theoretical interpretation of the Venus 1.05-micron CO2 band and the Venus 0.8189-micron H2O line.

NASA Technical Reports Server (NTRS)

Regas, J. L.; Giver, L. P.; Boese, R. W.; Miller, J. H.

1972-01-01

The synthetic-spectrum technique was used in the analysis. The synthetic spectra were constructed with a model which takes into account both isotropic scattering and the inhomogeneity in the Venus atmosphere. The Potter-Hansen correction factor was used to correct for anisotropic scattering. The synthetic spectra obtained are, therefore, the first which contain all the essential physics of line formation. The results confirm Potter's conclusion that the Venus cloud tops resemble terrestrial cirrus or stratus clouds in their scattering properties.

Earth observations taken by the Expedition Seven crew

NASA Image and Video Library

2003-08-24

ISS007-E-13327 (24 August 2003) --- This view featuring Java’s Merapi volcano was photographed by one of the Expedition 7 crewmembers onboard the International Space Station (ISS). At 2,911 meters, the summit of Merapi and its vigorous steam plume rises above a bank of stratus clouds. One of Indonesia’s most active volcanoes, it has been almost continuously active for nearly ten years, including periodic pyroclastic flows and avalanches. The volcano is located less than 25 miles north of the city of Yogykarta in central Java.

Airborne Hyperspectral Remote Sensing

DTIC Science & Technology

1999-09-30

REFERENCES Davis, C. O., M. Kappus , J. Bowles, J. Fisher, J. Antoniades, and M. Carney, “Calibration, Characterization and first Results with the Ocean...PUBLICATIONS Davis, C. O., M. Kappus , J. Bowles, J. Fisher, J. Antoniades, and M. Carney, “Calibration, Characterization and first Results with the Ocean PHILLS Hyperspectral Imager”, Proceedings of the SPIE, V. 3753, In Press.

76 FR 10888 - Science Advisory Board (SAB); Notice of Open Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-28

... Secretary of Commerce for Oceans and Atmosphere on strategies for research, education, and application of....m. These times and the agenda topics described below are subject to change. Please refer to the Web... on Coastal and Marine Spatial Planning; (2) Discussion of NOAA and SAB Activities on Ocean Policy and...

Satellite Synthetic Aperture Radar Detection of Ocean Internal Waves in the South China Sea

DTIC Science & Technology

2006-09-30

waves will occur and what effects they will have on the hydrodynamic and acoustic environment. This project focuses on the use of remotely sensed...variability of the ITF and its associated heat and freshwater flux exported into the Indian Ocean. REFERENCES Boyer, T., and S. Levites , Quality

Super-Ensemble Techniques: Application to Surface Drift Prediction During the DART06 and MREA07 Campaigns

DTIC Science & Technology

2009-10-08

Fratianni, L. Torrisi, D. Pallela, J. Chiggiato , M. Tudor, J. Book, P. Martin, G. Peggion, M. Rixen 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...by the HydroMeteorological Service of ARPA Emilia Romagna, Bologna, Italy (see e.g. Chiggiato and Oddo (2008) and references herein, and http...143-151. Chiggiato , J.. Oddo, P.. 2008. Operational ocean models in the Adriatic Sea: a skill assessment. Ocean Science 4(1), 61-71. <http://www.ocean

Assimilation of satellite surface-height anomalies data into a Hybrid Coordinate Ocean Model (HYCOM) over the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Tanajura, C. A. S.; Lima, L. N.; Belyaev, K. P.

2015-09-01

The data of sea height anomalies calculated along the tracks of the Jason-1 and Jason-2 satellites are assimilated into the HYCOM hydrodynamic ocean model developed at the University of Miami, USA. We used a known method of data assimilation, the so-called ensemble method of the optimal interpolation scheme (EnOI). In this work, we study the influence of the assimilation of sea height anomalies on other variables of the model. The behavior of the time series of the analyzed and predicted values of the model is compared with a reference calculation (free run), i.e., with the behavior of model variables without assimilation but under the same initial and boundary conditions. The results of the simulation are also compared with the independent data of observations on moorings of the Pilot Research Array in the Tropical Atlantic (PIRATA) and the data of the ARGO floats using objective metrics. The investigations demonstrate that data assimilation under specific conditions results in a significant improvement of the 24-h prediction of the ocean state. The experiments also show that the assimilated fields of the ocean level contain a clearly pronounced mesoscale variability; thus they quantitatively differ from the dynamics obtained in the reference experiment.

Data availability and data archeology from the former Soviet Union

NASA Technical Reports Server (NTRS)

Sychev, Yuri; Mikhailov, Nickolai N.

1992-01-01

Acquisition of data on the ocean is believed to start in 1872, when the Royal Navy ship 'Challenger' performed oceanographic stations in its round-world voyage (1872-1876). The first oceanographic studies of the World Ocean refer to the 80s second half of the 19th century. During its round-world expedition 'Vityaz' (1886-1889) headed by S.O. Markov, performed hydrological measurements in the Baltic Sea, Atlantic and Pacific Oceans. According to information available the regular expedition observations (prototype of future complex international program on the ocean research) started in the second half of 80s last century under the auspice of Kiev commission for exploration of German Seas. Systematic hydrological observations were organized by Hydrographic Department of Russia in 1876-1879 according to the program similar to the Kiev one and observations were regularly made by ships of custom service over the Russian area of the Baltic Sea. The increasing demands in oceanographic data contributed to considerable progress in exploration of the World Ocean during current century whole tendency to increase and become more significant has been observed for the last 30-40 years. Most probably various expeditions which were carried out during International Geophysical Year in different regions of the World Ocean are to be reference point in performing intensive oceanographic observations of Marine environment. In the former USSR oceanographic observations are made by research and hydrographic vessels, commercial and fishery ships as well as oil production platforms, coastal hydrometeorological station and other observing platforms. Oceanographic observations data, available from main sources of information on the ocean-research vessels, are also considered in the report.

Ocean acoustic reverberation tomography.

PubMed

Dunn, Robert A

2015-12-01

Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

Remote sensing of ocean surface currents: a review of what is being observed and what is being assimilated

NASA Astrophysics Data System (ADS)

Isern-Fontanet, Jordi; Ballabrera-Poy, Joaquim; Turiel, Antonio; García-Ladona, Emilio

2017-10-01

Ocean currents play a key role in Earth's climate - they impact almost any process taking place in the ocean and are of major importance for navigation and human activities at sea. Nevertheless, their observation and forecasting are still difficult. First, no observing system is able to provide direct measurements of global ocean currents on synoptic scales. Consequently, it has been necessary to use sea surface height and sea surface temperature measurements and refer to dynamical frameworks to derive the velocity field. Second, the assimilation of the velocity field into numerical models of ocean circulation is difficult mainly due to lack of data. Recent experiments that assimilate coastal-based radar data have shown that ocean currents will contribute to increasing the forecast skill of surface currents, but require application in multidata assimilation approaches to better identify the thermohaline structure of the ocean. In this paper we review the current knowledge in these fields and provide a global and systematic view of the technologies to retrieve ocean velocities in the upper ocean and the available approaches to assimilate this information into ocean models.

Evidence and mechanism of Hurricane Fran-Induced ocean cooling in the Charleston Trough

NASA Astrophysics Data System (ADS)

Xie, Lian; Pietrafesa, L. J.; Bohm, E.; Zhang, C.; Li, X.

Evidence of enhanced sea surface cooling during and following the passage of Hurricane Fran in September 1996 over an oceanic depression located on the ocean margin offshore of Charleston, South Carolina (referred to as the Charleston Trough), [Pietrafesa, 1983] is documented. Approximately 4C° of sea surface temperature (SST) reduction within the Charleston Trough following the passage of Hurricane Fran was estimated based on SST imagery from Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-14 polar orbiting satellite. Simulations using a three-dimensional coastal ocean model indicate that the largest SST reduction occurred within the Charleston Trough. This SST reduction can be explained by oceanic mixing due to storm-induced internal inertia-gravity waves.

TOPEX watershed coming in oceanography

NASA Technical Reports Server (NTRS)

Cleven, G. C.; Neilson, R. A.; Yamarone, C. A., Jr.

1983-01-01

The NASA Ocean Topography Experiment (TOPEX) will use precision radar altimetry to determine topographic features of the global oceans from which currents may be deduced. TOPEX will coincide with the World Ocean Circulation Experiment (WOCE), which will be conducted at the end of this decade and shall involve ships, fixed and drifting buoys, aircraft observations, and satellite remote sensing, to resolve fundamental questions about the flow of water in the global ocean. TOPEX will contribute to WOCE the measurement of satellite height above the sea surface, and the precise radial position above a reference ellipsoid for the earth. The combination of these two measurements with the marine geoid yields the topographic data sought. Three years of topographic data, together with conventional oceanographic data and theoretical ocean models, will be needed to derive the mean and variable components of ocean circulation.

Analysis of Surface Albedo to Improve Upper-Ocean Heat Budget Calculations

NASA Astrophysics Data System (ADS)

Hogikyan, A.; Zhang, D.; Cronin, M. F.

2016-12-01

Over 90% of the Earth's energy imbalance is stored in the oceans, so it is important to understand the ocean-atmosphere heat transfer. The Ocean Climate Stations group (OCS) at the Pacific Marine Environmental Laboratory maintains two moored surface buoys in the North Pacific (PAPA and KEO) as air-sea flux reference sites. The goal of the reference sites is to validate global air-sea flux products from atmospheric reanalyses and satellite products, that are critical to understand and model the variability and trend of the earth climate. As other air-sea flux reference buoys in the world ocean, PAPA and KEO only measure downward shortwave radiation (SWdown), but utilize the albedo and the directly measured SWdown to calculate the SWup. Since the open ocean albedo is small, the errors associated with this practice are thought to be comparable or smaller than the instrumentation errors in the air-sea flux measurements. In addition, it is generally accepted that ocean surface albedos can be derived with reasonable confidence from surface radiative fluxes in satellite products such as the Clouds and the Earth's Radiant Energy System (CERES) and the International Satellite Cloud Climatology Project (ISCCP). This project developed a CERES-based albedo product for derivation of SWnet at PAPA and KEO, and assessed the impact of CERES-based albedo on the net surface heat fluxes relative to the currently used ISCCP-based albedo in the OCS air-sea flux data (http://www.pmel.noaa.gov/ocs/data/fluxdisdel/). The high-resolution surface fluxes from CERES are more frequently updated, and consider more physical factors in the approximation, than those from ISCCP. There was a greater change between ISCCP and CERES albedo during wintertime than during summer. There was a greater change at Station PAPA in the northeastern sub-Arctic Pacific, than at Station KEO in the northwestern subtropical Pacific. The rate of temperature change of the mixed-layer is shown to increase based on the new source of albedo data, .08 and .5 °C/year at KEO and PAPA, respectively. The differences in the net surface heat flux due to different albedos used in this study suggest that more comprehensive investigations of the albedo in different products and radiative models, and their impacts on oceanic and atmospheric processes are needed.

Climate change

USGS Publications Warehouse

Cronin, Thomas M.

2016-01-01

Climate change (including climate variability) refers to regional or global changes in mean climate state or in patterns of climate variability over decades to millions of years often identified using statistical methods and sometimes referred to as changes in long-term weather conditions (IPCC, 2012). Climate is influenced by changes in continent-ocean configurations due to plate tectonic processes, variations in Earth’s orbit, axial tilt and precession, atmospheric greenhouse gas (GHG) concentrations, solar variability, volcanism, internal variability resulting from interactions between the atmosphere, oceans and ice (glaciers, small ice caps, ice sheets, and sea ice), and anthropogenic activities such as greenhouse gas emissions and land use and their effects on carbon cycling.

Journal of Geophysical Research Publications: Community Characteristics

NASA Astrophysics Data System (ADS)

Pfirman, S. L.; Porter, A.

2009-12-01

Do earth science publications differ by subfield or gender? To figure this out we analyzed publications in JGR Atmosphere, Oceans, and Solid Earth for the year 2000. We assumed that the first author exerted controlling influence over publication characteristics and then we looked at the number of co-authors, number of institutions represented by co-author affiliations, page length of the article, number of references cited, number of subject categories represented in the cited references, number of times the article was cited, and the time between the date the article was submitted and the date when it was accepted for publication. We found that, within each field, there was remarkable similarity between the publications led by women and those led by men. Interesting differences showed up between subfields: for example, Solid Earth authors use more references than do authors publishing in Atmosphere or Oceans.

Notes on the Phonological History of the Austronesian Languages of the Sarmi Coast.

ERIC Educational Resources Information Center

Grace, George W.

This study analyzes the sound correspondences of six Oceanic languages using reconstructed forms from Proto-Oceanic as a frame of reference. Sobei, Wakde, Masimasi, Anus, Bojgo, and Tarpia provide the cognates used in the analysis. Consonants and vowels are analyzed, and sound correspondences are examined for regularity of development and possible…

Internal Waves, South China Sea

NASA Technical Reports Server (NTRS)

1983-01-01

Subsurface ocean currents, frequently referred to as internal waves, are frequently seen from space under the right lighting conditions when depth penetration can be achieved. These internal waves observed in the South China Sea off the SE coast of the island of Hainan (18.5N, 110.5E) visibly demonstrate turbidity in the ocean's depths at the confluence of conflicting currents.

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

...? 250.901 Section 250.901 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... Constructing Fixed Offshore Platforms—Working Stress Design (incorporated by reference as specified in § 250... Stress Cracking Resistant Metallic Materials for Oilfield Equipment, (incorporated by reference as...

PILOT STUDY FOR ESTABLISHMENT OF A NETWORK OF COASTAL REFERENCE SITES

EPA Science Inventory

The National Oceanic and Atmospheric Administration (NOAA), U.S. Environmental Protection Agency (EPA), and the National Aeronautics and Space Administration (NASA) have joined in partnership for a pilot study for the establishment of a network of reference sites, the Coastal Int...

Accuracy assessment of NOAA gridded daily reference evapotranspiration for the Texas High Plains

USDA-ARS?s Scientific Manuscript database

The National Oceanic and Atmospheric Administration (NOAA) provides daily reference evapotranspiration (ETref) maps for the contiguous United States using climatic data from North American Land Data Assimilation System (NLDAS). This data provides large-scale spatial representation of ETref, which i...

Optical Coherence Tomography (OCT) Device Independent Intraretinal Layer Segmentation

PubMed Central

Ehnes, Alexander; Wenner, Yaroslava; Friedburg, Christoph; Preising, Markus N.; Bowl, Wadim; Sekundo, Walter; zu Bexten, Erdmuthe Meyer; Stieger, Knut; Lorenz, Birgit

2014-01-01

Purpose To develop and test an algorithm to segment intraretinal layers irrespectively of the actual Optical Coherence Tomography (OCT) device used. Methods The developed algorithm is based on the graph theory optimization. The algorithm's performance was evaluated against that of three expert graders for unsigned boundary position difference and thickness measurement of a retinal layer group in 50 and 41 B-scans, respectively. Reproducibility of the algorithm was tested in 30 C-scans of 10 healthy subjects each with the Spectralis and the Stratus OCT. Comparability between different devices was evaluated in 84 C-scans (volume or radial scans) obtained from 21 healthy subjects, two scans per subject with the Spectralis OCT, and one scan per subject each with the Stratus OCT and the RTVue-100 OCT. Each C-scan was segmented and the mean thickness for each retinal layer in sections of the early treatment of diabetic retinopathy study (ETDRS) grid was measured. Results The algorithm was able to segment up to 11 intraretinal layers. Measurements with the algorithm were within the 95% confidence interval of a single grader and the difference was smaller than the interindividual difference between the expert graders themselves. The cross-device examination of ETDRS-grid related layer thicknesses highly agreed between the three OCT devices. The algorithm correctly segmented a C-scan of a patient with X-linked retinitis pigmentosa. Conclusions The segmentation software provides device-independent, reliable, and reproducible analysis of intraretinal layers, similar to what is obtained from expert graders. Translational Relevance Potential application of the software includes routine clinical practice and multicenter clinical trials. PMID:24820053

Macular thickness measurements using Copernicus Spectral Domain Optical Coherence Tomography.

PubMed

Gella, Laxmi; Raman, Rajiv; Sharma, Tarun

2015-01-01

To provide normal macular thickness measurements using Spectral Domain Optical Coherence Tomography (SDOCT, Copernicus, Optopol Technologies, Zawierci, Poland). Fifty-eight eyes of 58 healthy subjects were included in this prospective study. All subjects had comprehensive ophthalmic examination including best-corrected visual acuity (BCVA). All the subjects underwent Copernicus SDOCT. Central foveal thickness (CFT) and photoreceptor layer (PRL) thickness were measured and expressed as mean and standard deviation. Mean retinal thickness for each of the 9 regions defined in the Early Treatment Diabetic Retinopathy Study was reported. The data were compared with published literature in Indians using Stratus and Spectralis OCTs to assess variation in instrument measurements. The mean CFT in the study sample was 173.8 ± 18.16 microns (131-215 microns) and the mean PRL thickness was 65.48 ± 4.23 microns (56-74 microns). No significant difference (p = 0.148) was found between CFT measured automated (179.28 ± 22 microns) and manually (173.83 ± 18.1 microns). CFT was significantly lower in women (167.62 ± 16.36 microns) compared to men (180.03 ± 18 microns) (p = 0.008). Mean retinal thickness reported in this study was significantly different from published literature using Stratus OCT and Spectralis OCT. We report the normal mean retinal thickness in central 1 mm area to be between 138 and 242 microns in Indian population using Copernicus SDOCT. We suggest that different OCT instruments cannot be used interchangeably for the measurement of macular thickness as they vary in segmentation algorithms.

Aerosol microphysical and radiative effects on continental cloud ensembles

NASA Astrophysics Data System (ADS)

Wang, Yuan; Vogel, Jonathan M.; Lin, Yun; Pan, Bowen; Hu, Jiaxi; Liu, Yangang; Dong, Xiquan; Jiang, Jonathan H.; Yung, Yuk L.; Zhang, Renyi

2018-02-01

Aerosol-cloud-radiation interactions represent one of the largest uncertainties in the current climate assessment. Much of the complexity arises from the non-monotonic responses of clouds, precipitation and radiative fluxes to aerosol perturbations under various meteorological conditions. In this study, an aerosol-aware WRF model is used to investigate the microphysical and radiative effects of aerosols in three weather systems during the March 2000 Cloud Intensive Observational Period campaign at the US Southern Great Plains. Three simulated cloud ensembles include a low-pressure deep convective cloud system, a collection of less-precipitating stratus and shallow cumulus, and a cold frontal passage. The WRF simulations are evaluated by several ground-based measurements. The microphysical properties of cloud hydrometeors, such as their mass and number concentrations, generally show monotonic trends as a function of cloud condensation nuclei concentrations. Aerosol radiative effects do not influence the trends of cloud microphysics, except for the stratus and shallow cumulus cases where aerosol semi-direct effects are identified. The precipitation changes by aerosols vary with the cloud types and their evolving stages, with a prominent aerosol invigoration effect and associated enhanced precipitation from the convective sources. The simulated aerosol direct effect suppresses precipitation in all three cases but does not overturn the aerosol indirect effect. Cloud fraction exhibits much smaller sensitivity (typically less than 2%) to aerosol perturbations, and the responses vary with aerosol concentrations and cloud regimes. The surface shortwave radiation shows a monotonic decrease by increasing aerosols, while the magnitude of the decrease depends on the cloud type.

Feature Selection for Classification of Polar Regions Using a Fuzzy Expert System

NASA Technical Reports Server (NTRS)

Penaloza, Mauel A.; Welch, Ronald M.

1996-01-01

Labeling, feature selection, and the choice of classifier are critical elements for classification of scenes and for image understanding. This study examines several methods for feature selection in polar regions, including the list, of a fuzzy logic-based expert system for further refinement of a set of selected features. Six Advanced Very High Resolution Radiometer (AVHRR) Local Area Coverage (LAC) arctic scenes are classified into nine classes: water, snow / ice, ice cloud, land, thin stratus, stratus over water, cumulus over water, textured snow over water, and snow-covered mountains. Sixty-seven spectral and textural features are computed and analyzed by the feature selection algorithms. The divergence, histogram analysis, and discriminant analysis approaches are intercompared for their effectiveness in feature selection. The fuzzy expert system method is used not only to determine the effectiveness of each approach in classifying polar scenes, but also to further reduce the features into a more optimal set. For each selection method,features are ranked from best to worst, and the best half of the features are selected. Then, rules using these selected features are defined. The results of running the fuzzy expert system with these rules show that the divergence method produces the best set features, not only does it produce the highest classification accuracy, but also it has the lowest computation requirements. A reduction of the set of features produced by the divergence method using the fuzzy expert system results in an overall classification accuracy of over 95 %. However, this increase of accuracy has a high computation cost.

The Pacific Coast Fog Project: A Multi-disciplinary Effort to Provide Web-based Climate Products for Ecologists

NASA Astrophysics Data System (ADS)

Torregrosa, A.; Combs, C.; Ellrod, G. P.; Faloona, I. C.; Gultepe, I.

2012-12-01

The Pacific Coast Fog Project is an effort to pool the expertise from multiple science disciplines to provide regional and local climate information on the frequency and character of fog for effective management of coastal California natural resources. Marine stratocumulus (fog) is a major modifier of the climatic condition along the Pacific coast and has significant effects on the hydrologic cycle and thermodynamic balance in coastal ecological, biological, and economic systems. For example fog is the major source of moisture during summer months for redwood forests, a treasured natural resource. Fog also modulates shallow stream temperatures to reduce the mortality rate of young salmon during their freshwater life stages and adults returning from the ocean to spawn. Fog induced cooling reduces summer energy costs along the Pacific Coast and reduces sun burn on crops such as grapes that are important to the local economy. Furthermore, disruptions in fog distribution or frequency resulting from future climate change would change evapotranspiration rates impacting California water supply and use. Coastal fog is a complex phenomenon with many measurable parameters including extent, frequency, and duration of cloud cover; cloud deck thickness, liquid water content, base height above land, density, heterogeneity, and thermal properties. Variations in fog are a result of processes acting at multiple scales across ocean-land-atmosphere boundaries. Factors that drive the occurrence, duration, and type of fog events along the coast include dynamics of atmospheric summertime inversions, synoptic weather patterns, ocean upwelling, topography, aerosol-cloud dynamics, and differences in temperature between inland valleys and the littoral ocean areas. Estimating the distribution, frequency and characteristics of coastal fog and stratus and evaluating the resulting ecosystem responses require a diverse array of measurements and models that link processes at multiple scales. The project leverages results from existing research projects, such as long-term fog climatology based on surface land and buoy observations ongoing at the University of Washington, and California fog climatology derived from 11 years of Geostationary Operational Environmental Satellite (GOES) data underway at the Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University in Ft. Collins. There are numerous other collaborators from academia (such as several University of California oceanographic and atmospheric science departments) and government agencies (U. S. Geological Survey, National Weather Service, NASA, and Environment Canada). During the summer of 2012, a pilot project deployed sensors on loan from Environment Canada to augment existing instruments at Bodega Bay, California and Pepperwood Preserve in Sonoma County to gather important data sets on mesoscale and microphysical variables including liquid water content, surface wind, visibility, temperature, and boundary layer height that will be used to better describe the characteristics of coastal fog. Sample transects for significant fog events along with examples of antecedent synoptic weather conditions and mockups of possible graphic products for end users will be shown.

An inventory of Arctic Ocean data in the World Ocean Database

NASA Astrophysics Data System (ADS)

Zweng, Melissa M.; Boyer, Tim P.; Baranova, Olga K.; Reagan, James R.; Seidov, Dan; Smolyar, Igor V.

2018-03-01

The World Ocean Database (WOD) contains over 1.3 million oceanographic casts (where cast refers to an oceanographic profile or set of profiles collected concurrently at more than one depth between the ocean surface and ocean bottom) collected in the Arctic Ocean basin and its surrounding marginal seas. The data, collected from 1849 to the present, come from many submitters and countries, and were collected using a variety of instruments and platforms. These data, along with the derived products World Ocean Atlas (WOA) and the Arctic Regional Climatologies, are exceptionally useful - the data are presented in a standardized, easy to use format and include metadata and quality control information. Collecting data in the Arctic Ocean is challenging, and coverage in space and time ranges from excellent to nearly non-existent. WOD continues to compile a comprehensive collection of Arctic Ocean profile data, ideal for oceanographic, environmental and climatic analyses (https://doi.org/10.7289/V54Q7S16).

Thermodynamic neutral density: A new physically-based, energy-constrained, materially conserved neutral density variable for quantifying mixing and tracking water masses in the ocean

NASA Astrophysics Data System (ADS)

Tailleux, R.

2016-02-01

A new materially-conserved quasi-neutral density variable has been constructed, called thermodynamic neutral density. It is composed of two parts. The first part is the Lorenz reference density entering Lorenz theory of available potential energy, which can be interpreted as the potential density of a fluid parcel referenced to the pressure it would have in Lorenz reference state of minimum potential energy. The second part is an empirical correction for pressure, which can be suitably chosen to make thermodynamic neutral density a very good approximation of Jackett and McDougall (1997) neutral density over most of the ocean water masses for which the latter is defined. Thermodynamic neutral density possesses many advantages over the empirically constructed Jackett and McDougall (1997) neutral density: 1) it is physically-based; 2) it is easily computed using fast and efficient methods for arbitrary states of the ocean, not just the present state, using the recently developed methodology by Saenz et al. (2015); 3) it is exactly neutral in a state of rest, and approximately neutral in the present ocean; 4) it is exactly materially conserved (it is a function of salinity and potential temperature only) and not plagued by unphysical nonmaterial effects, so can be used unambiguously to define and diagnose diapycnal and isopycnal mixing; 5) it is based on available potential energy, and therefore is the most suitable variable to discuss the energy cost of adiabatic stirring; 6) it is the variable that should be used to define the isopycnal and diapycnal directions in rotated diffusion tensor, as it can be shown that using the directions defined by the local neutral tangent plane as currently done causes spurious destruction of water masses. References: J. A. Saenz, R. Tailleux, E.D. Butler, G.O. Hughes, and K.I.C. Oliver, 2015: Estimating Lorenz's reference state in an ocean with a nonlinear equation of state for seawater. J. Phys. Oceanogr., 45, 1242—1257

Physical oceanography and tracer chemistry of the southern ocean

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

Not Available

This report considers technical and scientific developments and research questions in studies of the Southern Ocean since its predecessor, /open quotes/Southern Ocean Dynamics--A Strategy for Scientific Exploration 1973-1983/close quotes/ was published. The summary lists key research questions in Southern Ocean oceanography. Chapter 1 describes how Southern Ocean research has evolved to provide the basis for timely research toward more directed objectives. Chapter 2 recommends four research programs, encompassing many of the specific recommendations that follow. Appendix A provides the scientific background and Reference/Bibliography list for this report for: on air-sea-ice interaction; the Antarctic Circumpolar Current; water mass conversion; chemical tracermore » oceanography; and numerical modeling of the Southern Ocean. Appendix B describes the satellite-based observation systems expected to be active during the next decade. Appendix C is a list of relevant reports published during 1981-1987. 146 refs.« less

The influence of David Keeling on oceanic CO2 measurements

NASA Astrophysics Data System (ADS)

Brewer, Peter G.

Dave Keeling—only Roger Revelle called him "Charles David" and always in a tone that could command Dave's attention—had a remarkable influence on the creation of modern understanding of the oceanic CO2 system. Although Dave resided at an oceanographic institution for almost his entire professional career, the great majority of his work concerned atmospheric measurements; his own account of his work [Keeling, 1998] makes scant reference to his ocean science papers. But those relatively few oceanic papers, and more importantly his intense personal interest and unimpeachable reputation for classic measurement, had enormous impact. It is possible to trace Dave's influence on oceanic measurement through the course of five decades, and over that time, our understanding has grown enormously. The following is a somewhat personal account, but Dave so influenced the careers of the small group of ocean CO2 scientists that have led the way that any one of them would write a similar account.

Some General Laws of Chemical Elements Composition Dynamics in the Hydrosphere

NASA Astrophysics Data System (ADS)

Korzh, V.

2012-12-01

The biophysical oceanic composition is a result of substance migration and transformation on river-sea and ocean- atmosphere boundaries. Chemical composition of oceanic water is a fundamental multi-dimensional constant for our planet. Detailed studies revealed three types of chemical element distribution in the ocean: 1) Conservative: concentration normalized to salinity is constant in space and time; 2) Nutrient-type: element concentration in the surface waters decreases due to the biosphere consumption; and 3) Litho-generative: complex character of distribution of elements, which enter the ocean with the river runoff and interred almost entirely in sediments (Fig. 1). The correlation between the chemical compositions of the river and oceanic water is high (r = 0.94). We conclude that biogeochemical features of each element are determined by the relationship between its average concentration in the ocean and the intensity of its migration through hydrosphere boundary zones. In Fig.1 we show intensities of global migration and average concentrations in the ocean in the coordinates lgC - lg τ, where C is an average element concentration and τ is its residual time in the ocean. Fig. 1 shows a relationship between three main geochemical parameters of the dissolved forms of chemical elements in the hydrosphere: 1) average concentration in the ocean, 2) average concentration in the river runoff and 3) the type of distribution in oceanic water. Using knowledge of two of these parameters, it allows gaining theoretical knowledge of the third. The System covers all chemical elements for the entire range of observed concentrations. It even allows to predict the values of the annual river transport of dissolved Be, C, N, Ge, Tl, Re, to refine such estimates for P, V, Zn, Br, I, and to determine the character of distribution in the ocean for Au and U. Furthermore, the System allowed to estimate natural (unaffected by anthropogenic influence) mean concentrations of elements in the river runoff and use them as ecological reference data. Finally, due to the long response time of the ocean, the mean concentrations of elements and patterns of their distribution in the ocean can be used to determine pre-technogenic concentrations of elements in the river runoff. An example of such studies for the Northern Eurasia Arctic Rivers will be presented at the conference. References Korzh 1974: J. de Recher. Atmos, 8, 653-660. Korzh 2008: J. Ecol., 15, 13-21. Korzh 2012: Water: Chem. & Ecol., No. 1, 56-62; Fig.1. The System of chemical elements distribution in the hydrosphere. Types of distribution in the ocean: 1) conservative; 2) nutrient-type; 3) litho-generative.

Extrapolar climate reversal during the last deglaciation.

PubMed

Asmerom, Yemane; Polyak, Victor J; Lachniet, Matthew S

2017-08-02

Large ocean-atmosphere and hydroclimate changes occurred during the last deglaciation, although the interplay between these changes remains ambiguous. Here, we present a speleothem-based high resolution record of Northern Hemisphere atmospheric temperature driven polar jet variability, which matches the Greenland ice core records for the most of the last glacial period, except during the last deglaciation. Our data, combined with data from across the globe, show a dramatic climate reversal during the last deglaciation, which we refer to as the Extrapolar Climate Reversal (ECR). This is the most prominent feature in most tropical and subtropical hydroclimate proxies. The initiation of the ECR coincides with the rapid rise in CO 2 , in part attributed to upwelling in the Southern Ocean and the near collapse of the Atlantic Meridional Overturning Circulation. We attribute the ECR to upwelling of cold deep waters from the Southern Ocean. This is supported by a variety of proxies showing the incursion of deep Southern Ocean waters into the tropics and subtropics. Regional climate variability across the extropolar regions during the interval previously referred to as the "Mystery Interval" can now be explained in the context of the ECR event.

Assimilation of Ocean-Color Plankton Functional Types to Improve Marine Ecosystem Simulations

NASA Astrophysics Data System (ADS)

Ciavatta, S.; Brewin, R. J. W.; Skákala, J.; Polimene, L.; de Mora, L.; Artioli, Y.; Allen, J. I.

2018-02-01

We assimilated phytoplankton functional types (PFTs) derived from ocean color into a marine ecosystem model, to improve the simulation of biogeochemical indicators and emerging properties in a shelf sea. Error-characterized chlorophyll concentrations of four PFTs (diatoms, dinoflagellates, nanoplankton, and picoplankton), as well as total chlorophyll for comparison, were assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The reanalysis simulations spanned the years 1998-2003. The skill of the reference and reanalysis simulations in estimating ocean color and in situ biogeochemical data were compared by using robust statistics. The reanalysis outperformed both the reference and the assimilation of total chlorophyll in estimating the ocean-color PFTs (except nanoplankton), as well as the not-assimilated total chlorophyll, leading the model to simulate better the plankton community structure. Crucially, the reanalysis improved the estimates of not-assimilated in situ data of PFTs, as well as of phosphate and pCO2, impacting the simulation of the air-sea carbon flux. However, the reanalysis increased further the model overestimation of nitrate, in spite of increases in plankton nitrate uptake. The method proposed here is easily adaptable for use with other ecosystem models that simulate PFTs, for, e.g., reanalysis of carbon fluxes in the global ocean and for operational forecasts of biogeochemical indicators in shelf-sea ecosystems.

Visual observations over oceans

NASA Technical Reports Server (NTRS)

Terry, R. D.

1979-01-01

Important factors in locating, identifying, describing, and photographing ocean features from space are presented. On the basis of crew comments and other findings, the following recommendations can be made for Earth observations on Space Shuttle missions: (1) flyover exercises must include observations and photography of both temperate and tropical/subtropical waters; (2) sunglint must be included during some observations of ocean features; (3) imaging remote sensors should be used together with conventional photographic systems to document visual observations; (4) greater consideration must be given to scheduling earth observation targets likely to be obscured by clouds; and (5) an annotated photographic compilation of ocean features can be used as a training aid before the mission and as a reference book during space flight.

A genesis potential index for Western North Pacific tropical cyclones by using oceanic parameters

NASA Astrophysics Data System (ADS)

Zhang, Min; Zhou, Lei; Chen, Dake; Wang, Chunzai

2016-09-01

This study attempts to create a tropical cyclone (TC) genesis potential index (GPI) by considering oceanic parameters and necessary atmospheric parameters. Based on the general understanding of the oceanic impacts on TC genesis, many candidate factors are evaluated and discriminated, resulting in a new GPI index, which is referred to as GPIocean. GPIocean includes the parameters of (1) absolute vorticity at 1000 hPa, (2) net sea surface longwave radiation, (3) mean ocean temperature in the upper mixed layer, and (4) depth of the 26°C isotherm. GPIocean is comparable to existing GPIs in representing TC genesis over the western North Pacific on seasonal and interannual variations. The same procedure can be applied to create a similar GPI for the other ocean basins. In the context of climate change, this new index is expected to be useful for evaluating the oceanic influences on TC genesis by using ocean reanalysis products and climate model outputs.

The combined effects of ocean warming and acidification on shallow-water meiofaunal assemblages.

PubMed

Lee, Matthew R; Torres, Rodrigo; Manríquez, Patricio H

2017-10-01

Climate change due to increased anthropogenic CO 2 in the atmosphere is causing an increase in seawater temperatures referred to as ocean warming and a decrease in seawater pH, referred to as ocean acidification. The meiofauna play an important role in the ecology of marine ecosystems and the functions they provide. Using microcosms, meiofaunal assemblages were exposed to two temperatures (15 and 19 °C) and two pHs (pCO 2 of 400 and 1000 ppm), both individually and in combination, for a period of 90 days. The hypothesis that increased temperature will increase meiofaunal abundance was not supported. The hypothesis that a reduced pH will reduce meiofaunal abundance and species richness was supported. The combination of future conditions of temperature and pH (19 °C and pCO 2 of 1000 ppm) did not affect overall abundance but the structure of the nematode assemblage changed becoming dominated by a few opportunistic species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Year of Tropical Convection (YOTC): Status and Research Agenda

NASA Astrophysics Data System (ADS)

Moncrieff, M. W.; Waliser, D. E.

2009-12-01

The realistic representation of tropical convection in global models is a long-standing challenge for numerical weather prediction and an emerging grand challenge for climate prediction in respect to its physical basis. Insufficient knowledge and practical capabilities in this area disadvantage the modeling and prediction of prominent multi-scale phenomena such as the ITCZ, ENSO, monsoons and their active/break periods, the MJO, subtropical stratus decks, near-surface ocean properties, and tropical cyclones. Science elements include the diurnal cycle of precipitation, multi-scale convective organization, the global energy and water cycle, and interaction between the tropics and extra-tropics which interact strongly on timescales of weeks-to-months: the intersection of weather and climate. To address such challenges, the WCRP and WWRP/THORPEX are conducting a joint international research project, the Year of Tropical Convection (YOTC) which is a coordinated observing, modeling and forecasting project. The focus-year and integrated framework is intended to exploit the vast observational datasets, the modern high-resolution modeling frameworks, and theoretical insights. The over-arching objective is to advance the characterization, diagnosis, modeling, parameterization and prediction of multi-scale organized tropical phenomena and their interaction with the global circulation. The “Year” (May 2008 - April 2010) is intended to leverage recent major investments in Earth Science infrastructure and overlapping observational activities, e.g., Asian Monsoon Years (AMY) and the THORPEX Pacific Asian Regional Campaign (T-PARC). The research agenda involves phenomena and scale-interactions that are problematic for prediction models and have important socio-economic implications: MJO and convectively coupled equatorial waves; easterly waves and tropical cyclones; the monsoons including their intraseasonal variability; the diurnal cycle of precipitation; and two-way tropical-extratropical interaction. This presentation will summarize the status of the above.

Antarctica Cloud Cover for October 2003 from GLAS Satellite Lidar Profiling

NASA Technical Reports Server (NTRS)

Spinhirne, J. D.; Palm, S. P.; Hart, W. D.

2005-01-01

Seeing clouds in polar regions has been a problem for the imagers used on satellites. Both clouds and snow and ice are white, which makes clouds over snow hard to see. And for thermal infrared imaging both the surface and the clouds cold. The Geoscience Laser Altimeter System (GLAS) launched in 2003 gives an entirely new way to see clouds from space. Pulses of laser light scatter from clouds giving a signal that is separated in time from the signal from the surface. The scattering from clouds is thus a sensitive and direct measure of the presence and height of clouds. The GLAS instrument orbits over Antarctica 16 times a day. All of the cloud observations for October 2003 were summarized and compared to the results from the MODIS imager for the same month. There are two basic cloud types that are observed, low stratus with tops below 3 km and high cirrus form clouds with cloud top altitude and thickness tending at 12 km and 1.3 km respectively. The average cloud cover varies from over 93 % for ocean and coastal regions to an average of 40% over the East Antarctic plateau and 60-90% over West Antarctica. When the GLAS monthly average cloud fractions are compared to the MODIS cloud fraction data product, differences in the amount of cloud cover are as much as 40% over the continent. The results will be used to improve the way clouds are detected from the imager observations. These measurements give a much improved understanding of distribution of clouds over Antarctica and may show how they are changing as a result of global warming.

The Thermodynamic Structure of Arctic Coastal Fog Occurring During the Melt Season over East Greenland

NASA Astrophysics Data System (ADS)

Gilson, Gaëlle F.; Jiskoot, Hester; Cassano, John J.; Gultepe, Ismail; James, Timothy D.

2018-05-01

An automated method to classify Arctic fog into distinct thermodynamic profiles using historic in-situ surface and upper-air observations is presented. This classification is applied to low-resolution Integrated Global Radiosonde Archive (IGRA) soundings and high-resolution Arctic Summer Cloud Ocean Study (ASCOS) soundings in low- and high-Arctic coastal and pack-ice environments. Results allow investigation of fog macrophysical properties and processes in coastal East Greenland during melt seasons 1980-2012. Integrated with fog observations from three synoptic weather stations, 422 IGRA soundings are classified into six fog thermodynamic types based on surface saturation ratio, type of temperature inversion, fog-top height relative to inversion-base height and stability using the virtual potential temperature gradient. Between 65-80% of fog observations occur with a low-level inversion, and statically neutral or unstable surface layers occur frequently. Thermodynamic classification is sensitive to the assigned dew-point depression threshold, but categorization is robust. Despite differences in the vertical resolution of radiosonde observations, IGRA and ASCOS soundings yield the same six fog classes, with fog-class distribution varying with latitude and environmental conditions. High-Arctic fog frequently resides within an elevated inversion layer, whereas low-Arctic fog is more often restricted to the mixed layer. Using supplementary time-lapse images, ASCOS microwave radiometer retrievals and airmass back-trajectories, we hypothesize that the thermodynamic classes represent different stages of advection fog formation, development, and dissipation, including stratus-base lowering and fog lifting. This automated extraction of thermodynamic boundary-layer and inversion structure can be applied to radiosonde observations worldwide to better evaluate fog conditions that affect transportation and lead to improvements in numerical models.

Role of the North Atlantic Ocean in Low Frequency Climate Variability

NASA Astrophysics Data System (ADS)

Danabasoglu, G.; Yeager, S. G.; Kim, W. M.; Castruccio, F. S.

2017-12-01

The Atlantic Ocean is a unique basin with its extensive, North - South overturning circulation, referred to as the Atlantic meridional overturning circulation (AMOC). AMOC is thought to represent the dynamical memory of the climate system, playing an important role in decadal and longer time scale climate variability as well as prediction of the earth's future climate on these time scales via its large heat and salt transports. This oceanic memory is communicated to the atmosphere primarily through the influence of persistent sea surface temperature (SST) variations. Indeed, many modeling studies suggest that ocean circulation, i.e., AMOC, is largely responsible for the creation of coherent SST variability in the North Atlantic, referred to as Atlantic Multidecadal Variability (AMV). AMV has been linked to many (multi)decadal climate variations in, e.g., Sahel and Brazilian rainfall, Atlantic hurricane activity, and Arctic sea-ice extent. In the absence of long, continuous observations, much of the evidence for the ocean's role in (multi)decadal variability comes from model simulations. Although models tend to agree on the role of the North Atlantic Oscillation in creating the density anomalies that proceed the changes in ocean circulation, model fidelity in representing variability characteristics, mechanisms, and air-sea interactions remains a serious concern. In particular, there is increasing evidence that models significantly underestimate low frequency variability in the North Atlantic compared to available observations. Such model deficiencies can amplify the relative influence of external or stochastic atmospheric forcing in generating (multi)decadal variability, i.e., AMV, at the expense of ocean dynamics. Here, a succinct overview of the current understanding of the (North) Atlantic Ocean's role on the regional and global climate, including some outstanding questions, will be presented. In addition, a few examples of the climate impacts of the AMV via atmospheric teleconnections from a set of coupled simulations, also considering the relative roles of its tropical and extratropical components, will be highlighted.

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

PubMed

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

2015-05-22

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

Flows of the Tycho Crater type, comparative analysis

NASA Astrophysics Data System (ADS)

Bratkov, Yury

Some embeddings of the Tycho Crater type flow or, more generally, of the Tycho Butterfly type flow, are demonstrated, and comparative analysis is given. Additionally, identity of the Earthen World Ocean and the Moon Global Ocean is demonstrated. Supersonic flows (jets, shock waves, Mach stems) are comparatively studied [1]. References: [1] Bratkov Yu.N., Caspian Seas, http://viXra.org/abs/1211.0067, 12 Nov 2012

Computation, Mathematics and Logistics Department Report for Fiscal Year 1978.

DTIC Science & Technology

1980-03-01

storage technology. A reference library on these and related areas is now composed of two thousand documents. The most comprehensive tool available...at DTNSRDC on the CDC 6000 Computer System for a variety of applications including Navy Logistics, Library Science, Ocean Science, Contract Manage... Library Science) Track technical documents on advanced ship design Univ. of Virginia at Charlottesville - (Ocean Science) Monitor research projects for

Evaluation of decadal hindcasts by application of a satellite simulator for SSM/I & SSMIS

NASA Astrophysics Data System (ADS)

Spangehl, T.; Schroeder, M.; Glowienka-Hense, R.; Hense, A.; Bodas-Salcedo, A.; Hollmann, R.

2017-12-01

A satellite simulator for the Special Sensor Microwave Imager (SSM/I) and for the Special Sensor Microwave Imager and Sounder (SSMIS) is developed and applied to decadal hindcast simulations performed within the MiKlip project (http://fona-miklip.de, funded by the Federal Ministry of Education and Research in Germany). The aim is to evaluate the climatological and predictive skill of the hindcasts focusing on water cycle components. Classical evaluation approaches commonly focus on geophysical parameters such as temperature, precipitation or wind speed using observational datasets and reanalysis as reference. The employment of the satellite simulator enables an evaluation in the instrument's parameter and thereby reduces uncertainties on the reference side. The simulators are developed utilizing the CFMIP Observation Simulator Package (COSP, http://cfmip.metoffice.com/COSP.html). On the reference side the SSM/I & SSMIS Fundamental Climate Data Record (FCDR) provided by the CM SAF (DOI: 10.5676/EUM_SAF_CM/FCDR_MWI/V003) is used which constitutes a quality controlled, recalibrated and intercalibrated record of brightness temperatures for the period from 1978 to 2015. Simulated brightness temperatures for selected channels which are sensitive to either water vapor content (22 GHz) or hydrometeor content (85 GHz, vertical minus horizontal polarization) as an indicator for precipitation are used. For lead year 1 analysis of variance (ANOVA) reveals potential predictability for large parts of the tropical ocean areas for both water vapor and precipitation related channels. Furthermore, the Conditional Ranked Probability Skill Score (CRPSS) indicates predictive skill for large parts of the tropical/sub-tropical Pacific, parts of the tropical/sub-tropical Atlantic and the equatorial Indian Ocean. For lead years 2-3 ANOVA still indicates potential predictability for equatorial ocean areas. Moreover, CRPSS indicates predictive skill for parts of the tropical/subtropical ocean areas. These results suggest that the hindcasts show skill even beyond lead year 1 when comparing against climatology as a reference forecast.

15 CFR Appendix Vii to Subpart P... - Areas To Be Avoided Boundary Coordinates

Code of Federal Regulations, 2014 CFR

2014-01-01

....10′ W In the Vicinity of Key West Harbor [Reference Chart: United States 11434, 21st Edition—August... COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Florida Keys... Avoided Boundary Coordinates In The Vicinity of the Florida Keys [Reference Charts: United States 11466...

Reference samples for the earth sciences

USGS Publications Warehouse

Flanagan, F.J.

1974-01-01

A revised list of reference samples of interest to geoscientists has been extended to include samples for the agronomist, the archaeologist and the environmentalist. In addition to the source from which standard samples may be obtained, references or pertinent notes for some samples are included. The number of rock reference samples is now almost adequate, and the variety of ore samples will soon be sufficient. There are very few samples for microprobe work. Oil shales will become more important because of the outlook for world petroleum resources. The dryland equivalent of a submarine basalt might be useful in studies of sea-floor spreading and of the geochemistry of basalts. The Na- and K-feldspars of BCS (British Chemical Standards-Bureau of Analysed Samples), NBS (National Bureau of Standards), and ANRT (Association Kationale de la Recherche Technique) could serve as trace-element standards if such data were available. Similarly, the present NBS flint and plastic clays, as well as their predecessors, might be useful for archaeological pottery studies. The International Decade for Ocean Exploration may stimulate the preparation of ocean-water standards for trace elements or pollutants and a standard for manganese nodules. ?? 1974.

Iron budgets for three distinct biogeochemical sites around the Kerguelen Archipelago (Southern Ocean) during the natural fertilisation study, KEOPS-2

NASA Astrophysics Data System (ADS)

Bowie, A. R.; van der Merwe, P.; Quéroué, F.; Trull, T.; Fourquez, M.; Planchon, F.; Sarthou, G.; Chever, F.; Townsend, A. T.; Obernosterer, I.; Sallée, J.-B.; Blain, S.

2015-07-01

Iron availability in the Southern Ocean controls phytoplankton growth, community composition and the uptake of atmospheric CO2 by the biological pump. The KEOPS-2 (KErguelen Ocean and Plateau compared Study 2) "process study", took place around the Kerguelen Plateau in the Indian sector of the Southern Ocean. This is a region naturally fertilised with iron on the scale of hundreds to thousands of square kilometres, producing a mosaic of spring blooms which show distinct biological and biogeochemical responses to fertilisation. This paper presents biogeochemical iron budgets (incorporating vertical and lateral supply, internal cycling, and sinks) for three contrasting sites: an upstream high-nutrient low-chlorophyll reference, over the plateau and in the offshore plume east of the Kerguelen Islands. These budgets show that distinct regional environments driven by complex circulation and transport pathways are responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. Iron supply from "new" sources (diffusion, upwelling, entrainment, lateral advection, atmospheric dust) to the surface waters of the plume was double that above the plateau and 20 times greater than at the reference site, whilst iron demand (measured by cellular uptake) in the plume was similar to that above the plateau but 40 times greater than at the reference site. "Recycled" iron supply by bacterial regeneration and zooplankton grazing was a relatively minor component at all sites (< 8 % of new supply), in contrast to earlier findings from other biogeochemical iron budgets in the Southern Ocean. Over the plateau, a particulate iron dissolution term of 2.5 % was invoked to balance the budget; this approximately doubled the standing stock of dissolved iron in the mixed layer. The exchange of iron between dissolved, biogenic particulate and lithogenic particulate pools was highly dynamic in time and space, resulting in a decoupling of the iron supply and carbon export and, importantly, controlling the efficiency of fertilisation.

Effect of hemoglobin- and Perflubron-based oxygen carriers on common clinical laboratory tests.

PubMed

Ma, Z; Monk, T G; Goodnough, L T; McClellan, A; Gawryl, M; Clark, T; Moreira, P; Keipert, P E; Scott, M G

1997-09-01

Polymerized hemoglobin solutions (Hb-based oxygen carriers; HBOCs) and a second-generation perfluorocarbon (PFC) emulsion (Perflubron) are in clinical trials as temporary oxygen carriers ("blood substitutes"). Plasma and serum samples from patients receiving HBOCs look markedly red, whereas those from patients receiving PFC appear to be lipemic. Because hemolysis and lipemia are well-known interferents in many assays, we examined the effects of these substances on clinical chemistry, immunoassay, therapeutic drug, and coagulation tests. HBOC concentrations up to 50 g/L caused essentially no interference for Na, K, Cl, urea, total CO2, P, uric acid, Mg, creatinine, and glucose values determined by the Hitachi 747 or Vitros 750 analyzers (or both) or for immunoassays of lidocaine, N-acetylprocainamide, procainamide, digoxin, phenytoin, quinidine, or theophylline performed on the Abbott AxSym or TDx. Gentamycin and vancomycin assays on the AxSym exhibited a significant positive and negative interference, respectively. Immunoassays for TSH on the Abbott IMx and for troponin I on the Dade Stratus were unaffected by HBOC at this concentration. Tests for total protein, albumin, LDH, AST, ALT, GGT, amylase, lipase, and cholesterol were significantly affected to various extents at different HBOC concentrations on the Hitachi 747 and Vitros 750. The CK-MB assay on the Stratus exhibited a negative interference at 5 g/L HBOC. HBOC interference in coagulation tests was method-dependent-fibrometer-based methods on the BBL Fibro System were free from interference, but optical-based methods on the MLA 1000C exhibited interferences at 20 g/L HBOC. A 1:20 dilution of the PFC-based oxygen carrier (600 g/L) caused no interference on any of these chemistry or immunoassay tests except for amylase and ammonia on the Vitros 750 and plasma iron on the Hitachi 747.

Large Eddy Simulations of Continental Boundary Layer Clouds Observed during the RACORO Field Campaign

NASA Astrophysics Data System (ADS)

Endo, S.; Fridlind, A. M.; Lin, W.; Vogelmann, A. M.; Toto, T.; Liu, Y.

2013-12-01

Three cases of boundary layer clouds are analyzed in the FAst-physics System TEstbed and Research (FASTER) project, based on continental boundary-layer-cloud observations during the RACORO Campaign [Routine Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations] at the ARM Climate Research Facility's Southern Great Plains (SGP) site. The three 60-hour case study periods are selected to capture the temporal evolution of cumulus, stratiform, and drizzling boundary-layer cloud systems under a range of conditions, intentionally including those that are relatively more mixed or transitional in nature versus being of a purely canonical type. Multi-modal and temporally varying aerosol number size distribution profiles are derived from aircraft observations. Large eddy simulations (LESs) are performed for the three case study periods using the GISS Distributed Hydrodynamic Aerosol and Radiative Modeling Application (DHARMA) model and the WRF-FASTER model, which is the Weather Research and Forecasting (WRF) model implemented with forcing ingestion and other functions to constitute a flexible LES. The two LES models commonly capture the significant transitions of cloud-topped boundary layers in the three periods: diurnal evolution of cumulus layers repeating over multiple days, nighttime evolution/daytime diminution of thick stratus, and daytime breakup of stratus and stratocumulus clouds. Simulated transitions of thermodynamic structures of the cloud-topped boundary layers are examined by balloon-borne soundings and ground-based remote sensors. Aircraft observations are then used to statistically evaluate the predicted cloud droplet number size distributions under varying aerosol and cloud conditions. An ensemble approach is used to refine the model configuration for the combined use of observations with parallel LES and single-column model simulations. See Lin et al. poster for single-column model investigation.

Machine learning classifiers for glaucoma diagnosis based on classification of retinal nerve fibre layer thickness parameters measured by Stratus OCT.

PubMed

Bizios, Dimitrios; Heijl, Anders; Hougaard, Jesper Leth; Bengtsson, Boel

2010-02-01

To compare the performance of two machine learning classifiers (MLCs), artificial neural networks (ANNs) and support vector machines (SVMs), with input based on retinal nerve fibre layer thickness (RNFLT) measurements by optical coherence tomography (OCT), on the diagnosis of glaucoma, and to assess the effects of different input parameters. We analysed Stratus OCT data from 90 healthy persons and 62 glaucoma patients. Performance of MLCs was compared using conventional OCT RNFLT parameters plus novel parameters such as minimum RNFLT values, 10th and 90th percentiles of measured RNFLT, and transformations of A-scan measurements. For each input parameter and MLC, the area under the receiver operating characteristic curve (AROC) was calculated. There were no statistically significant differences between ANNs and SVMs. The best AROCs for both ANN (0.982, 95%CI: 0.966-0.999) and SVM (0.989, 95% CI: 0.979-1.0) were based on input of transformed A-scan measurements. Our SVM trained on this input performed better than ANNs or SVMs trained on any of the single RNFLT parameters (p < or = 0.038). The performance of ANNs and SVMs trained on minimum thickness values and the 10th and 90th percentiles were at least as good as ANNs and SVMs with input based on the conventional RNFLT parameters. No differences between ANN and SVM were observed in this study. Both MLCs performed very well, with similar diagnostic performance. Input parameters have a larger impact on diagnostic performance than the type of machine classifier. Our results suggest that parameters based on transformed A-scan thickness measurements of the RNFL processed by machine classifiers can improve OCT-based glaucoma diagnosis.

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

NASA Astrophysics Data System (ADS)

Valdivieso, Maria

2014-05-01

The GODAE OceanView and CLIVAR-GSOP ocean synthesis program has been assessing the degree of consistency between global air-sea flux data sets obtained from ocean or coupled reanalyses (Valdivieso et al., 2014). So far, fifteen global air-sea heat flux products obtained from ocean or coupled reanalyses have been examined: seven are from low-resolution ocean reanalyses (BOM PEODAS, ECMWF ORAS4, JMA/MRI MOVEG2, JMA/MRI MOVECORE, Hamburg Univ. GECCO2, JPL ECCOv4, and NCEP GODAS), five are from eddy-permitting ocean reanalyses developed as part of the EU GMES MyOcean program (Mercator GLORYS2v1, Reading Univ. UR025.3, UR025.4, UKMO GloSea5, and CMCC C-GLORS), and the remaining three are couple reanalyses based on coupled climate models (JMA/MRI MOVE-C, GFDL ECDA and NCEP CFSR). The global heat closure in the products over the period 1993-2009 spanned by all data sets is presented in comparison with observational and atmospheric reanalysis estimates. Then, global maps of ensemble spread in the seasonal cycle, and of the Signal to Noise Ratio of interannual flux variability over the 17-yr common period are shown to illustrate the consistency between the products. We have also studied regional variability in the products, particularly at the OceanSITES project locations (such as, for instance, the TAO/TRITON and PIRATA arrays in the Tropical Pacific and Atlantic, respectively). Comparisons are being made with other products such as OAFlux latent and sensible heat fluxes (Yu et al., 2008) combined with ISCCP satellite-based radiation (Zhang et al., 2004), the ship-based NOC2.0 product (Berry and Kent, 2009), the Large and Yeager (2009) hybrid flux dataset CORE.2, and two atmospheric reanalysis products, the ECMWF ERA-Interim reanalysis (referred to as ERAi, Dee et al., 2011) and the NCEP/DOE reanalysis R2 (referred to as NCEP-R2, Kanamitsu et al., 2002). Preliminary comparisons with the observational flux products from OceanSITES are also underway. References Berry, D.I. and E.C. Kent (2009), A New Air-Sea Interaction Gridded Dataset from ICOADS with Uncertainty Estimates. Bull. Amer. Meteor. Soc 90(5), 645-656. doi: 10.1175/2008BAMS2639.1. Dee, D. P. et al. (2011), The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q.J.R. Meteorol. Soc., 137: 553-597. doi: 10.1002/qj.828. Kanamitsu M., Ebitsuzaki W., Woolen J., Yang S.K., Hnilo J.J., Fiorino M., Potter G. (2002), NCEP-DOE AMIP-II reanalysis (R-2). Bull. Amer. Meteor. Soc., 83:1631-1643. Large, W. and Yeager, S. (2009), The global climatology of an interannually varying air-sea flux data set. Clim. Dynamics, Volume 33, pp 341-364 Valdivieso, M. and co-authors (2014): Heat fluxes from ocean and coupled reanalyses, Clivar Exchanges. Issue 64. Yu, L., X. Jin, and R. A. Weller (2008), Multidecade Global Flux Datasets from the Objectively Analyzed Air-sea Fluxes (OAFlux) Project: Latent and Sensible Heat Fluxes, Ocean Evaporation, and Related Surface Meteorological Variables. Technical Report OAFlux Project (OA2008-01), Woods Hole Oceanographic Institution. Zhang, Y., WB Rossow, AA Lacis, V Oinas, MI Mishchenk (2004), Calculation of radiative fluxes from the surface to top of atmsophere based on ISCCP and other global data sets. Journal of Geophysical Research: Atmospheres (1984-2012) 109 (D19).

USSR Report Earth Sciences.

DTIC Science & Technology

1987-03-04

IZVESTIYA AKADEMII NAUK ARMYANSKOY SSR: NAUKI 0 ZEMLE, No 1, Jan-Feb 86) 62 Characteristics of Anomalies in Variable Magnetic Field From Remote...explanation for the observed changes in amplitude and form of magnetic anomalies with a transition from the slopes of the mid-oceanic ridges to...observed strength of magnetic anomalies in oceanic basins. Figures 3; references 36: 11 Russian, 25 Western. 5303/13046 CSO: 1865/381 UDC 551.242.5

Laminar Flow in the Ocean Ekman Layer

NASA Astrophysics Data System (ADS)

Woods, J. T. H.

INTRODUCTION THE EFFECT OF A STABLE DENSITY GRADIENT THE FATAL FLAW FLOW VISUALIZATION THE DISCOVERY OF LAMINAR FLOW FINE STRUCTURE WAVE-INDUCED SHEAR INSTABILITY BILLOW TURBULENCE REVERSE TRANSITION REVISED PARADIGM ONE-DIMENSIONAL MODELLING OF THE UPPER OCEAN DIURNAL VARIATION BUOYANT CONVECTION BILLOW TURBULENCE IN THE DIURNAL THERMOCLINE CONSEQUENCES FOR THE EKMAN CURRENT PROFILE SOLAR RADIATION APPLICATIONS Slippery Seas of Acapulco Pollution Afternoon Effect in Sonar Patchiness Fisheries Climate DISCUSSION CONCLUSION REFERENCES

Understanding the Nature of Marine Aerosols and Their Effects in the Coupled Ocean-Atmosphere System

DTIC Science & Technology

2013-09-30

into aqueous- phase mechanistic relationships leading up to oxalate production. Monocarboxylic and dicarboxylic acids exhibited contrasting spatial...ocean surface. Three case flights show that oxalate (and no other organic acid ) concentrations drop by nearly an order of magnitude relative to...aerosol- cloud interactions. REFERENCES Crahan, K. K., D. Hegg, D. S. Covert, and H. Jonsson (2004), An exploration of aqueous oxalic acid

Bottom Interaction in Long Range Acoustic Propagation

DTIC Science & Technology

2006-09-30

Pacific Ocean utilizing controlled sources and vertical and horizontal receiver arrays . Broadband sources are considered with typical center...The LOAPEX (Long-range Ocean Acoustic Propagation Experiment) vertical line arrays (VLA) are described on page 1 of the LOAPEX cruise report: " The...hydrophone arrays on the two combined VLAs covered most of the 5-km water column. We refer to one of the VLAs as the deep VLA (DVLA), located at

Selected Papers on Ocean-Seismo Acoustics Low-Frequency Underwater Acoustics Based on the SACLANTCEN Contributions to a Symposium Held by SACLANTCEN on 10-14 June 1985

DTIC Science & Technology

1986-06-01

properties of ocean sediments determined from numerical modelling of Scholte wave data (this volume). 6. de Strobel, F., Akal, T., and Hastrup , O.F...0. Hastrup and T. Akal of SACLANTCEN for the permission to use their bottom-reflectivit mea;urements. REFERENCES 1. M.A. Biot, ’Theory of propagation

Oceans and Human Health: a rising tide of challenges and opportunities for Europe.

PubMed

Fleming, L E; McDonough, N; Austen, M; Mee, L; Moore, M; Hess, P; Depledge, M H; White, M; Philippart, K; Bradbrook, P; Smalley, A

2014-08-01

The European Marine Board recently published a position paper on linking oceans and human health as a strategic research priority for Europe. With this position paper as a reference, the March 2014 Cornwall Oceans and Human Health Workshop brought together key scientists, policy makers, funders, business, and non governmental organisations from Europe and the US to review the recent interdisciplinary and cutting edge research in oceans and human health specifically the growing evidence of the impacts of oceans and seas on human health and wellbeing (and the effects of humans on the oceans). These impacts are a complex mixture of negative influences (e.g. from climate change and extreme weather to harmful algal blooms and chemical pollution) and beneficial factors (e.g. from natural products including seafood to marine renewable energy and wellbeing from interactions with coastal environments). Integrated approaches across disciplines, institutions, and nations in science and policy are needed to protect both the oceans and human health and wellbeing now and in the future. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

National Oceanic and Atmospheric Administration's Cetacean and Sound Mapping Effort: Continuing Forward with an Integrated Ocean Noise Strategy.

PubMed

Harrison, Jolie; Ferguson, Megan; Gedamke, Jason; Hatch, Leila; Southall, Brandon; Van Parijs, Sofie

2016-01-01

To help manage chronic and cumulative impacts of human activities on marine mammals, the National Oceanic and Atmospheric Administration (NOAA) convened two working groups, the Underwater Sound Field Mapping Working Group (SoundMap) and the Cetacean Density and Distribution Mapping Working Group (CetMap), with overarching effort of both groups referred to as CetSound, which (1) mapped the predicted contribution of human sound sources to ocean noise and (2) provided region/time/species-specific cetacean density and distribution maps. Mapping products were presented at a symposium where future priorities were identified, including institutionalization/integration of the CetSound effort within NOAA-wide goals and programs, creation of forums and mechanisms for external input and funding, and expanded outreach/education. NOAA is subsequently developing an ocean noise strategy to articulate noise conservation goals and further identify science and management actions needed to support them.

Hygroscopic Growth and Activation of Particles containing Algea-Exudate

NASA Astrophysics Data System (ADS)

Wex, Heike; Fuentes, Elena; Tsagkogeorgas, Georgios; Voigtländer, Jens; Clauss, Tina; Kiselev, Alexei; Green, David; Coe, Hugh; McFiggans, Gordon; Stratmann, Frank

2010-05-01

A large amount of the Earth is covered by oceans, which provide a constant source of marine aerosol particles, produced due to bubble bursting processes that depend on wind speed (O'Dowd and de Leeuw, 2007). In general, marine particles can be assumed to play an important role for the Earth atmosphere on a global scale, due to their abundance and due to their effect on clouds. E.g. marine stratus and stratocumulus clouds contribute about 30% to 40% to the Earth's albedo (Randall et al., 1984). The activation of aerosol particles to cloud droplets depends on the hygroscopic properties of the particles, which, in turn, depend on their chemical composition. For marine particles, is has been and still is discussed what the effects of organic substances being present in the particles might be. These substances originate from marine biota where they enrich at the ocean surface. To mimic marine aerosol particles, algae-exudates of different algae species were mixed with artificial sea-water. These samples were used in the laboratory to produce particles via a bubble bursting process (Fuentes et al., 2009). The hygroscopic growth and activation of the (size selected) particles was measured, using LACIS (Leipzig Aerosol Cloud Interaction Simulator, Stratmann et al., 2004) and the DMT-CCNc (Cloud Condensation Nucleus counter from Droplet Measurement Technologies, Roberts and Nenes, 2005). The hygroscopic growth was measured twice, 3 and 10 seconds after humidification, and no difference in the grown size was detected, i.e. no kinetic effect was observed for the examined time range. From LACIS and CCNc measurements, the hygroscopicity was deduced through determination of the amount of ions being effective in the particle / droplet solution (Rho(ion), Wex et al., 2007). A concentration dependent non-ideal behaviour was found for particles produced from an artificial sea-water sample that contained only inorganic salts, as can be expected (see e.g. Niedermeier et al., 2008). For particles containing also algae-exudate, however, the concentration dependent non-ideal behaviour was quenched, resulting in a quasi ideal solution behavior. Such solutions could be described by a single-parameter representation for all water-vapour saturations at which measurements had been done (from 0.8 up to supersaturation). References: Fuentes, E., H. Coe, D. Green, G. De Leeuw, and G. McFiggans (2009), Laboratory-generated primary marine aerosol via bubble-bursting and atomization, Aerosol Meas. Tech. Discuss., 2, 2281-2320. O'Dowd, C. D., and G. de Leeuw (2007), Marine aerosol production: A review of the current knowledge, Phil. Trans. R. Soc. A, 365(1856), 1753-1774, doi:1710.1098/rsta.2007.2043. Niedermeier, D., H. Wex, J. Voigtländer, F. Stratmann, E. Brüggemann, A. Kiselev, H. Henk, and J. Heintzenberg (2008), LACIS-measurements and parameterization of sea-salt particle hygroscopic growth and activation, Atmos. Chem. Phys., 8, 579-590. Randall, D. A., Coakley, J. A., Fairall, C. W., Kropfli, R. A., and Lenschow, D. H. (1984) Outlook for research on subtropical marine stratiform clouds, Bull. Am. Meteor. Soc., 65, 1290-1301, 1984. Roberts, G., and A. Nenes (2005), A continuous-flow streamwise thermal-gradient CCN chamber for atmospheric measurements, Aerosol Sci. Technol., 39, 206-221. Stratmann, F., A. Kiselev, S. Wurzler, M. Wendisch, J. Heintzenberg, R. J. Charlson, K. Diehl, H. Wex, and S. Schmidt (2004), Laboratory studies and numerical simulations of cloud droplet formation under realistic super-saturation conditions, J. Atmos. Oceanic Technol., 21, 876-887. Wex, H., T. Hennig, I. Salma, R. Ocskay, A. Kiselev, S. Henning, A. Massling, A. Wiedensohler, and F. Stratmann (2007), Hygroscopic growth and measured and modeled critical super-saturations of an atmospheric HULIS sample, Geophys. Res. Lett., 34(L02818), doi:10.1029/2006GL028260.

IODP Expedition 335: Deep Sampling in ODP Hole 1256D

NASA Astrophysics Data System (ADS)

Teagle, D. A. H.; Ildefonse, B.; Blum, P.; IODP Expedition 335 Scientists, the

2012-04-01

Observations of the gabbroic layers of untectonized ocean crust are essential to test theoretical models of the accretion of new crust at mid-ocean ridges. Integrated Ocean Drilling Program (IODP) Expedition 335 ("Superfast Spreading Rate Crust 4") returned to Ocean Drilling Program (ODP) Hole 1256D with the intention of deepening this reference penetration of intact ocean crust a significant distance (~350 m) into cumulate gabbros. Three earlier cruises to Hole 1256D (ODP 206, IODP 309/312) have drilled through the sediments, lavas, and dikes and 100 m into a complex dike-gabbro transition zone. Operations on IODP Expedition 335 proved challenging throughout, with almost three weeks spent re-opening and securing unstable sections of the hole. When coring commenced, the comprehensive destruction of the coring bit required further remedial operations to remove junk and huge volumes of accumulated drill cuttings. Hole-cleaning operations using junk baskets were successful, and they recovered large irregular samples that document a hitherto unseen sequence of evolving geological conditions and the intimate coupling between temporally and spatially intercalated intrusive, hydrothermal, contact-metamorphic, partial melting, and retrogressive processes. Hole 1256D is now clean of junk, and it has been thoroughly cleared of the drill cuttings that hampered operations during this and previous expeditions. At the end of Expedition 335, we briefly resumed coring before undertaking cementing operations to secure problematic intervals. To ensure the greatest scientific return from the huge efforts to stabilize this primary ocean lithosphere reference site, it would be prudent to resume the deepening of Hole 1256D in the nearest possible future while it is open to full depth. doi:10.2204/iodp.sd.13.04.2011

Global Ocean Vertical Velocity From a Dynamically Consistent Ocean State Estimate

NASA Astrophysics Data System (ADS)

Liang, Xinfeng; Spall, Michael; Wunsch, Carl

2017-10-01

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

BOATS Act

THOMAS, 113th Congress

Rep. Israel, Steve [D-NY-3

2014-05-09

House - 05/20/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

FISH Act

THOMAS, 113th Congress

Rep. Herrera Beutler, Jaime [R-WA-3

2013-10-30

House - 11/07/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

MAST Act

THOMAS, 113th Congress

Rep. Southerland, Steve II [R-FL-2

2014-06-26

House - 07/07/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Consumer Bounty Act

THOMAS, 112th Congress

Rep. Kucinich, Dennis J. [D-OH-10

2012-12-20

House - 01/02/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Fluke Fairness Act

THOMAS, 113th Congress

Rep. Bishop, Timothy H. [D-NY-1

2014-01-14

House - 01/16/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

EEZ Clarification Act

THOMAS, 113th Congress

Rep. Bishop, Timothy H. [D-NY-1

2014-05-22

House - 05/30/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Data Report for the 1988 Ontario-New York-New England Seismic Refraction Experiment: Three-Component Profiles

DTIC Science & Technology

1990-02-23

Geophysical Data Center in Boulder, Colorado, and tapes are available from: U.S. Department of Commerce National Oceanic and Atmospheric Administration 325...and structural characteristics of the North American continent were formed primarily during the closing of the prowo-Atlantic Ocean from the early...collision that is generally referred to as the Appalachian Orogeny. The theory that the Appalachian Orogen consists of several microplates accreted during

Study of the global positioning system for maritime concepts/applications: Study of the feasibility of replacing maritime shipborne navigation systems with NAVSTAR

NASA Technical Reports Server (NTRS)

Winn, C. B.; Huston, W.

1981-01-01

A geostationary reference satellite (REFSAT) that broadcasts every four seconds updated GPS satellite coordinates was developed. This procedure reduces the complexity of the GPS receiver. The economic and performance payoffs associated with replacing maritime stripborne navigation systems with NAVSTAR was quantified and the use of NAVSTAR for measurements of ocean currents in the broad ocean areas of the world was evaluated.

Ocean, Platform, and Signal Processing Effects on Synthetic Aperture Sonar Performance

DTIC Science & Technology

1991-02-01

Canadian Reginald A. Fessenden , of the Submarine Signal Company, Boston, MA during the period from 1912 to 1914 [Fay, c. 19441. Fessenden’s invention...usually referred to as the Fessenden oscillator. It was conceived by Fessenden as an instrument for underwater communication from ship to ship, and more...accident it was observed that the ocean depth could also be measured. In these landmark experiments, Fessenden showed telemetry, echolocation and

Intraseasonal Variability in the Atmosphere-Ocean Climate System. Second Edition

NASA Technical Reports Server (NTRS)

Lau, William K. M.; Waliser, Duane E.

2011-01-01

Understanding and predicting the intraseasonal variability (ISV) of the ocean and atmosphere is crucial to improving long-range environmental forecasts and the reliability of climate change projections through climate models. This updated, comprehensive and authoritative second edition has a balance of observation, theory and modeling and provides a single source of reference for all those interested in this important multi-faceted natural phenomenon and its relation to major short-term climatic variations.

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

Asay-Davis, Xylar Storm

The project performed under this award, referred to from here on as CLARION (CoupLed simulations of Antarctic Ice-sheet/Ocean iNteractions), included important advances in two models of ice sheet and ocean interactions. Despite its short duration (one year), the project made significant progress on its three major foci. First, together with collaborator Daniel Martin at Lawrence Berkeley National Laboratory (LBNL), I developed the POPSICLES coupled ice sheet-ocean model to the point where it could perform a number of pan-Antarctic simulations under various forcing conditions. The results were presented at a number of major conferences and workshops worldwide, and are currently beingmore » incorporated into two manuscripts in preparation.« less

Summary of Skylab S-193 altimeter altitude results. [orbit calculation and studies of the ocean bottom

NASA Technical Reports Server (NTRS)

Mcgoogan, J. T.; Leitao, C. D.; Wells, W. T.

1975-01-01

The SKYLAB S-193 altimeter altitude results are presented in a concise format for further use and analysis by the scientific community. The altimeter mission and instrumentation is described along with the altimeter processing techniques and values of parameters used for processing. The determination of reference orbits is discussed, and the tracking systems utilized are tabulated. Techniques for determining satellite pointing are presented and a tabulation of pointing for each data mission included. The geographical location, the ocean bottom topography, the altimeter-determined ocean surface topography, and the altimeter automatic gain control history is presented. Some typical applications of this data are suggested.

Stop Asian Carp Act

THOMAS, 112th Congress

Rep. Camp, Dave [R-MI-4

2011-03-03

House - 03/07/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Gulf Coast Restoration Act

THOMAS, 112th Congress

Rep. Bonner, Jo [R-AL-1

2011-05-05

House - 05/16/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Gulf Coast Restoration Act

THOMAS, 112th Congress

Rep. Scalise, Steve [R-LA-1

2011-01-05

House - 01/26/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Captive Primate Safety Act

THOMAS, 112th Congress

Rep. Fitzpatrick, Michael G. [R-PA-8

2012-03-29

House - 04/16/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Captive Primate Safety Act

THOMAS, 113th Congress

Rep. Fitzpatrick, Michael G. [R-PA-8

2013-07-30

House - 08/06/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

The System of Chemical Elements Distribution in the Hydrosphere

NASA Astrophysics Data System (ADS)

Korzh, Vyacheslav D.

2013-04-01

The chemical composition of the hydrosphere is a result of substance migration and transformation on lithosphere-river, river-sea, and ocean-atmosphere boundaries. The chemical elements composition of oceanic water is a fundamental multi-dimensional constant for our planet. Detailed studies revealed three types of chemical element distribution in the ocean: 1) Conservative: concentration normalized to salinity is the constant in space and time; 2) Nutrient-type: element concentration in the surface waters decreases due to the biosphere consumption; and 3) Litho-generative: complex character of distribution of elements, which enter the ocean with the river runoff and interred almost entirely in sediments. The correlation between the chemical elements compositions of the river and oceanic water is high (r = 0.94). We conclude that biogeochemical features of each chemical element are determined by the relationship between its average concentration in the ocean and the intensity of its migration through hydrosphere boundary zones. In our presentation, we shall show intensities of global migration and average concentrations in the ocean in the co ordinates lgC - lg [tau], where C is an average element concentration and [tau] is its residence time in the ocean. We have derived a relationship between three main geochemical parameters of the dissolved forms of chemical elements in the hydrosphere: 1) average concentration in the ocean, 2) average concentration in the river runoff and 3) the type of distribution in oceanic water. Using knowledge of two of these parameters, it allows gaining theoretical knowledge of the third. The System covers all chemical elements for the entire range of observed concentrations. It even allows to predict the values of the annual river transport of dissolved Be, C, N, Ge, Tl, Re, to refine such estimates for P, V, Zn, Br, I, and to determine the character of distribution in the ocean for Au and U. Furthermore, the System allowed estimating natural (unaffected by anthropogenic influence) mean concentrations of elements in the river runoff and using them as ecological reference data. Finally, due to the long response time of the ocean, the mean concentrations of elements and patterns of their distribution in the ocean can be used to determine pre-techno-generative concentrations of elements in the river runoff. In our presentation, we shall show several examples of implementation of the System for studying the sediments' transport by the rivers of the Arctic slope of Northern Eurasia. References 1. Korzh V.D. 1974: Some general laws governing the turnover of substance within the ocean-atmosphere-continent-ocean cycle. Journal de Recherches Atmospheriques, 8, 653-660. 2. Korzh V.D. 2008: The general laws in the formation of the element composition of the Hydrosphere and Biosphere. J. Ecologica, 15, 13-21. 3. Korzh V.D. 2012: Determination of general laws of the chemical element composition in Hydrosphere. Water: Chemistry & Ecology, Journal of Water Science and its Practical Application. No. 1, 56-62.

Farmers Protection Act of 2012

THOMAS, 112th Congress

Rep. Crawford, Eric A. "Rick" [R-AR-1

2012-12-13

House - 12/21/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Meers Point Boundary Adjustment Act

THOMAS, 112th Congress

Rep. Grijalva, Raul M. [D-AZ-7

2011-12-05

House - 12/09/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Meers Point Boundary Adjustment Act

THOMAS, 113th Congress

Rep. Grijalva, Raul M. [D-AZ-3

2013-03-21

House - 04/11/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

78 FR 4124 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-18

...: National Oceanic and Atmospheric Administration (NOAA). Title: Social Capital Survey of Northeast... relationships is commonly referred to in social and economic literature. A baseline of existing social capital...

Udall-Eisenhower Arctic Wilderness Act

THOMAS, 112th Congress

Rep. Markey, Edward J. [D-MA-7

2011-01-05

House - 01/26/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

REFI Pacific Act of 2012

THOMAS, 112th Congress

Rep. Thompson, Mike [D-CA-1

2012-09-10

House - 09/11/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Refuge from Cruel Trapping Act

THOMAS, 113th Congress

Rep. Lowey, Nita M. [D-NY-17

2013-11-15

House - 11/19/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Refuge from Cruel Trapping Act

THOMAS, 112th Congress

Rep. Lowey, Nita M. [D-NY-18

2011-07-26

House - 07/28/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Digital Coast Act of 2013

THOMAS, 113th Congress

Rep. Ruppersberger, C. A. Dutch [D-MD-2

2013-03-21

House - 04/11/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Digital Coast Act of 2012

THOMAS, 112th Congress

Rep. Ruppersberger, C. A. Dutch [D-MD-2

2012-09-20

House - 10/03/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

The Ocean State Report of the Copernicus Marine Environment Monitoring Service

NASA Astrophysics Data System (ADS)

von Schuckmann, Karina

2017-04-01

COPERNICUS is the European Earth observation and monitoring programme, which aims to give the European Union autonomous and operational capability in space-based observation facilities (see the Sentinel missions) and in situ (measurements in the atmosphere, in the ocean and on the ground), and to operate six interlinked environmental monitoring services for the oceans, the atmosphere, territorial development, emergency situations, security and climate change. In this context, the Copernicus Marine Environment Monitoring Service provides an open and free access to regular and systematic information about the physical state and dynamics of the ocean and marine ecosystems for the global ocean and six European regional seas. Mercator Ocean, the French center of global ocean analysis and forecast has been entrusted by the EU to implement and operate the Copernicus Marine Service. The first Ocean State Report Copernicus Marine Environment Monitoring Service has been prepared, and is planned to appear at an annual basis (fall each year) as a unique reference for ocean state reporting. This report contains a state-of-the-art value-added synthesis of the ocean state for the global ocean and the European regional seas from the Copernicus Marine Environment Monitoring Service data products and expert analysis. This activity is aiming to reach a wide audience -from the scientific community, over climate and environmental service and agencies, environmental reporting and bodies to the general public. We will give here an overview on the report, highlight main outcomes, and introduce future plans and developments.

The Ocean State Report of the Copernicus Marine Environment Monitoring Service

NASA Astrophysics Data System (ADS)

von Schuckmann, K.

2016-12-01

COPERNICUS is the European Earth observation and monitoring programme, which aims to give the European Union autonomous and operational capability in space-based observation facilities (see the Sentinel missions) and in situ (measurements in the atmosphere, in the ocean and on the ground), and to operate six interlinked environmental monitoring services for the oceans, the atmosphere, territorial development, emergency situations, security and climate change. In this context, the Copernicus Marine Environment Monitoring Service provides an open and free access to regular and systematic information about the physical state and dynamics of the ocean and marine ecosystems for the global ocean and six European regional seas. Mercator Ocean, the French center of global ocean analysis and forecast has been entrusted by the EU to implement and operate the Copernicus Marine Service. In fall 2016, the first Ocean State Report Copernicus Marine Environment Monitoring Service will be published, and is planned to appear at an annual basis (June each year) as a unique reference for ocean state reporting. This report contains a state-of-the-art value-added synthesis of the ocean state for the global ocean and the European regional seas from the Copernicus Marine Environment Monitoring Service data products and expert analysis. This activity is aiming to reach a wide audience -from the scientific community, over climate and environmental service and agencies, environmental reporting and bodies to the general public. We will give here an overview on the report, highlight main outcomes, and introduce future plans and developments.

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

NASA Astrophysics Data System (ADS)

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

2014-05-01

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

Juvenile Osprey Navigation during Trans-Oceanic Migration

PubMed Central

Horton, Travis W.; Bierregaard, Richard O.; Zawar-Reza, Peyman; Holdaway, Richard N.; Sagar, Paul

2014-01-01

To compensate for drift, an animal migrating through air or sea must be able to navigate. Although some species of bird, fish, insect, mammal, and reptile are capable of drift compensation, our understanding of the spatial reference frame, and associated coordinate space, in which these navigational behaviors occur remains limited. Using high resolution satellite-monitored GPS track data, we show that juvenile ospreys (Pandion haliaetus) are capable of non-stop constant course movements over open ocean spanning distances in excess of 1500 km despite the perturbing effects of winds and the lack of obvious landmarks. These results are best explained by extreme navigational precision in an exogenous spatio-temporal reference frame, such as positional orientation relative to Earth's magnetic field and pacing relative to an exogenous mechanism of keeping time. Given the age (<1 year-old) of these birds and knowledge of their hatching site locations, we were able to transform Enhanced Magnetic Model coordinate locations such that the origin of the magnetic coordinate space corresponded with each bird's nest. Our analyses show that trans-oceanic juvenile osprey movements are consistent with bicoordinate positional orientation in transformed magnetic coordinate or geographic space. Through integration of movement and meteorological data, we propose a new theoretical framework, chord and clock navigation, capable of explaining the precise spatial orientation and temporal pacing performed by juvenile ospreys during their long-distance migrations over open ocean. PMID:25493430

Location Accuracy of INS/Gravity-Integrated Navigation System on the Basis of Ocean Experiment and Simulation

PubMed Central

Wang, Hubiao; Chai, Hua; Bao, Lifeng; Wang, Yong

2017-01-01

An experiment comparing the location accuracy of gravity matching-aided navigation in the ocean and simulation is very important to evaluate the feasibility and the performance of an INS/gravity-integrated navigation system (IGNS) in underwater navigation. Based on a 1′ × 1′ marine gravity anomaly reference map and multi-model adaptive Kalman filtering algorithm, a matching location experiment of IGNS was conducted using data obtained using marine gravimeter. The location accuracy under actual ocean conditions was 2.83 nautical miles (n miles). Several groups of simulated data of marine gravity anomalies were obtained by establishing normally distributed random error N(u,σ2) with varying mean u and noise variance σ2. Thereafter, the matching location of IGNS was simulated. The results show that the changes in u had little effect on the location accuracy. However, an increase in σ2 resulted in a significant decrease in the location accuracy. A comparison between the actual ocean experiment and the simulation along the same route demonstrated the effectiveness of the proposed simulation method and quantitative analysis results. In addition, given the gravimeter (1–2 mGal accuracy) and the reference map (resolution 1′ × 1′; accuracy 3–8 mGal), location accuracy of IGNS was up to reach ~1.0–3.0 n miles in the South China Sea. PMID:29261136

Location Accuracy of INS/Gravity-Integrated Navigation System on the Basis of Ocean Experiment and Simulation.

PubMed

Wang, Hubiao; Wu, Lin; Chai, Hua; Bao, Lifeng; Wang, Yong

2017-12-20

An experiment comparing the location accuracy of gravity matching-aided navigation in the ocean and simulation is very important to evaluate the feasibility and the performance of an INS/gravity-integrated navigation system (IGNS) in underwater navigation. Based on a 1' × 1' marine gravity anomaly reference map and multi-model adaptive Kalman filtering algorithm, a matching location experiment of IGNS was conducted using data obtained using marine gravimeter. The location accuracy under actual ocean conditions was 2.83 nautical miles (n miles). Several groups of simulated data of marine gravity anomalies were obtained by establishing normally distributed random error N ( u , σ 2 ) with varying mean u and noise variance σ 2 . Thereafter, the matching location of IGNS was simulated. The results show that the changes in u had little effect on the location accuracy. However, an increase in σ 2 resulted in a significant decrease in the location accuracy. A comparison between the actual ocean experiment and the simulation along the same route demonstrated the effectiveness of the proposed simulation method and quantitative analysis results. In addition, given the gravimeter (1-2 mGal accuracy) and the reference map (resolution 1' × 1'; accuracy 3-8 mGal), location accuracy of IGNS was up to reach ~1.0-3.0 n miles in the South China Sea.

The Ocean as a teaching tool: the first MOOC on Ocean Literacy

NASA Astrophysics Data System (ADS)

Santin, Selvaggia; Santoro, Francesca

2017-04-01

Education its broader understanding (in both formal and informal settings) serves as a high potential channel to reach young citizens. As a lack of sufficient 'Ocean Literacy' has been identified in many countries, this clearly presents a barrier for citizens to engage in ocean responsible behaviour or consider ocean-related careers. In order to sensitize and enable teachers and students to incorporate ocean literacy into educational programmes we build up a first Massive Open Online Course on Emma Platform, an European Multiple MOOC Aggregator that provides a system for the delivery of free, open, online courses in multiple languages from different European universities. Almost 500 students were enrolled from all over the world and we proposed a multi-perspective approach building on the UNESCO experience in the field of education for sustainable development. The course had two sections: a narrative format which introduces to the Ocean Literacy principles, focusing on how to incorporate them into lessons with tips, advice, references and activities; and an interactive section with webinairs which covers contemporary and emerging issues such as seafood, marine pollution and human health, simulating a "real-world experiences" with a problems-solutions approach.

Coordination and Integration of Global Ocean Observing through JCOMM

NASA Astrophysics Data System (ADS)

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

2016-02-01

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

Kanaka Maoli and Kamáāina Seascapes - Knowing Our Ocean Through Times of Change

NASA Astrophysics Data System (ADS)

Puniwai, N.

2017-12-01

In Hawaíi our oceans define us, we come from the ocean. Our oceans change, and we change with them, as we always have. By learning from people who are dependent on their environment, we learn how to observe and how to adapt. Through the lens of climate change, we interviewed respected ocean observers and surfers to learn about changes they have witnessed over time and the spatial scales and ocean conditions important to them. We looked at our ancient and historical texts to see what processes they recorded and the language they used to ascribe their observations, interactions and relationships to these places. Yet, we also integrate what our mechanical data sensors have recorded over recent time. By expanding our time scales of reference, knowledge sources, and collaborators, these methods teach us how our ancestors adapted and how climate change may impact our subsistence, recreation, and interactions with the environment. Managing complex seascapes requires the integration of multiple ways of knowing; strengthening our understanding of seascapes and their resiliency in this changing environment.

A global reference model of Curie-point depths based on EMAG2

NASA Astrophysics Data System (ADS)

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-03-01

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C)-1 for the ocean and K = ~2.5 W(m°C)-1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m2, leading to a global heat loss ranging from ~34.6 to 36.6 TW.

A global reference model of Curie-point depths based on EMAG2.

PubMed

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-03-21

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C) -1 for the ocean and K = ~2.5 W(m°C) -1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m 2 , leading to a global heat loss ranging from ~34.6 to 36.6 TW.

Compact-Impact Reimbursement Act of 2011

THOMAS, 112th Congress

Rep. Hanabusa, Colleen W. [D-HI-1

2011-11-02

House - 11/08/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Compact-Impact Aid Act of 2013

THOMAS, 113th Congress

Rep. Hanabusa, Colleen W. [D-HI-1

2013-03-15

House - 03/26/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

15 CFR 990.30 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the United States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa... Comp., p. 22), including the ocean waters of the areas referred to as “eastern special areas” in...

15 CFR 990.30 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the United States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa... Comp., p. 22), including the ocean waters of the areas referred to as “eastern special areas” in...

15 CFR 990.30 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the United States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa... Comp., p. 22), including the ocean waters of the areas referred to as “eastern special areas” in...

15 CFR 990.30 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the United States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa... Comp., p. 22), including the ocean waters of the areas referred to as “eastern special areas” in...

CLEAN Energy Producers Act of 2014

THOMAS, 113th Congress

Rep. Duncan, Jeff [R-SC-3

2014-06-02

House - 06/10/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Sage Grouse Protection and Conservation Act

THOMAS, 113th Congress

Rep. Gardner, Cory [R-CO-4

2014-05-22

House - 05/30/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

30 CFR 556.7 - Cross references.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (c) For multiple use conflicts, see the Environmental Protection Agency listing of ocean dumping...) Coastal Energy Impact Program, 15 CFR part 931; (e) For Coast Guard regulations on the oil spill liability...

30 CFR 556.7 - Cross references.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (c) For multiple use conflicts, see the Environmental Protection Agency listing of ocean dumping...) Coastal Energy Impact Program, 15 CFR part 931; (e) For Coast Guard regulations on the oil spill liability...

Coastal State Climate Change Planning Act

THOMAS, 113th Congress

Rep. Capps, Lois [D-CA-24

2013-02-15

House - 03/01/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Coastal State Climate Change Planning Act

THOMAS, 112th Congress

Rep. Capps, Lois [D-CA-23

2012-03-29

House - 04/16/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Rigs to Reefs Habitat Protection Act

THOMAS, 112th Congress

Rep. Palazzo, Steven M. [R-MS-4

2011-11-15

House - 11/29/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Dr. Rita Hocog Inos Fellowship Act

THOMAS, 112th Congress

Rep. Sablan, Gregorio Kilili Camacho [D-MP-At Large

2011-01-26

House - 02/04/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

30 CFR 556.7 - Cross references.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (c) For multiple use conflicts, see the Environmental Protection Agency listing of ocean dumping...) Coastal Energy Impact Program, 15 CFR part 931; (e) For Coast Guard regulations on the oil spill liability...

30 CFR 256.7 - Cross references.

Code of Federal Regulations, 2010 CFR

2010-07-01

... multiple use conflicts, see the Environmental Protection Agency listing of ocean dumping sites—40 CFR part... sanctuary regulations, 15 CFR part 922; (2) Fishermen's Contingency Fund, 50 CFR part 296; (3) Coastal...

Marine Debris Emergency Act of 2012

THOMAS, 112th Congress

Rep. Bonamici, Suzanne [D-OR-1

2012-08-01

House - 08/09/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

How strange was the Strangelove Ocean? New insights from Boron Isotopes.

NASA Astrophysics Data System (ADS)

Henehan, M. J.; Ridgwell, A.; Thomas, E.; Zhang, S.; Planavsky, N.; Alegret, L.; Schmidt, D. N.; Rae, J. W. B.; Foster, G. L.; Huber, B. T.; Hull, P. M.

2016-12-01

The idea of the `Strangelove Ocean'1 has captured the imagination of palaeoceanographers (and the public) since it was posited to explain the collapse or reverse in surface-deep ocean δ13C gradients after the Cretaceous-Palaeogene (K-Pg) boundary1. It describes a post-extinction ocean where primary productivity was drastically reduced, eliminating the surface-to-deep carbon isotope gradient produced by the biological pump. Survival of benthic foraminifera across the K-Pg (suggesting a persistent supply of organic matter to the deep) is difficult to reconcile with this ideae.g. 2. Geochemical proxies also suggest that severe export productivity reductions were at most regional3. This mismatch between patterns in δ13C and other indicators has thus been interpreted as a signal of changing vital effects in post-extinction pelagic calcifiers, toward lighter δ13C e.g. 2. However, it may be that vital effects in earliest Palaeocene foraminiferal survivors can account for only part of the convergence in δ13C between surface and deep ocean.4 In addition, analysis of carbonate preservation after the K-Pg boundary indicates large-scale carbonate system/ocean pH shifts at this time5, which could have produced secular changes in carbon isotope signals. Here we present new paired benthic and planktic boron isotope measurements that allow us to examine surface to deep ocean pH gradients (which in today's ocean are driven largely by biological activity) across the K-Pg boundary interval and into the early Palaeocene. We then couple these to model simulations to untangle the carbon cycle drivers, both physical and biological, that could have caused these changes in ocean pH gradients. We discuss implications for our understanding of this important interval in Earth history, with reference to the mechanisms of Earth system recovery following mass extinction. References:1. Hsü, K. J. & McKenzie, J. A., 1985. AGU Geophysical Monograph Series 32. doi:10.1029/GM032p0487 2. Alegret, L., et al., 2012. PNAS 109, 728-732. doi:10.1073/pnas.1110601109 3. Hull, P.M. & Norris, R.D., 2011. Paleoceanography 26, PA3205. doi:10.1029/2010PA002082 4. Birch, H.S., et al., 2016. Geology 44, 287-290. doi:10.1130/G37581.1 5. Henehan et al., 2016. Phil. Trans. Roy. Soc. B. 371, 20150510. doi:10.1098/rstb.2015.0510

Rare Cats and Canids Act of 2014

THOMAS, 113th Congress

Rep. Grijalva, Raul M. [D-AZ-3

2014-12-10

House - 12/22/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Marine Turtle Conservation Reauthorization Act of 2013

THOMAS, 113th Congress

Rep. Pierluisi, Pedro R. [D-PR-At Large

2013-03-21

House - 04/11/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Migratory Bird Treaty Amendment Act of 2011

THOMAS, 112th Congress

Rep. Boustany, Charles W., Jr. [R-LA-7

2011-05-05

House - 05/16/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Ocean and Coastal Mapping Integration Act

THOMAS, 111th Congress

Sen. Inouye, Daniel K. [D-HI

2009-01-08

Senate - 01/08/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Strategic Response to Asian Carp Invasion Act

THOMAS, 112th Congress

Rep. McCollum, Betty [D-MN-4

2012-09-12

House - 09/14/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Long Island Sound Restoration and Stewardship Act

THOMAS, 112th Congress

Rep. Israel, Steve [D-NY-2

2011-12-16

House - 01/03/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Long Island Sound Restoration and Stewardship Act

THOMAS, 113th Congress

Rep. Israel, Steve [D-NY-3

2013-05-23

House - 06/03/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Dr. Rita Hocog Inos Territorial Fellowship Act

THOMAS, 113th Congress

Rep. Sablan, Gregorio Kilili Camacho [D-MP-At Large

2013-02-05

House - 02/13/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Ocean and Coastal Adaptation Planning Act

THOMAS, 111th Congress

Sen. Whitehouse, Sheldon [D-RI

2009-04-02

Senate - 04/02/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Sustainable Offshore Aquaculture Act of 2011

THOMAS, 112th Congress

Rep. Capps, Lois [D-CA-23

2011-06-24

House - 07/06/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Endowment for the Oceans Act

THOMAS, 112th Congress

Sen. Whitehouse, Sheldon [D-RI

2011-05-12

Senate - 05/12/2011 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Oceans Protection Act of 2009

THOMAS, 111th Congress

Sen. Boxer, Barbara [D-CA

2009-04-22

Senate - 04/22/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Endowment for the Oceans Act

THOMAS, 113th Congress

Sen. Whitehouse, Sheldon [D-RI

2013-03-21

Senate - 03/21/2013 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Endowment for the Oceans Act

THOMAS, 111th Congress

Sen. Whitehouse, Sheldon [D-RI

2010-07-22

Senate - 07/22/2010 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Heller Public Firearms Range Act of 2014

THOMAS, 113th Congress

Rep. Stockman, Steve [R-TX-36

2014-11-20

House - 12/02/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Big Cats and Public Safety Protection Act

THOMAS, 113th Congress

Rep. McKeon, Howard P. "Buck" [R-CA-25

2013-05-15

House - 05/21/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Big Cats and Public Safety Protection Act

THOMAS, 112th Congress

Rep. McKeon, Howard P. "Buck" [R-CA-25

2012-03-01

House - 03/09/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Cormorant Management and Natural Resources Protection Act

THOMAS, 113th Congress

Rep. Bachmann, Michele [R-MN-6

2013-04-26

House - 05/03/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Delaware River Basin Conservation Act of 2011

THOMAS, 112th Congress

Rep. Carney, John C., Jr. [D-DE-At Large

2011-06-23

House - 07/11/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Nutria Eradication and Control Act of 2011

THOMAS, 112th Congress

Rep. Boustany, Charles W., Jr. [R-LA-7

2011-05-11

House - 05/24/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Fisheries Disaster Relief and Research Investment Act

THOMAS, 113th Congress

Rep. Tierney, John F. [D-MA-6

2013-02-15

House - 03/01/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Keep America's Waterfronts Working Act of 2011

THOMAS, 112th Congress

Rep. Pingree, Chellie [D-ME-1

2011-10-05

House - 10/17/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Delaware River Basin Conservation Act of 2013

THOMAS, 113th Congress

Rep. Carney, John C., Jr. [D-DE-At Large

2013-02-13

House - 02/22/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Guam World War II Loyalty Recognition Act

THOMAS, 113th Congress

Rep. Bordallo, Madeleine Z. [D-GU-At Large

2013-01-03

House - 01/31/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Provenance Usage in the OceanLink Project

NASA Astrophysics Data System (ADS)

Narock, T.; Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Fils, D.; Finin, T.; Hitzler, P.; Janowicz, K.; Jones, M.; Krisnadhi, A.; Lehnert, K. A.; Mickle, A.; Raymond, L. M.; Schildhauer, M.; Shepherd, A.; Wiebe, P. H.

2014-12-01

A wide spectrum of maturing methods and tools, collectively characterized as the Semantic Web, is helping to vastly improve thedissemination of scientific research. The OceanLink project, an NSF EarthCube Building Block, is utilizing semantic technologies tointegrate geoscience data repositories, library holdings, conference abstracts, and funded research awards. Provenance is a vital componentin meeting both the scientific and engineering requirements of OceanLink. Provenance plays a key role in justification and understanding when presenting users with results aggregated from multiple sources. In the engineering sense, provenance enables the identification of new data and the ability to determine which data sources to query. Additionally, OceanLink will leverage human and machine computation for crowdsourcing, text mining, and co-reference resolution. The results of these computations, and their associated provenance, will be folded back into the constituent systems to continually enhance precision and utility. We will touch on the various roles provenance is playing in OceanLink as well as present our use of the PROV Ontology and associated Ontology Design Patterns.

Tropical CO2 seeps reveal the impact of ocean acidification on coral reef invertebrate recruitment.

PubMed

Allen, Ro; Foggo, Andrew; Fabricius, Katharina; Balistreri, Annalisa; Hall-Spencer, Jason M

2017-11-30

Rising atmospheric CO 2 concentrations are causing ocean acidification by reducing seawater pH and carbonate saturation levels. Laboratory studies have demonstrated that many larval and juvenile marine invertebrates are vulnerable to these changes in surface ocean chemistry, but challenges remain in predicting effects at community and ecosystem levels. We investigated the effect of ocean acidification on invertebrate recruitment at two coral reef CO 2 seeps in Papua New Guinea. Invertebrate communities differed significantly between 'reference' (median pH7.97, 8.00), 'high CO 2 ' (median pH7.77, 7.79), and 'extreme CO 2 ' (median pH7.32, 7.68) conditions at each reef. There were also significant reductions in calcifying taxa, copepods and amphipods as CO 2 levels increased. The observed shifts in recruitment were comparable to those previously described in the Mediterranean, revealing an ecological mechanism by which shallow coastal systems are affected by near-future levels of ocean acidification. Copyright © 2016 Elsevier Ltd. All rights reserved.

First satellite tracks of neonate sea turtles redefine the ‘lost years’ oceanic niche

PubMed Central

Mansfield, Katherine L.; Wyneken, Jeanette; Porter, Warren P.; Luo, Jiangang

2014-01-01

Few at-sea behavioural data exist for oceanic-stage neonate sea turtles, a life-stage commonly referred to as the sea turtle ‘lost years’. Historically, the long-term tracking of small, fast-growing organisms in the open ocean was logistically or technologically impossible. Here, we provide the first long-term satellite tracks of neonate sea turtles. Loggerheads (Caretta caretta) were remotely tracked in the Atlantic Ocean using small solar-powered satellite transmitters. We show that oceanic-stage turtles (i) rarely travel in Continental Shelf waters, (ii) frequently depart the currents associated with the North Atlantic Subtropical Gyre, (iii) travel quickly when in Gyre currents, and (iv) select sea surface habitats that are likely to provide a thermal benefit or refuge to young sea turtles, supporting growth, foraging and survival. Our satellite tracks help define Atlantic loggerhead nursery grounds and early loggerhead habitat use, allowing us to re-examine sea turtle ‘lost years’ paradigms. PMID:24598420

Mass, heat and freshwater fluxes in the South Indian Ocean

NASA Technical Reports Server (NTRS)

Fu, Lee-Lueng

1986-01-01

Six hydrographic sections were used to examine the circulation and property fluxes in the South Indian Ocean from 10 to 32 deg S. The calculations were made by applying an inverse method to the data. In the interior of the South Indian Ocean, the geostrophic flow is generally northward. At 18 deg S, the northward interior mass flux is balanced by the southward Ekman mass flux at the surface, whereas at 32 deg S the northward interior mass flux is balanced by the southward mass flux of the Agulhas Current. There is a weak, southward mass flux of 6 x 10 to the 9th kg/s in the Mozambique Channel. The rate of water exchange between the Pacific Ocean and the Indian Ocean is dependent on the choice of the initial reference level used in the inverse calculation. The choice of 1500 m, the depth of the deep oxygen minimum, has led to a flux of water from the Pacific Ocean to the Indian Ocean at a rate of 6.6 x 10 to the 9th kg/s. Heat flux calculations indicate that the Indian Ocean is exporting heat to the rest of the world's oceans at a rate of -0.69 x 10 to the 15th W at 18 deg S and -0.25 x 10 to the 15th W at 32 deg S (negative values being southward).

Global plate motion frames: Toward a unified model

NASA Astrophysics Data System (ADS)

Torsvik, Trond H.; Müller, R. Dietmar; van der Voo, Rob; Steinberger, Bernhard; Gaina, Carmen

2008-09-01

Plate tectonics constitutes our primary framework for understanding how the Earth works over geological timescales. High-resolution mapping of relative plate motions based on marine geophysical data has followed the discovery of geomagnetic reversals, mid-ocean ridges, transform faults, and seafloor spreading, cementing the plate tectonic paradigm. However, so-called "absolute plate motions," describing how the fragments of the outer shell of the Earth have moved relative to a reference system such as the Earth's mantle, are still poorly understood. Accurate absolute plate motion models are essential surface boundary conditions for mantle convection models as well as for understanding past ocean circulation and climate as continent-ocean distributions change with time. A fundamental problem with deciphering absolute plate motions is that the Earth's rotation axis and the averaged magnetic dipole axis are not necessarily fixed to the mantle reference system. Absolute plate motion models based on volcanic hot spot tracks are largely confined to the last 130 Ma and ideally would require knowledge about the motions within the convecting mantle. In contrast, models based on paleomagnetic data reflect plate motion relative to the magnetic dipole axis for most of Earth's history but cannot provide paleolongitudes because of the axial symmetry of the Earth's magnetic dipole field. We analyze four different reference frames (paleomagnetic, African fixed hot spot, African moving hot spot, and global moving hot spot), discuss their uncertainties, and develop a unifying approach for connecting a hot spot track system and a paleomagnetic absolute plate reference system into a "hybrid" model for the time period from the assembly of Pangea (˜320 Ma) to the present. For the last 100 Ma we use a moving hot spot reference frame that takes mantle convection into account, and we connect this to a pre-100 Ma global paleomagnetic frame adjusted 5° in longitude to smooth the reference frame transition. Using plate driving force arguments and the mapping of reconstructed large igneous provinces to core-mantle boundary topography, we argue that continental paleolongitudes can be constrained with reasonable confidence.

Great Lakes Maritime Heritage Assessment Act of 2014

THOMAS, 113th Congress

Rep. Kaptur, Marcy [D-OH-9

2014-11-14

House - 11/20/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Joint Ventures for Bird Habitat Conservation Act of 2013

THOMAS, 113th Congress

Rep. Kind, Ron [D-WI-3

2013-03-13

House - 03/21/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Deep Ocean Energy Resources Act of 2009

THOMAS, 111th Congress

Rep. Myrick, Sue Wilkins [R-NC-9

2009-04-27

House - 06/12/2009 Referred to the Subcommittee on Immigration, Citizenship, Refugees, Border Security, and International Law. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Fish and Wildlife Foundation Reauthorization Act of 2012

THOMAS, 112th Congress

Rep. Grimm, Michael G. [R-NY-13

2012-09-19

House - 09/24/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Fish and Wildlife Foundation Reauthorization Act of 2013

THOMAS, 113th Congress

Rep. Grimm, Michael G. [R-NY-11

2013-01-15

House - 01/31/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Multinational Species Conservation Funds Reauthorization Act of 2013

THOMAS, 113th Congress

Rep. Young, Don [R-AK-At Large

2013-01-03

House - 01/31/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Multinational Species Conservation Funds Semipostal Stamp Reauthorization Act

THOMAS, 113th Congress

Rep. Grimm, Michael G. [R-NY-11

2013-01-15

House - 01/31/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Multinational Species Conservation Funds Semipostal Stamp Reauthorization Act

THOMAS, 112th Congress

Rep. Grimm, Michael G. [R-NY-13

2011-11-29

House - 12/05/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Great Lakes and Fresh Water Algal Bloom Information Act

THOMAS, 113th Congress

Rep. Latta, Robert E. [R-OH-5

2014-09-11

House - 09/16/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Coastal and Ocean Observation System Act of 2009

THOMAS, 111th Congress

Sen. Snowe, Olympia J. [R-ME

2009-01-08

Senate - 01/08/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Northwest Straits Marine Conservation Initiative Reauthorization Act of 2011

THOMAS, 112th Congress

Rep. Larsen, Rick [D-WA-2

2011-05-12

House - 05/24/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Stopping Non-Native Animals from Killing Endangered Species Act

THOMAS, 112th Congress

Rep. Hastings, Alcee L. [D-FL-23

2012-06-07

House - 06/14/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To reauthorize the Neotropical Migratory Bird Conservation Act.

THOMAS, 112th Congress

Rep. Kind, Ron [D-WI-3

2011-04-08

House - 04/18/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Great Ape Conservation Reauthorization Amendments Act of 2013

THOMAS, 113th Congress

Rep. Miller, George [D-CA-11

2013-03-21

House - 04/11/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To reauthorize the Neotropical Migratory Bird Conservation Act.

THOMAS, 113th Congress

Rep. Kind, Ron [D-WI-3

2013-03-20

House - 03/28/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Fisheries Investment and Regulatory Relief Act of 2012

THOMAS, 112th Congress

Rep. Frank, Barney [D-MA-4

2012-03-19

House - 03/26/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Primary Reference Cell Calibration | Photovoltaic Research | NREL

Science.gov Websites

0.01-sun to several suns. A device is linear if the current measured with both lamps illuminating the , "Spectroradiometric Sun Photometry," Journal of Atmospheric and Oceanic Technology 17, 1171

Author Correction: Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa.

PubMed

Khodri, Myriam; Izumo, Takeshi; Vialard, Jérôme; Janicot, Serge; Cassou, Christophe; Lengaigne, Matthieu; Mignot, Juliette; Gastineau, Guillaume; Guilyardi, Eric; Lebas, Nicolas; Robock, Alan; McPhaden, Michael J

2018-02-22

The original version of this Article omitted a reference to previous work in 'Mann, M.E., Cane, M.A., Zebiak, S.E., Clement, A., Volcanic and Solar Forcing of the Tropical Pacific Over the Past 1000 Years, J. Climate 18, 447-456 (2005)'. This has been added as reference 62 at the end of the fourth sentence of the fourth paragraph of the Introduction: 'Early studies using simple coupled ocean-atmosphere models 26 proposed that following volcano-induced surface cooling, upwelling in the eastern equatorial Pacific acting on a reduced vertical temperature contrast between the ocean surface and interior leads to anomalous warming in this region, thereby favouring El Niño development the following year 12, 27, 62 .' This has been corrected in the PDF and HTML versions of the Article.

Vertical structure of cumulonimbus towers and intense convective clouds over the South Asian region during the summer monsoon season

NASA Astrophysics Data System (ADS)

Bhat, G. S.; Kumar, Shailendra

2015-03-01

The vertical structure of radar reflectivity factor in active convective clouds that form during the South Asian monsoon season is reported using the 2A25 version 6 data product derived from the precipitation radar measurements on board the Tropical Rainfall Measuring Mission satellite. We define two types of convective cells, namely, cumulonimbus towers (CbTs) and intense convective cells (ICCs). CbT is defined referring to a reflectivity threshold of 20 dBZ at 12 km altitude and is at least 9 km thick. ICCs are constructed referring to reflectivity thresholds at 8 km and 3 km altitudes. Cloud properties reported here are based on 10 year climatology. It is observed that the frequency of occurrence of CbTs is highest over the foothills of Himalayas, plains of northern India and Bangladesh, and minimum over the Arabian Sea and equatorial Indian Ocean west of 90°E. The regional differences depend on the reference height selected, namely, small in the case of CbTs and prominent in 6-13 km height range for ICCs. Land cells are more intense than the oceanic ones for convective cells defined using the reflectivity threshold at 3 km, whereas land versus ocean contrasts are not observed in the case of CbTs. Compared to cumulonimbus clouds elsewhere in the tropics, the South Asian counterparts have higher reflectivity values above 11 km altitude.

TCL2 Ocean Scenario Replay

NASA Technical Reports Server (NTRS)

Mohlenbrink, Christoph P.; Omar, Faisal Gamal; Homola, Jeffrey R.

2017-01-01

This is a video replay of system data that was generated from the UAS Traffic Management (UTM) Technical Capability Level (TCL) 2 flight demonstration in Nevada and rendered in Google Earth. What is depicted in the replay is a particular set of flights conducted as part of what was referred to as the Ocean scenario. The test range and surrounding area are presented followed by an overview of operational volumes. System messaging is also displayed as well as a replay of all of the five test flights as they occurred.

Evaluation of Regional Travel-Time and Location Improvement Along the Tethyan Margin Using a New Three-Dimensional Velocity Model

DTIC Science & Technology

2008-09-01

part of the Atlantic Ocean for reference. The Moho depth result is broadly consistent with CRUST2.0, except in mid-northern Africa, where the crust...plate boundaries is shown by the pink line in Figure 1. The interaction of these five major tectonic plates with each other and with several microplates ...acquired from literatures. Artificial point constraints of 10 km depth are placed to the Atlantic and Indian Oceans where measurements are absent

Joint Inversion for 3-Dimensional S-Velocity Mantle Structure Along the Tethyan Margin

DTIC Science & Technology

2007-09-01

Hindu Kush and encompasses northeastern Africa, the Arabian peninsula, the Middle East, and part of the Atlantic Ocean for reference. We have fitted...several microplates within an area of one quarter of the Earth’s circumference yields this region rich with tectonic complexity. The three...assigned the largest errors. For the oceans we use a constraint of 10 km for Moho depth, but only for points also covered by data from our other data sets

Evaluation of Dredged Material Proposed for Disposal at Island, Nearshore, or Upland Confined Disposal Facilities - Testing Manual

DTIC Science & Technology

2003-01-01

disposal in the ocean is regulated under the Marine Protection, Research and Sanctuaries Act (MPRSA), commonly referred to as the Ocean Dumping Act. The...Federal Water Pollution Control Act (33 U.S.C. 1344) or Section 103 of the Marine Protection, Research, and Sanctuaries Act of 1972 (33 U.S.C. 1413... abiotic resources such as water quality, groundwater quality, and air quality as well as the more commonly thought of biotic resources such as

Climatological mean and decadal change in surface ocean pCO 2, and net sea-air CO 2 flux over the global oceans

NASA Astrophysics Data System (ADS)

Takahashi, Taro; Sutherland, Stewart C.; Wanninkhof, Rik; Sweeney, Colm; Feely, Richard A.; Chipman, David W.; Hales, Burke; Friederich, Gernot; Chavez, Francisco; Sabine, Christopher; Watson, Andrew; Bakker, Dorothee C. E.; Schuster, Ute; Metzl, Nicolas; Yoshikawa-Inoue, Hisayuki; Ishii, Masao; Midorikawa, Takashi; Nojiri, Yukihiro; Körtzinger, Arne; Steinhoff, Tobias; Hoppema, Mario; Olafsson, Jon; Arnarson, Thorarinn S.; Tilbrook, Bronte; Johannessen, Truls; Olsen, Are; Bellerby, Richard; Wong, C. S.; Delille, Bruno; Bates, N. R.; de Baar, Hein J. W.

2009-04-01

A climatological mean distribution for the surface water pCO 2 over the global oceans in non-El Niño conditions has been constructed with spatial resolution of 4° (latitude) ×5° (longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO 2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. Global sea-air CO 2 flux based on climatological surface ocean pCO 2, and seasonal biological and temperature effects. Deep-Sea Res. II, 49, 1601-1622]. A time-trend analysis using deseasonalized surface water pCO 2 data in portions of the North Atlantic, North and South Pacific and Southern Oceans (which cover about 27% of the global ocean areas) indicates that the surface water pCO 2 over these oceanic areas has increased on average at a mean rate of 1.5 μatm y -1 with basin-specific rates varying between 1.2±0.5 and 2.1±0.4 μatm y -1. A global ocean database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Niño periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO 2 and the sea-air pCO 2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern Oceans are presented. Over the Southern Ocean seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO 2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net air-sea CO 2 flux is estimated using the sea-air pCO 2 difference and the air-sea gas transfer rate that is parameterized as a function of (wind speed) 2 with a scaling factor of 0.26. This is estimated by inverting the bomb 14C data using Ocean General Circulation models and the 1979-2005 NCEP-DOE AMIP-II Reanalysis (R-2) wind speed data. The equatorial Pacific (14°N-14°S) is the major source for atmospheric CO 2, emitting about +0.48 Pg-C y -1, and the temperate oceans between 14° and 50° in the both hemispheres are the major sink zones with an uptake flux of -0.70 Pg-C y -1 for the northern and -1.05 Pg-C y -1 for the southern zone. The high-latitude North Atlantic, including the Nordic Seas and portion of the Arctic Sea, is the most intense CO 2 sink area on the basis of per unit area, with a mean of -2.5 tons-C month -1 km -2. This is due to the combination of the low pCO 2 in seawater and high gas exchange rates. In the ice-free zone of the Southern Ocean (50°-62°S), the mean annual flux is small (-0.06 Pg-C y -1) because of a cancellation of the summer uptake CO 2 flux with the winter release of CO 2 caused by deepwater upwelling. The annual mean for the contemporary net CO 2 uptake flux over the global oceans is estimated to be -1.6±0.9 Pg-C y -1, which includes an undersampling correction to the direct estimate of -1.4±0.7 Pg-C y -1. Taking the pre-industrial steady-state ocean source of 0.4±0.2 Pg-C y -1 into account, the total ocean uptake flux including the anthropogenic CO 2 is estimated to be -2.0±1.0 Pg-C y -1 in 2000.

Aerosol spectral optical depths - Jet fuel and forest fire smokes

NASA Technical Reports Server (NTRS)

Pueschel, R. F.; Livingston, J. M.

1990-01-01

The Ames autotracking airborne sun photometer was used to investigate the spectral depth between 380 and 1020 nm of smokes from a jet fuel pool fire and a forest fire in May and August 1988, respectively. Results show that the forest fire smoke exhibited a stronger wavelength dependence of optical depths than did the jet fuel fire smoke at optical depths less than unity. At optical depths greater than or equal to 1, both smokes showed neutral wavelength dependence, similar to that of an optically thin stratus deck. These results verify findings of earlier investigations and have implications both on the climatic impact of large-scale smokes and on the wavelength-dependent transmission of electromagnetic signals.

USGS-NoGaDat - A global dataset of noble gas concentrations and their isotopic ratios in volcanic systems

USGS Publications Warehouse

Abedini, Atosa A.; Hurwitz, S.; Evans, William C.

2006-01-01

The database (Version 1.0) is a MS-Excel file that contains close to 5,000 entries of published information on noble gas concentrations and isotopic ratios from volcanic systems in Mid-Ocean ridges, ocean islands, seamounts, and oceanic and continental arcs (location map). Where they were available we also included the isotopic ratios of strontium, neodymium, and carbon. The database is sub-divided both into material sampled (e.g., volcanic glass, different minerals, fumarole, spring), and into different tectonic settings (MOR, ocean islands, volcanic arcs). Included is also a reference list in MS-Word and pdf from which the data was derived. The database extends previous compilations by Ozima (1994), Farley and Neroda (1998), and Graham (2002). The extended database allows scientists to test competing hypotheses, and it provides a framework for analysis of noble gas data during periods of volcanic unrest.

Intercontinental Transport of Ozone from Tropical Biomass Burning

NASA Technical Reports Server (NTRS)

Thompson, A. M.

2003-01-01

Researchers have been looking at the connection between tropical biomass burning and ozone formation and long-range transport for roughly 15 years. One can see the linkage and transport patterns from satellite though aircraft and/or balloon-sonde profiles are required to observe the fine structure (ozone transport over thousands of km often happens in thin layers). In this review, I survey the pyrogenic ozone transport in the large oceanic basins - Indian Ocean, Pacific and Atlantic. Mechanistic complexities are discussed and examples shown from satellite, aircraft and soundings, including NASA results from TOMS, the GTE experiments and the SHADOZ sounding program. Experiments referred to include SAFARI-92, TRACE-A, INDOEX, PEM-Tropics and TRACE-P. augmented by subsidence, a variable tropopause height, and lightning - even ozone pollution from the Indian Ocean has been implicated. Over the Indian Ocean, pollution interacts with convection and the monsoon cycle.

Feral Swine Eradication and Control Pilot Program Act of 2011

THOMAS, 112th Congress

Rep. Boustany, Charles W., Jr. [R-LA-7

2011-05-11

House - 05/24/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Coral Reef Conservation Act Reauthorization and Enhancement Amendments of 2011

THOMAS, 112th Congress

Rep. Bordallo, Madeleine Z. [D-GU-At Large

2011-02-16

House - 02/18/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Coral Reef Conservation Act Reauthorization and Enhancement Amendments of 2013

THOMAS, 113th Congress

Rep. Bordallo, Madeleine Z. [D-GU-At Large

2013-01-03

House - 01/31/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Ocean Acidification Research And Monitoring Act of 2009

THOMAS, 111th Congress

Sen. Lautenberg, Frank R. [D-NJ

2009-01-08

Senate - 01/08/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Chesapeake Bay Science, Education, and Ecosystem Enhancement Act of 2011

THOMAS, 112th Congress

Rep. Sarbanes, John P. [D-MD-3

2011-04-15

House - 04/27/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Arctic Ocean Research, Monitoring, and Observing Act of 2012

THOMAS, 112th Congress

Sen. Begich, Mark [D-AK

2012-03-01

Senate - 03/01/2012 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

NOAA Ocean Exploration and Undersea Research Program Act of 2009

THOMAS, 111th Congress

Sen. Snowe, Olympia J. [R-ME

2009-01-08

Senate - 01/08/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Evaluating the performance of Sentinel-3 SRAL SAR Altimetry in the Coastal and Open Ocean, and developing improved retrieval methods - The ESA SCOOP Project.

NASA Astrophysics Data System (ADS)

Benveniste, J.; Cotton, D.; Moreau, T.; Varona, E.; Roca, M.; Cipollini, P.; Cancet, M.; Martin, F.; Fenoglio-Marc, L.; Naeije, M.; Fernandes, J.; Restano, M.; Ambrozio, A.

2016-12-01

The ESA Sentinel-3 satellite, launched in February 2016 as a part of the Copernicus programme, is the second satellite to operate a SAR mode altimeter. The Sentinel 3 Synthetic Aperture Radar Altimeter (SRAL) is based on the heritage from Cryosat-2, but this time complemented by a Microwave Radiometer (MWR) to provide a wet troposphere correction, and operating at Ku and C-Bands to provide an accurate along-track ionospheric correction. Together this instrument package, including both GPS and DORIS instruments for accurate positioning, allows accurate measurements of sea surface height over the ocean, as well as measurements of significant wave height and surface wind speed. SCOOP (SAR Altimetry Coastal & Open Ocean Performance) is a project funded under the ESA SEOM (Scientific Exploitation of Operational Missions) Programme Element, started in September 2015, to characterise the expected performance of Sentinel-3 SRAL SAR mode altimeter products, in the coastal zone and open-ocean, and then to develop and evaluate enhancements to the baseline processing scheme in terms of improvements to ocean measurements. There is also a work package to develop and evaluate an improved Wet Troposphere correction for Sentinel-3, based on the measurements from the on-board MWR, further enhanced mostly in the coastal and polar regions using third party data, and provide recommendations for use. At the end of the project recommendations for further developments and implementations will be provided through a scientific roadmap. In this presentation we provide an overview of the SCOOP project, highlighting the key deliverables and discussing the potential impact of the results in terms of the application of delay-Doppler (SAR) altimeter measurements over the open-ocean and coastal zone. We also present the initial results from the project, including: Key findings from a review of the current "state-of-the-art" for SAR altimetry, Specification of the initial "reference" delay-Doppler and echo modelling /retracking processing schemes, Evaluation of the initial Test Data Set in the Open Ocean and Coastal Zone Overview of modifications planned to the reference delay-Doppler and echo modelling/ re-tracking processing schemes.

Iron budgets for three distinct biogeochemical sites around the Kerguelen archipelago (Southern Ocean) during the natural fertilisation experiment KEOPS-2

NASA Astrophysics Data System (ADS)

Bowie, A. R.; van der Merwe, P.; Quéroué, F.; Trull, T.; Fourquez, M.; Planchon, F.; Sarthou, G.; Chever, F.; Townsend, A. T.; Obernosterer, I.; Sallée, J.-B.; Blain, S.

2014-12-01

Iron availability in the Southern Ocean controls phytoplankton growth, community composition and the uptake of atmospheric CO2 by the biological pump. The KEOPS-2 experiment took place around the Kerguelen plateau in the Indian sector of the Southern Ocean, a region naturally fertilised with iron at the scale of hundreds to thousands of square kilometres, producing a mosaic of spring blooms which showed distinct biological and biogeochemical responses to fertilisation. This paper presents biogeochemical iron budgets (incorporating vertical and lateral supply, internal cycling, and sinks) for three contrasting sites: an upstream high-nutrient low-chlorophyll reference, over the plateau, and in the offshore plume east of Kerguelen Island. These budgets show that distinct regional environments driven by complex circulation and transport pathways are responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. Iron supply from "new" sources to surface waters of the plume was double that above the plateau and 20 times greater than at the reference site, whilst iron demand (measured by cellular uptake) in the plume was similar to the plateau but 40 times greater than the reference. "Recycled" iron supply by bacterial regeneration and zooplankton grazing was a relative minor component at all sites (<8% of "new" supply), in contrast to earlier findings from other biogeochemical iron budgets in the Southern Ocean. Over the plateau, a particulate iron dissolution term of 2.5% was invoked to balance the budget; this approximately doubled the standing stock of dissolved iron in the mixed layer. The exchange of iron between dissolved, biogenic and lithogenic particulate pools was highly dynamic in time and space, resulting in a decoupling of iron supply and carbon export and, importantly, controlling the efficiency of fertilisation.

Impact of Idealized Stratospheric Aerosol Injection on the Future Ocean and Land Carbon Cycles

NASA Astrophysics Data System (ADS)

Tjiputra, J.; Lauvset, S.

2017-12-01

Using a state-of-the-art Earth system model, we simulate stratospheric aerosol injection (SAI) on top of the Representative Concentration Pathways 8.5 future scenario. Our idealized method prescribes aerosol concentration, linearly increasing from 2020 to 2100, and thereafter remaining constant until 2200. In one of the scenarios, the model able to project future warming below 2 degree toward 2100, despite greatier warming persists in the high latitudes. When SAI is terminated in 2100, a rapid global warming of 0.35 K yr-1 (as compared to 0.05 K yr-1 under RCP8.5) is simulated in the subsequent 10 years, and the global mean temperature rapidly returns to levels close to the reference state. In contrast to earlier findings, we show a weak response in the terrestrial carbon sink during SAI implementation in the 21st century, which we attribute to nitrogen limitation. The SAI increases the land carbon uptake in the temperate forest-, grassland-, and shrub-dominated regions. The resultant lower temperatures lead to a reduction in the heterotrophic respiration rate and increase soil carbon retention. Changes in precipitation patterns are key drivers for variability in vegetation carbon. Upon SAI termination, the level of vegetation carbon storage returns to the reference case, whereas the soil carbon remains high. The ocean absorbs nearly 10% more carbon in the geoengineered simulation than in the reference simulation, leading to a ˜15 ppm lower atmospheric CO2 concentration in 2100. The largest enhancement in uptake occurs in the North Atlantic. In both hemispheres' polar regions, SAI delays the sea ice melting and, consequently, export production remains low. Despite inducing little impact on surface acidification, in the deep water of North Atlantic, SAI-induced circulation changes accelerate the ocean acidification rate and broaden the affected area. Since the deep ocean provides vital ecosystem function and services, e.g., fish stocks, this accelerated changes could introduce broader negative impacts on human welfare.

High-precision GNSS ocean positioning with BeiDou short-message communication

NASA Astrophysics Data System (ADS)

Li, Bofeng; Zhang, Zhiteng; Zang, Nan; Wang, Siyao

2018-04-01

The current popular GNSS RTK technique would be not applicable on ocean due to the limited communication access for transmitting differential corrections. A new technique is proposed for high-precision ocean RTK, referred to as ORTK, where the corrections are transmitted by employing the function of BeiDou satellite short-message communication (SMC). To overcome the limitation of narrow bandwidth of BeiDou SMC, a new strategy of simplifying and encoding corrections is proposed instead of standard differential corrections, which reduces the single-epoch corrections from more than 1000 to less than 300 bytes. To solve the problems of correction delays, cycle slips, blunders and abnormal epochs over ultra-long baseline ORTK, a series of powerful algorithms were designed at the user-end software for achieving the stable and precise kinematic solutions on far ocean applications. The results from two long baselines of 240 and 420 km and real ocean experiments reveal that the kinematic solutions with horizontal accuracy of 5 cm and vertical accuracy of better than 15 cm are achievable by convergence time of 3-10 min. Compared to commercial ocean PPP with satellite telecommunication, ORTK is of much cheaper expense, higher accuracy and shorter convergence. It will be very prospective in many location-based ocean services.

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

PubMed Central

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

2016-01-01

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

234Th-based export fluxes during a natural iron fertilization experiment in the Southern Ocean (KEOPS)

NASA Astrophysics Data System (ADS)

Savoye, N.; Trull, T. W.; Jacquet, S. H. M.; Navez, J.; Dehairs, F.

2008-03-01

Five iron-fertilization experiments in the Southern Ocean have clearly demonstrated that adding iron increases primary production, but the implications for carbon export to the ocean interior have been less clear. This reflects both observational limitations of short-term experiments and their uncertain relevance to quantifying ecosystem level processes that are likely to be structured differently under conditions of punctual versus persistent stimulation. To avoid these biases, KEOPS (KErguelen Ocean and Plateau compared Study) investigated the naturally iron-fertilized Kerguelen Plateau region in the Indian Sector of the Southern Ocean that exhibits an annual phytoplankton bloom. Here, we report particulate organic carbon (POC) and nitrogen export from this system based on the 234Th approach. Results indicate that the export fluxes were variable both on and off the Kerguelen Plateau (9.0-38.4 mmol C m -2 d -1 and 1.6-4.8 mmol N m -2 d -1) and were in the range of values reported for natural Southern Ocean ecosystems. Export fluxes were compared at two reference stations, one above and one outside the Plateau. The station above the plateau was characterized by higher iron supply and export fluxes compared to the station outside the plateau. The difference in the export flux between these two reference stations defines the export excess induced by iron fertilization. It was 10.8±4.9 mmol C m -2 d -1 and 0.9±0.7 mmol N m -2 d -1 at 100 m, and 14.2±7.7 mmol C m -2 d -1 and 2.0±1.3 mmol N m -2 d -1 at 200 m. This POC export excess was similar to those found during other studies of artificial (SOFeX) and natural (CROZEX) iron fertilization in the Southern Ocean. The examination of the export efficiency (defined as the ratio of export to primary production) revealed significant variability over the plateau related to the temporal decoupling of production and export during the demise of the bloom. On average, the export efficiency was lower over the plateau than in surrounding waters, suggesting that increased iron supply may increase total export but lower export efficiency. Our findings are very important for evaluating present and past carbon cycling in the Southern and global oceans and for assessing predictive scenarios of carbon cycling and budget.

Climate and Ocean Circulation During "The Boring Billion" Simulated by CCSM3

NASA Astrophysics Data System (ADS)

Liu, P.; Hu, Y.; Liu, Y.

2017-12-01

The Boring Billion is referred to the era between approximately 1.8 and 0.8 billion years ago. Geological evidence suggests that no dramatic climate changes in the billions of years, at least in terms of permanent glaciation. The atmospheric oxygen maintained at a relatively low level without significant perturbations. Life had a certain degree of evolution with a quite gentle pace. Relative to the Great Oxidation Event occurred previously, and the Snowball Earth Event and Cambrian Explosion occurred afterwards, this billion years was calm in all aspects so it's often referred to as "the Boring Billion". Why were both the climate and oxygen concentration so stable, and how the anoxic condition in the deep ocean maintained are the questions that motivated our research. We use the Atmosphere Ocean General Circulation Model CCSM3 in this study. The climate of the Boring Billion is simulated for two distinct continental configurations reconstructed for 1540 Ma and 1420 Ma, with continental fragments concentrating towards the North Pole and equator, respectively. The solar constant is set to be 10% weaker than that of the present day. The results show that when the concentration of CO2 is 20 times the present atmospheric level (PAL), the global mean surface temperatures are 19 ° C and 20 ° C for the 1540 Ma and 1420 Ma continental configuration, respectively. Large scale permanent glaciers cannot develop in such a warm climate even for the continents at the polar region. The largest mixed-layer depth in the high-latitude ocean is approximately 1200 m and meridional overturning circulation can reach depth of 3000 m with strength of 40 Sv for both continental configuration. This implies that the material and energy exchange between shallow and deep ocean, as well as atmosphere and ocean, is efficient. When CO2 concentration is reduced to 10 PAL, 5 PAL or 2.5 PAL, global average temperature becomes 16 ° C, 13 ° C and 2 ° C respectively, and permanent glaciers start to form at the polar regions. Therefore, our simulations suggest that the CO2 concentration had to be close to or higher than 20 PAL in order for the simulated climate to be consistent with the observations. Moreover, the oceans were not dynamically stratified, to maintain an anoxic deep ocean biogeochemical processes which are not included in the model have to be invoked.

A global reference model of Curie-point depths based on EMAG2

PubMed Central

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-01-01

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C)−1 for the ocean and K = ~2.5 W(m°C)−1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m2, leading to a global heat loss ranging from ~34.6 to 36.6 TW. PMID:28322332

Activity measurements of a suite of radionuclides (241Am, 239,240Pu, 238Pu, 238U, 234U, 235U, 232Th, 230Th, 228Th, 228Ra, 137Cs, 210Pb, 90Sr and 40K) in biota reference material (Ocean Shellfish): CCRI(II)-S3

NASA Astrophysics Data System (ADS)

Nour, S.; Karam, L. R.; Inn, K. G. W.

2012-01-01

In 2005, the CCRI decided that a comparison undertaken from 2002 to 2008 by the NIST (under the auspices of the Inter-America Metrology System [SIM]) in the development of a new biota (Ocean Shellfish) standard reference material (SRM) was sufficiently well constructed that it could be converted into a supplementary comparison under CCRI(II), with comparison identifier CCRI(II)-S3. This would enable the comparison to be used to support calibration and measurement capability (CMC) claims for radionuclide measurements in reference materials (specifically, animal-based organic materials). Previous comparisons of radionuclides have been of single or multiple nuclides in non-complex matrices and results of such could not be extended to support capabilities to measure the same nuclides in reference materials. The results of this comparison have been used to determine the certified reference value of the SRM. The key comparison working group (KCWG) of the CCRI(II) has approved this approach as a mechanism to link all the results to certified 'reference values' in lieu of the key comparison reference value (KCRV) of these specified radionuclides in this type of matrix (shellfish) so as to support CMCs of similar materials submitted by the present participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Ocean, Coastal, and Watershed Education Act

THOMAS, 111th Congress

Rep. Capps, Lois [D-CA-23

2009-09-24

Senate - 03/22/2010 Received in the Senate and Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Targeted Use of Sanctions for Killing Elephants in Their Range Act of 2014

THOMAS, 113th Congress

Rep. DeFazio, Peter A. [D-OR-4

2014-09-11

House - 09/16/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Restoration of the U.S.-Russia Polar Bear Conservation Fund Act of 2013

THOMAS, 113th Congress

Rep. Young, Don [R-AK-At Large

2013-04-26

House - 05/06/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Restoration of the U.S.-Russia Polar Bear Conservation Fund Act of 2011

THOMAS, 112th Congress

Rep. Young, Don [R-AK-At Large

2011-03-09

House - 03/11/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Marianas Trench Marine National Monument Visitor Facility Authorization Act of 2011

THOMAS, 112th Congress

Rep. Sablan, Gregorio Kilili Camacho [D-MP-At Large

2011-03-17

House - 09/01/2011 Re-referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Prevention of Escapement of Genetically Altered Salmon in the United States Act

THOMAS, 113th Congress

Rep. Young, Don [R-AK-At Large

2013-04-23

House - 05/01/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Oceanic and Atmospheric Administration Commissioned Officer Corps Amendments Act of 2013

THOMAS, 113th Congress

Rep. Grayson, Alan [D-FL-9

2014-09-09

House - 09/26/2014 Referred to the Subcommittee on Crime, Terrorism, Homeland Security, and Investigations. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Aerosol Microphysical and Radiative Effects on Continental Cloud Ensembles

DOE PAGES

Wang, Yuan; Vogel, Jonathan M.; Lin, Yun; ...

2018-01-10

Aerosol-cloud-radiation interactions represent one of the largest uncertainties in the current climate assessment. Much of the complexity arises from the non-monotonic responses of clouds, precipitation and radiative fluxes to aerosol perturbations under various meteorological conditions. Here, an aerosol-aware Weather Research and Forecasting (WRF) model is used to investigate the microphysical and radiative effects of aerosols in three weather systems during the March 2000 Cloud Intensive Observational Period campaign at the Southern Great Plains site of the US Atmospheric Radiation Measurement Program. Three cloud ensembles with different meteorological conditions are simulated, including a low-pressure deep convective cloud system, a series ofmore » lessprecipitating stratus and shallow cumulus, and a cold frontal passage. The WRF simulations are evaluated by the available observations of cloud fraction, liquid water path, precipitation, and surface temperature. The microphysical properties of cloud hydrometeors, such as their mass and number concentrations, generally show monotonic trends as a function of cloud condensation nuclei concentrations. Aerosol radiative effects do not interfere the trends of cloud microphysics, except for the stratus and shallow cumulus cases where aerosol semi-direct effects are identified. The precipitation changes by aerosols vary with the cloud types and their evolving stages, with more prominent aerosol invigoration effect and associated enhanced precipitation from the convective sources. Furthermore, the simulated aerosol direct effect suppresses precipitation in all three cases but does not overturn the direction of precipitation changes by the aerosol indirect effect. Cloud fraction exhibits much smaller sensitivity (typically less than 2%) to aerosol perturbations than the cloud microphysics, and the responses vary with aerosol concentrations and cloud regimes. The surface shortwave radiation shows a monotonic decrease by increasing aerosols, while the magnitude of the decrease depends on the cloud type. Surface temperature changes closely follow the modulation of the surface radiation fluxes.« less

Aerosol Microphysical and Radiative Effects on Continental Cloud Ensembles

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

Wang, Yuan; Vogel, Jonathan M.; Lin, Yun

Aerosol-cloud-radiation interactions represent one of the largest uncertainties in the current climate assessment. Much of the complexity arises from the non-monotonic responses of clouds, precipitation and radiative fluxes to aerosol perturbations under various meteorological conditions. Here, an aerosol-aware Weather Research and Forecasting (WRF) model is used to investigate the microphysical and radiative effects of aerosols in three weather systems during the March 2000 Cloud Intensive Observational Period campaign at the Southern Great Plains site of the US Atmospheric Radiation Measurement Program. Three cloud ensembles with different meteorological conditions are simulated, including a low-pressure deep convective cloud system, a series ofmore » lessprecipitating stratus and shallow cumulus, and a cold frontal passage. The WRF simulations are evaluated by the available observations of cloud fraction, liquid water path, precipitation, and surface temperature. The microphysical properties of cloud hydrometeors, such as their mass and number concentrations, generally show monotonic trends as a function of cloud condensation nuclei concentrations. Aerosol radiative effects do not interfere the trends of cloud microphysics, except for the stratus and shallow cumulus cases where aerosol semi-direct effects are identified. The precipitation changes by aerosols vary with the cloud types and their evolving stages, with more prominent aerosol invigoration effect and associated enhanced precipitation from the convective sources. Furthermore, the simulated aerosol direct effect suppresses precipitation in all three cases but does not overturn the direction of precipitation changes by the aerosol indirect effect. Cloud fraction exhibits much smaller sensitivity (typically less than 2%) to aerosol perturbations than the cloud microphysics, and the responses vary with aerosol concentrations and cloud regimes. The surface shortwave radiation shows a monotonic decrease by increasing aerosols, while the magnitude of the decrease depends on the cloud type. Surface temperature changes closely follow the modulation of the surface radiation fluxes.« less

Heat Shock Partially Dissociates the Overlapping Modules of the Yeast Protein-Protein Interaction Network: A Systems Level Model of Adaptation

PubMed Central

Mihalik, Ágoston; Csermely, Peter

2011-01-01

Network analysis became a powerful tool giving new insights to the understanding of cellular behavior. Heat shock, the archetype of stress responses, is a well-characterized and simple model of cellular dynamics. S. cerevisiae is an appropriate model organism, since both its protein-protein interaction network (interactome) and stress response at the gene expression level have been well characterized. However, the analysis of the reorganization of the yeast interactome during stress has not been investigated yet. We calculated the changes of the interaction-weights of the yeast interactome from the changes of mRNA expression levels upon heat shock. The major finding of our study is that heat shock induced a significant decrease in both the overlaps and connections of yeast interactome modules. In agreement with this the weighted diameter of the yeast interactome had a 4.9-fold increase in heat shock. Several key proteins of the heat shock response became centers of heat shock-induced local communities, as well as bridges providing a residual connection of modules after heat shock. The observed changes resemble to a ‘stratus-cumulus’ type transition of the interactome structure, since the unstressed yeast interactome had a globally connected organization, similar to that of stratus clouds, whereas the heat shocked interactome had a multifocal organization, similar to that of cumulus clouds. Our results showed that heat shock induces a partial disintegration of the global organization of the yeast interactome. This change may be rather general occurring in many types of stresses. Moreover, other complex systems, such as single proteins, social networks and ecosystems may also decrease their inter-modular links, thus develop more compact modules, and display a partial disintegration of their global structure in the initial phase of crisis. Thus, our work may provide a model of a general, system-level adaptation mechanism to environmental changes. PMID:22022244

A radiation closure study of Arctic stratus cloud microphysical properties using the collocated satellite-surface data and Fu-Liou radiative transfer model

NASA Astrophysics Data System (ADS)

Dong, Xiquan; Xi, Baike; Qiu, Shaoyue; Minnis, Patrick; Sun-Mack, Sunny; Rose, Fred

2016-09-01

Retrievals of cloud microphysical properties based on passive satellite imagery are especially difficult over snow-covered surfaces because of the bright and cold surface. To help quantify their uncertainties, single-layered overcast liquid-phase Arctic stratus cloud microphysical properties retrieved by using the Clouds and the Earth's Radiant Energy System Edition 2 and Edition 4 (CERES Ed2 and Ed4) algorithms are compared with ground-based retrievals at the Atmospheric Radiation Measurement North Slope of Alaska (ARM NSA) site at Barrow, AK, during the period from March 2000 to December 2006. A total of 206 and 140 snow-free cases (Rsfc ≤ 0.3), and 108 and 106 snow cases (Rsfc > 0.3), respectively, were selected from Terra and Aqua satellite passes over the ARM NSA site. The CERES Ed4 and Ed2 optical depth (τ) and liquid water path (LWP) retrievals from both Terra and Aqua are almost identical and have excellent agreement with ARM retrievals under snow-free and snow conditions. In order to reach a radiation closure study for both the surface and top of atmosphere (TOA) radiation budgets, the ARM precision spectral pyranometer-measured surface albedos were adjusted (63.6% and 80% of the ARM surface albedos for snow-free and snow cases, respectively) to account for the water and land components of the domain of 30 km × 30 km. Most of the radiative transfer model calculated SW↓sfc and SW↑TOA fluxes by using ARM and CERES cloud retrievals and the domain mean albedos as input agree with the ARM and CERES flux observations within 10 W m-2 for both snow-free and snow conditions. Sensitivity studies show that the ARM LWP and re retrievals are less dependent on solar zenith angle (SZA), but all retrieved optical depths increase with SZA.

Ocean acidification in the Meso- vs. Cenozoic: lessons from modeling about the geological expression of paleo-ocean acidification

NASA Astrophysics Data System (ADS)

Greene, S. E.; Ridgwell, A.; Kirtland Turner, S.

2015-12-01

Rapid climatic and biotic events putatively associated with ocean acidification are scattered throughout the Meso-Cenozoic. Many of these rapid perturbations, variably referred to as hyperthermals (Paleogene) and oceanic anoxic events or mass extinction events (Mesozoic), share a number of characteristic features, including some combination of negative carbon isotopic excursion, global warming, and a rise in atmospheric CO2 concentration. Comparisons between ocean acidification events over the last ~250 Ma are, however, problematic because the types of marine geological archives and carbon reservoirs that can be interrogated are fundamentally different for early Mesozoic vs. late Mesozoic-Cenozoic events. Many Mesozoic events are known primarily or exclusively from geological outcrops of relatively shallow water deposits, whereas the more recent Paleogene hyperthermal events have been chiefly identified from deep sea records. In addition, these earlier events are superimposed on an ocean with a fundamentally different carbonate buffering capacity, as calcifying plankton (which created the deep-sea carbonate sink) originate in the mid-Mesozoic. Here, we use both Earth system modeling and reaction transport sediment modeling to explore the ways in which comparable ocean acidification-inducing climate perturbations might manifest in the Mesozoic vs. the Cenozoic geological record. We examine the role of the deep-sea carbonate sink in the expression of ocean acidification, as well as the spatial heterogeneity of surface ocean pH and carbonate saturation state. These results critically inform interpretations of ocean acidification prior to the mid-Mesozoic advent of calcifying plankton and expectations about the recording of these events in geological outcrop.

Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

PubMed

Pham, M K; van Beek, P; Carvalho, F P; Chamizo, E; Degering, D; Engeler, C; Gascó, C; Gurriaran, R; Hanley, O; Harms, A V; Herrmann, J; Hult, M; Ikeuchi, Y; Ilchmann, C; Kanisch, G; Kis-Benedek, G; Kloster, M; Laubenstein, M; Llaurado, M; Mas, J L; Nakano, M; Nielsen, S P; Osvath, I; Povinec, P P; Rieth, U; Schikowski, J; Smedley, P A; Suplinska, M; Sýkora, I; Tarjan, S; Varga, B; Vasileva, E; Zalewska, T; Zhou, W

2016-03-01

The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improved Climate Simulations through a Stochastic Parameterization of Ocean Eddies

NASA Astrophysics Data System (ADS)

Williams, Paul; Howe, Nicola; Gregory, Jonathan; Smith, Robin; Joshi, Manoj

2016-04-01

In climate simulations, the impacts of the sub-grid scales on the resolved scales are conventionally represented using deterministic closure schemes, which assume that the impacts are uniquely determined by the resolved scales. Stochastic parameterization relaxes this assumption, by sampling the sub-grid variability in a computationally inexpensive manner. This presentation shows that the simulated climatological state of the ocean is improved in many respects by implementing a simple stochastic parameterization of ocean eddies into a coupled atmosphere-ocean general circulation model. Simulations from a high-resolution, eddy-permitting ocean model are used to calculate the eddy statistics needed to inject realistic stochastic noise into a low-resolution, non-eddy-permitting version of the same model. A suite of four stochastic experiments is then run to test the sensitivity of the simulated climate to the noise definition, by varying the noise amplitude and decorrelation time within reasonable limits. The addition of zero-mean noise to the ocean temperature tendency is found to have a non-zero effect on the mean climate. Specifically, in terms of the ocean temperature and salinity fields both at the surface and at depth, the noise reduces many of the biases in the low-resolution model and causes it to more closely resemble the high-resolution model. The variability of the strength of the global ocean thermohaline circulation is also improved. It is concluded that stochastic ocean perturbations can yield reductions in climate model error that are comparable to those obtained by refining the resolution, but without the increased computational cost. Therefore, stochastic parameterizations of ocean eddies have the potential to significantly improve climate simulations. Reference PD Williams, NJ Howe, JM Gregory, RS Smith, and MM Joshi (2016) Improved Climate Simulations through a Stochastic Parameterization of Ocean Eddies. Journal of Climate, under revision.

Automated segmentation of intraretinal layers from macular optical coherence tomography images

NASA Astrophysics Data System (ADS)

Haeker, Mona; Sonka, Milan; Kardon, Randy; Shah, Vinay A.; Wu, Xiaodong; Abràmoff, Michael D.

2007-03-01

Commercially-available optical coherence tomography (OCT) systems (e.g., Stratus OCT-3) only segment and provide thickness measurements for the total retina on scans of the macula. Since each intraretinal layer may be affected differently by disease, it is desirable to quantify the properties of each layer separately. Thus, we have developed an automated segmentation approach for the separation of the retina on (anisotropic) 3-D macular OCT scans into five layers. Each macular series consisted of six linear radial scans centered at the fovea. Repeated series (up to six, when available) were acquired for each eye and were first registered and averaged together, resulting in a composite image for each angular location. The six surfaces defining the five layers were then found on each 3-D composite image series by transforming the segmentation task into that of finding a minimum-cost closed set in a geometric graph constructed from edge/regional information and a priori-determined surface smoothness and interaction constraints. The method was applied to the macular OCT scans of 12 patients with unilateral anterior ischemic optic neuropathy (corresponding to 24 3-D composite image series). The boundaries were independently defined by two human experts on one raw scan of each eye. Using the average of the experts' tracings as a reference standard resulted in an overall mean unsigned border positioning error of 6.7 +/- 4.0 μm, with five of the six surfaces showing significantly lower mean errors than those computed between the two observers (p < 0.05, pixel size of 50 × 2 μm).

Risk Quantification for Sustaining Coastal Military Installation Asset and Mission Capabilities (RC-1701)

DTIC Science & Technology

2014-06-06

al. 2012, and references therein). The world’s oceans have an en01m ous capacity to store this heat , but the result is ocean wruming and all the...TC96 wind model computes surface stress and average wind speed and direction in the PBL of a tropical cyclone. The model inputs are meteorological...is the effective earth elasticity factor; τs,winds and τs,waves are surface stresses due to winds and waves, respectively; τb is bottom stress ; M

Clouds and Open Ocean near the Bahamas

NASA Image and Video Library

1982-07-04

STS004-41-1206 (27 June-4July 1982) --- Sunglint reflects off the water of the North Atlantic Ocean in an area to the east of the Bahamas Islands sometimes called the Sargasso Sea. The area has also been referred to as the ?Bermuda Triangle.? Astronauts Thomas K. Mattingly II, STS-4 commander, and Henry W. Hartsfield Jr., pilot, spent seven days and one hour aboard the Earth-orbiting space shuttle Columbia and performed a variety of duties in addition to those of recording 70mm and 35mm imagery. Photo credit: NASA

Gulf of the Farallones and Cordell Bank National Marine Sanctuaries Boundary Modification and Protection Act

THOMAS, 112th Congress

Rep. Woolsey, Lynn C. [D-CA-6

2011-01-05

House - 01/26/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Appendix.

ERIC Educational Resources Information Center

NatureScope, 1988

1988-01-01

Provides a glossary and bibliography which includes a listing of the following: general reference books, field guides, children's books, films, filmstrips, slides, videos, coloring books, games, posters, software, activity sources, where to get more information, Ranger Rick Ocean Index, and a metric conversion chart. (RT)

30 CFR 285.825 - When must I assess my facilities?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 285.825 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT... CONTINENTAL SHELF Environmental and Safety Management, Inspections, and Facility Assessments for Activities... and Constructing Fixed Offshore Platforms—Working Stress Design (incorporated by reference, as...

A bill to establish the National Endowment for the Oceans, and for other purposes.

THOMAS, 112th Congress

Sen. Whitehouse, Sheldon [D-RI

2011-12-14

Senate - 12/14/2011 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Mixing and Transport.

ERIC Educational Resources Information Center

Ditmars, John D.

1978-01-01

Presents a literature review of longitudinal dispersion, mixing and transport in streams, rivers, lakes, reservoirs, estuaries, and oceans. This review covers also: (1) fluid-solid mixtures and (2) oil spill behavior. A list of 189 references published in 1976 and 1977 is presented. (HM)

Sludge Treatment, Utilization, and Disposal.

ERIC Educational Resources Information Center

Dick, Richard I.

1978-01-01

Presents the 1978 literature review of wastewater treatment. This review covers such areas: (1) industrial and hazardous sludges; (2) chemical sludges; (3) stabilization and combustion; (4) ocean disposal; and (5) land application. A list of 411 references is also presented. (HM)

Low Clouds and Fog Characterization over Iberian Peninsula using Meteosat Second Generation Images

NASA Astrophysics Data System (ADS)

Sánchez, Beatriz; Maqueda, Gregorio

2014-05-01

Fog is defined as a collection of suspended water droplets or ice crystals in the air near the Earth's surface that lead to a reduction of horizontal visibility below 1 km (National Oceanic and Atmospheric Administration, 1995). Fog is a stratiform cloud with similar radiative characteristics, for this reason the difference between fog and low stratus clouds is of little importance for remote sensing applications. Fog and low clouds are important atmospheric phenomena, mainly because of their impact on traffic safety and air quality, acting as an obstruction to traffic at land, sea and in the air. The purpose of this work is to develop the method of fog/low clouds detection and analysis on nighttime using Meteosat Second Generation data. This study is focused on the characterization of these atmospheric phenomena in different study cases over the Iberian Peninsula with distinct orography. Firstly, fog/low clouds detection is implemented as a composition of three infrared channels 12.0, 10.8 and 3.9 µm from SEVIRI radiometer on board European geostationary satellite Meteosat (Meteosat-9). The algorithm of detection makes use of a combination of these channels and their differences by creating RGB composites images. On this way, it displays the spatial coverage and location of fog entities. Secondly, this technique allows separating pixels which are indicated as fog/low clouds from clear pixels, assessing the properties of individual pixels using appropriated thresholds of brightness temperature. Thus, it achieves a full analysis of the extent and distribution of fog and its evolution over time. The results of this study have been checked by using ground-based point measurements available as METAR data. Despite the flaws in this sort of inter-comparison approach, the outcome produces to accurate fog/low clouds detection. This work encompasses the way to obtain spatial information from this atmospheric phenomenon by means of satellite imagery.

Automated cloud classification with a fuzzy logic expert system

NASA Technical Reports Server (NTRS)

Tovinkere, Vasanth; Baum, Bryan A.

1993-01-01

An unresolved problem in current cloud retrieval algorithms concerns the analysis of scenes containing overlapping cloud layers. Cloud parameterizations are very important both in global climate models and in studies of the Earth's radiation budget. Most cloud retrieval schemes, such as the bispectral method used by the International Satellite Cloud Climatology Project (ISCCP), have no way of determining whether overlapping cloud layers exist in any group of satellite pixels. One promising method uses fuzzy logic to determine whether mixed cloud and/or surface types exist within a group of pixels, such as cirrus, land, and water, or cirrus and stratus. When two or more class types are present, fuzzy logic uses membership values to assign the group of pixels partially to the different class types. The strength of fuzzy logic lies in its ability to work with patterns that may include more than one class, facilitating greater information extraction from satellite radiometric data. The development of the fuzzy logic rule-based expert system involves training the fuzzy classifier with spectral and textural features calculated from accurately labeled 32x32 regions of Advanced Very High Resolution Radiometer (AVHRR) 1.1-km data. The spectral data consists of AVHRR channels 1 (0.55-0.68 mu m), 2 (0.725-1.1 mu m), 3 (3.55-3.93 mu m), 4 (10.5-11.5 mu m), and 5 (11.5-12.5 mu m), which include visible, near-infrared, and infrared window regions. The textural features are based on the gray level difference vector (GLDV) method. A sophisticated new interactive visual image Classification System (IVICS) is used to label samples chosen from scenes collected during the FIRE IFO II. The training samples are chosen from predefined classes, chosen to be ocean, land, unbroken stratiform, broken stratiform, and cirrus. The November 28, 1991 NOAA overpasses contain complex multilevel cloud situations ideal for training and validating the fuzzy logic expert system.

A Reference Section through the Lower Fast-spreading Oceanic Crust in the Wadi Gideah (Sumail ophiolite, Sultanate Oman): Drill Sites GT1A and GT2A within the ICDP Oman Drilling Project

NASA Astrophysics Data System (ADS)

Mueller, S.; Koepke, J.; Garbe-Schoenberg, C. D.; Müller, T.; Mock, D.; Strauss, H.; Schuth, S.; Ildefonse, B.

2017-12-01

In the absence of a complete profile through fast-spreading oceanic crust in modern oceans, we established a reference profile through the whole paleocrust of the Sumail Ophiolite (Oman), which is regarded as the best analogue for fast-spreading oceanic crust on land. For establishing a coherent data set, we sampled the Wadi Gideah in the Wadi-Tayin massif from the mantle section up to the pillow basalts and performed different analytical and structural investigations on the same suite of samples (pool sample concept). The whole sample set contains about 400 samples focusing on both primary magmatic rocks and hydrothermal fault zones to characterize initial formation processes and cooling of the crust. The Wadi Gideah hosts the sites GT1A (lower crust) and GT2A (foliated / layered gabbro transition) where 400 m long cores have been drilled in the frame of the ICDP Oman Drilling Project (OmanDP). Thus, the Wadi Gideah crustal transect is well-suited for providing a reference frame for these two drill cores. Major and trace element data on minerals and rocks reveal in-situ crystallization in the deep crust, thus strongly supporting a hybrid accretion model that is characterized by sheeted sill intrusion in the lower part of the plutonic crust and gabbro glacier features in the upper section. This hybrid model is also supported by results on crystallographic preferred orientations (CPO) of the minerals within the gabbros, which call for distinct formation mechanisms in the upper and lower gabbro sections. A requirement for our hybrid model is significant hydrothermal cooling in the lower crust for the consumption of the latent heat of crystallization. This was facilitated by channelled hydrothermal flow zones, preserved today in faulted zones of extensively altered gabbro cutting both layered and foliated gabbros. These gabbros show higher Sr87/Sr86 ratios if compared to the background gabbro, the presence of late stage minerals (amphibole, oxides, orthopyroxene, apatite) and evidence for hydrous partial melting, as consequence of fluid / rock interaction at very high temperatures. Obviously, these fault zones remained active for channelled fluid flow during the entire cooling stage of the oceanic crust down to low-temperature mineral assemblages.

Inter comparison of Tropical Indian Ocean features in different ocean reanalysis products

NASA Astrophysics Data System (ADS)

Karmakar, Ananya; Parekh, Anant; Chowdary, J. S.; Gnanaseelan, C.

2017-09-01

This study makes an inter comparison of ocean state of the Tropical Indian Ocean (TIO) in different ocean reanalyses such as global ocean data assimilation system (GODAS), ensemble coupled data assimilation (ECDA), ocean reanalysis system 4 (ORAS4) and simple ocean data assimilation (SODA) with reference to the in-situ buoy observations, satellite observed sea surface temperature (SST), EN4 analysis and ocean 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 Ocean (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 ocean stability in the TIO, underestimation of surface current in the EIO, overestimation of vertical shear of current and improper variability in different oceanic variables. To improve the skill of reanalyses over the TIO, salinity vertical structure and upper ocean circulation need to be better represented in reanalyses.

Reflectivities of uniform and broken marine stratiform clouds

NASA Technical Reports Server (NTRS)

Coakley, James A., Jr.

1990-01-01

Plane-parallel radiative transfer models are often used to estimate the effects of clouds on the earth's energy budget and to retrieve cloud properties from satellite observations. An attempt is made to assess the performance of such models by using AVHRR data collected during the FIRE MARINE Stratus IFO to determine the reflectivities and, in particular, the anisotropy of the reflected radiances for the clouds observed during the field experiment. The intent is to determine the anisotropy for conditions that are overcast and to compare this anisotropy with that produced by the same cloud when broken. The observations are used to quantify aspects of the differences between reflection by plane-parallel clouds and non-planar clouds expected on the basis of theoretical studies.

Usher syndrome in Puerto Rico: a clinical and genetic study.

PubMed

Colón-Casasnovas, Jaime E; Izquierdo, Natalio J; Millán, Jose M

2010-01-01

To evaluate patients with the Usher syn drome in Puerto Rico. Three patients with the Usher syndrome underwent an ophthalmic and audiologic evaluation; and genetic linkage analysis. All patients were legally blind based on visual acuity and visual field results. Two patients had macular edema as shown on Stratus OCT. All patients had moderate hearing loss as part of the syndrome. A patient, and two family members had three mutations leading to protein changes including: p.S4588Y; p.Y4505C; and p.14474M. Phenotypic findings in patients with the Usher syndrome in Puerto Rico are similar to those previously reported. However, to our knowledge, neither these mutations nor OCT findings have been previously described in patients with the syndrome.

Central Andes mountains, Chile/Argentina as seen from STS-67

NASA Technical Reports Server (NTRS)

1995-01-01

The Chilean coastline and the arid Atacama Desert stretch the length of the view with the high Andes on the eastern margin where hundreds of volcanoes dot the landscape. The wider (250-350 kilometers) Altiplano ('plains') sector of the Andes appears in the top half of the view, and the narrow (120 kilometers) 'mountain-chain-dominated' sector to the bottom. The northern half of Chile can be seen, with the 'hammer-head' peninsula at the city of Antofagasta, top left. Up welling of cold water as the Humboldt Current immediately offshore gives rise to low stratus cloud. The extensive cloud mass on the right lies beyond the Andes in the low country of Argentina's 'pampas' grasslands and Chaco semi-desert.

The Specific Features of Pollution Transport in the Northwest Pacific Ocean

NASA Astrophysics Data System (ADS)

Diansky, Nikolay; Fomin, Vladimir; Gusev, Anatoly

2013-04-01

Two calculations of pollutant dispersal in the Northwest Pacific Ocean are presented: (1) during possible shipwrecks in the process of spent nuclear fuel transportation from Petropavlovsk-Kamchatsky and (2) pollutant spread from the Japanese coast after the Fukushima 1 nuclear disaster on March 11, 2011. The circulation was simulated using a σ - coordinate ocean model INMOM (Institute of Numerical Mathematics Ocean Model) developed at the INM RAS. The INMOM is based on the primitive equations using the spherical σ - coordinate system with a free ocean surface. The INMOM was realized for the Pacific Ocean basin from the equator to the Bering Strait with a high 1/8° spatial resolution for reproducing the mesoscale ocean variability. The pollutant dispersal in the case of possible shipwrecks was estimated for currents for a statistically average year with atmospheric forcing from Common Ocean-ice Reference Experiments (CORE) for normal year data. The pollution spread from the Fukushima 1 nuclear power plant (NPP) was estimated for currents calculated with the real atmospheric forcing in accordance with the NCEP GFS (0.5 degree grid). The simulation period of pollutant dispersal from Fukushima 1 was 17 days: from March 11 to 28, 2011. The results of numerical simulation show that pollutant dispersal from the Fukushima 1 spread eastward according to the Kuroshio. Moreover, exceeding of natural background radiation level was simulated in the narrow region of the Japanese coast with width of less than 50 km.

Flagging optically shallow pixels for improved analysis of ocean color data

NASA Astrophysics Data System (ADS)

McKinna, L. I. W.; Werdell, J.; Knowles, D., Jr.

2016-02-01

Ocean color remote-sensing is routinely used to derive marine geophysical parameters from sensor-observed water-leaving radiances. However, in clear geometrically shallow regions, traditional ocean color algorithms can be confounded by light reflected from the seafloor. Such regions are typically referred to as "optically shallow". When performing spatiotemporal analyses of ocean color datasets, optically shallow features such as coral reefs can lead to unexpected regional biases. Benthic contamination of the water-leaving radiance is dependent on bathymetry, water clarity and seafloor albedo. Thus, a prototype ocean color processing flag called OPTSHAL has been developed that takes all three variables into account. In the method described here, the optical depth of the water column at 547 nm, ζ(547), is predicted from known bathymetry and estimated inherent optical properties. If ζ(547) is less then the pre-defined threshold, a pixel is flagged as optically shallow. Radiative transfer modeling was used to identify the appropriate threshold value of ζ(547) for a generic benthic sand albedo. OPTSHAL has been evaluated within the NASA Ocean Biology Processing Group's L2GEN code. Using MODIS Aqua imagery, OPTSHAL was tested in two regions: (i) the Pedro Bank south-west of Jamaica, and (ii) the Great Barrier Reef, Australia. It is anticipated that OPTSHAL will benefit end-users when quality controlling derived ocean color products. Further, OPTSHAL may prove useful as a mechanism for switching between optically deep and shallow algorithms during ocean color processing.

Regimes for the ocean, outer space, and weather

NASA Technical Reports Server (NTRS)

Brown, S.; Cornell, N. W.; Fabian, L. L.; Weiss, E. B.

1977-01-01

The allocation of resources among users of the oceans, outer space and the weather is discussed. Attention is given to the international management of maritime navigation, the control of fisheries, offshore oil and gas exploitation, mineral exploitation in the deep seabed (especially the mining of manganese nodules), and the regulation of oceanographic studies. The management of outer space is considered, with special reference to remote sensing by satellites, television broadcasting, the technical requirements of maritime satellites, and problems associated with satellite frequency and orbit allocation. Rainmaking and typhoon modification, as well as the distribution of weather modification capabilities in the world, are also mentioned. The United Nations, international agencies and tribunals, and multi- or bilateral agreements are some of the implements suggested for use in the regulation of the oceans, outer space and the weather.

Estimation of mean sea surfaces in the North Atlantic, the Pacific and the Indian Ocean using GEOS-3 altimeter data

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Martin, T. V.; Mccarthy, J. J.; Chovitz, P. J.

1979-01-01

The sea surface heights above the reference ellipsoid were determined for several regions of the world's ocean using data from the radar altimeter on board the GEOS-3 satellite in conjunction with precise orbital position information derived from laser data. The resolution of the estimated sea surfaces varied from 0.25 degrees off the east coast of the United States to about 2 degrees in the Indian Ocean near Australia. The rms crossover discrepancy after adjustment varied from 30 cm to 70 cm depending on geographic location. Comparison of the altimeter derived mean sea surface in the North Atlantic with the 5 x 5 ft GEM-8 detailed gravimetric geoid indicated a relative consistency of better than one meter.

Ecological evaluation of proposed dredged material from St. Andrew Bay, Florida

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

Mayhew, H.L.; Word, J.Q.; Kohn, N.P.

1993-10-01

The US Army Corps of Engineers (USACE), Mobile District, requested that the Battelle/Marine Sciences Laboratory (MSL) conduct field sampling and chemical and biological testing to determine the suitability of potential dredged material for open ocean disposal. Sediment from St. Andrew Bay was chemically characterized and evaluated for biological toxicity and bioaccumulation of contaminants. The Tier III guidance for ocean disposal testing requires tests of water column effects (following dredged material disposal), deposited sediment toxicity, and bioaccumulation of contaminants from deposited sediment (dredged material). To meet these requirements, the MSL conducted suspended-particulate-phase (SPP) toxicity tests, solid-phase toxicity tests, and bioaccumulation testingmore » on sediment representing potential dredged material from Panama City Harbor. Physical and chemical characterization of sediment to support toxicity and bioaccumulation results was also conducted on both the test and reference sediments. The MSL collected sediment samples from five sites in St. Andrew Bay and one reference site near Lands End Peninsula. The five test sediments and the reference sediment were analyzed for physical and chemical sediment characteristics, SPP chemical contaminants, solid-phase toxicity, SPP toxicity, and bioaccumulation of contaminants.« less

Ship Noise in the SW Indian Ocean Recorded by Ocean Bottom Seismic and Hydroacoustic Sensors

NASA Astrophysics Data System (ADS)

Barruol, G.; Dreo, R.; Fontaine, F. R.; Scholz, J. R.; Sigloch, K.

2016-12-01

In the frame of the RHUM-RUM project (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel, www.rhum-rum.net), a network of 57 ocean-bottom seismometers (OBS) has been installed on the ocean floor around La Réunion Island, but also on the neighbouring Southwest and Central Indian Ridges. The OBS were equipped by wide- and broad-band three-components seismic and hydroacoustic sensors. They were deployed in Nov. 2012, and depending on the configuration, they recorded for 8 to 13 months. Interestingly, part of the network was located beneath a NE-SW trending lane of very dense ship traffic connecting SE-Asia and the South-Atlantic region. By combining the vessel position - provided by AIS GPS data - and our geophysical data recorded on the ocean floor, we analyze the seismic and hydroacoustic ship signatures. From spectral analyzes, we show clear signals over the whole high-frequency range available from our instruments (between 1 and 50 Hz). The RHUM-RUM network covering latitude between 17 and 34° South, this allows to detect numerous vessels and to compare the noise characteristics (frequency content, polarization) of each vessel. We also investigate the possibility of using the polarization of the noise emitted by ships passing above an ocean-bottom seismometer, to help retrieving the orientation of the OBS horizontal components on the ocean floor in the geographic reference frame.

OMIP contribution to CMIP6: experimental and diagnostic protocol for the physical component of the Ocean Model Intercomparison Project

NASA Astrophysics Data System (ADS)

Griffies, Stephen M.; Danabasoglu, Gokhan; Durack, Paul J.; Adcroft, Alistair J.; Balaji, V.; Böning, Claus W.; Chassignet, Eric P.; Curchitser, Enrique; Deshayes, Julie; Drange, Helge; Fox-Kemper, Baylor; Gleckler, Peter J.; Gregory, Jonathan M.; Haak, Helmuth; Hallberg, Robert W.; Heimbach, Patrick; Hewitt, Helene T.; Holland, David M.; Ilyina, Tatiana; Jungclaus, Johann H.; Komuro, Yoshiki; Krasting, John P.; Large, William G.; Marsland, Simon J.; Masina, Simona; McDougall, Trevor J.; Nurser, A. J. George; Orr, James C.; Pirani, Anna; Qiao, Fangli; Stouffer, Ronald J.; Taylor, Karl E.; Treguier, Anne Marie; Tsujino, Hiroyuki; Uotila, Petteri; Valdivieso, Maria; Wang, Qiang; Winton, Michael; Yeager, Stephen G.

2016-09-01

The Ocean Model Intercomparison Project (OMIP) is an endorsed project in the Coupled Model Intercomparison Project Phase 6 (CMIP6). OMIP addresses CMIP6 science questions, investigating the origins and consequences of systematic model biases. It does so by providing a framework for evaluating (including assessment of systematic biases), understanding, and improving ocean, sea-ice, tracer, and biogeochemical components of climate and earth system models contributing to CMIP6. Among the WCRP Grand Challenges in climate science (GCs), OMIP primarily contributes to the regional sea level change and near-term (climate/decadal) prediction GCs.OMIP provides (a) an experimental protocol for global ocean/sea-ice models run with a prescribed atmospheric forcing; and (b) a protocol for ocean diagnostics to be saved as part of CMIP6. We focus here on the physical component of OMIP, with a companion paper (Orr et al., 2016) detailing methods for the inert chemistry and interactive biogeochemistry. The physical portion of the OMIP experimental protocol follows the interannual Coordinated Ocean-ice Reference Experiments (CORE-II). Since 2009, CORE-I (Normal Year Forcing) and CORE-II (Interannual Forcing) have become the standard methods to evaluate global ocean/sea-ice simulations and to examine mechanisms for forced ocean climate variability. The OMIP diagnostic protocol is relevant for any ocean model component of CMIP6, including the DECK (Diagnostic, Evaluation and Characterization of Klima experiments), historical simulations, FAFMIP (Flux Anomaly Forced MIP), C4MIP (Coupled Carbon Cycle Climate MIP), DAMIP (Detection and Attribution MIP), DCPP (Decadal Climate Prediction Project), ScenarioMIP, HighResMIP (High Resolution MIP), as well as the ocean/sea-ice OMIP simulations.

Evaluation of radiative fluxes over the north Indian Ocean

NASA Astrophysics Data System (ADS)

Ramesh Kumar, M. R.; Pinker, Rachel T.; Mathew, Simi; Venkatesan, R.; Chen, W.

2018-05-01

Radiative fluxes are a key component of the surface heat budget of the oceans. Yet, observations over oceanic region are sparse due to the complexity of radiation measurements; moreover, certain oceanic regions are substantially under-sampled, such as the north Indian Ocean. The National Institute of Ocean Technology, Chennai, India, under its Ocean Observation Program has deployed an Ocean Moored Network for the Northern Indian Ocean (OMNI) both in the Arabian Sea and the Bay of Bengal. These buoys are equipped with sensors to measure radiation and rainfall, in addition to other basic meteorological parameters. They are also equipped with sensors to measure sub-surface currents, temperature, and conductivity from the surface up to a depth of 500 m. Observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the National Aeronautics and Space Administration (NASA) AQUA and TERRA satellites have been used to infer surface radiation over the north Indian Ocean. In this study, we focus only on the shortwave (SW↓) fluxes. The evaluations of the MODIS-based SW↓ fluxes against the RAMA observing network have shown a very good agreement between them, and therefore, we use the MODIS-derived fluxes as a reference for the evaluation of the OMNI observations. In an early deployment of the OMNI buoys, the radiation sensors were placed at 2 m above the sea surface; subsequently, the height of the sensors was raised to 3 m. In this study, we show that there was a substantial improvement in the agreement between the buoy observations and the satellite estimates, once the sensors were raised to higher levels. The correlation coefficient increased from 0.87 to 0.93, and both the bias and standard deviations decreased substantially.

Supplemental Information Letter from RA to EPA HQ - signed March 10, 2003

EPA Pesticide Factsheets

Memorandum referring to a decision to issue a permit authorizing the Virginia Seafood Council's proposal to introduce up to a million non-native, triploid Surninoe oysters into the waters of the Chesapeake Bay and Atlantic Ocean.

To revise the boundaries of the John H. Chafee Coastal Barrier System Saddlebunch Keys Unit FL-57.

THOMAS, 112th Congress

Rep. Ros-Lehtinen, Ileana [R-FL-18

2012-09-14

House - 09/21/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To correct the boundaries of the John H. Chafee Coastal Barrier Resources System Unit P-31P.

THOMAS, 112th Congress

Rep. Southerland, Steve II [R-FL-2

2012-08-02

House - 08/16/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

NASA Oceanic Processes Program

NASA Technical Reports Server (NTRS)

1988-01-01

An overview of the recent accomplishments, present activities, and future plans is provided. Sections following the introduction provides summaries of current flight projects and definition studies, brief descriptions of individual research activities, and a bibliography of referred Journal Articles appearing within the last three years.

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... satisfies the National Fire Protection Association (NFPA) Standard 2001 (incorporated by reference in § 27... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

46 CFR 27.101 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS TOWING VESSELS General Provisions for Fire-Protection... satisfies the National Fire Protection Association (NFPA) Standard 2001 (incorporated by reference in § 27... or coastal service. Towing vessel in ocean or coastal service means a towing vessel that operates...

To convey certain submerged lands to the Government of the Virgin Islands, and for other purposes.

THOMAS, 112th Congress

Rep. Christensen, Donna M. [D-VI-At Large

2011-02-09

House - 02/14/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Precise GPS/Acoustic Positioning of Seafloor Reference Points for Tectonic Studies

NASA Technical Reports Server (NTRS)

Spiess, F. N.; Chadwell, C.; Hildebrand, J. A.; Young, L. E.; Purcell, G. H., Jr.; Dragert, H.

1998-01-01

Global networks for crustal strain measurement provide important constraints for studies of tectonic plate motion and deformation. To date, crustal strain measurements have been possible only in terrestrial settings: on continental plates and island sites within oceanic plates.

To remove from the John H. Chafee Coastal Barrier Resources System certain properties in North Carolina.

THOMAS, 113th Congress

Rep. McIntyre, Mike [D-NC-7

2013-06-06

House - 06/13/2013 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To correct the boundaries of the John H. Chafee Coastal Barrier Resources System Unit P17.

THOMAS, 112th Congress

Rep. Mack, Connie [R-FL-14

2011-06-13

House - 06/15/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To correct the boundaries of the John H. Chafee Coastal Barrier Resources System Unit P16.

THOMAS, 112th Congress

Rep. Mack, Connie [R-FL-14

2011-06-13

House - 06/15/2011 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Delineating ecologically significant taxonomic units from global patterns of marine picocyanobacteria

PubMed Central

Farrant, Gregory K.; Doré, Hugo; Cornejo-Castillo, Francisco M.; Partensky, Frédéric; Ratin, Morgane; Ostrowski, Martin; Pitt, Frances D.; Wincker, Patrick; Scanlan, David J.; Iudicone, Daniele; Acinas, Silvia G.; Garczarek, Laurence

2016-01-01

Prochlorococcus and Synechococcus are the two most abundant and widespread phytoplankton in the global ocean. To better understand the factors controlling their biogeography, a reference database of the high-resolution taxonomic marker petB, encoding cytochrome b6, was used to recruit reads out of 109 metagenomes from the Tara Oceans expedition. An unsuspected novel genetic diversity was unveiled within both genera, even for the most abundant and well-characterized clades, and 136 divergent petB sequences were successfully assembled from metagenomic reads, significantly enriching the reference database. We then defined Ecologically Significant Taxonomic Units (ESTUs)—that is, organisms belonging to the same clade and occupying a common oceanic niche. Three major ESTU assemblages were identified along the cruise transect for Prochlorococcus and eight for Synechococcus. Although Prochlorococcus HLIIIA and HLIVA ESTUs codominated in iron-depleted areas of the Pacific Ocean, CRD1 and the yet-to-be cultured EnvB were the prevalent Synechococcus clades in this area, with three different CRD1 and EnvB ESTUs occupying distinct ecological niches with regard to iron availability and temperature. Sharp community shifts were also observed over short geographic distances—for example, around the Marquesas Islands or between southern Indian and Atlantic Oceans—pointing to a tight correlation between ESTU assemblages and specific physico-chemical parameters. Together, this study demonstrates that there is a previously overlooked, ecologically meaningful, fine-scale diversity within some currently defined picocyanobacterial ecotypes, bringing novel insights into the ecology, diversity, and biology of the two most abundant phototrophs on Earth. PMID:27302952

Potential benefits to fisheries and biodiversity of the Chagos Archipelago/British Indian Ocean Territory as a no-take marine reserve.

PubMed

Koldewey, Heather J; Curnick, David; Harding, Simon; Harrison, Lucy R; Gollock, Matthew

2010-11-01

On 1st April 2010, the British Government announced designation of the British Indian Ocean Territory--or Chagos Archipelago--as the world's largest marine protected area (MPA). This near pristine ocean ecosystem now represents 16% of the worlds fully protected coral reef, 60% of the world's no-take protected areas and an uncontaminated reference site for ecological studies. In addition these gains for biodiversity conservation, the Chagos/BIOT MPA also offers subsidiary opportunities to act as a fisheries management tool for the western Indian Ocean, considering its size and location. While the benefits of MPAs for coral-reef dwelling species are established, there is uncertainty about their effects on pelagic migratory species. This paper reviews the increasing body of evidence to demonstrate that positive, measurable reserve effects exist for pelagic populations and that migratory species can benefit from no-take marine reserves. Copyright © 2010 Elsevier Ltd. All rights reserved.

Investigating the Effects of Variable Water Type for VIIRS Calibration

NASA Astrophysics Data System (ADS)

Bowers, J.; Ladner, S.; Martinolich, P.; Arnone, R.; Lawson, A.; Crout, R. L.; Vandermeulen, R. A.

2016-02-01

The Naval Research Laboratory - Stennis Space Center (NRL-SSC) currently provides calibration and validation support for the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite ocean color products. NRL-SSC utilizes the NASA Ocean Biology Processing Group (OBPG) methodology for on-orbit vicarious calibration with in situ data collected in blue ocean water by the Marine Optical Buoy (MOBY). An acceptable calibration consists of 20-40 satellite to in situ matchups that establish the radiance correlation at specific points within the operating range of the VIIRS instrument. While the current method improves the VIIRS performance, the MOBY data alone does not represent the full range of radiance values seen in the coastal oceans. However, by utilizing data from the AERONET-OC coastal sites we expand our calibration matchups to cover a more realistic range of continuous values particularly in the green and red spectral regions of the sensor. Improved calibration will provide more accurate data to support daily operations and enable construction of valid climatology for future reference.

Satellite Sounder Observations of Contrasting Tropospheric Moisture Transport Regimes: Saharan Air Layers, Hadley Cells, and Atmospheric Rivers

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

Nalli, Nicholas R.; Barnet, Christopher D.; Reale, Tony

This paper examines the performance of satellite sounder atmospheric vertical moisture proles (AVMP) under tropospheric conditions encompassing moisture contrasts driven by convection and advection transport mechanisms, specifically Atlantic Ocean Saharan air layers (SALs) and Pacific Ocean moisture conveyer belts (MCBs) commonly referred to as atmospheric rivers (ARs), both of these being mesoscale to synoptic meteorological phenomena within the vicinity of subtropical Hadley subsidence zones. Operational AVMP environmental data records retrieved from the Suomi National Polar-orbiting Partnership (SNPP) NOAA-Unique Combined Atmospheric Processing System (NUCAPS) are collocated with dedicated radiosonde observations (RAOBs) obtained from ocean-based intensive field campaigns; these RAOBs provide uniquelymore » independent correlative truth data not assimilated into numerical weather prediction models for satellite sounder validation over open ocean. Using these marine-based data, we empirically assess the performance of the operational NUCAPS AVMP product for detecting and resolving these tropospheric moisture features over otherwise RAOB-sparse regions.« less

FERROMANGANESE CRUST RESOURCES IN THE PACIFIC AND ATLANTIC OCEANS.

USGS Publications Warehouse

Commeau, R.F.; Clark, A.; Johnson, Chad; Manheim, F.T.; Aruscavage, P. J.; Lane, C.M.

1984-01-01

Ferromanganese crusts on raised areas of the ocean floor have joined abyssal manganese nodules and hydrothermal sulfides as potential marine resources. Significant volumes of cobalt-rich (about 1% Co) crusts have been identified to date within the US Exclusive Economic Zone (EEZ) in the Central Pacific: in the NW Hawaiian Ridge and Seamount region and in the seamounts in the Johnston Island and Palmyra Island regions. Large volumes of lower grade crusts, slabs, and nodules are also present in shallow ( greater than 1000 m) waters on the Blake plateau, off Florida-South Carolina in the Atlantic Ocean. Data on ferromanganese crusts have been increased by recent German and USGS cruises, but are still sparse, and other regions having crust potential are under current investigation. The authors discuss economic potentials for cobalt-rich crusts in the Central Pacific and Western North Atlantic oceans, with special reference to US EEZ areas. Additional research is needed before more quantitative resource estimates can be made.

Coral reefs will transition to net dissolving before end of century.

PubMed

Eyre, Bradley D; Cyronak, Tyler; Drupp, Patrick; De Carlo, Eric Heinen; Sachs, Julian P; Andersson, Andreas J

2018-02-23

Ocean acidification refers to the lowering of the ocean's pH due to the uptake of anthropogenic CO 2 from the atmosphere. Coral reef calcification is expected to decrease as the oceans become more acidic. Dissolving calcium carbonate (CaCO 3 ) sands could greatly exacerbate reef loss associated with reduced calcification but is presently poorly constrained. Here we show that CaCO 3 dissolution in reef sediments across five globally distributed sites is negatively correlated with the aragonite saturation state (Ω ar ) of overlying seawater and that CaCO 3 sediment dissolution is 10-fold more sensitive to ocean acidification than coral calcification. Consequently, reef sediments globally will transition from net precipitation to net dissolution when seawater Ω ar reaches 2.92 ± 0.16 (expected circa 2050 CE). Notably, some reefs are already experiencing net sediment dissolution. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Global distribution of naturally occurring marine hypoxia on continental margins

NASA Astrophysics Data System (ADS)

Helly, John J.; Levin, Lisa A.

2004-09-01

Hypoxia in the ocean influences biogeochemical cycling of elements, the distribution of marine species and the economic well being of many coastal countries. Previous delineations of hypoxic environments focus on those in enclosed seas where hypoxia may be exacerbated by anthropogenically induced eutrophication. Permanently hypoxic water masses in the open ocean, referred to as oxygen minimum zones, impinge on a much larger seafloor surface area along continental margins of the eastern Pacific, Indian and western Atlantic Oceans. We provide the first global quantification of naturally hypoxic continental margin floor by determining upper and lower oxygen minimum zone depth boundaries from hydrographic data and computing the area between the isobaths using seafloor topography. This approach reveals that there are over one million km 2 of permanently hypoxic shelf and bathyal sea floor, where dissolved oxygen is <0.5 ml l -1; over half (59%) occurs in the northern Indian Ocean. We also document strong variation in the intensity, vertical position and thickness of the OMZ as a function of latitude in the eastern Pacific Ocean and as a function of longitude in the northern Indian Ocean. Seafloor OMZs are regions of low biodiversity and are inhospitable to most commercially valuable marine resources, but support a fascinating array of protozoan and metazoan adaptations to hypoxic conditions.

Timing of Crystallisation of the Lunar Magma Ocean Constrained by the Oldest Zircon

NASA Technical Reports Server (NTRS)

Nemchin, A.; Timms, N.; Pidgeon, R.; Geisler, T.; Reddy, S.; Meyer, C.

2009-01-01

The presently favoured concept for the early evolution of the Moon involves consolidation of debris from a giant impact of a Mars sized body with Earth forming a primitive Moon with a thick global layer of melt referred to as the Lunar Magma Ocean1 . It is widely accepted that many significant features observed on the Moon today are the result of crystallisation of this magma ocean. However, controversy exists over the precise timing and duration of the crystallisation process. Resolution of this problem depends on the establishment of precise and robust key crystallisation time points. We report a 4417 6 Myr old zircon in lunar breccia sample 72215,195, which provides a precisely determined younger limit for the solidification of the Lunar Magma Ocean. A model based on these data, together with the age of the Moon forming giant impact, defines an exponential time frame for crystallisation and suggests formation of anorthositic crust after about 80-85% of the magma ocean was solidified. In combination with other zircon ages the 4417 +/- 6 Myr age also suggests that the very small (less than a few per cent) residual portion of the magma ocean continued to solidify during the following 300-500 m.y.

The Atlantic Multidecadal Variability in surface and deep ocean temperature and salinity fields from unperturbed climate simulations

NASA Astrophysics Data System (ADS)

Zanchettin, D.; Jungclaus, J. H.

2013-12-01

Large multidecadal fluctuations in basin-average sea-surface temperature (SST) are a known feature of observed, reconstructed and simulated variability in the North Atlantic Ocean. This phenomenon is often referred to as Multidecadal Atlantic Variability or AMV. Historical AMV fluctuations are associated with analog basin-scale changes in sea-surface salinity, so that warming corresponds to salinification and cooling to freshening [Polyakov et al., 2005]. The surface imprint of the AMV further corresponds to same-sign fluctuations in the shallow ocean and with opposite-sign fluctuations in the deep ocean for both temperature and salinity [Polyakov et al., 2005]. This out-of-phase behavior reflects the thermohaline overturning circulation shaping North Atlantic's low-frequency variability. Several processes contribute to the AMV, involving both ocean-atmosphere coupled processes and deep ocean circulation [e.g., Grossmann and Klotzbach, 2009]. In particular, recirculation in the North Atlantic subpolar gyre region of salinity anomalies from Arctic freshwater export may trigger multidecadal variability in the Atlantic meridional overturning circulation, and therefore may be part of the AMV [Jungclaus et al., 2005; Dima and Lohmann, 2007]. With this contribution, we aim to improve the physical interpretation of the AMV by investigating spatial and temporal patterns of temperature and salinity fields in the shallow and deep ocean. We focus on two unperturbed millennial-scale simulations performed with the Max Planck Institute Earth system model in its paleo (MPI-ESM-P) and low-resolution (MPI-ESM-LR) configurations, which provide reference control climates for assessments of pre-industrial and historical climate simulations. The two model configurations only differ for the presence, in MPI-ESM-LR, of an active module for dynamical vegetation. We use spatial-average indices and empirical orthogonal functions/principal components to track the horizontal and vertical propagation of temperature and salinity anomalies related to the AMV. In particular, we discuss the potential predictability of multidecadal fluctuations in North Atlantic SSTs based on indices derived from the sea-surface salinity field. We show how the two simulations provide AMV realizations with some distinguishable characteristics, e.g., the typical fluctuations' frequencies and the linkage with the North Atlantic meridional overturning and gyre circulations. We further show how information gained by investigating different definitions of the AMV [Zanchettin et al., 2013] helps designing numerical sensitivity studies for understanding the mechanism(s) behind this phenomenon, concerning both its origin and global impacts. References Dima, M., and G. Lohmann [2007], J. Clim., 20, 2706-2719, doi:10.1175/JCLI4174.1 Jungclaus, J.H., et al. [2005], J. Clim., 18, 4013- 4031, doi:10.1175/JCLI3462.1 Polyakov, I. V., et al. [2005], J. Clim., 18:4562-4581 Grossmann, I., and P. J. Klotzbach [2009], J. Geophys. Res., 114, D24107, doi:10.1029/2009JD012728 Zanchettin D., et al. [2013], Clim. Dyn., doi:10.1007/s00382-013-1669-0

MODEL-BASED HYDROACOUSTIC BLOCKAGE ASSESSMENT AND DEVELOPMENT OF AN EXPLOSIVE SOURCE DATABASE

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

Matzel, E; Ramirez, A; Harben, P

2005-07-11

We are continuing the development of the Hydroacoustic Blockage Assessment Tool (HABAT) which is designed for use by analysts to predict which hydroacoustic monitoring stations can be used in discrimination analysis for any particular event. The research involves two approaches (1) model-based assessment of blockage, and (2) ground-truth data-based assessment of blockage. The tool presents the analyst with a map of the world, and plots raypath blockages from stations to sources. The analyst inputs source locations and blockage criteria, and the tool returns a list of blockage status from all source locations to all hydroacoustic stations. We are currently usingmore » the tool in an assessment of blockage criteria for simple direct-path arrivals. Hydroacoustic data, predominantly from earthquake sources, are read in and assessed for blockage at all available stations. Several measures are taken. First, can the event be observed at a station above background noise? Second, can we establish backazimuth from the station to the source. Third, how large is the decibel drop at one station relative to other stations. These observational results are then compared with model estimates to identify the best set of blockage criteria and used to create a set of blockage maps for each station. The model-based estimates are currently limited by the coarse bathymetry of existing databases and by the limitations inherent in the raytrace method. In collaboration with BBN Inc., the Hydroacoustic Coverage Assessment Model (HydroCAM) that generates the blockage files that serve as input to HABAT, is being extended to include high-resolution bathymetry databases in key areas that increase model-based blockage assessment reliability. An important aspect of this capability is to eventually include reflected T-phases where they reliably occur and to identify the associated reflectors. To assess how well any given hydroacoustic discriminant works in separating earthquake and in-water explosion populations it is necessary to have both a database of reference earthquake events and of reference in-water explosive events. Although reference earthquake events are readily available, explosive reference events are not. Consequently, building an in-water explosion reference database requires the compilation of events from many sources spanning a long period of time. We have developed a database of small implosive and explosive reference events from the 2003 Indian Ocean Cruise data. These events were recorded at some or all of the IMS Indian Ocean hydroacoustic stations: Diego Garcia, Cape Leeuwin, and Crozet Island. We have also reviewed many historical large in-water explosions and identified five that have adequate source information and can be positively associated to the hydrophone recordings. The five events are: Cannekin, Longshot, CHASE-3, CHASE-5, and IITRI-1. Of these, the first two are nuclear tests on land but near water. The latter three are in-water conventional explosive events with yields from ten to hundreds of tons TNT equivalent. The objective of this research is to enhance discrimination capabilities for events located in the world's oceans. Two research and development efforts are needed to achieve this: (1) improvement in discrimination algorithms and their joint statistical application to events, and (2) development of an automated and accurate blockage prediction capability that will identify all stations and phases (direct and reflected) from a given event that will have adequate signal to be used in a discrimination analysis. The strategy for improving blockage prediction in the world's oceans is to improve model-based prediction of blockage and to develop a ground-truth database of reference events to assess blockage. Currently, research is focused on the development of a blockage assessment software tool. The tool is envisioned to develop into a sophisticated and unifying package that optimally and automatically assesses both model and data based blockage predictions in all ocean basins, for all NDC stations, and accounting for reflected phases (Pulli et al., 2000). Currently, we have focused our efforts on the Diego Garcia, Cape Leeuwin and Crozet Island hydroacoustic stations in the Indian Ocean.« less

Revised estimates of the ocean energy cycle and the key role of the western boundary in the APE to KE conversion due to high latitude cooling

NASA Astrophysics Data System (ADS)

Tailleux, Remi

2014-05-01

The ocean energy cycle is a key aspect of the ocean circulation, and has been traditionally framed in terms of Lorenz (1955) theory of available potential energy. However, the latest available observational estimate of the ocean energy cycle is due to Oort and Peixoto (1994) and is now very dated. Moreover, the latter estimate relies on the so-called Lorenz quasi-geostrophic approximation, which is known to be very inaccurate. Oort and Peixoto also neglected the internal energy contribution to the total available potential energy, which is now understood to be far from negligible, and to account for up to 40 percent of the total APE. The purpose of this work is to revisit observational estimates of the ocean energy cycle by taking advantage of a newly developed APE framework, as well as of the many new available observational products for temperature, salinity and surface buoyancy fluxes. In contrast to previous frameworks, our APE framework (Tailleux, 2013) relies on a physically well defined local APE definition, which is valid for a binary Boussinesq or fully compressible fluid with an arbitrary nonlinear equation of state. As part of our approach, we also developed a new fast and accurate way to construct Lorenz reference state of minimum potential energy, based on using the joint probability distribution function for temperature and salinity. Results will be presented for a variety of observational products, as well as for the ECCO2 ocean state estimate. The role of the deep western boundary as the place where the APE created by high latitude is converted into kinetic energy (KE) as part of driving the Atlantic meridional overturning circulation will be emphasized. References: Tailleux, R., 2013: Available potential energy density for a multicomponent Boussinesq fluid with arbitrary nonlinear equation of state.J. Fluid Mech., 735,499-518. Sijp, W., J.M.Gregory, R. Tailleux, P. Spence, 2012: The key role of the western boundary in linking the AMOC strength to the North South pressure gradient. J. Phys. Oceanogr., 42, 628-643.

To correct the boundaries of the John H. Chafee Coastal Barrier Resources System Unit L06, Topsail, North Carolina.

THOMAS, 112th Congress

Rep. Jones, Walter B., Jr. [R-NC-3

2012-03-29

House - 04/16/2012 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Arctic Ocean Paleoceanography and Future IODP Drilling

NASA Astrophysics Data System (ADS)

Stein, Ruediger

2015-04-01

Although the Arctic Ocean is a major player in the global climate/earth system, this region is one of the last major physiographic provinces on Earth where the short- and long-term geological history is still poorly known. This lack in knowledge is mainly due to the major technological/logistical problems in operating within the permanently ice-covered Arctic region which makes it difficult to retrieve long and undisturbed sediment cores. Prior to 2004, in the central Arctic Ocean piston and gravity coring was mainly restricted to obtaining near-surface sediments, i.e., only the upper 15 m could be sampled. Thus, all studies were restricted to the late Pliocene/Quaternary time interval, with a few exceptions. These include the four short cores obtained by gravity coring from drifting ice floes over the Alpha Ridge, where older pre-Neogene organic-carbon-rich muds and laminated biosiliceous oozes were sampled. Continuous central Arctic Ocean sedimentary records, allowing a development of chronologic sequences of climate and environmental change through Cenozoic times and a comparison with global climate records, however, were missing prior to the IODP Expedition 302 (Arctic Ocean Coring Expedition - ACEX), the first scientific drilling in the central Arctic Ocean. By studying the unique ACEX sequence, a large number of scientific discoveries that describe previously unknown Arctic paleoenvironments, were obtained during the last decade (for most recent review and references see Stein et al., 2014). While these results from ACEX were unprecedented, key questions related to the climate history of the Arctic Ocean remain unanswered, in part because of poor core recovery, and in part because of the possible presence of a major mid-Cenozoic hiatus or interval of starved sedimentation within the ACEX record. In order to fill this gap in knowledge, international, multidisciplinary expeditions and projects for scientific drilling/coring in the Arctic Ocean are needed. Key areas and approaches for drilling and recovering undisturbed and complete sedimentary sequences are depth transects across the major ocean ridge systems, such as the Lomonosov Ridge. These new detailed climate records spanning time intervals from the (late Cretaceous/)Paleogene Greenhouse world to the Neogene-Quaternary Icehouse world will give new insights into our understanding of the Arctic Ocean within the global climate system and provide an opportunity to test the performance of climate models used to predict future climate change. During the Polarstern Expedition PS87 in August-September 2014, new site survey data including detailed multibeam bathymetry, multi-channel seismic and Parasound profiling as well as geological coring, were obtained on Lomonosov Ridge (Stein, 2015), being the basis for a more precise planning and update for a future IODP drilling campaign. Reference: Stein, R. (Ed.), 2015. Cruise Report of Polarstern Expedition PS87-2014 (Arctic Ocean/Lomonosov Ridge). Reps. Pol. Mar. Res., in press. Stein, R. , Weller, P. , Backman, J. , Brinkhuis, H., Moran, K. , Pälike, H., 2014. Cenozoic Arctic Ocean Climate History: Some highlights from the IODP Arctic Coring Expedition (ACEX). Developments in Marine Geology 7, Elsevier Amsterdam/New York, pp. 259-293.

Characterisation and deployment of an immobilised pH sensor spot towards surface ocean pH measurements.

PubMed

Clarke, Jennifer S; Achterberg, Eric P; Rérolle, Victoire M C; Abi Kaed Bey, Samer; Floquet, Cedric F A; Mowlem, Matthew C

2015-10-15

The oceans are a major sink for anthropogenic atmospheric carbon dioxide, and the uptake causes changes to the marine carbonate system and has wide ranging effects on flora and fauna. It is crucial to develop analytical systems that allow us to follow the increase in oceanic pCO2 and corresponding reduction in pH. Miniaturised sensor systems using immobilised fluorescence indicator spots are attractive for this purpose because of their simple design and low power requirements. The technology is increasingly used for oceanic dissolved oxygen measurements. We present a detailed method on the use of immobilised fluorescence indicator spots to determine pH in ocean waters across the pH range 7.6-8.2. We characterised temperature (-0.046 pH/°C from 5 to 25 °C) and salinity dependences (-0.01 pH/psu over 5-35), and performed a preliminary investigation into the influence of chlorophyll on the pH measurement. The apparent pKa of the sensor spots was 6.93 at 20 °C. A drift of 0.00014 R (ca. 0.0004 pH, at 25 °C, salinity 35) was observed over a 3 day period in a laboratory based drift experiment. We achieved a precision of 0.0074 pH units, and observed a drift of 0.06 pH units during a test deployment of 5 week duration in the Southern Ocean as an underway surface ocean sensor, which was corrected for using certified reference materials. The temperature and salinity dependences were accounted for with the algorithm, R=0.00034-0.17·pH+0.15·S(2)+0.0067·T-0.0084·S·1.075. This study provides a first step towards a pH optode system suitable for autonomous deployment. The use of a short duration low power illumination (LED current 0.2 mA, 5 μs illumination time) improved the lifetime and precision of the spot. Further improvements to the pH indicator spot operations include regular application of certified reference materials for drift correction and cross-calibration against a spectrophotometric pH system. Desirable future developments should involve novel fluorescence spots with improved response time and apparent pKa values closer to the pH of surface ocean waters. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

A system to measure the data quality of spectral remote-sensing reflectance of aquatic environments

NASA Astrophysics Data System (ADS)

Wei, Jianwei; Lee, Zhongping; Shang, Shaoling

2016-11-01

Spectral remote-sensing reflectance (Rrs, sr-1) is the key for ocean color retrieval of water bio-optical properties. Since Rrs from in situ and satellite systems are subject to errors or artifacts, assessment of the quality of Rrs data is critical. From a large collection of high quality in situ hyperspectral Rrs data sets, we developed a novel quality assurance (QA) system that can be used to objectively evaluate the quality of an individual Rrs spectrum. This QA scheme consists of a unique Rrs spectral reference and a score metric. The reference system includes Rrs spectra of 23 optical water types ranging from purple blue to yellow waters, with an upper and a lower bound defined for each water type. The scoring system is to compare any target Rrs spectrum with the reference and a score between 0 and 1 will be assigned to the target spectrum, with 1 for perfect Rrs spectrum and 0 for unusable Rrs spectrum. The effectiveness of this QA system is evaluated with both synthetic and in situ Rrs spectra and it is found to be robust. Further testing is performed with the NOMAD data set as well as with satellite Rrs over coastal and oceanic waters, where questionable or likely erroneous Rrs spectra are shown to be well identifiable with this QA system. Our results suggest that applications of this QA system to in situ data sets can improve the development and validation of bio-optical algorithms and its application to ocean color satellite data can improve the short-term and long-term products by objectively excluding questionable Rrs data.

Impact of idealized future stratospheric aerosol injection on the large-scale ocean and land carbon cycles

NASA Astrophysics Data System (ADS)

Tjiputra, J. F.; Grini, A.; Lee, H.

2016-01-01

Using an Earth system model, we simulate stratospheric aerosol injection (SAI) on top of the Representative Concentration Pathways 8.5 future scenario. Our idealized method prescribes aerosol concentration, linearly increasing from 2020 to 2100, and thereafter remaining constant until 2200. In the aggressive scenario, the model projects a cooling trend toward 2100 despite warming that persists in the high latitudes. Following SAI termination in 2100, a rapid global warming of 0.35 K yr-1 is simulated in the subsequent 10 years, and the global mean temperature returns to levels close to the reference state, though roughly 0.5 K cooler. In contrast to earlier findings, we show a weak response in the terrestrial carbon sink during SAI implementation in the 21st century, which we attribute to nitrogen limitation. The SAI increases the land carbon uptake in the temperate forest-, grassland-, and shrub-dominated regions. The resultant lower temperatures lead to a reduction in the heterotrophic respiration rate and increase soil carbon retention. Changes in precipitation patterns are key drivers for variability in vegetation carbon. Upon SAI termination, the level of vegetation carbon storage returns to the reference case, whereas the soil carbon remains high. The ocean absorbs nearly 10% more carbon in the geoengineered simulation than in the reference simulation, leading to a ˜15 ppm lower atmospheric CO2 concentration in 2100. The largest enhancement in uptake occurs in the North Atlantic. In both hemispheres' polar regions, SAI delays the sea ice melting and, consequently, export production remains low. In the deep water of North Atlantic, SAI-induced circulation changes accelerate the ocean acidification rate and broaden the affected area.

Nonlinearity Role in Long-Term Interaction of the Ocean Gravity Waves

DTIC Science & Technology

2012-09-30

3 4 =s We found that in the fetch-limited case the wind forcing index s is similar to the time domain situation, and the wind forcing is given by...of its evolution. Fig.5 gives a graphical summary of four reference cases of self-similar evolution of wind-driven waves. These cases are shown as...different R, tangents of one-parametric dependencies H~TR height-to-period in logarithmic axes. Reference cases of growing wind sea are shown as

A Marine Aerosol Reference Tank system as a breaking wave analogue

NASA Astrophysics Data System (ADS)

Stokes, M. D.; Deane, G. B.; Prather, K.; Bertram, T. H.; Ruppel, M. J.; Ryder, O. S.; Brady, J. M.; Zhao, D.

2012-12-01

In order to better understand the processes governing the production of marine aerosols a repeatable, controlled method for their generation is required. The Marine Aerosol Reference Tank (MART) has been designed to closely approximate oceanic conditions by producing an evolving bubble plume and surface foam patch. The tank utilizes an intermittently plunging sheet of water and large volume tank reservoir to simulate turbulence, plume and foam formation, and is monitored volumetrically and acoustically to ensure the repeatability of conditions.

APL-UW High-Frequency Ocean Environmental Acoustic Models Handbook

DTIC Science & Technology

1994-10-01

120 160-180 Sperm Whale 0.2-32 5 -6 1 Killer Whale 0.1-30 14 178 Bottlenose Dolphin 15-130 100-130 >20M "Unknown C. GENERALIZED MARINE MAMMAL AMBIENT...DoD contractors only; Software Documentation; Apr 95. Other requests shall be referred to Chief of Naval Research , 800 N. Quincy St., Arlington, VA...Documentation. Date of Determination: April 1995. Other requests shall be referred to the Chief of Naval Research , 800 North Quincy Street, Arlington

The Influence of the General Board of the Navy on Interwar Destroyer Design

DTIC Science & Technology

2011-06-10

how the Board refers to using commissioned and crewed new designs and learing from ―experience,‖ this was an obvious reference to the annual Fleet...but also on the stability of the Gleaves-class of 2000 plus tons. Admiral Ernest J. King , the next CNO for the Navy and Commander in Chief of the...over the next few years.186 Admiral King outlined the priorities in the Navy’s two-ocean building program in an important memorandum to the

Can deformation of a polymer film with a rigid coating model geophysical processes?

NASA Astrophysics Data System (ADS)

Volynskii, A. L.; Bazhenov, S. L.

2007-12-01

The structural and mechanical behavior of polymer films with a thin rigid coating is analyzed. The behavior of such systems under applied stress is accompanied by the formation of a regular wavy surface relief and by regular fragmentation of the coating. The above phenomena are shown to be universal. Both phenomena (stress-induced development of a regular wavy surface relief and regular fragmentation of the coating) are provided by the specific features of mechanical stress transfer from a compliant soft support to a rigid thin coating. The above phenomena are associated with a specific structure of the system, which is referred to as “a rigid coating on a soft substratum” system (RCSS). Surface microrelief in RCSS systems is similar to the ocean floor relief in the vicinity of mid-oceanic ridges. Thus, the complex system composed of a young oceanic crust and upper Earth's mantle may be considered as typically “a solid coating on a soft substratum” system. Specific features of the ocean floor relief are analyzed in terms of the approach advanced for the description of the structural mechanical behavior of polymer films with a rigid coating. This analysis allowed to estimate the strength of an ocean floor.

Pathways of Atlantic Waters in the Nordic seas: locally eddy-permitting ocean simulation in a global setup

NASA Astrophysics Data System (ADS)

Wekerle, C.; Wang, Q.; Danilov, S.; Jung, T.; Schourup-Kristensen, V.

2016-02-01

Atlantic Water (AW) passes through the Nordic Seas and enters the Arctic Ocean through the shallow Barents Sea and the deep Fram Strait. Since the 1990's, observations indicate a series of anomalously warm pulses of Atlantic Water that entered the Arctic Ocean. In fact, poleward oceanic heat transport may even increase in the future, which might have implications for the heat uptake in the Arctic Ocean as well as for the sea ice cover. The ability of models to faithfully simulate the pathway of the AW and accompanying dynamics is thus of high climate relevance. In this study, we explore the potential of a global multi-resolution sea ice-ocean model with a locally eddy-permitting resolution (around 4.5 km) in the Nordic seas region and Arctic Ocean in improving the representation of Atlantic Water inflow, and more broadly, the dynamics of the circulation in the Northern North Atlantic and Arctic. The simulation covers the time period 1969-2009. We find that locally increased resolution improves the localization and thickness of the Atlantic Water layer in the Nordic seas, compared with a 20 km resolution reference simulation. In particular, the inflow of Atlantic Waters through the Greenland Scotland Ridge and the narrow branches of the Norwegian Atlantic Current can be realistically represented. Lateral spreading due to simulated eddies essentially reduces the bias in the surface temperature. In addition, a qualitatively good agreement of the simulated eddy kinetic energy field with observations can be achieved. This study indicates that a substantial improvement in representing local ocean dynamics can be reached through the local refinement, which requires a rather moderate computational effort. The successful model assessment allows us to further investigate the variability and mechanisms behind Atlantic Water transport into the Arctic Ocean.

Acoustic gravity microseismic pressure signal at shallow stations

NASA Astrophysics Data System (ADS)

Peureux, Charles; Ardhuin, Fabrice; Royer, Jean-Yves

2017-04-01

It has been known for decades that the background permanent seismic noise, the so-called microseimic signal, is generated by the nonlinear interaction of oppositely travelling ocean surface waves [Longuet-Higgins 1951]. It can especially be used to infer the time variability of short ocean waves statistics [Peureux and Ardhuin 2016]. However, better quantitative estimates of the latter are made difficult due to a poor knowledge of the Earth's crust characteristics, whose coupling with acoustic modes can affect large uncertainties to the frequency response at the bottom of the ocean. The pressure field at depths less than an acoustic wave length to the surface is made of evanescent acoustic-gravity modes [Cox and Jacobs 1989]. For this reason, they are less affected by the ocean bottom composition. This near field is recorded and analyzed in the frequency range 0.1 to 0.5 Hz approximately, at two locations : at a shallow site in the North-East Atlantic continental shelf and a deep water site in the Southern Indian ocean, at the ocean bottom and 100 m below sea-surface and in the upper part of the water column respectively. Evanescent and propagating Rayleigh modes are compared against theoretical predictions. Comparisons against surface waves hindcast based on WAVEWATCH(R) III modelling framework help assessing its performances and can be used to help future model improvements. References Longuet-Higgins, M. S., A Theory of the Origin of Microseisms, Philos. Trans. Royal Soc. A, The Royal Society, 1950, 243, 1-3. Peureux, C. and Ardhuin, F., Ocean bottom pressure records from the Cascadia array and short surface gravity waves, J. Geophys. Res. Oceans, 2016, 121, 2862-2873. Cox, C. S. & Jacobs, D. C., Cartesian diver observations of double frequency pressure fluctuations in the upper levels of the ocean, Geophys. Res. Lett., 1989, 16, 807-810.

Coral reefs will transition to net dissolving before end of century

NASA Astrophysics Data System (ADS)

Eyre, Bradley D.; Cyronak, Tyler; Drupp, Patrick; De Carlo, Eric Heinen; Sachs, Julian P.; Andersson, Andreas J.

2018-02-01

Ocean acidification refers to the lowering of the ocean’s pH due to the uptake of anthropogenic CO2 from the atmosphere. Coral reef calcification is expected to decrease as the oceans become more acidic. Dissolving calcium carbonate (CaCO3) sands could greatly exacerbate reef loss associated with reduced calcification but is presently poorly constrained. Here we show that CaCO3 dissolution in reef sediments across five globally distributed sites is negatively correlated with the aragonite saturation state (Ωar) of overlying seawater and that CaCO3 sediment dissolution is 10-fold more sensitive to ocean acidification than coral calcification. Consequently, reef sediments globally will transition from net precipitation to net dissolution when seawater Ωar reaches 2.92 ± 0.16 (expected circa 2050 CE). Notably, some reefs are already experiencing net sediment dissolution.

The large-scale freshwater cycle of the Arctic

NASA Astrophysics Data System (ADS)

Serreze, Mark C.; Barrett, Andrew P.; Slater, Andrew G.; Woodgate, Rebecca A.; Aagaard, Knut; Lammers, Richard B.; Steele, Michael; Moritz, Richard; Meredith, Michael; Lee, Craig M.

2006-11-01

This paper synthesizes our understanding of the Arctic's large-scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA-40 reanalysis and land surface and ice-ocean models. Annual mean freshwater input to the Arctic Ocean is dominated by river discharge (38%), inflow through Bering Strait (30%), and net precipitation (24%). Total freshwater export from the Arctic Ocean to the North Atlantic is dominated by transports through the Canadian Arctic Archipelago (35%) and via Fram Strait as liquid (26%) and sea ice (25%). All terms are computed relative to a reference salinity of 34.8. Compared to earlier estimates, our budget features larger import of freshwater through Bering Strait and larger liquid phase export through Fram Strait. While there is no reason to expect a steady state, error analysis indicates that the difference between annual mean oceanic inflows and outflows (˜8% of the total inflow) is indistinguishable from zero. Freshwater in the Arctic Ocean has a mean residence time of about a decade. This is understood in that annual freshwater input, while large (˜8500 km3), is an order of magnitude smaller than oceanic freshwater storage of ˜84,000 km3. Freshwater in the atmosphere, as water vapor, has a residence time of about a week. Seasonality in Arctic Ocean freshwater storage is nevertheless highly uncertain, reflecting both sparse hydrographic data and insufficient information on sea ice volume. Uncertainties mask seasonal storage changes forced by freshwater fluxes. Of flux terms with sufficient data for analysis, Fram Strait ice outflow shows the largest interannual variability.

Reversal of ocean acidification enhances net coral reef calcification.

PubMed

Albright, Rebecca; Caldeira, Lilian; Hosfelt, Jessica; Kwiatkowski, Lester; Maclaren, Jana K; Mason, Benjamin M; Nebuchina, Yana; Ninokawa, Aaron; Pongratz, Julia; Ricke, Katharine L; Rivlin, Tanya; Schneider, Kenneth; Sesboüé, Marine; Shamberger, Kathryn; Silverman, Jacob; Wolfe, Kennedy; Zhu, Kai; Caldeira, Ken

2016-03-17

Approximately one-quarter of the anthropogenic carbon dioxide released into the atmosphere each year is absorbed by the global oceans, causing measurable declines in surface ocean pH, carbonate ion concentration ([CO3(2-)]), and saturation state of carbonate minerals (Ω). This process, referred to as ocean acidification, represents a major threat to marine ecosystems, in particular marine calcifiers such as oysters, crabs, and corals. Laboratory and field studies have shown that calcification rates of many organisms decrease with declining pH, [CO3(2-)], and Ω. Coral reefs are widely regarded as one of the most vulnerable marine ecosystems to ocean acidification, in part because the very architecture of the ecosystem is reliant on carbonate-secreting organisms. Acidification-induced reductions in calcification are projected to shift coral reefs from a state of net accretion to one of net dissolution this century. While retrospective studies show large-scale declines in coral, and community, calcification over recent decades, determining the contribution of ocean acidification to these changes is difficult, if not impossible, owing to the confounding effects of other environmental factors such as temperature. Here we quantify the net calcification response of a coral reef flat to alkalinity enrichment, and show that, when ocean chemistry is restored closer to pre-industrial conditions, net community calcification increases. In providing results from the first seawater chemistry manipulation experiment of a natural coral reef community, we provide evidence that net community calcification is depressed compared with values expected for pre-industrial conditions, indicating that ocean acidification may already be impairing coral reef growth.

Reversal of ocean acidification enhances net coral reef calcification

NASA Astrophysics Data System (ADS)

Albright, Rebecca; Caldeira, Lilian; Hosfelt, Jessica; Kwiatkowski, Lester; MacLaren, Jana K.; Mason, Benjamin M.; Nebuchina, Yana; Ninokawa, Aaron; Pongratz, Julia; Ricke, Katharine L.; Rivlin, Tanya; Schneider, Kenneth; Sesboüé, Marine; Shamberger, Kathryn; Silverman, Jacob; Wolfe, Kennedy; Zhu, Kai; Caldeira, Ken

2016-03-01

Approximately one-quarter of the anthropogenic carbon dioxide released into the atmosphere each year is absorbed by the global oceans, causing measurable declines in surface ocean pH, carbonate ion concentration ([CO32-]), and saturation state of carbonate minerals (Ω). This process, referred to as ocean acidification, represents a major threat to marine ecosystems, in particular marine calcifiers such as oysters, crabs, and corals. Laboratory and field studies have shown that calcification rates of many organisms decrease with declining pH, [CO32-], and Ω. Coral reefs are widely regarded as one of the most vulnerable marine ecosystems to ocean acidification, in part because the very architecture of the ecosystem is reliant on carbonate-secreting organisms. Acidification-induced reductions in calcification are projected to shift coral reefs from a state of net accretion to one of net dissolution this century. While retrospective studies show large-scale declines in coral, and community, calcification over recent decades, determining the contribution of ocean acidification to these changes is difficult, if not impossible, owing to the confounding effects of other environmental factors such as temperature. Here we quantify the net calcification response of a coral reef flat to alkalinity enrichment, and show that, when ocean chemistry is restored closer to pre-industrial conditions, net community calcification increases. In providing results from the first seawater chemistry manipulation experiment of a natural coral reef community, we provide evidence that net community calcification is depressed compared with values expected for pre-industrial conditions, indicating that ocean acidification may already be impairing coral reef growth.

To direct the Secretary of Education to establish a clearinghouse of information on best practices for ocean lifeguard training programs.

THOMAS, 111th Congress

Rep. Weiner, Anthony D. [D-NY-9

2010-08-10

House - 11/18/2010 Referred to the Subcommittee on Higher Education, Lifelong Learning, and Competitiveness. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Measurement of curium in marine samples

NASA Astrophysics Data System (ADS)

Schneider, D. L.; Livingston, H. D.

1984-06-01

Measurement of environmentally small but detectable amounts of curium requires reliable, accureate, and sensitive analytical methods. The radiochemical separation developed at Woods Hole is briefly reviewed with specific reference to radiochemical interferences in the alpha spectrometric measurement of curium nuclides and to the relative amounts of interferences expected in different oceanic regimes and sample types. Detection limits for 242 Cm and 244 Cm are ultimately limited by their presence in the 243Am used as curium yield monitor. Environmental standard reference materials are evaluated with regard to curium. The marine literature is reviewed and curium measurements are discussed in relation to their source of introduction to the environment. Sources include ocean dumping of low-level radioactive wastes and discharges from nuclear fuel reporcessing activities, In particular, the question of a detectable presence of 244Cm in global fallout from nuclear weapons testing is addressed and shown to be essentially negligible. Analyses of Scottish coastal sedimantes show traces of 242Cm and 244Cm activity which are believed to originate from transport from sources in the Irish Sea.

Long-term seafloor monitoring at an open ocean aquaculture site in the western Gulf of Maine, USA: development of an adaptive protocol.

PubMed

Grizzle, R E; Ward, L G; Fredriksson, D W; Irish, J D; Langan, R; Heinig, C S; Greene, J K; Abeels, H A; Peter, C R; Eberhardt, A L

2014-11-15

The seafloor at an open ocean finfish aquaculture facility in the western Gulf of Maine, USA was monitored from 1999 to 2008 by sampling sites inside a predicted impact area modeled by oceanographic conditions and fecal and food settling characteristics, and nearby reference sites. Univariate and multivariate analyses of benthic community measures from box core samples indicated minimal or no significant differences between impact and reference areas. These findings resulted in development of an adaptive monitoring protocol involving initial low-cost methods that required more intensive and costly efforts only when negative impacts were initially indicated. The continued growth of marine aquaculture is dependent on further development of farming methods that minimize negative environmental impacts, as well as effective monitoring protocols. Adaptive monitoring protocols, such as the one described herein, coupled with mathematical modeling approaches, have the potential to provide effective protection of the environment while minimize monitoring effort and costs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improved Climate Simulations through a Stochastic Parameterization of Ocean Eddies

NASA Astrophysics Data System (ADS)

Williams, Paul; Howe, Nicola; Gregory, Jonathan; Smith, Robin; Joshi, Manoj

2017-04-01

In climate simulations, the impacts of the subgrid scales on the resolved scales are conventionally represented using deterministic closure schemes, which assume that the impacts are uniquely determined by the resolved scales. Stochastic parameterization relaxes this assumption, by sampling the subgrid variability in a computationally inexpensive manner. This study shows that the simulated climatological state of the ocean is improved in many respects by implementing a simple stochastic parameterization of ocean eddies into a coupled atmosphere-ocean general circulation model. Simulations from a high-resolution, eddy-permitting ocean model are used to calculate the eddy statistics needed to inject realistic stochastic noise into a low-resolution, non-eddy-permitting version of the same model. A suite of four stochastic experiments is then run to test the sensitivity of the simulated climate to the noise definition by varying the noise amplitude and decorrelation time within reasonable limits. The addition of zero-mean noise to the ocean temperature tendency is found to have a nonzero effect on the mean climate. Specifically, in terms of the ocean temperature and salinity fields both at the surface and at depth, the noise reduces many of the biases in the low-resolution model and causes it to more closely resemble the high-resolution model. The variability of the strength of the global ocean thermohaline circulation is also improved. It is concluded that stochastic ocean perturbations can yield reductions in climate model error that are comparable to those obtained by refining the resolution, but without the increased computational cost. Therefore, stochastic parameterizations of ocean eddies have the potential to significantly improve climate simulations. Reference Williams PD, Howe NJ, Gregory JM, Smith RS, and Joshi MM (2016) Improved Climate Simulations through a Stochastic Parameterization of Ocean Eddies. Journal of Climate, 29, 8763-8781. http://dx.doi.org/10.1175/JCLI-D-15-0746.1

Coarsening of physics for biogeochemical model in NEMO

NASA Astrophysics Data System (ADS)

Bricaud, Clement; Le Sommer, Julien; Madec, Gurvan; Deshayes, Julie; Chanut, Jerome; Perruche, Coralie

2017-04-01

Ocean mesoscale and submesoscale turbulence contribute to ocean tracer transport and to shaping ocean biogeochemical tracers distribution. Representing adequately tracer transport in ocean models therefore requires to increase model resolution so that the impact of ocean turbulence is adequately accounted for. But due to supercomputers power and storage limitations, global biogeochemical models are not yet run routinely at eddying resolution. Still, because the "effective resolution" of eddying ocean models is much coarser than the physical model grid resolution, tracer transport can be reconstructed to a large extent by computing tracer transport and diffusion with a model grid resolution close to the effective resolution of the physical model. This observation has motivated the implementation of a new capability in NEMO ocean model (http://www.nemo-ocean.eu/) that allows to run the physical model and the tracer transport model at different grid resolutions. In a first time, we present results obtained with this new capability applied to a synthetic age tracer in a global eddying model configuration. In this model configuration, ocean dynamic is computed at ¼° resolution but tracer transport is computed at 3/4° resolution. The solution obtained is compared to 2 reference setup ,one at ¼° resolution for both physics and passive tracer models and one at 3/4° resolution for both physics and passive tracer model. We discuss possible options for defining the vertical diffusivity coefficient for the tracer transport model based on information from the high resolution grid. We describe the impact of this choice on the distribution and one the penetration of the age tracer. In a second time we present results obtained by coupling the physics with the biogeochemical model PISCES. We look at the impact of this methodology on some tracers distribution and dynamic. The method described here can found applications in ocean forecasting, such as the Copernicus Marine service operated by Mercator-Ocean, and in Earth System Models for climate applications.

Applications of Geostationary Satellite Data to Aviation

NASA Astrophysics Data System (ADS)

Ellrod, Gary P.; Pryor, Kenneth

2018-03-01

Weather is by far the most important factor in air traffic delays in the United States' National Airspace System (NAS) according to the Federal Aviation Administration (FAA). Geostationary satellites have been an effective tool for the monitoring of meteorological conditions that affect aviation operations since the launch of the first Synchronous Meteorological Satellite (SMS) in the United States in 1974. This paper will review the global use of geostationary satellites in support of aviation weather since their inception, with an emphasis on the latest generation of satellites, such as Geostationary Operational Environmental Satellite (GOES)-R (16) with its Advanced Baseline Imager (ABI) and Geostationary Lightning Mapper (GLM). Specific applications discussed in this paper include monitoring of convective storms and their associated hazards, fog and low stratus, turbulence, volcanic hazards, and aircraft icing.

Assimilation of altimeter data into a quasigeostrophic ocean model using optimal interpolation and eofs

NASA Astrophysics Data System (ADS)

Rienecker, M. M.; Adamec, D.

1995-01-01

An ensemble of fraternal-twin experiments is used to assess the utility of optimal interpolation and model-based vertical empirical orthogonal functions (eofs) of streamfunction variability to assimilate satellite altimeter data into ocean models. Simulated altimeter data are assimilated into a basin-wide 3-layer quasi-geostrophic model with a horizontal grid spacing of 15 km. The effects of bottom topography are included and the model is forced by a wind stress curl distribution which is constant in time. The simulated data are extracted, along altimeter tracks with spatial and temporal characteristics of Geosat, from a reference model ocean with a slightly different climatology from that generated by the model used for assimilation. The use of vertical eofs determined from the model-generated streamfunction variability is shown to be effective in aiding the model's dynamical extrapolation of the surface information throughout the rest of the water column. After a single repeat cycle (17 days), the analysis errors are reduced markedly from the initial level, by 52% in the surface layer, 41% in the second layer and 11% in the bottom layer. The largest differences between the assimilation analysis and the reference ocean are found in the nonlinear regime of the mid-latitude jet in all layers. After 100 days of assimilation, the error in the upper two layers has been reduced by over 50% and that in the bottom layer by 38%. The essence of the method is that the eofs capture the statistics of the dynamical balances in the model and ensure that this balance is not inappropriately disturbed during the assimilation process. This statistical balance includes any potential vorticity homogeneity which may be associated with the eddy stirring by mid-latitude surface jets.

Investigating Atmospheric Rivers using GPS PW from Ocean Transits

NASA Astrophysics Data System (ADS)

Almanza, V.; Foster, J. H.; Businger, S.

2014-12-01

Atmospheric Rivers (AR) can be described as a long narrow feature within a warm conveyor belt where anomalous precipitable water (PW) is transported from low to high latitudes. Close monitoring of ARs is heavily reliant on satellites, which are limited both in space and time, to capture the fluctuations PW particularly over the ocean. Ship-based Global Positioning System (GPS) receivers have been successful in obtaining millimeter PW accuracy within 100 km from the nearest ground-based reference receiver at a 30 second sampling rate. We extended this capability with a field experiment using ship-based GPS PW on board a cargo ship to traverse over the Eastern Pacific Ocean. In one 14-day cruise cycle, between the periods of February 3-16, 2014, the ship-based GPS captured PW spikes >50 mm during the early development of two ARs, which lead to moderate to heavy rainfall events for Hawaii and flood conditions along the West Coast of the United States. Comparisons between PW solutions processed using different GPS reference sites at distances 100-2000 km provided an internal validation for the ship-based GPS PW with errors typically less than 5 mm. Land-based observations provided an external validation and are in good agreement with ship-based GPS PW at distances <100 km from the coast, a zone heavily trafficked by cargo containers and a challenge area for satellite retrievals. From these preliminary results, commercial ship-based GPS receivers offer an extremely cost-effective approach for acquiring continuous meteorological observations over the oceans, which can provide important calibration/validation data for satellite retrieval algorithms. Ship-based systems could be particularly useful for augmenting our meteorological observing networks to improve weather prediction and nowcasting, which in turn provide critical support for hazard response and mitigation efforts in coastal regions.

The Kweyol Language and Literacy Project.

ERIC Educational Resources Information Center

Morris, Carol; Nwenmely, Hubisi

1993-01-01

French Creoles are spoken in many different parts of the world, including the Indian Ocean, United States, Caribbean, and South America. These Kweyol speech communities are described, in the Kweyol Project, which examines Kweyol language issues and the establishment of a Kweyol Literacy Scheme. (Contains 15 references.) (LB)

30 CFR 585.825 - When must I assess my facilities?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Section 585.825 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE... Safety Management, Inspections, and Facility Assessments for Activities Conducted Under SAPs, COPs and... Offshore Platforms—Working Stress Design (as incorporated by reference in § 585.115). (b) You must initiate...

30 CFR 585.825 - When must I assess my facilities?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 585.825 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE... Safety Management, Inspections, and Facility Assessments for Activities Conducted Under SAPs, COPs and... Offshore Platforms—Working Stress Design (as incorporated by reference in § 585.115). (b) You must initiate...

30 CFR 585.825 - When must I assess my facilities?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 585.825 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE... Safety Management, Inspections, and Facility Assessments for Activities Conducted Under SAPs, COPs and... Offshore Platforms—Working Stress Design (as incorporated by reference in § 585.115). (b) You must initiate...

32 CFR 281.2 - Applicability and scope.

Code of Federal Regulations, 2011 CFR

2011-07-01

... organizational entities in the Department of Defense (hereafter referred to collectively as “the DoD Components... Department of Homeland Security, and the Commissioned Corps of the Public Health Service (PHS) and the National Oceanic and Atmospheric Administration (NOAA), under agreements with the Departments of Health and...

32 CFR 281.2 - Applicability and scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... organizational entities in the Department of Defense (hereafter referred to collectively as “the DoD Components... Department of Homeland Security, and the Commissioned Corps of the Public Health Service (PHS) and the National Oceanic and Atmospheric Administration (NOAA), under agreements with the Departments of Health and...

Thermal Pollution by Nuclear Power Plants. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 320. [Project COAST].

ERIC Educational Resources Information Center

Delaware Univ., Newark. Coll. of Education.

This publication includes several activities regarding the use of nuclear power plants and possible effects on the environment. The materials are designed for secondary school students and include reference materials and masters for transparencies. (RH)

To amend the National Marine Sanctuaries Act to prescribe an additional requirement for the designation of marine sanctuaries off the coast of Alaska.

THOMAS, 113th Congress

Rep. Young, Don [R-AK-At Large

2014-07-31

House - 08/19/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

75 FR 23244 - North Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

...: North Pacific Fishery Management Council will host a meeting of the Council Coordination Committee (CCC... North Pacific Research Board/Alaska Ocean Observing System; adopt the CCC Terms of Reference; discuss...); Enforcement Issues; 5-year grant application process; and discuss the January 2011 CCC meeting agenda...

Mg/Ca ratios of two Globigerinoides ruber (white) morphotypes: Implications for reconstructing past tropical/subtropical surface water conditions

NASA Astrophysics Data System (ADS)

Steinke, Stephan; Chiu, Han-Yi; Yu, Pai-Sen; Shen, Chuan-Chou; LöWemark, Ludvig; Mii, Horng-Sheng; Chen, Min-Te

2005-11-01

Tests of the planktonic foraminifer Globigerinoides ruber (white; d'Orbigny) have become a standard tool for reconstructing past oceanic environments. Paleoceanographers often utilize the Mg/Ca ratios of the foraminiferal tests for reconstructing low-latitude ocean glacial-interglacial changes in sea surface temperatures (SST). We report herein a comparison of Mg/Ca measurements on sample pairs (n = 20) of two G. ruber (white) morphotypes (G. ruber sensu stricto (s.s.) and G. ruber sensu lato (s.l.)) from surface and downcore samples of the western Pacific and Indian Oceans. G. ruber s.s. refers to specimens with spherical chambers sitting symmetrically over previous sutures with a wide, high arched aperture, whereas G. ruber s.l. refers to a more compact test with a diminutive final chamber and small aperture. The G. ruber s.s. specimens generally show significantly higher Mg/Ca ratios compared to G. ruber s.l. Our results from the Mg/Ca ratio analysis suggest that G. ruber s.l. specimens precipitated their shells in slightly colder surface waters than G. ruber s.s. specimens. This conclusion is supported by the differences in δ18O and δ13C values between the two morphotypes. Although it is still unclear if these two morphotypes represent phenotypic variants or sibling species, our findings seem to support the hypothesis of depth and/or seasonal allopatry within a single morphospecies.

Ecosystem Models as Support to Eutrophication Management in the North Atlantic Ocean (EMoSEM)

NASA Astrophysics Data System (ADS)

Lacroix, Geneviève; Billen, Gilles; Desmit, Xavier; Garnier, Josette; Gypens, Nathalie; Lancelot, Christiane; Lenhart, Hermann; Los, Hans; Mateus, Marcos; Ménesguen, Alain; Neves, Ramiro; Troost, Tineke; van der Molen, Johan

2013-04-01

One of the leading challenges in marine science and governance is to improve scientific guidance of management measures to mitigate eutrophication nuisances in the EU seas. Existing approaches do not integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic and scientific-based nutrient reduction scenarios. The SEAS-ERA project EMoSEM aims to develop and combine the state-of-the-art modelling tools describing the river-ocean continuum in the North-East Atlantic (NEA) continental seas. This will allow to link the eutrophication nuisances in specific marine regions to anthropogenic inputs, trace back their sources up to the watersheds, then test nutrient reduction options that might be implemented in these watersheds, and propose consistent indicators and reference levels to assess the Good Environmental Status (GES). At the end, EMoSEM will deliver coupled river-coastal-sea mathematical models and will provide guidance to end-users (policy- and decision makers) for assessing and combating eutrophication problems in the NEA continental waters.

State-of-the-art satellite laser range modeling for geodetic and oceanographic applications

NASA Technical Reports Server (NTRS)

Klosko, Steve M.; Smith, David E.

1993-01-01

Significant improvements have been made in the modeling and accuracy of Satellite Laser Range (SLR) data since the launch of LAGEOS in 1976. Some of these include: improved models of the static geopotential, solid-Earth and ocean tides, more advanced atmospheric drag models, and the adoption of the J2000 reference system with improved nutation and precession. Site positioning using SLR systems currently yield approximately 2 cm static and 5 mm/y kinematic descriptions of the geocentric location of these sites. Incorporation of a large set of observations from advanced Satellite Laser Ranging (SLR) tracking systems have directly made major contributions to the gravitational fields and in advancing the state-of-the-art in precision orbit determination. SLR is the baseline tracking system for the altimeter bearing TOPEX/Poseidon and ERS-1 satellites and thus, will play an important role in providing the Conventional Terrestrial Reference Frame for instantaneously locating the geocentric position of the ocean surface over time, in providing an unchanging range standard for altimeter range calibration, and for improving the geoid models to separate gravitational from ocean circulation signals seen in the sea surface. Nevertheless, despite the unprecedented improvements in the accuracy of the models used to support orbit reduction of laser observations, there still remain systematic unmodeled effects which limit the full exploitation of modern SLR data.

Longitudinal biases in the Seychelles Dome simulated by 35 ocean-atmosphere coupled general circulation models

NASA Astrophysics Data System (ADS)

Nagura, Motoki; Sasaki, Wataru; Tozuka, Tomoki; Luo, Jing-Jia; Behera, Swadhin K.; Yamagata, Toshio

2013-02-01

Seychelles Dome refers to the shallow climatological thermocline in the southwestern Indian Ocean, where ocean wave dynamics efficiently affect sea surface temperature, allowing sea surface temperature anomalies to be predicted up to 1-2 years in advance. Accurate reproduction of the dome by ocean-atmosphere coupled general circulation models (CGCMs) is essential for successful seasonal predictions in the Indian Ocean. This study examines the Seychelles Dome as simulated by 35 CGCMs, including models used in phase five of the Coupled Model Intercomparison Project (CMIP5). Among the 35 CGCMs, 14 models erroneously produce an upwelling dome in the eastern half of the basin whereas the observed Seychelles Dome is located in the southwestern tropical Indian Ocean. The annual mean Ekman pumping velocity in these models is found to be almost zero in the southern off-equatorial region. This result is inconsistent with observations, in which Ekman upwelling acts as the main cause of the Seychelles Dome. In the models reproducing an eastward-displaced dome, easterly biases are prominent along the equator in boreal summer and fall, which result in shallow thermocline biases along the Java and Sumatra coasts via Kelvin wave dynamics and a spurious upwelling dome in the region. Compared to the CMIP3 models, the CMIP5 models are even worse in simulating the dome longitudes.

High Resolution Numerical Simulations and Diagnostic Studies Atmospheric Transport During TRACE-A

NASA Technical Reports Server (NTRS)

Krishnamurti, T. N.; Fuelberg, Henry

1995-01-01

The enclosed publications constitute our final report. These are publications completed in referred journals. The completed work includes: Meteorological conditions associated with vertical distributions of aerosols off the west coast of Africa. TRACE-A trajectory intercomparison 2. Isentropic and kinematic methods. Chemical characteristics of tropospheric air over the tropical South Atlantic Ocean: Relationship to trajectory history. Passive Tracer Transport Relevant to the TRACE-A Experiment. The meteorological environment of the tropospheric ozone maximum over the tropical south Atlantic Ocean. : Influence of a middle-latitude cyclone on tropospheric ozone distributions during a period of TRACE-A. All of this work provided the meteorological background for the Transport of Atmospheric Chemistry near the Equator (TRACE-A) project sponsored by Dr,, Joe McNeal of NASA. Our principal findings are that bio-mass burning sources from Africa and South America did contribute to the accumulation of tropospheric ozone over the tropical Atlantic Ocean. Other findings relate to circulations, advections of Ozone and other plausible sources for the TOMS based ozone maximum over the Atlantic Ocean.

Sea surface temperature estimates for the mid-Piacenzian Indian Ocean—Ocean Drilling Program sites 709, 716, 722, 754, 757, 758, and 763

USGS Publications Warehouse

Robinson, Marci M.; Dowsett, Harry J.; Stoll, Danielle K.

2018-01-30

Despite the wealth of global paleoclimate data available for the warm period in the middle of the Piacenzian Stage of the Pliocene Epoch (about 3.3 to 3.0 million years ago [Ma]; Dowsett and others, 2013, and references therein), the Indian Ocean has remained a region of sparse geographic coverage in terms of microfossil analysis. In an effort to characterize the surface Indian Ocean during this interval, we examined the planktic foraminifera from Ocean Drilling Program (ODP) sites 709, 716, 722, 754, 757, 758, and 763, encompassing a wide range of oceanographic conditions. We quantitatively analyzed the data for sea surface temperature (SST) estimation using both the modern analog technique (MAT) and a factor analytic transfer function. The data will contribute to the U.S. Geological Survey (USGS) Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project’s global SST reconstruction and climate model SST boundary condition for the mid-Piacenzian and will become part of the PRISM verification dataset designed to ground-truth Pliocene climate model simulations (Dowsett and others, 2013).

Hole 504B reclaimed for future drilling

NASA Astrophysics Data System (ADS)

Leg 137 Scientific Drilling Party

Hole 504B, perhaps the most important in situ reference section for the structure and composition of the oceanic crust, has been reopened for future drilling and downhole measurements after remedial operations during Leg 137 of the Ocean Drilling Program. By far the deepest penetration into oceanic crust, Hole 504B had been feared lost when a large diamond bit and assorted hardware (“junk”) broke off in the bottom of the hole at the end of ODP Leg 111 in 1986. Since then ODP's drill ship, JOIDES Resolution, has circumnavigated the globe, with no opportunity to redress this situation. But the objective of deep penetration into the oceanic crust and the hole itself are considered so important by marine Earth scientists that remedial measures in Hole 504B were undertaken as soon as the drill ship returned to the eastern Pacific. These measures succeeded better than had been hoped. Hole 504B was reopened after less than a week of cleaning operations, which included grappling for the lost junk with tools to pull it from the hole (called “fishing”) and grinding or milling the junk away.

Near Field Ocean Surface Waves Acoustic Radiation Observation and Modeling

NASA Astrophysics Data System (ADS)

Ardhuin, F.; Peureux, C.; Royer, J. Y.

2016-12-01

The acoustic noise generation by nonlinearly interacting surface gravity waves has been studied for a long time both theoretically and experimentally [Longuet-Higgins 1951]. The associated far field noise is continuously measured by a vast network of seismometers at the ocean bottom and on the continents. It can especially be used to infer the time variability of short ocean waves statistics [Peureux and Ardhuin 2016]. However, better quantitative estimates of the latter are made difficult due to a poor knowledge of the Earth's crust characteristics, whose coupling with acoustic modes can affect large uncertainties to the frequency response at the bottom of the ocean.The pressure field at depths less than an acoustic wave length to the surface is made of evanescent modes which vanish away from their sources (near field) [Cox and Jacobs 1989]. For this reason, they are less affected by the ocean bottom composition. This near field is recorded and analyzed in the frequency range 0.1 to 0.5 Hz approximately, at two locations : at a shallow site in the North-East Atlantic continental shelf and a deep water site in the Southern Indian ocean, where pressure measurements are performed at the ocean bottom (ca. 100 m) and at 300 m water depth respectively. Evanescent and propagating Rayleigh modes are compared against theoretical predictions. Comparisons against surface waves hindcast based on WAVEWATCH(R) III modeling framework help assessing its performances and can be used to help future model improvements.References Longuet-Higgins, M. S., A Theory of the Origin of Microseisms, Philos. Trans. Royal Soc. A, 1950, 243, 1-3. Peureux, C. and Ardhuin, F., Ocean bottom pressure records from the Cascadia array and short surface gravity waves, J. Geophys. Res. Oceans, 2016, 121, 2862-2873. Cox, C. S. & Jacobs, D. C., Cartesian diver observations of double frequency pressure fluctuations in the upper levels of the ocean, Geophys. Res. Lett., 1989, 16, 807-810.

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

NASA Astrophysics Data System (ADS)

Polonsky, A.

2016-02-01

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

Global Ocean Sedimentation Patterns: Plate Tectonic History Versus Climate Change

NASA Astrophysics Data System (ADS)

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

2014-12-01

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

Harriet Tubman National Historical Parks Act

THOMAS, 113th Congress

Sen. Cardin, Benjamin L. [D-MD

2013-02-07

House - 07/14/2014 Referred to the Subcommittee on Fisheries, Wildlife, Oceans, and Insular Affairs. (All Actions) Notes: For further action, see H.R.3979, which became Public Law 113-291 on 12/19/2014. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

High School Oceanography.

ERIC Educational Resources Information Center

Falmouth Public Schools, MA.

This book is a compilation of a series of papers designed to aid high school teachers in organizing a course in oceanography for high school students. It consists of twelve papers, with references, covering each of the following: (1) Introduction to Oceanography, (2) Geology of the Ocean, (3) The Continental Shelves, (4) Physical Properties of Sea…