Science.gov

Sample records for ocean environment based

  1. Sequential Model-Based Detection in a Shallow Ocean Acoustic Environment

    SciTech Connect

    Candy, J V

    2002-03-26

    A model-based detection scheme is developed to passively monitor an ocean acoustic environment along with its associated variations. The technique employs an embedded model-based processor and a reference model in a sequential likelihood detection scheme. The monitor is therefore called a sequential reference detector. The underlying theory for the design is developed and discussed in detail.

  2. Model-based processing for shallow ocean environments: The broadband problem

    SciTech Connect

    Candy, J.V.; Sullivan, E.J.

    1996-01-31

    Most acoustic sources found is the ocean environmental are spatially complex and broadband. When propagating in a shallow ocean these source characteristics complicate the analysis of received acoustic data considerably. The enhancement of broadband acoustic pressure- field measurements using a vertical array is discussed. Here a model- based approach is developed for a broadband source using a normal- mode propagation model.

  3. Supporting Teachers' Use of a Project-Based Learning Environment in Ocean Science: Web-Based Educative Curriculum Materials

    ERIC Educational Resources Information Center

    Duncan, Ravit Golan; El-Moslimany, Hebbah; McDonnell, Janice; Lichtenwalner, Sage

    2011-01-01

    The development of inquiry and project-based materials is challenging in many ways, not the least of which is the design of supports for teachers implementing such materials. We report on the design of educative and just-in-time teacher supports for an online project-based unit in ocean science. The teacher supports were visible as tabs on the…

  4. Connections: Ocean Environments. Unit Grade 5.

    ERIC Educational Resources Information Center

    Ney, Catherine R.

    Ocean Environments for Grade 5 is a 12-week interdisciplinary ocean environmental unit designed for teachers to use with their students. The unit emphasizes investigation and understanding of our ocean environments, including their geological, physical, and biological characteristics. It also stresses awareness of public policy decisions related…

  5. Ocean engineering and the environment (Conference record)

    SciTech Connect

    Not Available

    1985-01-01

    This book present the papers given at a conference on offshore operations. Topics considered include ocean engineering and the environment, marine information systems, oil spill cleanup, economic potential, the design and analysis of offshore structures, water current measurements, ocean thermal energy conversion, ocean thermal power plants, corrosion, materials testing, biofouling, and aquaculture.

  6. Cross-correlations of diffuse noise in an ocean environment using eigenvalue based statistical inference.

    PubMed

    Menon, Ravishankar; Gerstoft, Peter; Hodgkiss, William S

    2012-11-01

    Cross-correlations of diffuse noise fields can be used to extract environmental information. The influence of directional sources (usually ships) often results in a bias of the travel time estimates obtained from the cross-correlations. Using an array of sensors, insights from random matrix theory on the behavior of the eigenvalues of the sample covariance matrix (SCM) in an isotropic noise field are used to isolate the diffuse noise component from the directional sources. A sequential hypothesis testing of the eigenvalues of the SCM reveals eigenvalues dominated by loud sources that are statistical outliers for the assumed diffuse noise model. Travel times obtained from cross-correlations using only the diffuse noise component (i.e., by discarding or attenuating the outliers) converge to the predicted travel times based on the known array sensor spacing and measured sound speed at the site and are stable temporally (i.e., unbiased estimates). Data from the Shallow Water 2006 experiment demonstrates the effectiveness of this approach and that the signal-to-noise ratio builds up as the square root of time, as predicted by theory.

  7. Predicting the Arctic Ocean Environment in the 21st century

    NASA Astrophysics Data System (ADS)

    Aksenov, Yevgeny; Popova, Ekaterina; Yool, Andrew; Nurser, George

    2015-04-01

    Recent environmental changes in the Arctic have clearly demonstrated that climate change is faster and more vigorously in the Polar Regions than anywhere else. Significantly, change in the Arctic Ocean (AO) environment presents a variety of impacts, from ecological to social-economic and political. Mitigation of this change and adaptation to it requires detailed and robust environmental predictions. Here we present a detailed projection of ocean circulation and sea ice from the present until 2099, based on an eddy-permitting high-resolution global simulation of the NEMO ¼ degree ocean model. The model is forced at the surface with HadGEM2-ES atmosphere model output from the UK Met. Office IPCC Assessment Report 5 (AR5) Representative Concentration Pathways 8.5 (RCP8.5) scenario. The HadGEM2-ES simulations span 1860-2099 and are one of an ensemble of runs performed for the Coupled Model Intercomparison Project 5 (CMIP5) and IPCC AR5. Between 2000-2009 and 2090-2099 the AO experiences a significant warming, with sea surface temperature increasing on average by about 4° C, particularly in the Barents and Kara Seas, and in the Greenland Sea and Hudson Bay. By the end of the simulation, Arctic sea ice has an average annual thickness of less than 10 cm in the central AO, and less than 0.5 m in the East-Siberian Sea and Canadian Archipelago, and disappears entirely during the Arctic summer. In summer, opening of large areas of the Arctic Ocean to the wind and surface waves leads to the Arctic pack ice cover evolving into the Marginal Ice Zone (MIZ). In winter, sea ice persists until the 2030s; then it sharply declines and disappears from the Central Arctic Ocean by the end of the 21st century, with MIZ provinces remaining in winter along the Siberian, Alaskan coasts and in the Canadian Arctic Archipelago. Analysis of the AO circulation reveals evidence of (i) the reversal of the Arctic boundary currents in the Canadian Basin, from a weak cyclonic current in 2040-2049 to

  8. Oceanic satellite data service system based on web

    NASA Astrophysics Data System (ADS)

    Kang, Yan; Pan, Delu; He, Xianqiang; Wang, Difeng; Chen, Jianyu; Chen, Xiaoyan

    2011-11-01

    The ocean satellite observation is more and more important to study the global change, protect ocean resource and implement ocean engineering for their large area cover and high frequency observation, which have already given us a global view of ocean environment parameters, including the sea surface temperature, ocean color, wind, wave, sea level and sea ice, etc... China has made great progress in ocean environment remote sensing over the last couple of years. These data are widely used for a variety of applications in ocean environment studies, coastal water quality monitoring environmental, fishery resources protection, development and utilization of fishery resources, coastal engineering and oceanography. But the data are no online information access and dissemination, no online visualization & browsing, no online query and analyze capability. To facilitate the application of the data and to help disseminating the data, a web-service system has developed. The system provides capabilities of online oceanic satellite information access, query, visualize and analyze. It disseminates oceanic satellite data to the users via real time retrieval, processing and publishing through standards-based geospatial web services. A region of interest can also be exported directly to Google Earth for displaying or downloaded. This web service system greatly improves accessibility, interoperability, usability, and visualization of oceanic satellite data without any client-side software installation.

  9. Phytoplankton adapt to changing ocean environments.

    PubMed

    Irwin, Andrew J; Finkel, Zoe V; Müller-Karger, Frank E; Troccoli Ghinaglia, Luis

    2015-05-05

    Model projections indicate that climate change may dramatically restructure phytoplankton communities, with cascading consequences for marine food webs. It is currently not known whether evolutionary change is likely to be able to keep pace with the rate of climate change. For simplicity, and in the absence of evidence to the contrary, most model projections assume species have fixed environmental preferences and will not adapt to changing environmental conditions on the century scale. Using 15 y of observations from Station CARIACO (Carbon Retention in a Colored Ocean), we show that most of the dominant species from a marine phytoplankton community were able to adapt their realized niches to track average increases in water temperature and irradiance, but the majority of species exhibited a fixed niche for nitrate. We do not know the extent of this adaptive capacity, so we cannot conclude that phytoplankton will be able to adapt to the changes anticipated over the next century, but community ecosystem models can no longer assume that phytoplankton cannot adapt.

  10. Ocean Ambient Noise Studies for Shallow and Deep Water Environments

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Ocean Ambient Noise Studies for Shallow and Deep Water...Siderius.php LONG-TERM GOALS The objective of this research is to study the ocean ambient noise field by means of new physics-based processing... ambient -noise field using a vertical line array has been developed by Harrison and Simons [Harrison, 2002]. The advantages of passive bottom-survey

  11. Acoustic Blind Deconvolution and Source Localization in Shallow Ocean Environments

    DTIC Science & Technology

    2011-09-01

    2011. PUBLICATIONS [1] Kundu , P.K., Cohen, I.M., and Dowling, D.R., Fluid Mechanics , 5th Ed. (Academic Press, Oxford, 2012), 891 pages. ...Shallow Ocean Environments David R. Dowling Department of Mechanical Engineering University of Michigan Ann Arbor, MI 48109-2133 phone: (734...NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) University of Michigan,Department of Mechanical Engineering,Ann Arbor,MI,48109-2133 8

  12. Non-deterministic analysis of ocean environment loads

    SciTech Connect

    Fang Huacan; Xu Fayan; Gao Guohua; Xu Xingping

    1995-12-31

    Ocean environment loads consist of the wind force, sea wave force etc. Sea wave force not only has randomness, but also has fuzziness. Hence the non-deterministic description of wave environment must be carried out, in designing of an offshore structure or evaluation of the safety of offshore structure members in service. In order to consider the randomness of sea wave, the wind speed single parameter sea wave spectrum is proposed in the paper. And a new fuzzy grading statistic method for considering fuzziness of sea wave height H and period T is given in this paper. The principle and process of calculating fuzzy random sea wave spectrum will be published lastly.

  13. Paludification and Forest Retreat in Northern Oceanic Environments

    PubMed Central

    CRAWFORD, R. M. M.; JEFFREE, C. E.; REES, W. G.

    2003-01-01

    Examination of temperature variations over the past century for Europe and the Arctic from northern Norway to Siberia suggests that variations in the North Atlantic Oscillation are associated with an increase in oceanicity in certain maritime regions. A southward depression of the treeline in favour of wet heaths, bogs and wetland tundra communities is also observed in northern oceanic environments. The physiological basis for this change in ecological succession from forest to bog is discussed in relation to the long‐term effects of flooding on tree survival. The heightened values currently detected in the North Atlantic Oscillation Index, together with rising winter temperatures, and increased rainfall in many areas in northern Europe, presents an increasing risk of paludification with adverse consequences for forest regeneration, particularly in areas with oceanic climates. Climatic warming in oceanic areas may increase the area covered by bogs and, contrary to general expectations, lead to a retreat rather than an advance in the northern limit of the boreal forest. High water‐table levels are not automatically detrimental to forest survival as can be seen in swamp, bottomland and mangrove forests. Consequently, the inhibitory effects of flooding on tree survival and regeneration in northern regions should not be uncritically accepted as merely due to high water levels. Evidence is discussed which suggests that physiological and ecological factors may interact to inhibit forest regeneration in habitats where there is a risk of prolonged winter‐flooding combined with warmer winters and cool moist summers. PMID:12509342

  14. Particles in the oceans: Implication for a safe marine environment.

    PubMed

    Blasco, Julian; Corsi, Ilaria; Matranga, Valeria

    2015-10-01

    Strategies and technologies for the ecosafety assessment and design of engineered particles entering the marine environment are urgently needed. As the application of nanoparticles in science and technology grows, the need to understand their impact on the marine environment becomes increasingly important. This Editorial introduces a Special Issue on the topic of a sustainable and safety use of nanoparticles for protecting, recovering and supporting the oceans' environment and consequently human health. The issue focus on the impact of micro/nano-plastics and metallic nanoparticles on marine organisms, as well as some methodological aspects associated to the eco/toxicity and analytical approaches for in deep physico-chemical characterization of nanoparticles in marine waters and sediment media. Important and urgent topics are addressed in the field of nano-ecosafety in order to assess more precisely both exposure routes and environmental hazards of nanoparticles in the ocean. Ecotoxicological and toxicological data, obtained using a wide variety of organisms representative of different trophic levels and biological organization, from whole animals to macromolecules, will be useful for a better definition of cleaner and safer nanoparticles. Efforts in developing a broad understanding of target species, expected results, benchmarks and timelines, will be of primary importance.

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

    PubMed

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

    2015-05-18

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

  16. Radioactive pollution: Ocean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    Not Available

    1994-04-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains a minimum of 161 citations and includes a subject term index and title list.)

  17. Radioactive pollution: Ocean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    1996-05-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  18. Radioactive pollution: Ocean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    1997-07-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  19. Ensemble-based global ocean data assimilation

    NASA Astrophysics Data System (ADS)

    Nadiga, Balasubramanya T.; Casper, W. Riley; Jones, Philip W.

    2013-12-01

    We present results of experiments performing global, ensemble-based, ocean-only data assimilation and assess the utility of such data assimilation in improving model predictions. The POP (Parallel Ocean Program) Ocean General Circulation Model (OGCM) is forced by interannually varying atmospheric fields of version 2 of the Coordinated Ocean Reference Experiment (CORE) data set, and temperature and salinity observations from the World Ocean Database 2009 (WOD09) are assimilated. The assimilation experiments are conducted over a period of about two years starting January 1, 1990 using the framework of the Data Assimilation Research Testbed (DART). We find that an inflation scheme that blends the ensemble-based sample error covariance with a static estimate of ensemble spread is necessary for the assimilations to be effective in the ocean model. We call this Climatology-based Spread Inflation or CSI for short. The effectiveness of the proposed inflation scheme is investigated in a low-order model; a series of experiments in this context demonstrates its effectiveness. Using a number of diagnostics, we show that the resulting assimilated state of ocean circulation is more realistic: In particular, the sea surface temperature (SST) shows reduced errors with respect to an unassimilated SST data set, and the subsurface temperature shows reduced errors with respect to observations. Finally, towards assessing the utility of assimilations for predictions, we show that the use of an assimilated state as initial condition leads to improved hindcast skill over a significant period of time; that is when the OGCM is initialized with an assimilated state and run forward, it is better able to predict unassimilated observations of the WOD09 than a control non-assimilating run (≈ 20% reduction in error) over a period of about three months. The loss of skill beyond this period is conjectured to be due, in part, to model error and prevents an improvement in the representation of

  20. Microplastics in coastal and marine environments of the western tropical and sub-tropical Atlantic Ocean.

    PubMed

    Costa, Monica F; Barletta, Mário

    2015-11-01

    Microplastic pollution is a global issue. It is present even in remote and pristine coastal and marine environments, likely causing impacts of unknown scale. Microplastics are primary- and secondary-sourced plastics with diameters of 5 mm or less that are either free in the water column or mixed in sandy and muddy sediments. Since the early 1970s, they have been reported to pollute marine environments; recently, concern has increased as soaring amounts of microplastics in the oceans were detected and because the development of unprecedented processes involving this pollutant at sea is being unveiled. Coastal and marine environments of the western tropical and sub-tropical Atlantic Ocean (WTAO) are contaminated with microplastics at different quantities and from a variety of types. The main environmental compartments (water, sediments and biota) are contaminated, but the consequences are still poorly understood. Rivers and all scales of fishery activities are identified as the most likely sources of this pollutant to coastal waters; however, based on the types of microplastics observed, other maritime operations are also possible sources. Ingestion by marine biota occurs in the vertebrate groups (fish, birds, and turtles) in these environments. In addition, the presence of microplastics in plankton samples from different habitats of estuaries and oceanic islands is confirmed. The connectivity among environmental compartments regarding microplastic pollution is a new research frontier in the region.

  1. Bayesian multiple-source localization in an uncertain ocean environment.

    PubMed

    Dosso, Stan E; Wilmut, Michael J

    2011-06-01

    This paper considers simultaneous localization of multiple acoustic sources when properties of the ocean environment (water column and seabed) are poorly known. A Bayesian formulation is developed in which the environmental parameters, noise statistics, and locations and complex strengths (amplitudes and phases) of multiple sources are considered to be unknown random variables constrained by acoustic data and prior information. Two approaches are considered for estimating source parameters. Focalization maximizes the posterior probability density (PPD) over all parameters using adaptive hybrid optimization. Marginalization integrates the PPD using efficient Markov-chain Monte Carlo methods to produce joint marginal probability distributions for source ranges and depths, from which source locations are obtained. This approach also provides quantitative uncertainty analysis for all parameters, which can aid in understanding of the inverse problem and may be of practical interest (e.g., source-strength probability distributions). In both approaches, closed-form maximum-likelihood expressions for source strengths and noise variance at each frequency allow these parameters to be sampled implicitly, substantially reducing the dimensionality and difficulty of the inversion. Examples are presented of both approaches applied to single- and multi-frequency localization of multiple sources in an uncertain shallow-water environment, and a Monte Carlo performance evaluation study is carried out.

  2. Stock assessment and management implications of horse mackerel ( Trachurus japonicus) in Korean waters, based on the relationships between recruitment and the ocean environment

    NASA Astrophysics Data System (ADS)

    Zhang, Chang Ik; Lee, Jae Bong

    This study presents an example of horse mackerel ( Trachurus japonicus) stock to demonstrate that marine environmental factors are important in stock assessment for the new Korean Total Allowable Catch (TAC)-based fisheries management system. The estimated survival rate ( S) of horse mackerel ranged from 0.25 to 0.36. The instantaneous coefficient of natural mortality ( M) was 0.48/year, and the age at first capture was 0.83 year. Annual biomass of horse mackerel in Korean waters was estimated by a biomass-based cohort analysis using annual catch in weight at age during 1965-1995. Yield-per-recruit and spawning biomass-per-recruit were estimated under various harvest strategies at Fmax, F0.1, F30% and F40%. A method for estimating acceptable biological catch (ABC) is proposed for dealing with the large differences in the quality and quantity of information and data available. Using recruitment of horse mackerel estimated from various spawner-recruitment relationship models combined with salinity, volume transport, and zooplankton biomass as environmental factors, the ABC under the best information available was estimated to range from 3100 to 3800 mt.

  3. Natural gas hydrate in oceanic and permafrost environments

    USGS Publications Warehouse

    Max, Michael D.

    2003-01-01

    THE BEGINNINGS OF HYDRATE RESEARCH Until very recently, our understanding of hydrate in the natural environment and its impact on seafloor stability, its importance as a sequester of methane, and its potential as an important mechanism in the Earth's climate change system, was masked by our lack of appreciation of the vastness of the hydrate resource. Only a few publications on naturally occurring hydrate existed prior to 1975. The first published reference to oceanic gas hydrate (Bryan and Markl, 1966) and the first publication in the scientific literature (Stoll, et a1., 1971) show how recently it has been since the topic of naturally occurring hydrate has been raised. Recently, however, the number of hydrate publications has increased substantially, reflecting increased research into hydrate topics and the initiation of funding to support the researchers. Awareness of the existence of naturally occurring gas hydrate now has spread beyond the few scientific enthusiasts who pursued knowledge about the elusive hydrate because of simple interest and lurking suspicions that hydrate would prove to be an important topic. The first national conference on gas hydrate in the U.S. was held as recently as April, 1991 at the U.S. National Center of the U.s. Geological Survey in Reston Virginia (Max et al., 1991). The meeting was co-hosted by the U.s. Geological Survey, the Naval Research Laboratory, and the U.S.

  4. Model-based inversion for a shallow ocean application

    SciTech Connect

    Candy, J.V.; Sullivan, E.J.

    1994-03-01

    A model-based approach to invert or estimate the sound speed profile (SSP) from noisy pressure-field measurements is discussed. The resulting model-based processor (MBP) is based on the state-space representation of the normal-mode propagation model. Using data obtained from the well-known Hudson Canyon experiment, a noisy shallow water ocean environment, the processor is designed and the results compared to those predicted using various propagation models and data. It is shown that the MBP not only predicts the sound speed quite well, but also is able to simultaneously provide enhanced estimates of both modal and pressure-field measurements which are useful for localization and rapid ocean environmental characterization.

  5. Ecological impacts of ocean acidification in coastal marine environments (Invited)

    NASA Astrophysics Data System (ADS)

    Harley, C.; Crim, R.; Gooding, R.; Nienhuis, S.; Tang, E.

    2010-12-01

    Rising atmospheric carbon dioxide concentrations are driving rapid and potentially unprecedented reductions in pH and carbonate ion availability in coastal marine environments. This process, known as ocean acidification (OA), has far-reaching implications for the performance and survival of marine organisms, particularly those with calcified shells and skeletons. Here, we highlight the ways in which OA impacts plants and animals in a coastal benthic food web, with an emphasis on what we know and what we don’t know about the ways in which the responses of individual organisms will scale up to long-term changes in community structure. Our system of interest is the rocky shore benthic community that is broadly represented from Alaska through California. Ecologically important species include producers (micro- and macro-algae), grazers (urchins and gastropods), filter feeders (mussels), and predators (sea stars). Although the direct effects of OA on coastal phytoplankton and kelps remain poorly understood, it appears as though elevated CO2 will increase the doubling rate of benthic diatoms. Small changes in food supply, however, may pale in comparison to the direct effects of OA on heavily calcified grazers and filter feeders. Sea urchin and mussel growth are both reduced by increased CO2 in the lab, and decadal-scale reductions in pH are associated with reduced turban snail growth in the field. Although adult abalone growth appears to be unaffected by CO2, larval development is impaired and larval survival is significantly reduced in acidified conditions. In contrast to the negative effects of OA on heavily calcified herbivores and filter feeders, lightly calcified sea stars actually grow faster when CO2 is experimentally increased. The acidification-induced changes described here are likely to result in substantial shifts in the benthic ecosystem. Increasing predation pressure may further reduce the abundance of grazers and filter feeders that are already suffering

  6. TARA OCEANS: A Global Analysis of Oceanic Plankton Ecosystems (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Karsenti, Eric

    2013-03-01

    Eric Karsenti of EMBL delivers the closing keynote on "TARA OCEANS: A Global Analysis of Oceanic Plankton Ecosystems" at the 8th Annual Genomics of Energy & Environment Meeting on March 28, 2013 in Walnut Creek, Calif.

  7. Oceanic minerals: Their origin, nature of their environment, and significance

    PubMed Central

    Kastner, Miriam

    1999-01-01

    The chemical and isotopic compositions of oceanic biogenic and authigenic minerals contain invaluable information on the evolution of seawater, hence on the history of interaction between tectonics, climate, ocean circulation, and the evolution of life. Important advances and greater understanding of (a) key minor and trace element cycles with various residence times, (b) isotopic sources and sinks and fractionation behaviors, and (c) potential diagenetic problems, as well as developments in high-precision instrumentation, recently have been achieved. These advances provided new compelling evidence that neither gradualism nor uniformitarianism can explain many of the new important discoveries obtained from the chemistry and isotopic compositions of oceanic minerals. Presently, the best-developed geochemical proxies in biogenic carbonates are 18O/16O and Sr/Ca ratios (possibly Mg/Ca) for temperature; 87Sr/86Sr for input sources, Cd/Ca and Ba/Ca ratios for phosphate and alkalinity concentrations, respectively, thus also for ocean circulation; 13C/12C for ocean productivity; B isotopes for seawater pH;, U, Th isotopes, and 14C for dating; and Sr and Mn concentrations for diagenesis. The oceanic authigenic minerals most widely used for chemical paleoceanography are barite, evaporite sulfates, and hydrogenous ferromanganese nodules. Marine barite is an effective alternative monitor of seawater 87Sr/86Sr, especially where carbonates are diagenetically altered or absent. It also provides a high-resolution record of seawater sulfate S isotopes, (evaporite sulfates only carry an episodic record), with new insights on factors affecting the S and C cycles and atmospheric oxygen. High-resolution studies of Sr, Nd, and Pb isotopes of well-dated ferromanganese nodules contain invaluable records on climate driven changes in oceanic circulation. PMID:10097047

  8. Oceanic minerals: their origin, nature of their environment, and significance.

    PubMed

    Kastner, M

    1999-03-30

    The chemical and isotopic compositions of oceanic biogenic and authigenic minerals contain invaluable information on the evolution of seawater, hence on the history of interaction between tectonics, climate, ocean circulation, and the evolution of life. Important advances and greater understanding of (a) key minor and trace element cycles with various residence times, (b) isotopic sources and sinks and fractionation behaviors, and (c) potential diagenetic problems, as well as developments in high-precision instrumentation, recently have been achieved. These advances provided new compelling evidence that neither gradualism nor uniformitarianism can explain many of the new important discoveries obtained from the chemistry and isotopic compositions of oceanic minerals. Presently, the best-developed geochemical proxies in biogenic carbonates are 18O/16O and Sr/Ca ratios (possibly Mg/Ca) for temperature; 87Sr/86Sr for input sources, Cd/Ca and Ba/Ca ratios for phosphate and alkalinity concentrations, respectively, thus also for ocean circulation; 13C/12C for ocean productivity; B isotopes for seawater pH;, U, Th isotopes, and 14C for dating; and Sr and Mn concentrations for diagenesis. The oceanic authigenic minerals most widely used for chemical paleoceanography are barite, evaporite sulfates, and hydrogenous ferromanganese nodules. Marine barite is an effective alternative monitor of seawater 87Sr/86Sr, especially where carbonates are diagenetically altered or absent. It also provides a high-resolution record of seawater sulfate S isotopes, (evaporite sulfates only carry an episodic record), with new insights on factors affecting the S and C cycles and atmospheric oxygen. High-resolution studies of Sr, Nd, and Pb isotopes of well-dated ferromanganese nodules contain invaluable records on climate driven changes in oceanic circulation.

  9. Coastal Ocean Observing Network - Open Source Architecture for Data Management and Web-Based Data Services

    NASA Astrophysics Data System (ADS)

    Pattabhi Rama Rao, E.; Venkat Shesu, R.; Udaya Bhaskar, T. V. S.

    2012-07-01

    The observations from the oceans are the backbone for any kind of operational services, viz. potential fishing zone advisory services, ocean state forecast, storm surges, cyclones, monsoon variability, tsunami, etc. Though it is important to monitor open Ocean, it is equally important to acquire sufficient data in the coastal ocean through coastal ocean observing systems for re-analysis, analysis and forecast of coastal ocean by assimilating different ocean variables, especially sub-surface information; validation of remote sensing data, ocean and atmosphere model/analysis and to understand the processes related to air-sea interaction and ocean physics. Accurate information and forecast of the state of the coastal ocean at different time scales is vital for the wellbeing of the coastal population as well as for the socio-economic development of the country through shipping, offshore oil and energy etc. Considering the importance of ocean observations in terms of understanding our ocean environment and utilize them for operational oceanography, a large number of platforms were deployed in the Indian Ocean including coastal observatories, to acquire data on ocean variables in and around Indian Seas. The coastal observation network includes HF Radars, wave rider buoys, sea level gauges, etc. The surface meteorological and oceanographic data generated by these observing networks are being translated into ocean information services through analysis and modelling. Centralized data management system is a critical component in providing timely delivery of Ocean information and advisory services. In this paper, we describe about the development of open-source architecture for real-time data reception from the coastal observation network, processing, quality control, database generation and web-based data services that includes on-line data visualization and data downloads by various means.

  10. Ocean Ambient Noise Studies for Shallow and Deep Water Environments

    DTIC Science & Technology

    2012-09-30

    full wave ocean noise model OASN [Schmidt 2004]. OASN is part of the OASES acoustic propagation package that numerically implements a full wave...solution producing a CSDM for surface noise in a horizontally stratified media using a spectral integration technique [Kuperman 1980, Jensen 2011]. OASES ...2004] H. Schmidt, OASES Version 3.1 User Guide and Reference Manual, Massachusetts Institute of Technology, http://acoustics.mit.edu/faculty/henrik

  11. The Chinese FY-1 Meteorological Satellite Application in Observation on Oceanic Environment

    NASA Astrophysics Data System (ADS)

    Weimin, S.

    meteorological satellite is stated in this paper. exploration of the ocean resources has been a very important question of global strategy in the world. The exploration of the ocean resources includes following items: Making full use of oceanic resources and space, protecting oceanic environment. to observe the ocean is by using of satellite. In 1978, US successfully launched the first ocean observation satellite in the world --- Sea Satellite. It develops ancient oceanography in to advanced space-oceanography. FY-1 B and FY- IC respectively. High quality data were acquired at home and abroad. FY-1 is Chinese meteorological satellite, but with 0.43 ~ 0.48 μm ,0.48 ~ 0.53 μm and 0.53 ~ 0.58 μm three ocean color channels, actually it is a multipurpose remote sensing satellite of meteorology and oceanography. FY-1 satellite's capability of observation on ocean partly, thus the application field is expanded and the value is increased. With the addition of oceanic channels on FY-1, the design of the satellite is changed from the original with meteorological observation as its main purpose into remote sensing satellite possessing capability of observing meteorology and ocean as well. Thus, the social and economic benefit of FY-1 is increased. the social and economic benefit of the development of the satellite is the key technique in the system design of the satellite. technically feasible but also save the funds in researching and manufacturing of the satellite, quicken the tempo of researching and manufacturing satellite. the scanning radiometer for FY-1 is conducted an aviation experiment over Chinese ocean. This experiment was of vital importance to the addition of oceanic observation channel on FY-1. FY-1 oceanic channels design to be correct. detecting ocean color. This is the unique character of Chinese FY-1 meteorological satellite. meteorological remote sensing channel on FY-1 to form detecting capability of three visible channels: red, yellow and blue

  12. Optimization of spectral bands for ocean colour remote sensing of aquatic environments

    NASA Astrophysics Data System (ADS)

    Nagamani, P. V.; Lotliker, Aneesh; Navalgund, R. R.; Dadhwal, V. K.; Rao, K. H.; Kumar, T. Srinivasa; Preethi Latha, T.

    2016-05-01

    Selection of central wavelengths, bandwidths and the number of spectral bands of any sensor to be flown on a remote sensing satellite is important to ensure discriminability of targets and adequate signal-to-noise ratio for the retrieval of parameters. In recent years, a large number of spectral measurements over a wide variety of water types in the Arabian Sea and the Bay of Bengal have been carried out through various ship cruises. It was felt pertinent to use this precious data set to arrive at meaningful selection of spectral bands and their bandwidths of the ocean colour sensor to be flown on the forthcoming Oceansat-3 of ISRO. According to IOOCG reports and studies by Lee and Carder (2002) it is better for a sensor to have 15 bands in the 400-800 nm range for adequate derivation of major properties (phytoplankton biomass, colored dissolved organic matter, suspended sediments, and bottom properties) in both oceanic and coastal environments from observation of water color. In this study, 417 hyper-spectral remote-sensing reflectance spectra (spectral range varies from 380-800 nm) covering different water types like open, coastal, mid coastal and near coastal waters have been used to identify the suitable spectral bands for OCM-3. Central wavelengths were identified based on the results obtained from hyper-spectral underwater radiometer measurements of Rrs, HPLC pigments and spectrometer analyzed absorption spectra for all the above water types. Derivative analysis has been carried out from 1st to 5th order to identify the inflection and null points for better discrimination / identification of spectral peaks from the in situ Rrs spectra. The results showed that open ocean and coastal ocean waters has spectra peaks mostly in the blue, green region; turbid coastal waters has maximum spectral peaks in the red region. Apart from this, the spectral peaks were identified in the red region for the chlorophyll fluorescence in the open ocean and coastal waters. Based on

  13. Ocean Wave Simulation Based on Wind Field.

    PubMed

    Li, Zhongyi; Wang, Hao

    2016-01-01

    Ocean wave simulation has a wide range of applications in movies, video games and training systems. Wind force is the main energy resource for generating ocean waves, which are the result of the interaction between wind and the ocean surface. While numerous methods to handle simulating oceans and other fluid phenomena have undergone rapid development during the past years in the field of computer graphic, few of them consider to construct ocean surface height field from the perspective of wind force driving ocean waves. We introduce wind force to the construction of the ocean surface height field through applying wind field data and wind-driven wave particles. Continual and realistic ocean waves result from the overlap of wind-driven wave particles, and a strategy was proposed to control these discrete wave particles and simulate an endless ocean surface. The results showed that the new method is capable of obtaining a realistic ocean scene under the influence of wind fields at real time rates.

  14. Marine birds and ice-influenced environments of polar oceans

    NASA Astrophysics Data System (ADS)

    Hunt, G. L.

    1991-07-01

    In polar oceans, sea ice both blocks the access of marine birds to aquatic foraging habitats and provides habitats at its margins where some species of birds find enhanced foraging opportunities. Sea ice harbors on its underside a community of organisms dependent on ice algae. In both the Arctic and the Antarctic Oceans, the larger zooplankton and small fishes of the under-ice community are important prey for birds that forage in leads or along the ice edge. Marine birds also forage seaward of the ice edge, where meltwater-induced stability leads to enhanced primary production in spring. Although few data are available on avian use of the open melt-water zone, because of its large area it is likely to be important for total energy flux to marine birds. We may expect considerable variation in avian use of the marginal ice zone. In regions where coupling exists between primary producers, secondary consumers, and higher level predators, marine birds are likely to be abundant. Where coupling is weak, avian use is less likely.

  15. Parallel Implementation of the Unified Curvilinear Ocean and Atmospheric (UCOAM) Model and Supporting Computational Environment

    NASA Astrophysics Data System (ADS)

    Thomas, Mary Prouty

    A new parallel framework and associated cyberinfrastructure has been verified to efficiently and accurately run Unified Curvilinear Ocean and Atmospheric Model (UCOAM) simulations. UCOAM is a high-resolution (sub-km), non-hydrostatic, large eddie simulation (LES) computational fluid dynamics model that is capable of running ocean and atmospheric simulations. UCOAM is the only environmental model in existence today that uses a full 3D curvilinear coordinate system, which results in increased accuracy, resolution, and reduced times to solution. UCOAM is a petascale model: for 10 meter resolutions, array sizes will scale as theta(1012) bytes, resulting in a large on node memory footprint; meaningful model simulations will generate terabytes of data and run for long periods of time; the non-hydrostatic model will require 3D communications. A parallel framework (PFW) has been developed that is capable of distributing data and computations across arbitrary 3D processor arrangements, of managing the Arikawa-C staggered grid variables and several finite difference stencils. The framework is written in Fortran 95, is component based and modular, and is completely decoupled from the application. The PFW communication model is based on the Message Passing Interface (MPI), but can be extended to include other parallel approaches. The framework uses a simple block-block data distribution scheme and can handle arbitrary processor arrangements. The framework manages and tracks communications between arbitrary groups of processors in 1, 2, and 3 dimensions, and is aware of the locations of axial, diagonal and tri-diagonal neighbors. The application framework is based on the PFW and can support any UCOAM based application. To facilitate simulations, a computational environment (CE) based on the Cyberinfrastructure Web Application Framework (CyberWeb) has been developed to support access to and development of web services, portals, and cyberinfrastructure. The parallel framework has

  16. 11th National Conference on Science, Policy, and the Environment: Our Changing Oceans

    SciTech Connect

    Peter Saundry

    2012-04-17

    On January 19-21, 2011, The National Council for Science and the Environment (NCSE) successfully convened its 11th National Conference on Science, Policy and the Environment: Our Changing Oceans in Washington, DC at the Ronald Reagan Building and International Trade Center. Over 1,247 participants attended the conference, representing federal, state and local governments, university and colleges across the US, civil society organizations, the business community, and international entities. In addition, the conference was webcast to an audience across several states. The conference provided a forum to examine the profound changes our ocean will undergo over the next 25-50 years and share various perspectives on the new research, tools, and policy initiatives to protect and sustain our ocean. Conference highlights and recommendations are available to the public on NCSE's conference website, www.OurChangingOceans.org.

  17. Plastic pollution in the marine environment. (Latest citations from Oceanic Abstracts). Published Search

    SciTech Connect

    Not Available

    1993-02-01

    The bibliography contains citations concerning the adverse effects of synthetic polymers on oceans and beaches. The citations examine the impact of discarded plastics upon fish, seabirds, and other aquatic animals. The sources of plastic litter and the efforts of coastal communities to manage plastics pollution are referenced. International agreements designed to protect the marine environment by banning ocean dumping of plastics are discussed. (Contains a minimum of 145 citations and includes a subject term index and title list.)

  18. Development of a computational environment for the General Curvilinear Ocean Model

    NASA Astrophysics Data System (ADS)

    Thomas, Mary P.; Castillo, Jose E.

    2009-07-01

    The General Curvilinear Ocean Model (GCOM) differs significantly from the traditional approach, where the use of Cartesian coordinates forces the model to simulate terrain as a series of steps. GCOM utilizes a full three-dimensional curvilinear transformation, which has been shown to have greater accuracy than similar models and to achieve results more efficiently. The GCOM model has been validated for several types of water bodies, different coastlines and bottom shapes, including the Alarcon Seamount, Southern California Coastal Region, the Valencia Lake in Venezuela, and more recently the Monterey Bay. In this paper, enhancements to the GCOM model and an overview of the computational environment (GCOM-CE) are presented. Model improvements include migration from F77 to F90; approach to a component design; and initial steps towards parallelization of the model. Through the use of the component design, new models are being incorporated including biogeochemical, pollution, and sediment transport. The computational environment is designed to allow various client interactions via secure Web applications (portal, Web services, and Web 2.0 gadgets). Features include building jobs, managing and interacting with long running jobs; managing input and output files; quick visualization of results; publishing of Web services to be used by other systems such as larger climate models. The CE is based mainly on Python tools including a grid-enabled Pylons Web application Framework for Web services, pyWSRF (python-Web Services-Resource Framework), pyGlobus based web services, SciPy, and Google code tools.

  19. Radioactive pollution: ocean environments. January 1974-May 1989 (Citations from Oceanic Abstracts). Report for January 1974-May 1989

    SciTech Connect

    Not Available

    1989-06-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distributions of radionuclides indicative of artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, cesium-137, cobalt-60, strontium-90, ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil-fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains 108 citations fully indexed and including a title list.)

  20. Oil spill detection in ocean environment via ultrasonic imaging and spectral fringe-adjusted joint transform correlation

    NASA Astrophysics Data System (ADS)

    Chowdhury, Nizam U.; Sakla, Adel A.; Alam, Mohammad S.

    2013-08-01

    A novel technique for oil spill detection in an ocean environment from ultrasonic hyperspectral imagery (UHI) using spectral fringe-adjusted joint transform correlation (SFJTC) is presented. Since UHI is a new concept and such data are not available, for this work an UHI dataset is created from pure target (oil) and background (sea water) signatures using a linear mixing model. A new SFJTC-based technique for oil spill detection in ocean environment has been developed and tested by using the UHI dataset. To evaluate the performance of the proposed technique, we used the receiver operating characteristics (ROC) curves and the area under the ROC. Test results confirm that the proposed technique shows excellent results even in the presence of a large amount of noise in the UHI data.

  1. Cycling of DDT in the global environment 1950-2002: World ocean returns the pollutant

    NASA Astrophysics Data System (ADS)

    Stemmler, Irene; Lammel, Gerhard

    2009-12-01

    The global distribution and fate of the insecticide DDT was modeled for the first time using a spatially resolved global multicompartment chemistry-transport model comprising a 3D coupled atmosphere and ocean GCM, coupled to 2D vegetation surfaces and top soils. DDT enters the model environment as a pesticide in agriculture only. Final sinks of DDT in the total environment are degradation in air (hydroxyl radical reaction), on vegetation surfaces, in ocean sediments and soils. The process resolution of the ocean compartment, i.e., either a fixed or variable size and sinking velocity of suspended particles, has almost no effect on the large-scale cycling and fate of DDT. The residence times in various ocean basins were declining but varied regionally. The global ocean absorbed until 1977 and since then has been losing DDT, while large sea areas are still accumulating the pollutant. The main sink is volatilization to the atmosphere. In 1990, the year when emissions ceased, 292 kt of DDT were deposited to the global ocean, 301 kt were volatilized, and 41 kt were exported from the surface layer to the deeper levels. The sea region that has been representing the most significant (secondary) DDT source is the western N Atlantic (Gulf stream and N Atlantic Drift regions). It has been a source since approximately 1970. Also large parts of the tropical ocean and the southern mid-latitude ocean have turned net volatilizational (i.e., volatilization flux > deposition flux) during the 1980s. Despite the emissions migrating southward as a consequence of substance ban in mid latitudes, the geographic distribution of the contaminant (and, hence, environmental exposure) has been migrating steadily northward since the 1960s.

  2. Frequency-Difference Source Localization and Blind Deconvolution in Shallow Ocean Environments

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Frequency-Difference Source Localization and Blind ... blind deconvolution technique to dynamic multipath environments, and (ii) determining the utility of the frequency difference concept within matched...goals of this project are: i) to determine the effectiveness of STR for the purposes of blind deconvolution in dynamic noisy unknown ocean sound channels

  3. Brachiopod taxa and shell portions reliably recording past ocean environments: Toward establishing a robust paleoceanographic proxy

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kazuyuki; Asami, Ryuji; Iryu, Yasufumi

    2011-07-01

    Fossils of rhynchonelliform brachiopods (marine invertebrates) constitute ˜70% of the samples used for delineating a well-known Phanerozoic trend in oxygen isotope composition (δ18O) of low-Mg calcite shells. The trend represents secular variations in temperature and/or δ18O of ancient seawater. However, the use of brachiopods as a paleoceanographic proxy is based on the presupposition that the shell calcite is precipitated in isotopic equilibrium with ambient seawater. Here, we show that high-resolution time series of the shell δ18O values along the maximum growth axes of two long-lived cool-water brachiopods are identical to, greater than, or less than those of calcite precipitated in isotopic equilibrium with ambient seawater, depending on the difference in shell growth rates. Coupled with δ18O data from subtropical and warm-temperate brachiopod species examined in our previous studies, we provide a sound framework illustrating which taxa and shell portions reliably recorded past ocean environments.

  4. Geoacoustic inversion in range-dependent ocean environments using a plane wave reflection coefficient approach

    NASA Astrophysics Data System (ADS)

    Stotts, S. A.; Knobles, D. P.; Koch, R. A.; Grant, D. E.; Focke, K. C.; Cook, A. J.

    2004-03-01

    A new, efficient, versatile ray-based model is presented that performs geoacoustic inversions in range-dependent ocean waveguides faster than alternative forward models for which the computation time becomes extremely long, especially for broadband inversions. The water propagation is approximately separated from the seabed interaction using predetermined bathymetry and a possibly range-dependent water sound speed profile. The geometrical optics approximation is used to calculate eigenrays between sources and receivers, including bottom reflecting paths. Modeled broadband pressure fields are obtained by computing the plane wave reflection coefficient at specific angles and frequencies and by then linking this result with the bottom reflected eigenrays. Each perturbation of the seabed requires a recalculation of the plane wave reflection coefficient, but not a recalculation of the eigenrays, resulting in a highly efficient method. Range-independent problems are treated as a limiting case of the approach. The method is first described and then demonstrated with a few simple range-independent theoretical models. The versatility of addressing range-dependence in the bottom seabed is demonstrated with a simulated data set. Finally, the new model is applied to inversion from a measured data set, taken with impulsive sources, for both range-independent and range-dependent continental shelf environments.

  5. Studies of oceanic tectonics based on GEOS-3 satellite altimetry

    NASA Technical Reports Server (NTRS)

    Poehls, K. A.; Kaula, W. M.; Schubert, G.; Sandwell, D.

    1979-01-01

    Using statistical analysis, geoidal admittance (the relationship between the ocean geoid and seafloor topography) obtained from GEOS-3 altimetry was compared to various model admittances. Analysis of several altimetry tracks in the Pacific Ocean demonstrated a low coherence between altimetry and seafloor topography except where the track crosses active or recent tectonic features. However, global statistical studies using the much larger data base of all available gravimetry showed a positive correlation of oceanic gravity with topography. The oceanic lithosphere was modeled by simultaneously inverting surface wave dispersion, topography, and gravity data. Efforts to incorporate geoid data into the inversion showed that the base of the subchannel can be better resolved with geoid rather than gravity data. Thermomechanical models of seafloor spreading taking into account differing plate velocities, heat source distributions, and rock rheologies were discussed.

  6. Imaging Enhancement on Deep Seismic Reflection with Petrel and Ocean Working Environment

    NASA Astrophysics Data System (ADS)

    Yu, P.; Huang, D.; Feng, X.; Li, L.; Liu, W.; Wang, Y.; Zhao, Q.

    2011-12-01

    SinoProbe has been initiated to enhance understanding of earth deep structure, resources and geological disasters forecasting throughout Chinese continent. Besides traditional deep exploration methods, various state-of-the-art technologies have been carried out in order to acquire data and jointly utilize all possible information reflecting deep crust and mantle structures and evolution.Petrel, a powerful software application developed by Schlumberger, has been successfully applied to the O&G industry. It is now a complete seismic-to-simulation application for 3D and 2D seismic interpretation. However, it has a great potential to allow the user to extend utilization with multiple types of data sets to deal with much deeper geophysical information. Petrel all-in-one concept, that functionally comprises of massive data integration, multiple domains experts participation and 3D geological object-oriented etc., will come benefit to the deep earth study. Currently, there is no special tool designed for this purpose so that Petrel is required to extend its potential to cope with not only O&G area but also a larger area with unique requests of deeper objects.Ocean, a software framework for Petrel, provides an open development environment offering seamless integration of developer intellectual contribution to the Petrel mainstream workflow. It is able to accelerate the development and deployment of user's Petrel-like workflows to resolve complex problems. It can be implemented by means of plug-ins utilities although there is additional challenge to write a robust code with Ocean framework. Deep seismic reflection profiling is a well recognized technique to reveal the fine structure of lithosphere. Moreover, it can perform a significant role for prospective evaluation of O&G and mineral resources, and geological disasters. Its near-vertical deep seismic reflection method can enhance broad band seismic observations for imaging of the deep crust and continental geodynamics

  7. Effect of the 'Vesulian events' on the foraminifers and ostracods in the Tethyan oceanic environment

    NASA Astrophysics Data System (ADS)

    Görög, Ágnes; Wernli, Roland; Tóth, Emőke

    2014-05-01

    In the north-western Tethys, at the Early/Late Bajocian boundary the 'Vesulian Unconformity' can be recognized as a result of carbonate crisis caused by transgression, culminating in the late Niortense -early Garantiana zones, followed by cooling and sudden regression. Later, in the Zigzag and Progracilis zones there was a regression causing also first-order crisis in the ammonite fauna. Up to know only the early Bajocian (BARBIERI, 1964; MONOSTORI, 1995; WERNLI and GöRöG, 1999, 2000) and middle - late Bathonian (GöRöG and WERNLI, 2002) microfauna of the Tethyan oceanic realm were studied and we have no information about late Bajocian -early Bathonian interval. The study of the foraminifera and ostracoda fauna from succession of Gyenespuszta, Bakony Mts, Hungary fill the gap of the records about these ages. The succession consists of ammonitico rosso type limestones, deposited on a submarine high. Despite the heavy condensation a relatively complete stratigraphic sequence (4 m) from the late Bajocian Humphresianum Zone up to late Bathonian Retrocostatum Zone could be identified based on ammonites (GALáCZ, 1970, 1980), which is unique in the Tethys. From each of the 18 beds, thin sections were made for microfauna and microfacies studies and the microfauna were extracted by pure acetic acid. In the ostracoda fauna is relative poor (13 species) consisting of smooth bairdids, Paracypris, Bythocypris, Pontocyprella and Polycope species. Several are known only from the Tethyan oceanic environment, while others occurred also in deep sublittoral - bathyal zone of the epicontinental areas. In the foraminifera fauna 55 benthic and 6 plankton protoglobigerinids (Globuligerina oxfordiana, G. bathoniana, G. aff. bathoniana, Conoglobigerina? aff. dagestanica, C.? avariformis forma alta and sphaerica) could be identified. The fauna differs from the epicontinental ones basically in the ratio of the different forms. Throughout the succession the protoglobigerinids (10

  8. Self-Organizing Maps-based ocean currents forecasting system

    PubMed Central

    Vilibić, Ivica; Šepić, Jadranka; Mihanović, Hrvoje; Kalinić, Hrvoje; Cosoli, Simone; Janeković, Ivica; Žagar, Nedjeljka; Jesenko, Blaž; Tudor, Martina; Dadić, Vlado; Ivanković, Damir

    2016-01-01

    An ocean surface currents forecasting system, based on a Self-Organizing Maps (SOM) neural network algorithm, high-frequency (HF) ocean radar measurements and numerical weather prediction (NWP) products, has been developed for a coastal area of the northern Adriatic and compared with operational ROMS-derived surface currents. The two systems differ significantly in architecture and algorithms, being based on either unsupervised learning techniques or ocean physics. To compare performance of the two methods, their forecasting skills were tested on independent datasets. The SOM-based forecasting system has a slightly better forecasting skill, especially during strong wind conditions, with potential for further improvement when data sets of higher quality and longer duration are used for training. PMID:26979129

  9. Self-Organizing Maps-based ocean currents forecasting system.

    PubMed

    Vilibić, Ivica; Šepić, Jadranka; Mihanović, Hrvoje; Kalinić, Hrvoje; Cosoli, Simone; Janeković, Ivica; Žagar, Nedjeljka; Jesenko, Blaž; Tudor, Martina; Dadić, Vlado; Ivanković, Damir

    2016-03-16

    An ocean surface currents forecasting system, based on a Self-Organizing Maps (SOM) neural network algorithm, high-frequency (HF) ocean radar measurements and numerical weather prediction (NWP) products, has been developed for a coastal area of the northern Adriatic and compared with operational ROMS-derived surface currents. The two systems differ significantly in architecture and algorithms, being based on either unsupervised learning techniques or ocean physics. To compare performance of the two methods, their forecasting skills were tested on independent datasets. The SOM-based forecasting system has a slightly better forecasting skill, especially during strong wind conditions, with potential for further improvement when data sets of higher quality and longer duration are used for training.

  10. Self-Organizing Maps-based ocean currents forecasting system

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Šepić, Jadranka; Mihanović, Hrvoje; Kalinić, Hrvoje; Cosoli, Simone; Janeković, Ivica; Žagar, Nedjeljka; Jesenko, Blaž; Tudor, Martina; Dadić, Vlado; Ivanković, Damir

    2016-03-01

    An ocean surface currents forecasting system, based on a Self-Organizing Maps (SOM) neural network algorithm, high-frequency (HF) ocean radar measurements and numerical weather prediction (NWP) products, has been developed for a coastal area of the northern Adriatic and compared with operational ROMS-derived surface currents. The two systems differ significantly in architecture and algorithms, being based on either unsupervised learning techniques or ocean physics. To compare performance of the two methods, their forecasting skills were tested on independent datasets. The SOM-based forecasting system has a slightly better forecasting skill, especially during strong wind conditions, with potential for further improvement when data sets of higher quality and longer duration are used for training.

  11. An Adaptive Particle Filtering Approach to Tracking Modes in a Varying Shallow Ocean Environment

    SciTech Connect

    Candy, J V

    2011-03-22

    The shallow ocean environment is ever changing mostly due to temperature variations in its upper layers (< 100m) directly affecting sound propagation throughout. The need to develop processors that are capable of tracking these changes implies a stochastic as well as an 'adaptive' design. The stochastic requirement follows directly from the multitude of variations created by uncertain parameters and noise. Some work has been accomplished in this area, but the stochastic nature was constrained to Gaussian uncertainties. It has been clear for a long time that this constraint was not particularly realistic leading a Bayesian approach that enables the representation of any uncertainty distribution. Sequential Bayesian techniques enable a class of processors capable of performing in an uncertain, nonstationary (varying statistics), non-Gaussian, variable shallow ocean. In this paper adaptive processors providing enhanced signals for acoustic hydrophonemeasurements on a vertical array as well as enhanced modal function estimates are developed. Synthetic data is provided to demonstrate that this approach is viable.

  12. Carbon-based ocean productivity and phytoplankton physiology from space

    NASA Astrophysics Data System (ADS)

    Behrenfeld, Michael J.; Boss, Emmanuel; Siegel, David A.; Shea, Donald M.

    2005-03-01

    Ocean biogeochemical and ecosystem processes are linked by net primary production (NPP) in the ocean's surface layer, where inorganic carbon is fixed by photosynthetic processes. Determinations of NPP are necessarily a function of phytoplankton biomass and its physiological status, but the estimation of these two terms from space has remained an elusive target. Here we present new satellite ocean color observations of phytoplankton carbon (C) and chlorophyll (Chl) biomass and show that derived Chl:C ratios closely follow anticipated physiological dependencies on light, nutrients, and temperature. With this new information, global estimates of phytoplankton growth rates (μ) and carbon-based NPP are made for the first time. Compared to an earlier chlorophyll-based approach, our carbon-based values are considerably higher in tropical oceans, show greater seasonality at middle and high latitudes, and illustrate important differences in the formation and demise of regional algal blooms. This fusion of emerging concepts from the phycological and remote sensing disciplines has the potential to fundamentally change how we model and observe carbon cycling in the global oceans.

  13. Temperature and depth profiles recorded during dives of elephant seals reflect distinct ocean environments

    NASA Astrophysics Data System (ADS)

    Campagna, Claudio; Rivas, Andrés L.; Marin, M. Rosa

    2000-03-01

    Foraging adult southern elephant seals, Mirounga leonina, from Penı´nsula Valdés, Argentina, dive continuously while travelling across the continental shelf towards deep waters of the SW Atlantic. This study attempted to identify distinct ocean environments encountered by these seals during foraging migrations based on bathymetric and water temperature profiles, and to interpret these profiles in terms of mixing and systems of currents. Depth and water temperature were obtained with data loggers carried by 14 diving adult animals during spring (October-December) and summer (February-March) months. Dive depths allowed us to unmistakably differentiate extensive areas of the SW Atlantic: the Patagonian shelf, shelf slope and open waters of the Argentine Basin. Water temperature profiles added further details to the latter general oceanographic areas, and could be related to large-scale oceanographic processes that led to different water column structures. Temperature data reflected the mixing effects of winds and tides in coastal waters, the formation of a thermocline in mid-shelf areas, the northward flow of the sub-antartic Malvinas Current at the edge of the shelf, and the effect of the subtropical Brazil Current further east over deep off-shelf waters. Some of these distinct areas are known for their enhanced primary production associated with frontal systems. The study shows that elephant seals could be useful, low-cost platforms to obtain oceanographic data. Studies that require extensive sampling of physical variables in large areas over long periods of time would benefit from this approach, pending on more precise and frequent locations of animals at sea.

  14. SSL: Signal Similarity-Based Localization for Ocean Sensor Networks

    PubMed Central

    Chen, Pengpeng; Ma, Honglu; Gao, Shouwan; Huang, Yan

    2015-01-01

    Nowadays, wireless sensor networks are often deployed on the sea surface for ocean scientific monitoring. One of the important challenges is to localize the nodes’ positions. Existing localization schemes can be roughly divided into two types: range-based and range-free. The range-based localization approaches heavily depend on extra hardware capabilities, while range-free ones often suffer from poor accuracy and low scalability, far from the practical ocean monitoring applications. In response to the above limitations, this paper proposes a novel signal similarity-based localization (SSL) technology, which localizes the nodes’ positions by fully utilizing the similarity of received signal strength and the open-air characteristics of the sea surface. In the localization process, we first estimate the relative distance between neighboring nodes through comparing the similarity of received signal strength and then calculate the relative distance for non-neighboring nodes with the shortest path algorithm. After that, the nodes’ relative relation map of the whole network can be obtained. Given at least three anchors, the physical locations of nodes can be finally determined based on the multi-dimensional scaling (MDS) technology. The design is evaluated by two types of ocean experiments: a zonal network and a non-regular network using 28 nodes. Results show that the proposed design improves the localization accuracy compared to typical connectivity-based approaches and also confirm its effectiveness for large-scale ocean sensor networks. PMID:26610520

  15. Radioactive pollution: Oean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    1995-02-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains a minimum of 168 citations and includes a subject term index and title list.)

  16. Convective available potential energy in the environment of oceanic and continental clouds: Correction and comments

    NASA Technical Reports Server (NTRS)

    Lucas, Christopher; Zipser, Edward J.; Lemone, Margaret A.

    1994-01-01

    In 1980, Zipser and LeMone estimated the convective available potential energy (CAPE) for the Thunderstorm Project cumulonimbus environment to be about 3000 J per kg. By assuming the most adiabat reported by Byers and Braham (1949) to be that of an undilute parcel rather than a reference moist adiabat, a significant error was introduced. On the basis of recent calculations made under similar conditions in Oklahoma and Florida, CAPE is now estimated to be considerably lower. These lower CAPE estimates shed doubt on the suggestion that differences in CAPE account for differences in the vertical velocities in convective updrafts over land and over the ocean.

  17. Search strategy in a complex and dynamic environment (the Indian Ocean case)

    NASA Astrophysics Data System (ADS)

    Loire, Sophie; Arbabi, Hassan; Clary, Patrick; Ivic, Stefan; Crnjaric-Zic, Nelida; Macesic, Senka; Crnkovic, Bojan; Mezic, Igor; UCSB Team; Rijeka Team

    2014-11-01

    The disappearance of Malaysia Airlines Flight 370 (MH370) in the early morning hours of 8 March 2014 has exposed the disconcerting lack of efficient methods for identifying where to look and how to look for missing objects in a complex and dynamic environment. The search area for plane debris is a remote part of the Indian Ocean. Searches, of the lawnmower type, have been unsuccessful so far. Lagrangian kinematics of mesoscale features are visible in hypergraph maps of the Indian Ocean surface currents. Without a precise knowledge of the crash site, these maps give an estimate of the time evolution of any initial distribution of plane debris and permits the design of a search strategy. The Dynamic Spectral Multiscale Coverage search algorithm is modified to search a spatial distribution of targets that is evolving with time following the dynamic of ocean surface currents. Trajectories are generated for multiple search agents such that their spatial coverage converges to the target distribution. Central to this DSMC algorithm is a metric for the ergodicity.

  18. An ENSO prediction approach based on ocean conditions and ocean-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Tseng, Yu-heng; Hu, Zeng-Zhen; Ding, Ruiqiang; Chen, Han-ching

    2017-03-01

    A simple statistical model for the El Niño-Southern Oscillation (ENSO) prediction is derived based on the evolution of the ocean heat condition and the oceanic Kelvin wave propagation associated with westerly wind events (WWEs) and easterly wind surges (EWSs) in the tropical Pacific. The multivariate linear regression model solely relies on the pentad thermocline depth anomaly evolution in 25 days along with the zonal surface wind modulation. It successfully hindcasts all ENSOs except for the 2000/01 La Niña, using the pentad (or monthly) mean tropical atmosphere ocean array data since 1994 with an averaged skill (measured by anomaly correlation) of 0.62 (or 0.67) with a 6-month lead. The exception is mainly due to the long-lasting cold sea surface temperature anomalies in the subtropics resulting from the strong 1998/99 La Niña, even though the tropical warm water volume (WWV) had rebounded and turned phases after 2000. We also note that the hindcast skill is comparable using pentad or monthly mean NCEP global ocean data assimilation system data for the same time period. The hindcast skill of the proposed statistical model is better than that based on the WWV index in terms of the monthly correlation, normalized RMSEs and ENSO occurrences, which suggest that including the evolution of the subsurface ocean temperature anomaly and the WWEs/EWSs in the central tropical Pacific can enhance the ability to predict ENSO. The hindcast skill is also comparable to the predictions using other dynamical and statistical models, indicating that these processes are the keys to ENSO development. The dynamics behind the statistical model are consistent with the physical processes of ENSO development as follows: the tropical WWV resulting from the interannually-varying meridional subtropical cell transport provides a sufficient heat source. When the seasonal phase lock of ocean-atmosphere coupling triggers the positive (negative) zonal wind anomaly in boreal summer and fall, an

  19. Identifying Rhodamine Dye Plume Sources in Near-Shore Oceanic Environments by Integration of Chemical and Visual Sensors

    PubMed Central

    Tian, Yu; Kang, Xiaodong; Li, Yunyi; Li, Wei; Zhang, Aiqun; Yu, Jiangchen; Li, Yiping

    2013-01-01

    This article presents a strategy for identifying the source location of a chemical plume in near-shore oceanic environments where the plume is developed under the influence of turbulence, tides and waves. This strategy includes two modules: source declaration (or identification) and source verification embedded in a subsumption architecture. Algorithms for source identification are derived from the moth-inspired plume tracing strategies based on a chemical sensor. The in-water test missions, conducted in November 2002 at San Clemente Island (California, USA) in June 2003 in Duck (North Carolina, USA) and in October 2010 at Dalian Bay (China), successfully identified the source locations after autonomous underwater vehicles tracked the rhodamine dye plumes with a significant meander over 100 meters. The objective of the verification module is to verify the declared plume source using a visual sensor. Because images taken in near shore oceanic environments are very vague and colors in the images are not well-defined, we adopt a fuzzy color extractor to segment the color components and recognize the chemical plume and its source by measuring color similarity. The source verification module is tested by images taken during the CPT missions. PMID:23507823

  20. Identifying rhodamine dye plume sources in near-shore oceanic environments by integration of chemical and visual sensors.

    PubMed

    Tian, Yu; Kang, Xiaodong; Li, Yunyi; Li, Wei; Zhang, Aiqun; Yu, Jiangchen; Li, Yiping

    2013-03-18

    This article presents a strategy for identifying the source location of a chemical plume in near-shore oceanic environments where the plume is developed under the influence of turbulence, tides and waves. This strategy includes two modules: source declaration (or identification) and source verification embedded in a subsumption architecture. Algorithms for source identification are derived from the moth-inspired plume tracing strategies based on a chemical sensor. The in-water test missions, conducted in November 2002 at San Clemente Island (California, USA) in June 2003 in Duck (North Carolina, USA) and in October 2010 at Dalian Bay (China), successfully identified the source locations after autonomous underwater vehicles tracked the rhodamine dye plumes with a significant meander over 100 meters. The objective of the verification module is to verify the declared plume source using a visual sensor. Because images taken in near shore oceanic environments are very vague and colors in the images are not well-defined, we adopt a fuzzy color extractor to segment the color components and recognize the chemical plume and its source by measuring color similarity. The source verification module is tested by images taken during the CPT missions.

  1. Environmental Risk Evaluation System – An Approach to Ranking Risk of Ocean Energy Development on Coastal and Estuarine Environments

    SciTech Connect

    Copping, Andrea E.; Hanna, Luke A.; Van Cleve, Frances B.; Blake, Kara M.; Anderson, Richard M.

    2015-01-01

    Deployment and operation of ocean energy devices does not represent the first foray into industrialization of the oceans; shipping, nearshore development, waste disposal, subsea mining, oil and gas extraction, and large-scale commercial fishing all coexist in various states of equilibrium with the marine environment. In most cases these industries were developed without a clear understanding of the likely outcomes of large-scale development. In virtually every country where the harvest of ocean energy is emerging, regulators and stakeholders require that the industry examine potential effects of devices, minimize the footprint of effects, and provide management measures that either avoid the impacts or mitigate to further reduce the residual impacts. The ERES analysis is based on scenarios that are consistent with sequences of events that lead to adverse impacts, distinguishing between episodic, intermittent, and chronic risks. In the context of ocean energy development, an episodic scenario might involve the exceedingly rare but potentially devastating event of an oil spill from vessels caused by the presence of the device, while vulnerable receptors are present; understanding the risk of such a scenario involves determining the probability of the occurrence by examining factors such as the petroleum content of ocean energy devices, the vessel traffic volume and the proximity of shipping lanes to the ocean energy devices, the reliability of the control measures to avoid an episodic event, and the likely presence of seabirds, marine mammals, or fish that may be affected by oil. In contrast, chronic risk scenarios involve events or circumstances that are continuous, so that risk characterization involves assessing only the severity of the consequences. An example of a chronic risk scenario might be the toxicity to marine organisms due to low-level chemical releases from anti-biofouling paints and coatings that may be used on devices, and the effect that the level of

  2. Spacecraft VHF Radio Propagation Analysis in Ocean Environments Including Atmospheric Effects

    NASA Technical Reports Server (NTRS)

    Hwu, Shian; Moreno, Gerardo; Desilva, Kanishka; Jih, CIndy

    2010-01-01

    The Communication Systems Simulation Laboratory (CSSL) at the National Aeronautics and Space Administration (NASA)/Johnson Space Center (JSC) is tasked to perform spacecraft and ground network communication system simulations. The CSSL has developed simulation tools that model spacecraft communication systems and the space/ground environment in which they operate. This paper is to analyze a spacecraft's very high frequency (VHF) radio signal propagation and the impact to performance when landing in an ocean. Very little research work has been done for VHF radio systems in a maritime environment. Rigorous Radio Frequency (RF) modeling/simulation techniques were employed for various environmental effects. The simulation results illustrate the significance of the environmental effects on the VHF radio system performance.

  3. Space-based lidar measurements of global ocean carbon stocks

    NASA Astrophysics Data System (ADS)

    Behrenfeld, Michael J.; Hu, Yongxiang; Hostetler, Chris A.; Dall'Olmo, Giorgio; Rodier, Sharon D.; Hair, John W.; Trepte, Charles R.

    2013-08-01

    Global ocean phytoplankton biomass (Cphyto) and total particulate organic carbon (POC) stocks have largely been characterized from space using passive ocean color measurements. A space-based light detection and ranging (lidar) system can provide valuable complementary observations for Cphyto and POC assessments, with benefits including day-night sampling, observations through absorbing aerosols and thin cloud layers, and capabilities for vertical profiling through the water column. Here we use measurements from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) to quantify global Cphyto and POC from retrievals of subsurface particulate backscatter coefficients (bbp). CALIOP bbp data compare favorably with airborne, ship-based, and passive ocean data and yield global average mixed-layer standing stocks of 0.44 Pg C for Cphyto and 1.9 Pg for POC. CALIOP-based Cphyto and POC data exhibit global distributions and seasonal variations consistent with ocean plankton ecology. Our findings support the use of spaceborne lidar measurements for advancing understanding of global plankton systems.

  4. Broadband Processing in a Noisy Shallow Ocean Environment: A Particle Filtering Approach

    SciTech Connect

    Candy, J. V.

    2016-04-14

    Here we report that when a broadband source propagates sound in a shallow ocean the received data can become quite complicated due to temperature-related sound-speed variations and therefore a highly dispersive environment. Noise and uncertainties disrupt this already chaotic environment even further because disturbances propagate through the same inherent acoustic channel. The broadband (signal) estimation/detection problem can be decomposed into a set of narrowband solutions that are processed separately and then combined to achieve more enhancement of signal levels than that available from a single frequency, thereby allowing more information to be extracted leading to a more reliable source detection. A Bayesian solution to the broadband modal function tracking, pressure-field enhancement, and source detection problem is developed that leads to nonparametric estimates of desired posterior distributions enabling the estimation of useful statistics and an improved processor/detector. In conclusion, to investigate the processor capabilities, we synthesize an ensemble of noisy, broadband, shallow-ocean measurements to evaluate its overall performance using an information theoretical metric for the preprocessor and the receiver operating characteristic curve for the detector.

  5. Broadband Processing in a Noisy Shallow Ocean Environment: A Particle Filtering Approach

    DOE PAGES

    Candy, J. V.

    2016-04-14

    Here we report that when a broadband source propagates sound in a shallow ocean the received data can become quite complicated due to temperature-related sound-speed variations and therefore a highly dispersive environment. Noise and uncertainties disrupt this already chaotic environment even further because disturbances propagate through the same inherent acoustic channel. The broadband (signal) estimation/detection problem can be decomposed into a set of narrowband solutions that are processed separately and then combined to achieve more enhancement of signal levels than that available from a single frequency, thereby allowing more information to be extracted leading to a more reliable source detection.more » A Bayesian solution to the broadband modal function tracking, pressure-field enhancement, and source detection problem is developed that leads to nonparametric estimates of desired posterior distributions enabling the estimation of useful statistics and an improved processor/detector. In conclusion, to investigate the processor capabilities, we synthesize an ensemble of noisy, broadband, shallow-ocean measurements to evaluate its overall performance using an information theoretical metric for the preprocessor and the receiver operating characteristic curve for the detector.« less

  6. Descriptive and grade-tonnage models of volcanogenic manganese deposits in oceanic environments; a modification

    USGS Publications Warehouse

    Mosier, Dan L.; Page, Norman J

    1988-01-01

    Four types of volcanogenic manganese deposits, distinguished on the basis of geologic, geochemical, and geophysical characteristics, appear to result from a combination of volcanic and hydrothermal processes related to hot-spring activity in oceanic environments. We compare these four desposit types, here called the Franciscan, Cuban, Olympic Peninsula, and Cyprus, with respect to host rocks, associated rocks, minerals, deposit shape, dimensions, volume, tonnage, grade, and mineral-deposit density (number of deposits per unit area). Franciscan-type deposits occur in obducted oceanic ridge and backarc marginal-basin environments, are associated with chert, shale, and graywacke aroun the margins of mafic volcanic centers, and have a median tonnage of 450 t and median grades of 36 weight percent Mn and less than 5.1 weight percent Fe. Cuban-type deposits occur in island-arc environments, are associated with tuff and limestone around domal structures or intrusions inferred to be volcanic centers, and have a median tonnage of 6,400 t and median grades of 39 weight percent Mn and less than 4.4 weight percent Fe. Olympic Peninsula-type deposits occur in obducted oceanic midplate settings, are associated with argillaceous limestone, argillite, and graywacke around mafic volcanic centers (seamounts or islands), and have a median tonnage of 340 t and median grades of 35 weight percent Mn and less than 6.5 weight percent Fe. Cyprus-type deposits occur in the same tectonic environments as Franciscan type but are associated with basalt, marl, chalk, silt, and chert off the ridge-axis position and have a median tonnage of 41,000 t and median grades of 33 weight percent Fe and 8 weight percent Mn. All these deposits are thin ellipsoids, concordant to the host rocks, but Cyprus-and Cuban-type deposits are larger than Franciscan- and Olympic Peninsula-type deposits. Except for Cyprus-type deposits, which are manganiferous iron (umber) deposits composed of hydrated iron and

  7. Spatio-temporal variability of aerosols in the tropics relationship with atmospheric and oceanic environments

    NASA Astrophysics Data System (ADS)

    Zuluaga-Arias, Manuel D.

    2011-12-01

    Earth's radiation budget is directly influenced by aerosols through the absorption of solar radiation and subsequent heating of the atmosphere. Aerosols modulate the hydrological cycle indirectly by modifying cloud properties, precipitation and ocean heat storage. In addition, polluting aerosols impose health risks in local, regional and global scales. In spite of recent advances in the study of aerosols variability, uncertainty in their spatio-temporal distributions still presents a challenge in the understanding of climate variability. For example, aerosol loading varies not only from year to year but also on higher frequency intraseasonal time scales producing strong variability on local and regional scales. An assessment of the impact of aerosol variability requires long period measurements of aerosols at both regional and global scales. The present dissertation compiles a large database of remotely sensed aerosol loading in order to analyze its spatio-temporal variability, and how this load interacts with different variables that characterize the dynamic and thermodynamic states of the environment. Aerosol Index (AI) and Aerosol Optical Depth (AOD) were used as measures of the atmospheric aerosol load. In addition, atmospheric and oceanic satellite observations, and reanalysis datasets is used in the analysis to investigate aerosol-environment interactions. A diagnostic study is conducted to produce global and regional aerosol satellite climatologies, and to analyze and compare the validity of aerosol retrievals. We find similarities and differences between the aerosol distributions over various regions of the globe when comparing the different satellite retrievals. A nonparametric approach is also used to examine the spatial distribution of the recent trends in aerosol concentration. A significant positive trend was found over the Middle East, Arabian Sea and South Asian regions strongly influenced by increases in dust events. Spectral and composite analyses

  8. Depth-based signal separation with vertical line arrays in the deep ocean.

    PubMed

    McCargar, Reid; Zurk, Lisa M

    2013-04-01

    Deep vertical line arrays can exploit the reliable acoustic path (RAP), which provides low transmission loss (TL) for targets at moderate ranges, and increased TL for distant interferers. However, nearby surface interference also has favorable RAP propagation and cannot be separated from a submerged target without horizontal aperture. In this work, a physics-based Fourier transform variant is introduced, which achieves depth-based signal separation by exploiting the spatial structure resulting from the coherent addition of the direct and surface-reflected propagation paths present for submerged sources. Simulation results demonstrate depth-based signal separation without requiring knowledge of the ocean environment.

  9. Abiogenic methane in deep-seated mid-ocean ridge environments: Insights from stable isotope analyses

    NASA Astrophysics Data System (ADS)

    Kelley, Deborah S.; Früh-Green, Gretchen L.

    1999-05-01

    In this paper we examine geochemical processes that control volatile chemistry at depth in mid-ocean ridge environments by focusing on CO2-CH4-H2O-H2 fluids entrapped in plutonic rocks from the Southwest Indian Ridge (SWIR), Ocean Drilling Program Hole 735B. Compositional and isotopic analyses of CO2-CH4-H2O and CH4-H2O-H2 fluids show that methane production involved two phases of magma-hydrothermal activity, which spanned supersolidus to greenschist facies metamorphic conditions. The first phase of methane generation is characterized by fluid inclusions that contain up to 30-50 mol % CO2 and 43 mol % CH4. Isotopic analyses of CO2, CH4, and H2O released at >900°C yields δ13C(CO2) values of -24‰ to -2‰, δ13C(CH4) values of -30‰ to -19‰, δD(CH4) values of -244‰ to -128‰, and average δD(H2O) values of -43±6‰. Phase equilibria and isotopic data strongly indicate that the CO2-CH4-H2O fluids reflect Rayleigh distillation of evolved magmatic CO2, subsequent closed-system respeciation, and attendant graphite precipitation at temperatures of ˜500-800°C, and at fO2 from -3 log units below, to close to quartz-fayalite-magnetite oxygen fugacity (QFM) conditions. The second phase of CH4 production involves CH4-H2O±H2±C-fluids that contain >40 mol % CH4. Phase equilibria indicate that the CH4-H2O fluids were trapped under equilibrium conditions at 400°C, very near to QFM conditions. Our study suggests that in the absence of CO2 as a stable fluid component, extensive distillation fractionation or alteration processes are required to form this later generation of methane. The mean δ13C values of methane extracted at 500°C from the gabbros (-25±4.4‰) are remarkably similar to the range of light carbon observed in studies of mantle rocks. We conclude that the presence of reduced carbon species in oceanic gabbros and mantle peridotites is a potential source of carbon in hydrothermal fluids and that serpentinization processes play a key role in the

  10. Accumulation of organic matter in Cretaceous oxygen-deficient depositional environments in the central Pacific Ocean

    USGS Publications Warehouse

    Dean, W.E.; Claypool, G.E.; Thide, J.

    1984-01-01

    and intercepts of C-S regression lines however, are different for each site and all are different from regression lines for samples from modern anoxic marine sediments and from Black Sea cores. The organic-carbon-rich limestones on Hess Rise, the Mid-Pacific Mountains, and other plateaus and seamounts in the Pacific Ocean are not synchronous but do occur within the same general middle Cretaceous time period as organic-carbon-rich lithofacies elsewhere in the world ocean, particularly in the Atlantic Ocean. Strata of equivalent age in the deep basins of the Pacific Ocean are not rich in organic carbon, and were deposited in oxygenated environments. This observation, together with the evidence that the plateau sites were considerably shallower and closse to the equator during the middle Creataceous suggests that local tectonic and hydrographic conditions may have resulted in high surface-water productivity and the preservation of organic matter in an oxygen-deficient environment where an expanded mid-water oxygen minimum developed and impinged on elevated platforms and seamounts. ?? 1984.

  11. Knowledge based programming environments: A perspective

    NASA Technical Reports Server (NTRS)

    Amin, Ashok T.

    1988-01-01

    Programming environments is an area of recent origin and refers to an integrated set of tools, such as program library, text editor, compiler, and debugger, in support of program development. Understanding of programs and programming has lead to automated techniques for program development. Knowledge based programming system using program transformations offer significant impact on future program development methodologies. A review of recent developments in the area of knowledge based programming environments, from the perspective of software engineering, is presented.

  12. Pressures on the marine environment and the changing climate of ocean biogeochemistry.

    PubMed

    Rees, Andrew P

    2012-12-13

    The oceans are under pressure from human activities. Following 250 years of industrial activity, effects are being seen at the cellular through to regional and global scales. The change in atmospheric CO(2) from 280 ppm in pre-industrial times to 392 ppm in 2011 has contributed to the warming of the upper 700 m of the ocean by approximately 0.1°C between 1961 and 2003, to changes in sea water chemistry, which include a pH decrease of approximately 0.1, and to significant decreases in the sea water oxygen content. In parallel with these changes, the human population has been introducing an ever-increasing level of nutrients into coastal waters, which leads to eutrophication, and by 2008 had resulted in 245,000 km(2) of severely oxygen-depleted waters throughout the world. These changes are set to continue for the foreseeable future, with atmospheric CO(2) predicted to reach 430 ppm by 2030 and 750 ppm by 2100. The cycling of biogeochemical elements has proved sensitive to each of these effects, and it is proposed that synergy between stressors may compound this further. The challenge, within the next few decades, for the marine science community, is to elucidate the scope and extent that biological processes can adapt or acclimatize to a changing chemical and physical marine environment.

  13. Assessment of uncertainties of ocean color parameters for the ocean Carbon-based Productivity Model

    NASA Astrophysics Data System (ADS)

    Sheng, M. A.; Xiaofeng, Yang; Zui, Tao; Ziwei, Li; Xuan, Zhou

    2014-03-01

    With the developments of ocean color remote sensing technology, some ocean color parameters can be derived by satellite globally. These terms, including chlorophyll concentration (Chl), particulate backscattering coefficients (bbp), photosynthetically available radiation (PAR), have been proved to be related to NPP of phytoplankton. Based on these parameters with other auxiliary data, a carbon-based productivity model (CbPM) had been developed. The model derives phytoplankton carbon(C) from bbp and utilizes the ratios of C and Chl to describe the phytoplankton growth rates (μ) which has physiological dependencies on light (through variations in PAR), nutrients, and temperature. This paper indicated how the uncertainties in satellite derived parameters (Chl, bbp and PAR) propagated through the CbPM using Monte Carlo method. Comparisons on the individual contributor to the random uncertainty in NPP between these input items were discussed. The analysis results showed that among the three parameters, the biggest contribution to the uncertainty in the model output came from Chl. Therefore, improvements in the accuracy of Chl would have the largest potential to improve the ability of CbPM in estimating NPP of phytoplankton.

  14. Research on strategy marine noise map based on i4ocean platform: Constructing flow and key approach

    NASA Astrophysics Data System (ADS)

    Huang, Baoxiang; Chen, Ge; Han, Yong

    2016-02-01

    Noise level in a marine environment has raised extensive concern in the scientific community. The research is carried out on i4Ocean platform following the process of ocean noise model integrating, noise data extracting, processing, visualizing, and interpreting, ocean noise map constructing and publishing. For the convenience of numerical computation, based on the characteristics of ocean noise field, a hybrid model related to spatial locations is suggested in the propagation model. The normal mode method K/I model is used for far field and ray method CANARY model is used for near field. Visualizing marine ambient noise data is critical to understanding and predicting marine noise for relevant decision making. Marine noise map can be constructed on virtual ocean scene. The systematic marine noise visualization framework includes preprocessing, coordinate transformation interpolation, and rendering. The simulation of ocean noise depends on realistic surface. Then the dynamic water simulation gird was improved with GPU fusion to achieve seamless combination with the visualization result of ocean noise. At the same time, the profile and spherical visualization include space, and time dimensionality were also provided for the vertical field characteristics of ocean ambient noise. Finally, marine noise map can be published with grid pre-processing and multistage cache technology to better serve the public.

  15. Deep Sea Shell Taphonomy: Interactive benthic experiments in hydrate environments of Barkley Canyon, Ocean Networks Canada.

    NASA Astrophysics Data System (ADS)

    Best, Mairi; Purser, Autun

    2015-04-01

    In order to quantify and track the rates and processes of modification of biogenic carbonate in gas hydrate environments, and their possible environmental/ecological correlates, ongoing observations of experimentally deployed specimens are being made using a remotely controlled crawler with camera and sensors. The crawler is connected to NEPTUNE Canada, an 800km, 5-node, regional cabled ocean network across the northern Juan de Fuca Plate, northeastern Pacific, part of Ocean Networks Canada. One of 15 study areas is an environment of exposed hydrate mounds along the wall of Barkley Canyon, at ˜865m water depth. This is the home of a benthic crawler developed by Jacobs University of Germany, who is affectionately known as Wally. Wally is equipped with a range of sensors including cameras, methane sensor, current meter, fluorometer, turbidity meter, CTD, and a sediment microprofiler with probes for oxygen, methane, sulphide, pH, temperature, and conductivity. In conjunction with this sensor suite, a series of experiments have been designed to assess the cycling of biogenic carbon and carbonate in this complex environment. The biota range from microbes, to molluscs, to large fish, and therefore the carbon inputs include both a range of organic carbon compounds as well as the complex materials that are "biogenic carbonate". Controlled experimental specimens were deployed of biogenic carbonate (Mytilus edulis fresh shells) and cellulose (pieces of untreated pine lumber) that had been previously well characterized (photographed, weighed, and numbered, matching valves and lumber kept as controls). Deployment at the sediment/water interface was in such a way to maximize natural burial exhumation cycles but to minimize specimen interaction. 10 replicate specimens of each material were deployed in two treatments: 1) adjacent to a natural life and death assemblage of chemosynthetic bivalves and exposed hydrate on a hydrate mound and 2) on the muddy seafloor at a distance

  16. Distribution and Abundance of Hopanoid Producers in Low-Oxygen Environments of the Eastern Pacific Ocean.

    PubMed

    Kharbush, Jenan J; Kejriwal, Kanchi; Aluwihare, Lihini I

    2016-02-01

    Hopanoids are bacterial membrane lipid biomarker molecules that feature prominently in the molecular fossil record. In the modern marine water column, recent reports implicate bacteria inhabiting low-oxygen environments as important sources of hopanoids to marine sediments. However, the preliminary biogeography reported by recent studies and the environmental conditions governing such distributions can only be confirmed when the numerical abundance of these organisms is known with more certainty. In this study, we employ two different approaches to examine the quantitative significance of phylogenetically distinct hopanoid producers in low-oxygen environments. First, we develop a novel quantitative PCR (qPCR) assay for the squalene hopene cyclase (sqhC) gene, targeting a subset of hopanoid producers previously identified to be important in the eastern North Pacific Ocean. The results represent the first quantitative gene abundance data of any kind for hopanoid producers in the marine water column and show that these putative alphaproteobacterial hopanoid producers are rare, comprising at most 0.2 % of the total bacterial community in our samples. Second, a complementary analysis of existing low-oxygen metagenomic datasets further examined the generality of the qPCR observation. We find that the dominant sqhC sequences in these metagenomic datasets are associated with phyla such as Nitrospinae rather than Proteobacteria, consistent with the qPCR finding that alphaproteobacterial hopanoid producers are not very abundant in low-oxygen environments. In fact, positive correlations between sqhC gene abundance and environmental parameters in these samples identify nitrite availability as a potentially important factor in the ecology of hopanoid producers that dominate low-oxygen environments.

  17. Ares I-X Ascent Base Environments

    NASA Technical Reports Server (NTRS)

    Mobley, B. L.; Bender, R. L.; Canabal, F.; Smith, Sheldon D.

    2011-01-01

    Plume induced base heating environments were measured during the flight of the NASA Constellation Ares I-X developmental launch vehicle, successfully flown on October 28, 2009. The Ares IX first stage is a four segment Space Shuttle derived booster with base consisting of a flared aft skirt, deceleration and tumble motors, and a thermal curtain surrounding the first stage 7.2 area ratio nozzle. Developmental Flight Instrumentation (DFI) consisted of radiometers, calorimeters, pressure transducers and gas temperature probes installed on the aft skirt and nozzle to measure the base environments. In addition, thermocouples were also installed between the layers of the flexible thermal curtain to provide insight into the curtain response to the base environments and to assist in understanding curtain failure during reentry. Plume radiation environment predictions were generated by the Reverse Monte Carlo (RMC) code and the convective base heating predictions utilized heritage MSFC empirical methods. These predictions were compared to the DFI data and results from the flight videography. Radiation predictions agreed with the flight measured data early in flight but gauge failures prevented high altitude comparisons. The convective environment comparisons demonstrated the need to improve the prediction methodology; particularly for low altitude, local plume recirculation. The convective comparisons showed relatively good agreement at altitudes greater than 50,000 feet.

  18. The base of the seismogenic zone in the oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Greg, H.; Behn, M.; McGuire, J.

    2008-12-01

    Geophysical observations indicate that seismicity in the oceanic lithosphere is generally limited to depths above the 600°C isotherm. This relationship is in good agreement with extrapolation of experimental data on the frictional behavior of olivine (Boettcher et al., 2007). Under laboratory conditions, a transition from unstable to stable frictional sliding is observed at a temperature of approximately 1000°C. By accounting for the rate-dependence of crystal plasticity at asperities, the same transition is predicted to occur at a temperature of approximately 600°C in the Earth. While this agreement is encouraging, several issues remain poorly constrained - resolution of which may provide important insights into understanding the dynamics of earthquakes in general. A unique aspect of many oceanic earthquakes is that they likely occur in what was previously undamaged rock. Owing to upwelling and corner flow, the mantle rocks cool below the 600°C isotherm prior to any brittle deformation. Thus, rocks in the source regions for these earthquakes are likely intact at relatively high pressure with no pore fluids present. In other words, almost all the mechanisms hypothesized to produce weakening along faults in continental settings are unlikely to be active prior to an earthquake in the oceanic lithosphere. These rocks could thus be capable of supporting shear stresses in the range of 500 MPa at depths of 20 to 30 km. We will review these rheological constraints, discuss the evidence (or lack thereof) for high stresses based on earthquake seismology, and investigate alternate mechanisms that could be responsible for weakening the oceanic lithosphere - such as penetration of fluid from the surface to the greatest depths of lithospheric seismicity.

  19. Oceans and Coasts. Teacher's Guide to World Resources. Comprehensive Coursework on the Global Environment.

    ERIC Educational Resources Information Center

    Snyder, Sarah A.

    This teacher's guide presents teaching suggestions and presentation materials about the world's oceans and the important role humans play in maintaining the life and health of the oceans. The lesson is divided into five parts and can be taught in one class period or divided into segments. Student handouts include: (1) "Facts about Oceans and…

  20. Land-Ocean Difference of the Warm Rain Formation Process in Satellite Observations, Ground-Based Observations, and Model Simulations

    NASA Astrophysics Data System (ADS)

    Takahashi, H.; Suzuki, K.; Stephens, G. L.

    2015-12-01

    This study examines the difference in the warm rain formation process between over land and over ocean using a combination of CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) observations. Previous studies (Nakajima et al. 2010; Suzuki et al. 2010) have devised a novel methodology for combining the CloudSat and MODIS satellite observations to investigate the microphysical processes. The statistics constructed with the methodology, referred to as the Contoured Frequency by Optical Depth Diagram (CFODD), provides a lifecycle view of warm clouds. Following the previous studies, we conduct detailed analyses of CFODD with a particular focus on comparisons between land and ocean. Our result shows that the coalescence process starts faster in the oceanic warm clouds than continental warm clouds. Also, oceanic clouds tend to produce more drizzle than continental clouds. Moreover, it is found that the difference between oceanic and continental cloud-to-precipitation process can be explained by different environmental conditions. For example, the cloud-to-precipitation processes in continental clouds are more similar to those in oceanic clouds over unstable environments than those over stable environments. Furthermore, ground-based measurement data obtained from Atmospheric Radiation Measurement (ARM) data and a cloud model simulation are analyzed to test how vertical velocity affects the warm rain formation process. Our result suggests that although the intensities of convective updrafts in warm clouds have been paid less attention, intensities of convective updrafts play a critical role in the warm rain formation process.

  1. Fast Simulation Method for Ocean Wave Base on Ocean Wave Spectrum and Improved Gerstner Model with GPU

    NASA Astrophysics Data System (ADS)

    Zhang, Wenqiao; Zhang, Jing; Zhang, Tianchi

    2017-01-01

    For the randomness and complexity of ocean wave, and the simulation of large-scale ocean requires a great amount of computation, but the computational efficiency is low, the real-time ability is poor, a fast method of wave simulation is proposed based on the observation and research results of oceanography, it takes advantage of the grid which combined with the technique of LOD and projection, and use the height map of ocean which is formd by retrieval of ocean wave spectrum and directional spectrum to compute with FFT, and it uses the height map to cyclic mapping for the grid on GPU which combined with the technique of LOD and projection to get the dynamic height data and simulation of ocean. The experimental results show that the method is vivid and it conforms with randomness and complexity of ocean wave, it effectively improves the simulation speed of the wave and satisfied with the real-time ability and fidelity in simulation system of ocean.

  2. Astronomical Ice: The Effects of Treating Ice as a Porous Media on the Dynamics and Evolution of Extraterrestrial Ice-Ocean Environments

    NASA Astrophysics Data System (ADS)

    Buffo, J.; Schmidt, B. E.

    2015-12-01

    With the prevalence of water and ice rich environments in the solar system, and likely the universe, becoming more apparent, understanding the evolutionary dynamics and physical processes of such locales is of great importance. Piqued interest arises from the understanding that the persistence of all known life depends on the presence of liquid water. As in situ investigation is currently infeasible, accurate numerical modeling is the best technique to demystify these environments. We will discuss an evolving model of ice-ocean interaction aimed at realistically describing the behavior of the ice-ocean interface by treating basal ice as a porous media, and its possible implications on the formation of astrobiological niches. Treating ice as a porous media drastically affects the thermodynamic properties it exhibits. Thus inclusion of this phenomenon is critical in accurately representing the dynamics and evolution of all ice-ocean environments. This model utilizes equations that describe the dynamics of sea ice when it is treated as a porous media (Hunke et. al. 2011), coupled with a basal melt and accretion model (Holland and Jenkins 1999). Combined, these two models produce the most accurate description of the processes occurring at the base of terrestrial sea ice and ice shelves, capable of resolving variations within the ice due to environmental pressures. While these models were designed for application to terrestrial environments, the physics occurring at any ice-water interface is identical, and these models can be used to represent the evolution of a variety of icy astronomical bodies. As terrestrial ice shelves provide a close analog to planetary ice-ocean environments, we truth test the models validity against observations of ice shelves. We apply this model to the ice-ocean interface of the icy Galilean moon Europa. We include profiles of temperature, salinity, solid fraction, and Darcy velocity, as well as temporally and spatially varying melt and

  3. Mechanistic site-based emulation of a global ocean biogeochemical model for parametric analysis and calibration

    NASA Astrophysics Data System (ADS)

    Hemmings, J. C. P.; Challenor, P. G.; Yool, A.

    2014-09-01

    Biogeochemical ocean circulation models used to investigate the role of plankton ecosystems in global change rely on adjustable parameters to compensate for missing biological complexity. In principle, optimal parameter values can be estimated by fitting models to observational data, including satellite ocean colour products such as chlorophyll that achieve good spatial and temporal coverage of the surface ocean. However, comprehensive parametric analyses require large ensemble experiments that are computationally infeasible with global 3-D simulations. Site-based simulations provide an efficient alternative but can only be used to make reliable inferences about global model performance if robust quantitative descriptions of their relationships with the corresponding 3-D simulations can be established. The feasibility of establishing such a relationship is investigated for an intermediate complexity biogeochemistry model (MEDUSA) coupled with a widely-used global ocean model (NEMO). A site-based mechanistic emulator is constructed for surface chlorophyll output from this target model as a function of model parameters. The emulator comprises an array of 1-D simulators and a statistical quantification of the uncertainty in their predictions. The unknown parameter-dependent biogeochemical environment, in terms of initial tracer concentrations and lateral flux information required by the simulators, is a significant source of uncertainty. It is approximated by a mean environment derived from a small ensemble of 3-D simulations representing variability of the target model behaviour over the parameter space of interest. The performance of two alternative uncertainty quantification schemes is examined: a direct method based on comparisons between simulator output and a sample of known target model "truths" and an indirect method that is only partially reliant on knowledge of target model output. In general, chlorophyll records at a representative array of oceanic sites

  4. Sustainable Management of Coastal Environments Through Coupled Terrestrial-Coastal Ocean Models

    NASA Astrophysics Data System (ADS)

    Lohrenz, S. E.; Cai, W.; Tian, H.; He, R.; Xue, Z.; Fennel, K.; Hopkinson, C.; Howden, S. D.

    2012-12-01

    Changing climate and land use practices have the potential to dramatically alter coupled hydrologic-biogeochemical processes and associated movement of water, carbon and nutrients through various terrestrial reservoirs into rivers, estuaries, and coastal ocean waters. Consequences of climate- and land use-related changes will be particularly evident in large river basins and their associated coastal outflow regions. The large spatial extent of such systems necessitates a combination of satellite observations and model-based approaches coupled with targeted ground-based site studies to adequately characterize relationships among climate forcing (e.g., wind, precipitation, temperature, solar radiation, humidity, extreme weather), land use practice/land cover change, and transport of materials through watersheds and, ultimately, to coastal regions. Here, we describe a NASA Interdisciplinary Science project that employs an integrated suite of models in conjunction with remotely sensed as well as targeted in situ observations with the objectives of describing processes controlling fluxes on land and their coupling to riverine, estuarine and ocean ecosystems. The objectives of this effort are to 1) assemble and evaluate long term datasets for the assessment of impacts of climate variability, extreme weather events, and land use practices on transport of water, carbon and nitrogen within terrestrial systems and the delivery of materials to waterways and rivers; 2) using the Mississippi River as a testbed, develop and evaluate an integrated suite of models to describe linkages between terrestrial and riverine systems, transport of carbon and nutrients in the Mississippi river and its tributaries, and associated cycling of carbon and nutrients in coastal ocean waters; and 3) evaluate uncertainty in model products and parameters and identify areas where improved model performance is needed through model refinement and data assimilation. The effort employs the Dynamic Land

  5. Ocean warming and spread of pathogenic vibrios in the aquatic environment.

    PubMed

    Vezzulli, Luigi; Colwell, Rita R; Pruzzo, Carla

    2013-05-01

    Vibrios are among the most common bacteria that inhabit surface waters throughout the world and are responsible for a number of severe infections both in humans and animals. Several reports recently showed that human Vibrio illnesses are increasing worldwide including fatal acute diarrheal diseases, such as cholera, gastroenteritis, wound infections, and septicemia. Many scientists believe this increase may be associated with global warming and rise in sea surface temperature (SST), although not enough evidence is available to support a causal link between emergence of Vibrio infections and climate warming. The effect of increased SST in promoting spread of vibrios in coastal and brackish waters is considered a causal factor explaining this trend. Field and laboratory studies carried out over the past 40 years supported this hypothesis, clearly showing temperature promotes Vibrio growth and persistence in the aquatic environment. Most recently, a long-term retrospective microbiological study carried out in the coastal waters of the southern North Sea provided the first experimental evidence for a positive and significant relationship between SST and Vibrio occurrence over a multidecadal time scale. As a future challenge, macroecological studies of the effects of ocean warming on Vibrio persistence and spread in the aquatic environment over large spatial and temporal scales would conclusively support evidence acquired to date combined with studies of the impact of global warming on epidemiologically relevant variables, such as host susceptibility and exposure. Assessing a causal link between ongoing climate change and enhanced growth and spread of vibrios and related illness is expected to improve forecast and mitigate future outbreaks associated with these pathogens.

  6. Salmon Migration Patterns Revealed the Temporal and Spatial Fluctuations of the Radiocesium Levels in Terrestrial and Ocean Environments

    PubMed Central

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3–40.2 Bq kg−1 in mean) and 137Cs (41.4–51.7 Bq kg−1 in mean) than did the anadromous (sea-run) type salmons (0.64–8.03 Bq kg−1 in mean 134Cs and 0.42–10.2 Bq kg−1 in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal. PMID:24964195

  7. Salmon migration patterns revealed the temporal and spatial fluctuations of the radiocesium levels in terrestrial and ocean environments.

    PubMed

    Arai, Takaomi

    2014-01-01

    The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3-40.2 Bq kg(-1) in mean) and 137Cs (41.4-51.7 Bq kg(-1) in mean) than did the anadromous (sea-run) type salmons (0.64-8.03 Bq kg(-1) in mean 134Cs and 0.42-10.2 Bq kg(-1) in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal.

  8. Forecasting the Ocean’s Optical Environment: Development of the BioCast System

    DTIC Science & Technology

    2014-09-01

    and is used to render operational products from INTRODUC TION The role of ocean optics in naval warfare dates back to ancient times. In the first...expansion. The ocean color information is overlaid onto a Google Earth image projection. (B) As in (A), but for the Chesapeake Bay and Virginia coastline...in the Pacific Ocean . (top left) A US Navy diver assigned to the Mobile Diving Salvage Unit (MDSU) 2 at work during operations off the coast of

  9. The polar oceans and their role in shaping the global environment

    SciTech Connect

    Johannessen, O.M.; Muench, R.D.; Overland, J.E.

    1994-12-31

    This book is a comprehensive treatment of major advances made in the past decade in understanding of the interactions between polar oceans and the local atmosphere and ocean system. Included are 38 papers discussing the circulation, dynamics and convective processes occurring in the polar oceans; its carbon cycle chemistry and biology; the paleooceanography and paleoclimate of the polar regions; the interaction between the polar ocean and the global climate, and a variety of strategies for detection of climate change in polar regions, predominantly Arctic.

  10. Ocean Community-based Approach to Increase Applications and Enrollment of Underrepresented Minorities in Ocean Science Graduate Programs

    NASA Astrophysics Data System (ADS)

    Yoder, J. A.

    2012-12-01

    Using funding provided by the Deerbrook Charitable Trust, the Woods Hole Oceanographic Institution hosted a community workshop in June, 2012, focused on recruitment of underrepresented minorities to graduate programs in ocean science. The participants included representatives from the graduate programs at ocean science institutions, as well as faculty and administrators from minority-serving institutions and programs. Observers from NSF, Institute for Broadening Participation (IBP) and Centers for Ocean Science Education Excellence (COSEE) also attended. The goal of the workshop was to develop a strategy for an ocean community-based approach to increase the number of applications to, and enrollment of, underrepresented minorities in ocean science graduate programs. A second goal was to initiate a national network involving the minority-serving institutions and the graduate programs to help achieve that goal. The workshop recommended both short-term and longer term recruiting strategies that would include activities for undergraduates to develop and sustain their interest in ocean science and prepare them for graduate school. Workshop recommendations and initial implementation steps will be discussed.

  11. gpuPOM: a GPU-based Princeton Ocean Model

    NASA Astrophysics Data System (ADS)

    Xu, S.; Huang, X.; Zhang, Y.; Fu, H.; Oey, L.-Y.; Xu, F.; Yang, G.

    2014-11-01

    Rapid advances in the performance of the graphics processing unit (GPU) have made the GPU a compelling solution for a series of scientific applications. However, most existing GPU acceleration works for climate models are doing partial code porting for certain hot spots, and can only achieve limited speedup for the entire model. In this work, we take the mpiPOM (a parallel version of the Princeton Ocean Model) as our starting point, design and implement a GPU-based Princeton Ocean Model. By carefully considering the architectural features of the state-of-the-art GPU devices, we rewrite the full mpiPOM model from the original Fortran version into a new Compute Unified Device Architecture C (CUDA-C) version. We take several accelerating methods to further improve the performance of gpuPOM, including optimizing memory access in a single GPU, overlapping communication and boundary operations among multiple GPUs, and overlapping input/output (I/O) between the hybrid Central Processing Unit (CPU) and the GPU. Our experimental results indicate that the performance of the gpuPOM on a workstation containing 4 GPUs is comparable to a powerful cluster with 408 CPU cores and it reduces the energy consumption by 6.8 times.

  12. Ocean interactions with the base of Amery Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    Hellmer, Hartmut H.; Jacobs, Stanley S.

    1992-01-01

    Using a two-dimensional ocean themohaline circulation model, we varied the cavity shape beneath Amery Ice Shelf in an attempt to reproduce the 150-m-thick marine ice layer observed at the 'G1' ice core site. Most simulations caused melting rates which decrease the ice thickness by as much as 400 m between grounding line and G1, but produce only minor accumulation at the ice core site and closer to the ice front. Changes in the sea floor and ice topographies revealed a high sensitivity of the basal mass balance to water column thickness near the grounding line, to submarine sills, and to discontinuities in ice thickness. Model results showed temperature/salinity gradients similar to observations from beneath other ice shelves where ice is melting into seawater. Modeled outflow characteristics at the ice front are in general agreement with oceanographic data from Prydz Bay. We concur with Morgan's inference that the G1 core may have been taken in a basal crevasse filled with marine ice. This ice is formed from water cooled by ocean/ice shelf interactions along the interior ice shelf base.

  13. MATLAB-Based VHDL Development Environment

    SciTech Connect

    Katko, K. K.; Robinson, S. H.

    2002-01-01

    The Reconfigurable Computing program at Los Alamos National Laboratory (LANL) required synthesizable VHDL Fast Fourier Transform (FFT) designs that could be quickly implemented into FPGA-based high speed Digital Signal Processing architectures. Several different FFTs were needed for the different systems. As a result, the MATLAB-Based VHDL Development Environment was developed so that with a small amount of work and forethought, arbitrarily sized FFTs with different bit-width parameters could be produced quickly from one VHDL generating algorithm. The result is highly readable VHDL that can be modified quickly via the generating function to adapt to new algorithmic requirements. Several additional capabilities are integrated into the development environment. These capabilities include a bit-true parameterized mathematical model, fixed-point design validation, test vector generation, VHDL design verification, and chip resource use estimation. LANL needed the flexibility to build a wide variety of FFTs with a quick turn around time. It was important to have an effective way of trading off size, speed and precision. The FFTs also needed to be efficiently implemented into our existing FPGA-based architecture. Reconfigurable computing systems at LANL have been designed to accept two or four inputs on each clock. This allows the data processing rate to be reduced to a more manageable speed. This approach, however, limits us from using existing FFT cores. A MATLAB-Based VHDL Development Environment (MBVDE) was created in response to our FFT needs. MBVDE provides more flexibility than is available with VHDL. The technique allows new designs to be implemented and verified quickly. In addition, analysis tools are incorporated to evaluate trade-offs. MBVDE incorporates the performance of VHDL, the fast design time of core generation, and the benefit of not having to know VHDL available with C-tools into one environment. The MBVDE approach is not a comprehensive solution, but

  14. Oceans and human health: Emerging public health risks n the marine environment

    PubMed Central

    Fleming, L.E.; Broad, K.; Clement, A.; Dewailly, E.; Elmir, S.; Knap, A.; Pomponi, S.A.; Smith, S.; Gabriele, H. Solo; Walsh, P.

    2008-01-01

    There has been an increasing recognition of the inter-relationship between human health and the oceans. Traditionally, the focus of research and concern has been on the impact of human activities on the oceans, particularly through anthropogenic pollution and the exploitation of marine resources. More recently, there has been recognition of the potential direct impact of the oceans on human health, both detrimental and beneficial. Areas identified include: global change, harmful algal blooms (HABs), microbial and chemical contamination of marine waters and seafood, and marine models and natural products from the seas. It is hoped that through the recognition of the inter-dependence of the health of both humans and the oceans, efforts will be made to restore and preserve the oceans. PMID:16996542

  15. Oceans and human health: Emerging public health risks in the marine environment.

    PubMed

    Fleming, L E; Broad, K; Clement, A; Dewailly, E; Elmir, S; Knap, A; Pomponi, S A; Smith, S; Solo Gabriele, H; Walsh, P

    2006-01-01

    There has been an increasing recognition of the inter-relationship between human health and the oceans. Traditionally, the focus of research and concern has been on the impact of human activities on the oceans, particularly through anthropogenic pollution and the exploitation of marine resources. More recently, there has been recognition of the potential direct impact of the oceans on human health, both detrimental and beneficial. Areas identified include: global change, harmful algal blooms (HABs), microbial and chemical contamination of marine waters and seafood, and marine models and natural products from the seas. It is hoped that through the recognition of the inter-dependence of the health of both humans and the oceans, efforts will be made to restore and preserve the oceans.

  16. Continuous, high-resolution spatial mapping of water isotopes in oceanic environment using a CRDS analyzer combined with a continuous water sampler.

    NASA Astrophysics Data System (ADS)

    Kim-Hak, David; Huang, Kuan; Winkler, Renato

    2016-04-01

    The recent advancements of the laser-based technology -in particular Cavity Ring Down Spectroscopy, CRDS- gave birth to a new generation of water stable isotope analyzers that are user-friendly, compact and field deployable providing in-situ measurements. Furthermore, with last year's launch of the Continuous Water Sampler front-end, CWS, the analyzer system added two additional dimensions to liquid water measurements: real-time and continuous. These features enable the user to construct high resolution water isotope data sets through time and space. Campaigns on the Sacramento-San Joaquin River Delta with the US Geological Survey where the CWS-CRDS system was deployed onto a boat to spatially map sections of the delta, validated the CWS performance and demonstrated its durability on brackish water. The next step for the CWS is to explore oceanic applications with seawater. Early in-house laboratory experiments showed stable performance with brine waters (3% concentration). For the field experiment, we have collaborated with the China State Oceanic Administration to deploy the CWS-CRDS in oceanic environments on cruises along the costal China and Antarctic. Here, we present the results of the analysis collected onboard and compared them with discrete sampling measurements. The long-term test has also allowed us to assess the durability and expected lifetime of the CWS membrane and to recommend the proper maintenance procedure for optimum performance under oceanic conditions.

  17. Depositional environments and processes in Upper Cretaceous nonmarine and marine sediments, Ocean Point dinosaur locality, North Slope, Alaska

    USGS Publications Warehouse

    Phillips, R.L.

    2003-01-01

    representing interdistributary bay deposits overlie the nonmarine beds and comprise about 15 m of section. Extensive vegetated sand flats, shoals, and shallow channels overlain by shallow bay deposits (less than 7 m deep), containing storm-generated strata characterize the marginal marine beds. Abundant bioturbation and roots characterize the stratigraphic lowest bay deposits; bioturbated sediment, pelecypods, barnacles, and benthic microfossils are found in the overlying bay storm deposits. The sediments abruptly change upward from hummocky cross-stratified bay deposits to a muddy marsh deposit containing shallow organic-rich channels to prograding nonmarine to marginal marine beds. Transgressive, abundantly fossiliferous shallow-marine strata more than 13 m thick comprise the uppermost exposures at Ocean Point. The marine beds overlie nonmarine and bay strata and represent an environment dominated episodically by storms. The age of the marginal marine and marine beds is late Maastrichtian based on pollen. ?? 2003 Elsevier Ltd. All rights reserved.

  18. VIIRS ocean color data visualization and processing with IDL-based NOAA-SeaDAS

    NASA Astrophysics Data System (ADS)

    Wang, Xiaolong; Liu, Xiaoming; Jiang, Lide; Wang, Menghua; Sun, Junqiang

    2014-11-01

    The NOAA Sea-viewing Data Analysis System (NOAA-SeaDAS) is an Interactive Data Language (IDL)-based satellite data visualization, analysis, and processing system based on the version 6.4 of the NASA's Sea-viewing Wide Field-ofview (SeaWiFS) Data Analysis System (SeaDAS) released in 2012. NOAA-SeaDAS inherited all the original functionalities of SeaDAS 6.4 and was upgraded with many new functions and new sensor supports, particularly the support of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-Orbiting Partnership (SNPP). The main goal of the NOAA-SeaDAS development is primarily in support of NOAA ocean color team's calibration and validation activities. The current version of NOAA-SeaDAS can visualize, analyze, and process VIIRS Sensor Data Records (SDR or Level-1B data) produced by the NOAA Interface Data Processing System (IDPS), ocean color Environmental Data Records (EDR or Level-2 data) produced by the NOAA Multi-Sensor Level-1 to Level- 2 (MSL12) ocean color data processing system, and Level-3 data binned or mapped from Level-2 data produced by NOAA-MSL12. NOAA-SeaDAS is currently serving an active IDL user group at NOAA and will serve other institutions and universities in the future. The goal is to allow various scientific users to visualize, analyze, and process VIIRS data from Level-1B through Level-2 and Level-3. In addition, NOAA-SeaDAS can also visualize satellite images from the Korean Geostationary Ocean Color Imager (GOCI), as well as many other satellite ocean color sensors, e.g., SeaWiFS, the Moderate Resolution Imaging Spectroradiometer (MODIS), etc. NOAA-SeaDAS is under constant development to create new system functionalities and enhance user experience. With constantly increasing volume in the global ocean color data archive, NOAA-SeaDAS will play an important role in support of global marine environment data analysis and various scientific applications.

  19. A Miniature Fiber-Optic Sensor for High-Resolution and High-Speed Temperature Sensing in Ocean Environment

    DTIC Science & Technology

    2015-11-05

    fiber-optic sensor for high-resolution and high-speed temperature sensing in ocean environment Guigen Liu1, Ming Han1,* Weilin Hou2, Silvia Matt2... sensor performance. In this paper, we present an optical fiber sensor for the high-resolution and high-speed temperature profiling. The developed sensor ...silicon, such as large thermal diffusivity, notable thermo-optic effects and thermal expansion coefficients of silicon, the proposed sensor exhibits

  20. From the Stream to the Shore: Forecasting Complex Ocean Environments in Trident Warrior 13

    DTIC Science & Technology

    2016-09-15

    numerical forecasting system includes atmospheric and oceanic components that exchange information regarding transfers of heat and momentum at very...Chong, K.G. Whitney, C. Deeney, C.A. Coverdale, and F.L. Cochran, “An Efficient Tabulated Collisional Radiative Equilibrium Radiation Transport Model...hierarchy of computer models with increasingly fine resolution followed evolving ocean conditions, spanning from the 7 km global system to a 3 km nest

  1. Nutritional and environmental studies on an ocean-going oil tanker. 1. Thermal environment

    PubMed Central

    Collins, K. J.; Eddy, T. P.; Lee, D. E.; Swann, P. G.

    1971-01-01

    Collins, K. J., Eddy, T. P., Lee, D. E., and Swann, P. G. (1971).Brit. J. industr. Med.,28, 237-245. Nutritional and environmental studies on an ocean-going oil tanker. I. Thermal environment. Investigations were made on board a modern, air-conditioned oil tanker (S.S. Esso Newcastle) en route to the Persian Gulf in July to August 1967 in order to study thermal conditions in the working environment, and the nutritional status of the crew, and to examine the interrelationship between climate and nutritional balance. In this introductory paper an account is given of the aims and design of the experiments together with details of the environmental survey. The voyage round Africa lasted one month, with high ambient temperatures of 37·7°C dry bulb, 30·8°C wet bulb (100/87°F) occurring only on the last few days into and out of the Persian Gulf. Mean accommodation temperature was maintained in the zone of comfort throughout, and at 23·9°C (75°F) Corrected Effective Temperature (CET) in the Gulf. On a previous voyage in a tanker without air-conditioning CETs up to 31·6°C (89°F) had been recorded in the accommodation in the same ambient conditions. With exposure to high solar radiation in the Gulf, the deck officer's cabins and bridge house in the upper superstructure became uncomfortably warm (CET exceeding 26·6°C (80°F)) and in these temperatures skilled performance is likely to deteriorate. The main thermal problems in the working environment were associated with the engine and boiler rooms which were consistently 11 to 17°C (20 to 30°F) higher than ambient temperature. For personnel on watch, the levels of heat stress were high but not intolerable if advantage was taken of the air blowers. Conditions under which emergency or repair tasks were carried out in very hot engine-room spaces were examined and often found to allow only a small margin of safety. Predicted average tolerance times were deduced from the Wet Bulb Globe Temperature (WBGT) scale of

  2. Characteristic Cryoseismic and Oceanic Waves Associated with Surface Environments at the Lützow-Holm Bay, East Antarctica

    NASA Astrophysics Data System (ADS)

    Kanao, M.

    2014-12-01

    In a international geoscience prospect at the IPY, the 'Polar Earth Observing Network (POLENET)' was the largest contributions in establishing a seismic and GPS network in Antarctica. Several kinds of environmental signals associated with the atmosphere - ocean - cryosphere - solid earth systems were detected in the continental margins and surrounding oceans. Ice-related seismic motions for small magnitude events are generally named 'ice-quakes' ( 'ice-shocks') and can be generated by glacially related dynamics (Kanao et al., 2012). Such kinds of cryoseismic sources are consisted from the movements of ice sheets, sea-ice, oceanic tide-cracks, oceanic gravity waves, icebergs and the calving fronts of ice caps. Nettles and Ekstrom (2010), moreover, determined the hopocenter and magnitude of several large ice-quakes (glacial earthquakes) around Antarctica by using the long period surface wave data. These hypocenters locate mainly at the outlet of the large glaciers, otherwise the edge of ice shelves. Cryoseismic and oceanic waves (microseismis) are likely to be influenced by the variations in environmental conditions, including lower atmosphere, and the continuous study of their time-space variation provides indirect evidence of climate change. In this presentation, several characteristic features of cryoseismic waves observed the stations around the Lützow-Holm Bay (LHB) region are demonstrated, involving the surface environmental variations in vicinity of the area from continental coastal to the southern ocean. Hypocenters of local events in LHB, waveforms invlolving discharge of sea-ice, tide relating signals, as well as the tremor signals with characteristic frequency contents are demonstrated. As the glacial earthquakes are the most prominent evidence found recently in the polar region, these new innovative studies of polar seismology has been achieved on the basis of observational experiments and long-term monitoring under the extreme conditions in polar

  3. Discovery of a chemosynthesis-based community in the western South Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Giongo, Adriana; Haag, Taiana; Simão, Taiz L. Lopes; Medina-Silva, Renata; Utz, Laura R. P.; Bogo, Maurício R.; Bonatto, Sandro L.; Zamberlan, Priscilla M.; Augustin, Adolpho H.; Lourega, Rogério V.; Rodrigues, Luiz F.; Sbrissa, Gesiane F.; Kowsmann, Renato O.; Freire, Antonio F. M.; Miller, Dennis J.; Viana, Adriano R.; Ketzer, João M. M.; Eizirik, Eduardo

    2016-06-01

    Chemosynthetic communities have been described from a variety of deep-sea environments across the world's oceans. They constitute very interesting biological systems in terms of their ecology, evolution and biogeography, and also given their potential as indicators of the presence and abundance of consistent hydrocarbon-based nutritional sources. Up to now such peculiar biotic assemblages have not been reported for the western South Atlantic Ocean, leaving this large region undocumented with respect to the presence, composition and history of such communities. Here we report on the presence of a chemosynthetic community off the coast of southern Brazil, in an area where high-levels of methane and the presence of gas hydrates have been detected. We performed metagenomic analyses of the microbial community present at this site, and also employed molecular approaches to identify components of its benthic fauna. We conducted phylogenetic analyses comparing the components of this assemblage to those found elsewhere in the world, which allowed a historical assessment of the structure and dynamics of these systems. Our results revealed that the microbial community at this site is quite diverse, and contains many components that are very closely related to lineages previously sampled in ecologically similar environments across the globe. Anaerobic methanotrophic (ANME) archaeal groups were found to be very abundant at this site, suggesting that methane is indeed an important source of nutrition for this community. In addition, we document the presence at this site of a vestimentiferan siboglinid polychaete and the bivalve Acharax sp., both of which are typical components of deep-sea chemosynthetic communities. The remarkable similarity in biotic composition between this area and other deep-sea communities across the world supports the interpretation that these assemblages are historically connected across the global oceans, undergoing colonization from distant sites and

  4. Collaborative environments for capability-based planning

    NASA Astrophysics Data System (ADS)

    McQuay, William K.

    2005-05-01

    Distributed collaboration is an emerging technology for the 21st century that will significantly change how business is conducted in the defense and commercial sectors. Collaboration involves two or more geographically dispersed entities working together to create a "product" by sharing and exchanging data, information, and knowledge. A product is defined broadly to include, for example, writing a report, creating software, designing hardware, or implementing robust systems engineering and capability planning processes in an organization. Collaborative environments provide the framework and integrate models, simulations, domain specific tools, and virtual test beds to facilitate collaboration between the multiple disciplines needed in the enterprise. The Air Force Research Laboratory (AFRL) is conducting a leading edge program in developing distributed collaborative technologies targeted to the Air Force's implementation of systems engineering for a simulation-aided acquisition and capability-based planning. The research is focusing on the open systems agent-based framework, product and process modeling, structural architecture, and the integration technologies - the glue to integrate the software components. In past four years, two live assessment events have been conducted to demonstrate the technology in support of research for the Air Force Agile Acquisition initiatives. The AFRL Collaborative Environment concept will foster a major cultural change in how the acquisition, training, and operational communities conduct business.

  5. An Ocean-Based Potential Intensity Index for Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Lin, I. I.; Black, P. G.; Price, J. F.; Yang, C.; Chen, S. S.; Chi, N.; Harr, P.; Lien, C.; D'Asaro, E. A.; Wu, C.

    2012-12-01

    Improvement in tropical cyclones' intensity prediction is an important ongoing effort. Cooling of the ocean by storm mixing reduces storm intensity by reducing the air-sea enthalpy flux. Here, we modify the widely used Sea Surface Temperature Potential Intensity (SST_PI) index by including information from the upper subsurface ocean to form a new Ocean Cooling Potential Intensity index, OC_PI. Applied to a 14-year (1998-2011) Western Pacific typhoon archive, the correlation coefficient between the predicted maximum intensity and the observed peak intensity increased from 0.08 to 0.31. For the sub group of slow-moving TCs that has the strongest interaction with subsurface ocean, r2 increases to 0.56. OC_PI thus contributes to the improvement on the existing PI through incorporation of ocean's subsurface information.

  6. Variability of the oceanic environment and basal melting of the Dotson Ice Shelf, West Antarctica, 2000 to 2014

    NASA Astrophysics Data System (ADS)

    Shoosmith, Deb; Jenkins, Adrian; Dutrieux, Pierre; Jacobs, Stan; Kim, Tae Wan; Lee, Sang Hoon; Ha, Ho Kyung; Stammerjohn, Sharon

    2016-04-01

    It is well known that the ocean plays a key role in the process of mass loss from ice sheets through iceberg calving and basal melting. The Amundsen Sea, in the eastern Pacific sector of the Southern Ocean, is a region where the ice shelves are rapidly thinning. The widespread, coherent nature of the thinning suggests oceanic forcing, which has now been well documented for Pine Island Glacier. Studies using satellite data have indicated that Dotson Ice Shelf was melting at a rate of 8 m per year and thinning by about 3 m per year during the 2003 - 2008 period. This study takes a slightly longer term perspective, exploiting oceanographic observations spanning a decade and a half (2000 - 2014) that have been obtained at the Dotson Ice Front. A total of 7 hydrographic sections reveal variability in the oceanographic environment in front of the ice shelf and associated changes in meltwater production over time. We quantify the variability in circulation and net meltwater transport from beneath the ice shelf to produce estimates of the basal melt rate for this 15 year period. We find that changes in ocean heat content in front of the ice shelf drive high variability in melting on multi-annual to decadal time-scales.

  7. Distribution and identification of red yeasts in deep-sea environments around the northwest Pacific Ocean.

    PubMed

    Nagahama, T; Hamamoto, M; Nakase, T; Takami, H; Horikoshi, K

    2001-10-01

    We isolated 99 yeast strains, including 40 red yeasts, from benthic animals and sediments collected from the deep-sea floor in various areas in the northwest Pacific Ocean. Comparing the yeast isolates from animals and sediments collected from shallow locations, the proportion of red yeasts differed considerably, comprising 81.5% and 10.6% of the isolates from animals and sediments, respectively. All of the red yeast isolates belonged to the genera Rhodotorula and Sporobolomyces. On the basis of morphological and physiological characteristics, the isolates were identified as R. aurantiaca, R. glutinis, R. minuta and R. mucilaginosa of the genus Rhodotorula, and S. salmonicolor and S. shibatanus of the genus Sporobolomyces. Only R. glutinis and R. mucilaginosa were isolated from sediments. All of the others were isolated from animal sources. Phylogenetic analyses based on internal transcribed spacer (ITS) regions and 5.8S rRNA gene sequences allowed us to establish the precise taxonomic placement of each of the isolates and thereby investigate the intraspecific relationships among the isolates. Twenty-two strains identified as members of R. glutinis, which showed a wide distribution in the deep-sea, and five isolates identified as R. minuta, which were isolated only from benthic animals, showed substantial heterogeneity within the species. The isolates phenotypically identified as Sporobolomyces species and R. mucilaginosa phylogenetically occupied the placements corresponding to these species. Some strains assigned to known species on the basis of phenotypic features should be regarded as new species as suggested by the results of molecular analysis.

  8. Distribution and controls on gas hydrate in the ocean-floor environment

    SciTech Connect

    Dillon, W.P.

    1995-12-31

    Methane hydrate, a crystalline solid that is formed of water and gas molecules, is widespread in oceanic sediments. It occurs at water depths that exceed 300 to 500 m and in a zone that commonly extends from the sea floor, down several hundred meters - the base of the zone is limited by increased temperature. To determine factors that control gas hydrate concentration, we have mapped its distribution off the U.S. Atlantic coast using acoustic remote-sensing methods. Most natural gas hydrate is formed from biogenic methane, and therefore it is concentrated where there is a rapid accumulation of organic detritus and also where there is a rapid accumulation of sediments (which protect detritus from oxidation). When hydrate fills the pore space of sediment, it can reduce permeability and create a gas trap. Such trapping of gas beneath hydrate may cause the formation of the most concentrated hydrate deposits, perhaps because the gas that is held in the trap can slowly diffuse upwards or migrate through faults. Hydrate-sealed traps are formed by hills on the sea floor, by dipping strata, or by salt(?) domes. Off the southeastern United States, a small area (only 3000 km{sup 2}) beneath a ridge formed by rapidly-deposited sediments appears to contain a volume of methane in hydrate that is equivalent to {approximately}30 times the U.S. annual consumption of gas. The breakdown of hydrate can cause submarine landslides by converting the hydrate to gas plus water and generating a rise of pore pressure. Conversely, sea-floor landslides can cause breakdown of hydrate by reducing the pressure in sediments. These interacting processes may cause cascading slides, which would result in breakdown of hydrate and release of methane to the atmosphere. This addition of methane to the global greenhouse would significantly influence climate. Gas hydrate in sea-floor sediments is potentially significant to climate, energy resources, and sea-floor stability.

  9. A CORBA-based manufacturing environment

    SciTech Connect

    Pancerella, C.M.; Whiteside, R.A.; Klevgard, P.A.

    1996-08-01

    A CORBA-based distributed object software system was developed for Sandia`s Agile Manufacturing Testbed (SAMT). This information architecture supports the goals of agile manufacturing: rapid response to changing requirements; small lot machining; reduction in both time and cost of the product realization process; and integration within a heterogeneous, wide-area networked enterprise. Features of the resulting software-controlled manufacturing environment are: (1) Easy plug-and-play of manufacturing devices. (2) Support for both automated and manual operations. (3) Information flow both into and out of manufacturing devices. (4) Dynamic task sequencer. Each of the heterogeneous physical objects (lathe, milling machine, robot arm, etc.) has a corresponding software object that supports a common IDL interface called IDevice. This interface provides operations for material processing, material movement, status monitoring, and other administrative tasks. CORBA objects allow for the encapsulation of a machine tool, its controller, and the network interface to the controller. Both manual and automated operations are supported by the software system. If an IDevice object receives a request for a non-automated operation, it uses an associated Console object to affect the operation by communications with a human machinist. A design goal of the Console object for a machine is to provide an information-intensive environment for the machinist, rather than just the transmittal of instructions to be carried out. In addition to the flow of information into manufacturing devices (e.g., control and NC code), the software architecture supports the easy extraction of data (e.g., sensor data or inspection reports) back out of the machine and into the broader information processing environment The task sequencer object dynamically locates devices, accepts jobs, and dispatches tasks in the manufacturing cell. A job script captures setup operations, material movement, and processing.

  10. Lunar base activities and the lunar environment

    NASA Technical Reports Server (NTRS)

    Vondrak, Richard R.

    1992-01-01

    The Moon is an attractive site for astronomical observatories and other facilities because of the absence of a substantial lunar atmosphere and the stability of the lunar surface. The present lunar atmosphere is sufficiently transparent that there is no significant image distortion due to absorption or refraction. This thin atmosphere results from a combination of small sources and prompt losses. The major source that has been identified is the solar wind, whose total mass input into the lunar atmosphere is approximately 50 gm/sec. The major components of the solar wind are light elements (H and He) that promptly escape from the lunar surface by exospheric evaporation (Jeans' escape). The principal atmospheric loss mechanism for heavier gases is photoionization within a period of weeks to months, followed by immediate loss to the solar wind. Lunar base activities will modify the lunar atmosphere if gas is released at a larger rate than that now occurring naturally. Possible gas sources are rocket exhaust, processing of lunar materials, venting of pressurized volumes, and astronaut life support systems. For even modest lunar base activity, such sources will substantially exceed natural sources, although effects are expected to be localized and transient. The Apollo database serves as a useful reference for both measurements of the natural lunar environment and its modification by lunar base activities.

  11. The Ocean as a Unique Therapeutic Environment: Developing a Surfing Program

    ERIC Educational Resources Information Center

    Clapham, Emily D.; Armitano, Cortney N.; Lamont, Linda S.; Audette, Jennifer G.

    2014-01-01

    Educational aquatic programming offers necessary physical activity opportunities to children with disabilities and the benefits of aquatic activities are more pronounced for children with disabilities than for their able-bodied peers. Similar benefits could potentially be derived from surfing in the ocean. This article describes an adapted surfing…

  12. Vision-based localization in urban environments

    NASA Astrophysics Data System (ADS)

    McHenry, Michael; Cheng, Yang; Matthies, Larry

    2005-05-01

    As part of DARPA's MARS2020 program, the Jet Propulsion Laboratory has developed a vision-based system for localization in urban environments that requires neither GPS nor active sensors. System hardware consists of a pair of small FireWire cameras and a standard Pentium-based computer. The inputs to the software system consist of: 1) a crude grid-based map describing the positions of buildings, 2) an initial estimate of robot location and 3) the video streams produced by the stereo pair. At each step during the traverse the system: captures new image data, finds image features hypothesized to lie on the outside of a building, computes the range to those features, determines an estimate of the robot's motion since the previous step and combines that data with the map to update a probabilistic representation of the robot's location. This probabilistic representation allows the system to simultaneously represent multiple possible locations. For our testing, we have derived the a priori map manually using non-orthorectified overhead imagery, although this process could be automated. The software system consists of three primary components. The first is a stereo-based visual odometry system that calculates the 6-degree of freedom camera motion between sequential frames. The second component uses a set of heuristics to identify straight-line segments that are likely to be part of a building exterior. Ranging to these straight-line features is computed using binocular or wide-baseline stereo. The resulting features and the associated range measurements are fed to the third software component, a particle-filter based localization system. This system uses the map and the most recent results from the first two to update the estimate of the robot's location. This report summarizes the design of both the hardware and software and describes the results of applying the system to the global localization of a camera system over an approximately half-kilometer traverse across JPL

  13. Experimentally-Based Ocean Acoustic Propagation and Coherence Studies

    DTIC Science & Technology

    2012-01-01

    water, where sound is highly bottom interacting, and the temperate deep -ocean sound channel. Acoustic field fluctuations have time scales varying from...that has been observed in both shallow and deep regimes. For shallow water, we seek to understand the mean and variability of transmission loss and...phase at frequencies from 50 to 3000 Hz. For the deep -ocean sound channel, the objective is to better characterize coupled-mode propagation at 50 to 100

  14. Experimentally-Based Ocean Acoustic Propagation and Coherence Studies

    DTIC Science & Technology

    2011-09-01

    temperate deep -ocean sound channel. Reliable predictions of temporal and spatial variability of received underwater sound can improve processing and...3000 Hz. For the deep -ocean sound channel, the objective is to better characterize coupled-mode propagation at 50 to 100 Hz, which may have some...Sea spring 2007 ONR/Taiwan NLIWI acoustics experiment [Reeder et al., 2010], and the Shelfbreak PRIMER study. For deep -water studies, data are from the

  15. Vision Based Localization in Urban Environments

    NASA Technical Reports Server (NTRS)

    McHenry, Michael; Cheng, Yang; Matthies, Larry

    2005-01-01

    As part of DARPA's MARS2020 program, the Jet Propulsion Laboratory developed a vision-based system for localization in urban environments that requires neither GPS nor active sensors. System hardware consists of a pair of small FireWire cameras and a standard Pentium-based computer. The inputs to the software system consist of: 1) a crude grid-based map describing the positions of buildings, 2) an initial estimate of robot location and 3) the video streams produced by each camera. At each step during the traverse the system: captures new image data, finds image features hypothesized to lie on the outside of a building, computes the range to those features, determines an estimate of the robot's motion since the previous step and combines that data with the map to update a probabilistic representation of the robot's location. This probabilistic representation allows the system to simultaneously represent multiple possible locations, For our testing, we have derived the a priori map manually using non-orthorectified overhead imagery, although this process could be automated. The software system consists of two primary components. The first is the vision system which uses binocular stereo ranging together with a set of heuristics to identify features likely to be part of building exteriors and to compute an estimate of the robot's motion since the previous step. The resulting visual features and the associated range measurements are software component, a particle-filter based localization system. This system uses the map and the then fed to the second primary most recent results from the vision system to update the estimate of the robot's location. This report summarizes the design of both the hardware and software and will include the results of applying the system to the global localization of a robot over an approximately half-kilometer traverse across JPL'S Pasadena campus.

  16. Software framework for prognostic health monitoring of ocean-based power generation

    NASA Astrophysics Data System (ADS)

    Bowren, Mark

    On August 5, 2010 the U.S. Department of Energy (DOE) has designated the Center for Ocean Energy Technology (COET) at Florida Atlantic University (FAU) as a national center for ocean energy research and development of prototypes for open-ocean power generation. Maintenance on ocean-based machinery can be very costly. To avoid unnecessary maintenance it is necessary to monitor the condition of each machine in order to predict problems. This kind of prognostic health monitoring (PHM) requires a condition-based maintenance (CBM) system that supports diagnostic and prognostic analysis of large amounts of data. Research in this field led to the creation of ISO13374 and the development of a standard open-architecture for machine condition monitoring. This thesis explores an implementation of such a system for ocean-based machinery using this framework and current open-standard technologies.

  17. Long-Term Fuid Flow Measurements From Widely Varied Oceanic Settings Elucidate Near-Surface Hydrologic Environments

    NASA Astrophysics Data System (ADS)

    Tryon, M. D.; Brown, K. M.

    2003-12-01

    The quantification of aqueous flux rates from various ocean floor environments has been a goal of numerous scientific programs for more than a decade with increasing focus on gas hydrate regions. Six years ago we developed the Chemical and Aqueous Transport (CAT) meter to collect long-term temporal records of low to moderate aqueous flow rates in sedimented ocean floor environments and, more specifically, to quantify to mass flux associated with the formation of gas hydrates. Since that time thirty of these instruments have been built and over a hundred deployments accomplished in a variety of hydrate and non-hydrate settings. We present here an overview of the results of these deployments and compare and contrast the flow records from these varied hydrological environments. Specific environments include: Gas Hydrates (Hydrate Ridge and the Eel River area on the Cascadia convergent margin, and Bush Hill in northern Gulf of Mexico), Hydrothermal (Japan's Sagami Bay and the incoming plate offshore Costa Rica's Nicoya Peninsula, TicoFlux area), and the tectonically active convergent margin off Nicoya and Osa. One of the most important outcomes of this research is the realization that fluid flow across the seabed/ocean interface is often dominated by shallow subsurface and oceanographic processes which vary significantly over time. These processes can be as simple as the diurnal pressure gradients caused by the rise and fall of tides to highly complex processes associated with the formation and transport of subsurface free gas. These processes have been both a boon and a bane to our research. Tidal oscillations have tended to mask the net flow in many very low flux settings. The high degree of spatial and temporal variation in some environments have revealed the extreme difficulty of quantifying the more widespread mass flux associated with the underlying tectonic processes. Yet, the nature of these variations have allowed us to better constrain the fundamental

  18. Olivine friction at the base of oceanic seismogenic zones

    USGS Publications Warehouse

    Boettcher, M.S.; Hirth, G.; Evans, B. M.

    2007-01-01

    We investigate the strength and frictional behavior of olivine aggregates at temperatures and effective confining pressures similar to those at the base of the seismogenic zone on a typical ridge transform fault. Triaxial compression tests were conducted on dry olivine powder (grain size ???60 ??m) at effective confining pressures between 50 and 300 MPa (using Argon as a pore fluid), temperatures between 600??C and 1000??C, and axial displacement rates from 0.06 to 60 ??m/s (axial strain rates from 3 ?? 10-6 to 3 ?? 10-3 s-1). Yielding shows a negative pressure dependence, consistent with predictions for shear enhanced compaction and with the observation that samples exhibit compaction during the initial stages of the experiments. A combination of mechanical data and microstructural observations demonstrate that deformation was accommodated by frictional processes. Sample strengths were pressure-dependent and nearly independent of temperature. Localized shear zones formed in initially homogeneous aggregates early in the experiments. The frictional response to changes in loading rate is well described by rate and state constitutive laws, with a transition from velocity-weakening to velocity-strengthening at 1000??C. Microstructural observations and physical models indicate that plastic yielding of asperities at high temperatures and low axial strain rates stabilizes frictional sliding. Extrapolation of our experimental data to geologic strain rates indicates that a transition from velocity weakening to velocity strengthening occurs at approximately 600??C, consistent with the focal depths of earthquakes in the oceanic lithosphere. Copyright 2007 by the American Geophysical Union.

  19. Spatio-temporal dynamics of alternative male phenotypes in coho salmon populations in response to ocean environment.

    PubMed

    Koseki, Yusuke; Fleming, Ian A

    2006-03-01

    1. The coexistence of alternative reproductive phenotypes will probably be shaped by spatial and temporal variability in the environment. However, the effects of such variability on coexistence and the scale at which it operates are seldom understood. 2. To quantify such effects, we examined spatial and temporal dynamics in the abundance and frequency of alternative phenotypes of male coho salmon, Oncorhynchus kisutch Walbaum, which mature as either large fighters (age-3 'hooknoses') or small sneakers (age-2 'jacks'). Using over 20 years of data on coded-wire tagged fish released from nine Oregon hatcheries, we tested for the effects of ocean environment independent of those due to freshwater rearing. 3. Annual fluctuations of the abundance of jack and hooknose males within populations were correlated strongly by brood year (cohort) but not by return year (breeding group). This occurred independently of significant effects of release practice (i.e. the number of fish released, body size at release and date of release), indicating that a synchronized fluctuation in mortality during the first year at sea was the predominant cause. As a result, the annual frequency of the alternative phenotypes at breeding varied considerably within populations. 4. Spatial patterns in the annual fluctuations of the two phenotypes were similar (i.e. synchronous among populations), except that jacks showed local spatial structure (decreased synchrony with distance) not evident among hooknoses. This suggests that oceanic processes affecting the two phenotypes operate at different spatial scales. Despite effects on salmon abundance, the ocean environment had little influence through its effects on salmon growth on the relative frequencies of the alternative phenotypes within and among populations. 5. The results provide insight into the evolutionary dynamics of alternative phenotypes, including an intragenerational time lag that increases annual variability in phenotype frequencies at

  20. 33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean at Naval Base... AND RESTRICTED AREA REGULATIONS § 334.866 Pacific Ocean at Naval Base Coronado, in the City of... westerly into the waters of the Pacific Ocean from a point on the beach of Naval Base Coronado,...

  1. New HST observations of Io's time-variable UV aurora: Probing Io's magma ocean and neutral and plasma environment

    NASA Astrophysics Data System (ADS)

    Roth, L.; Saur, J.; Retherford, K. D.; Strobel, D. F.; Feldman, P. D.; Bloecker, A.; Ivchenko, N.; Kullen, A.

    2014-12-01

    We report on new Space Telescope Imaging Spectrograph (STIS) observations of Io's oxygen and sulfur UV aurora obtained during two visits with the Hubble Space Telescope (HST) in December 2013 and January 2014. Io's aurora was monitored over a full variation cycle of the Jovian magnetic field to map the temporal behavior of the bright auroral spots. The aurora oscillates around the equator roughly in correlation with the time-variable orientation of the local magnetic field of Jupiter. Magnetic field perturbations near Io measured by the Galileo spacecraft were proposed to originate from induction in an electrically conductive global magma ocean. If magnetic induction modifies Io's local magnetic field environment, it will also alter the time-variable morphology of the aurora. We analyze the observed aurora variability and compare it to theoretically predicted spot morphologies for different magma ocean properties. Additionally, we compare the global O and S aurora morphology and brightness in the new observations to a large set of previous STIS images taken over a decade ago between 1997 and 2001 and investigate long-term changes of Io's neutral and plasma environment.

  2. North Atlantic Ocean deep-water processes and depositional environments: A study of the Cenozoic Norway Basin

    NASA Astrophysics Data System (ADS)

    Oline Hjelstuen, Berit; Andreassen, Elin V.

    2015-04-01

    Despite the enormous areas deep-water basins occupy in modern oceans, our knowledge about them remains poor. At depths of greater than 2000 m, the Cenozoic Norway Basin in the northernmost part of the Atlantic Ocean, is one such basin. Interpretation of 2D multichannel seismic data suggests a three-stage evolution for the Norway Basin. (1) Eocene-Pliocene. This time period is characterised by deposition of ooze-rich sediments in a widening and deepening basin. (2) Early-Middle Pleistocene. A significant shift in sedimentary processes and depositional environments took place in the Early Pleistocene. Mass failures initiated on the Norwegian continental slope, and three Early and Middle Pleistocene slide debrites, with maximum thicknesses of 600 m and sediment volumes of up to 25000 km3, were deposited. With ages estimated at c. 2.7-1.7 Ma, 1.7-1.1 Ma and 0.5 Ma, these slide deposits are among the largest identified worldwide, and among the oldest mapped along the entire NE Atlantic continental margin. (3) Late Pleistocene-Present. Since c. 0.5 Ma the Norway Basin has been effected by glacigenic debris flows, the Storegga Slide and hemipelagic-glacimarine sedimentation. These sedimentary processes were active during a time of repeated shelf-edge ice advances along the NE Atlantic continental margin. This study shows that deep-water basins represent dynamic depositional environments reflecting regional tectonic and climatic changes trough time.

  3. Sac-D Aquarius a Satellite for Ocean, Climate and Environment. One Year of Data

    NASA Astrophysics Data System (ADS)

    Torrusio, S.; Lagerloef, G.; Rabolli, M.; LeVine, D.

    2012-07-01

    The SAC-D/Aquarius satellite was launched in June 10, 2011. It's a joint mission between Argentina (through CONAE) and US (NASA). This satellite is a true Observatory with a suite of sensors for Earth Observation, its weight is 1400 kg, sun-synchronous orbit at 657 km (6 pm ascendant node), revisit of seven days. Other space agencies have contributed with instruments and support (facilities and ground segment), as CNES, CSI, ASI and AEB/INPE. The primary objective is to monitor global variations in ocean surface salinity (SSS) in order to improve the knowledge about ocean circulation, water cycle and climate. The SSS is performed with Aquarius instrument (NASA). Other oceanic and atmospheric parameters are measured with a MWR, from CONAE, in K and Ka band, as wind speed, rain rate, sea ice, water vapour and liquid water in clouds. The thermal camera (NIRST) estimates sea surface temperature and detect high temperature events (fires and volcanic eruptions). The High Sensitivity Camera (HSC) generates night images (very useful for fishery activity monitoring in the sea, studying of electrical storms, polar auroras and urban application). The DCS (Data Collection System, from CONAE) can receive meteorological and environmental data from ground platforms and distribute among users. The TDP (Technological Demonstration Package, from CONAE) measures different parameters of satellite position and velocity. Other two important instruments are ROSA (from Italy) and CARMEN 1 (from France). The first is an atmospheric sounder, it allows elaborating atmospheric profiles of temperature, pressure and humidity, and the second has detectors for studies of space debris and the effects of radiation on electronic devices. This work provides a review of the first year of data, including the status of calibration and validation, other finding and at the same time we want to present the progress in the active educational and outreach program including the information of SAC-D Aquarius

  4. The Polar Oceans and Their Role in Shaping the Global Environment

    NASA Astrophysics Data System (ADS)

    Johannessen, O. M.; Muench, R. D.; Overland, J. E.

    On June 24, 1993, one hundred years had passed since Fridtjof Nansen and his companions set out on one of the most daring and exciting research expeditions the world had ever seen. They allowed their vessel, the Fram, to be frozen into the ice close to the New Siberian Islands, in the Arctic Ocean. Three years were to elapse before the ice released its hold on the Fram and allowed her to return to Norway via the strait between Greenland and Spitsbergen, which later came to be known as Fram Strait. The research carried out during Fram's drift in the ice altered forever our concept of the Arctic Basin.

  5. Iron Resources and Oceanic Nutrients - Advancement of Global Environment Simulations (ironages)

    NASA Astrophysics Data System (ADS)

    de Baar, H. J. W.; Ironages Team

    Iron limits productivity in 40 percent of the oceans, and is a co-limitation in the re- maining 60 percent of surface waters. Moreover the paradigm of a single factor limit- ing plankton blooms, is presently giving way to co-limitation by light, and the nutri- ents N, P, Si, and Fe. Primary production, export into the deep sea, and CO2 uptake from the atmosphere together form the 'biological pump' in Ocean Biogeochemi- cal Climate Models (OBCM's). Thus far OBCM's assume just one limiting nutrient (P) and one universal phytoplankton species, for deriving C budgets and CO2 ex- change with the atmosphere. New realistic OBCM's are being developed in IRON- AGES for budgeting and air/sea exchanges of both CO2 and DMS, implementing (1) co-limitation by 4 nutrients of 5 major taxonomic classes of phytoplankton in a nested plankton ecosystem model, (ii) DMS(P) pathways, (iii) global iron cycling, (iv) chem- ical forms of iron and (v) iron supply in surface waters from above by aerosols and from below out of reducing margin sediments. IRONAGES is a consortium of 12 Eu- ropean institutes coordinated by the Royal NIOZ.

  6. Piezometer probe technology for geotechnical investigations in coastal and deep-ocean environments

    NASA Astrophysics Data System (ADS)

    Bennett, R. H.; Burns, J. T.; Lipkin, J.; Percival, C. M.

    Three multisensor piezometer probes were developed and field tested for use in coastal (shallow water) fine-grained marine soils. Offshore sites were investigated in the Mississippi Delta. Pore water pressure measurements were determined at several depths below the sea floor using both absolute and differential pressure sensors placed in a four inch diameter probe. Pressure sensors were hard-wired to nearby platforms where signals were conditioned and analog recording devices monitored pore water pressure changes in the marine soils. Pore water pressures were monitored for several months. Two single sensor piezometer probes, light millimeters in diameter, were developed for deep-ocean investigations. These probes use differential pressure sensors and were tested in a hyperbaric chamber pressurized to 55 MPa (8000 psi). Testing was performed for a period of five weeks under high hydrostatic pressure with the probes inserted in reconstituted illitic marine soil. Small differential pore water pressures responded to both mechanically and thermally generated forcing functions. During shallow water investigations and deep-ocean simulated pressure tests, the sensors exhibited excellent sensitivity and stability. These developments in piezometer probe technology provide a means of assessing important geotechnical parameters of fine-grained seabed deposits.

  7. Integrating Place-based and Cultural Knowledge Systems into a Communicating Ocean Sciences course in Hawaii

    NASA Astrophysics Data System (ADS)

    Lemus, J.; Coopersmith, A.; Duncan Seraphin, K.

    2011-12-01

    The Pacific Ocean Literacy for Youth, Publics, Professionals and Scientists (POLYPPS) collaborative program between the University of Hawaii and the Center for Ocean Sciences Education Excellence - California (COSEE CA) at UC Berkeley operates on the premise that ocean literacy is most effectively achieved through scientists and educators working together within a place-based context. We have partnered with a dynamic and respected group of traditional practitioners and a graduate student trained in Hawaiian Studies to advise efforts for respectfully and responsibly integrating aspects of traditional ecological knowledge with the existing course material. The goal is to build a collaborative network that connects ocean research and teaching with traditional knowledge to facilitate active engagement in stewardship and policy by all ocean users. This presentation will include details of ways in which we have adapted the COSEE-CA courses in Communicating Ocean Sciences (COS) and Communicating Ocean Sciences for Informal Audiences (COSIA) for our island setting; approaches for contextualizing course elements that utilize local and traditional exemplars and knowledge systems; and example outreach projects produced by students in our Communicating Ocean Sciences courses.

  8. Bacterial exopolysaccharides from extreme marine environments with special consideration of the southern ocean, sea ice, and deep-sea hydrothermal vents: a review.

    PubMed

    Nichols, C A Mancuso; Guezennec, J; Bowman, J P

    2005-01-01

    Exopolysaccharides (EPSs) are high molecular weight carbohydrate polymers that make up a substantial component of the extracellular polymers surrounding most microbial cells in the marine environment. EPSs constitute a large fraction of the reduced carbon reservoir in the ocean and enhance the survival of marine bacteria by influencing the physicochemical environment around the bacterial cell. Microbial EPSs are abundant in the Antarctic marine environment, for example, in sea ice and ocean particles, where they may assist microbial communities to endure extremes of temperature, salinity, and nutrient availability. The microbial biodiversity of Antarctic ecosystems is relatively unexplored. Deep-sea hydrothermal vent environments are characterized by high pressure, extreme temperature, and heavy metals. The commercial value of microbial EPSs from these habitats has been established recently. Extreme environments offer novel microbial biodiversity that produces varied and promising EPSs. The biotechnological potential of these biopolymers from hydrothermal vent environments as well as from Antarctic marine ecosystems remains largely untapped.

  9. Plasmonics Based Harsh Environment Compatible Chemical Sensors

    SciTech Connect

    Michael Carpenter

    2012-01-15

    Au-YSZ, Au-TiO{sub 2} and Au-CeO{sub 2} nanocomposite films have been investigated as a potential sensing element for high-temperature plasmonic sensing of H{sub 2}, CO, and NO{sub 2} in an oxygen containing environment. The Au-YSZ and Au-TiO{sub 2} films were deposited using PVD methods, while the CeO{sub 2} thin film was deposited by molecular beam epitaxy (MBE) and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. Each of the films were characterized by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H{sub 2}, CO, and NO{sub 2} were performed at a temperature of 500°C in oxygen backgrounds of 5.0, 10, and ~21% O{sub 2}. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the respective metal oxides. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles or by changes in the dielectric constant surrounding the particles. Hyperspectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used on the Au-CeO{sub 2} results and showed separation between analytes as well as trends in gas concentration. Results indicate that each of the films are is selective towards O{sub 2}, H{sub 2}, CO, and NO{sub 2} in separate exposures. However, when the films were analyzed in a sensor array based experiment, ie simultaneous exposures to the target gases, PCA analysis of the combined response showed an even greater selective character towards the target gases. Combined

  10. A novel spatio-temporal scale based on ocean currents unravels environmental drivers of reproductive timing in a marine predator

    PubMed Central

    Afán, Isabel; Chiaradia, André; Forero, Manuela G.; Dann, Peter; Ramírez, Francisco

    2015-01-01

    Life-history strategies have evolved in response to predictable patterns of environmental features. In practice, linking life-history strategies and changes in environmental conditions requires comparable space–time scales between both processes, a difficult match in most marine system studies. We propose a novel spatio-temporal and dynamic scale to explore marine productivity patterns probably driving reproductive timing in the inshore little penguin (Eudyptula minor), based on monthly data on ocean circulation in the Southern Ocean, Australia. In contrast to what occurred when considering any other fixed scales, little penguin's highly variable laying date always occurred within the annual peak of ocean productivity that emerged from our newly defined dynamic scale. Additionally, local sea surface temperature seems to have triggered the onset of reproduction, acting as an environmental cue informing on marine productivity patterns at our dynamic scale. Chlorophyll-a patterns extracted from this scale revealed that environment factors in marine ecosystems affecting breeding decisions are related to a much wider region than foraging areas that are commonly used in current studies investigating the link between animals' life history and their environment. We suggest that marine productivity patterns may be more predictable than previously thought when environmental and biological data are examined at appropriate scales. PMID:26063848

  11. A novel spatio-temporal scale based on ocean currents unravels environmental drivers of reproductive timing in a marine predator.

    PubMed

    Afán, Isabel; Chiaradia, André; Forero, Manuela G; Dann, Peter; Ramírez, Francisco

    2015-07-07

    Life-history strategies have evolved in response to predictable patterns of environmental features. In practice, linking life-history strategies and changes in environmental conditions requires comparable space-time scales between both processes, a difficult match in most marine system studies. We propose a novel spatio-temporal and dynamic scale to explore marine productivity patterns probably driving reproductive timing in the inshore little penguin (Eudyptula minor), based on monthly data on ocean circulation in the Southern Ocean, Australia. In contrast to what occurred when considering any other fixed scales, little penguin's highly variable laying date always occurred within the annual peak of ocean productivity that emerged from our newly defined dynamic scale. Additionally, local sea surface temperature seems to have triggered the onset of reproduction, acting as an environmental cue informing on marine productivity patterns at our dynamic scale. Chlorophyll-a patterns extracted from this scale revealed that environment factors in marine ecosystems affecting breeding decisions are related to a much wider region than foraging areas that are commonly used in current studies investigating the link between animals' life history and their environment. We suggest that marine productivity patterns may be more predictable than previously thought when environmental and biological data are examined at appropriate scales.

  12. Spatial Distribution and Temporal Patterns of Cassin’s Auklet Foraging and Their Euphausiid Prey in a Variable Ocean Environment

    PubMed Central

    Manugian, Suzanne; Elliott, Meredith L.; Bradley, Russ; Howar, Julie; Karnovsky, Nina; Saenz, Benjamin; Studwell, Anna; Warzybok, Pete; Nur, Nadav; Jahncke, Jaime

    2015-01-01

    Krill (Euphausiids) play a vital ecosystem role in many of the world’s most productive marine regions, providing an important trophic linkage. We introduce a robust modeling approach to link Cassin’s auklet (Ptychoramphus aleuticus) abundance and distribution to large-scale and local oceanic and atmospheric conditions and relate these patterns to similarly modeled distributions of an important prey resource, krill. We carried out at-sea strip transect bird surveys and hydroacoustic assessments of euphausiids (2004–2013). Data informed separate, spatially-explicit predictive models of Cassin’s auklet abundance (zero-inflated negative binomial regression) and krill biomass (two-part model) based on these surveys. We established the type of prey responsible for acoustic backscatter by conducting net tows of the upper 50 m during surveys. We determined the types of prey fed to Cassin’s auklet chicks by collecting diet samples from provisioning adults. Using time-depth-recorders, we found Cassin’s auklets utilized consistent areas in the upper water column, less than 30 m, where krill could be found (99.5% of dives were less than 30 m). Birds primarily preyed upon two species of euphausiids, Euphausia pacifica and Thysanoessa spinifera, which were available in the upper water column. Cassin’s auklet abundance was best predicted by both large scale and localized oceanic processes (upwelling) while krill biomass was best predicted by local factors (temperature, salinity, and fluorescence) and both large scale and localized oceanic processes (upwelling). Models predicted varying krill and bird distribution by month and year. Our work informs the use of Cassin’s auklet as a valuable indicator or krill abundance and distribution and strengthens our understanding of the link between Cassin’s auklet and its primary prey. We expect future increases in frequency and magnitude of anomalous ocean conditions will result in decreased availability of krill leading

  13. Nonlinear and Dissipation Characteristics of Ocean Surface Waves in Estuarine Environments

    DTIC Science & Technology

    2013-09-30

    Cihan Sahin (Ph.D. students) who are working on modeling nonlinear wave evolution in dissipative environments (mud), and the response of sea bed 2...2012). The combined effect of wave-current interaction and mud- induced damping on nonlinear wave evolution. Oc. Mod., 41, 22-34. Safak, I., Sahin , C

  14. Middle Miocene-early Pliocene paleo-oceanic environment of Japan Sea deduced from geochemical features of sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Kimura, S.; Shikazono, N.; Kashiwagi, H.; Nohara, M.

    2004-02-01

    Chemical and isotopic compositions (Sr isotopic ratio, major elements, trace elements, rare earth elements, total carbon, nitrogen, and sulfur contents) of rock samples collected from middle Miocene to early Pliocene sedimentary rocks on the Oga Peninsula, northern Japan, were analyzed to elucidate the paleo-oceanic environment of the Japan Sea. The rocks studied were shales from the Nishikurosawa, Onnagawa and Funakawa formations in stratigraphically ascending order. The Onnagawa sedimentary rocks in the lower (ca. 12.6-11.4 Ma), middle (ca. 10.6-9.0 Ma) and upper (ca. 8.3-7.0 Ma) horizons have high Mo/Al, Ni/Al, and Ba/Al ratios and high total organic carbon as well as high K/Ti and 87Sr/ 86Sr ratios and a positive Eu anomaly. These geochemical variations imply high primary productivity, and reducing conditions indicative of a deep paleo-ocean. The formation of petroleum source rocks on these horizons is attributed to increasing of nutrient delivery from the terrigenous system, which may have been induced by strong wind from Asian continent related to the uplift of Himalayan and Tibetan regions.

  15. Continent-ocean chemical heterogeneity in the mantle based on seismic tomography.

    PubMed

    Forte, A M; Dziewonski, A M; O'connell, R J

    1995-04-21

    Seismic models of global-scale lateral heterogeneity in the mantle show systematic differences below continents and oceans that are too large to be purely thermal in origin. An inversion of the geoid, based on a seismic model that includes viscous flow in the mantle, indicates that the differences beneath continents and oceans can be accounted for by differences in composition in the upper mantle superposed on mantle-wide thermal heterogeneities. The net continent-ocean density differences, integrated over depth, are small and cause only a low flux of mass and heat across the asthenosphere and mantle transition zone.

  16. Bottom interacting sound at 50 km range in a deep ocean environment.

    PubMed

    Udovydchenkov, Ilya A; Stephen, Ralph A; Duda, Timothy F; Bolmer, S Thompson; Worcester, Peter F; Dzieciuch, Matthew A; Mercer, James A; Andrew, Rex K; Howe, Bruce M

    2012-10-01

    Data collected during the 2004 Long-range Ocean Acoustic Propagation Experiment provide absolute intensities and travel times of acoustic pulses at ranges varying from 50 to 3200 km. In this paper a subset of these data is analyzed, focusing on the effects of seafloor reflections at the shortest transmission range of approximately 50 km. At this range bottom-reflected (BR) and surface-reflected, bottom-reflected energy interferes with refracted arrivals. For a finite vertical receiving array spanning the sound channel axis, a high mode number energy in the BR arrivals aliases into low mode numbers because of the vertical spacing between hydrophones. Therefore, knowledge of the BR paths is necessary to fully understand even low mode number processes. Acoustic modeling using the parabolic equation method shows that inclusion of range-dependent bathymetry is necessary to get an acceptable model-data fit. The bottom is modeled as a fluid layer without rigidity, without three dimensional effects, and without scattering from wavelength-scale features. Nonetheless, a good model-data fit is obtained for sub-bottom properties estimated from the data.

  17. Persistent organic pollutants carried by synthetic polymers in the ocean environment.

    PubMed

    Rios, Lorena M; Moore, Charles; Jones, Patrick R

    2007-08-01

    Thermoplastic resin pellets are melted and formed into an enormous number of inexpensive consumer goods, many of which are discarded after a relatively short period of use, dropped haphazardly onto watersheds and then make their way to the ocean where some get ingested by marine life. In 2003 and 2004 pre-production thermoplastic resin pellets and post-consumer plastic fragments were collected and analyzed for contamination for persistent organic pollutants (POPs). Samples were taken from the North Pacific Gyre, and selected sites in California, Hawaii, and from Guadalupe Island, Mexico. The total concentration of PCBs ranged from 27 to 980 ng/g; DDTs from 22 to 7100 ng/g and PAHs from 39 to 1200 ng/g, and aliphatic hydrocarbons from 1.1 to 8600 microg/g. Analytical methods were developed to extract, concentrate and identify POPs that may have accumulated on plastic fragments and plastic pellets. The results of this study confirm that plastic debris is a trap for POPs.

  18. Petrogenesis of dacite in an oceanic subduction environment: Raoul Island, Kermadec arc

    NASA Astrophysics Data System (ADS)

    Smith, Ian E. M.; Worthington, Timothy J.; Price, Richard C.; Stewart, Robert B.; Maas, R.

    2006-09-01

    Raoul Volcano in the northern Kermadec arc is typical of volcanoes in oceanic subduction systems in that it is composed mainly of low-K high-Al basalts and basaltic andesite. However, during the last 4 ka Raoul Volcano has produced mainly dacite magma in pyroclastic eruptions associated with caldera formation. The rocks produced in these episodes are almost aphyric containing only sparse crystals of plagioclase, clinopyroxene, orthopyroxene and magnetite. These apparent phenocrysts have chemical compositions that suggest that they did not crystallise from melts with the chemical composition of their host rocks. Rather they are xenocrysts and only their rims show evidence for crystallisation from their host melt. Chemical compositions of samples of the dacites show that each eruption has tapped a distinct magma batch. Compositional variations through the analysed suite cannot be accommodated in any reasonable model of fractional crystallisation from likely parental magma compositions. The hypothesis that best fits the petrology of Raoul Island dacites is one of crustal anatexis. This model requires heating of the lower crust by a magma flux to the point where dehydration melting associated with amphibole breakdown produces magma from a preconditioned source. It is suggested that Raoul is passing through an adolescent stage of development in which siliceous melts are part of an open system in which felsic and mafic magmas coexist.

  19. Nonlinear and Dissipation Characteristics of Ocean Surface Waves in Estuarine Environments

    DTIC Science & Technology

    2014-09-30

    Waves in Estuarine Environments James M. Kaihatu Zachry Department of Civil Engineering, Texas A&M University 3136 TAMU College Station, TX...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Texas A&M University,Zachry Department of Civil Engineering,3136 TAMU...marsh vegetation. Coast . Engrg. 83, 82-92. Freilich, M.H., and Guza, R.T., 1984. Nonlinear effects on shoaling surface gravity waves. Phil. Trans

  20. Extraction of ocean eddies based on contourlet analysis and morphology

    NASA Astrophysics Data System (ADS)

    Chen, Biao; Chen, Jie; Zhang, Bentao

    2009-10-01

    In this study, a combined algorithm using the Contourlet transform and morphology is proposed to detect the significant spatial patterns of ocean eddies. Contourlet transform, which is introduced recent years, has better performs in representation of geometry lines or curves than the wavelet transform. The source image was decomposed by Contourlet with several levles, the high-frequency images is divide into eight directions by the directional filter in each level. Then deal with the high-frequency and low-frequency coefficients separatically, use mathematical morphological method extracts edges in low-frequency approximate. At last, the two edge images were rebuilt to obtain an integrated and clear edge image. The Hough transform is than used to extract the characteristic of the eddies. The experimental results show that this algorithm cabin the priority of the Contourlet and morphological method and is superior to other traditional edge detection method such as the grads method, the Sobel method, or morphological method alone. The study verified that the algorithm proposed is an effective way to identify and detect ocean eddies with complex form.

  1. Isotopic evidence for the contemporary origin of high-molecular weight organic matter in oceanic environments

    NASA Astrophysics Data System (ADS)

    Santschi, Peter H.; Guo, Laodong; Baskaran, M.; Trumbore, Susan; Southon, John; Bianchi, Thomas S.; Honeyman, Bruce; Cifuentes, Luis

    1995-02-01

    Previous work has suggested that apparent old 14C ages for oceanic DOC are the result of mixing of different organic carbon fractions. This report provides direct evidence for a contemporary 14C age of a high-molecular-weight (HMW) fraction of colloidal organic carbon (≥10 kD). Colloidal organic matter, COM 10 (from 10 kDaltons (kD) to 0.2 μm), isolated from the upper water column of the Gulf of Mexico and the Middle Atlantic Bight (MAB) region, generally has a contemporary age (i.e., younger than a few decades), while COM 1 (from 1 kD to 0.2 μm), is apparently old: 380-4500 y BP. Thus, BMW COM 10 (3-5% of DOC) from the upper water column is derived from living particulate organic matter (POM) and cycles rapidly, while a significant fraction of low-molecular-weight (≤1 kD) DOM is likely more refractory, and cycles on much longer time scales. The presence of pigment biomarker compounds in COM 1 from the upper water column points to selected phytoplankton species as one of the sources of COM. Terrestrial carbon as another source of COM is suggested from the inverse correlation between Δ 14C and δ 13C values, as well as the increasing δ 13C values with increasing salinity. 234Th-derived turnover times of COM 10 and COM 1 from both the Gulf of Mexico and MAB are consistently short, 1-20 and 3-30 days, respectively. These short residence times support the hypothesis that 14C ages of colloidal fractions of DOC are the result of COM fractions being a mixture of several endmembers with fast and slow turnover rates.

  2. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  3. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  4. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  5. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  6. 33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Atlantic Ocean off Cape Canaveral... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore...

  7. Sequential detection of a weak target in a hostile ocean environment

    SciTech Connect

    Candy, J V; Sullivan, E J

    2005-03-14

    When the underlying physical phenomenology (medium, sediment, bottom, etc.) is space-time varying along with corresponding nonstationary statistics characterizing noise and uncertainties, then sequential methods must be applied to capture the underlying processes. Sequential detection and estimation techniques offer distinct advantages over batch methods. A reasonable signal processing approach to solve this class of problem is to employ adaptive or parametrically adaptive signal models and noise to capture these phenomena. In this paper, we develop a sequential approach to solve the signal detection problem in a nonstationary environment.

  8. Assessing Student Perceptions of Internet-Based Online Learning Environments.

    ERIC Educational Resources Information Center

    Teh, George P. L.

    1999-01-01

    Reports on a study of Web-based learning environments in Singapore that focuses on the cross-validation of the Geography Classroom Environment Inventory (GCEI) which assesses undergraduate students' perceptions of psychosocial aspects of their Web-based instruction. Examines gender equity, instructional innovation, internal consistency…

  9. New ERP predictions based on (sub-)daily ocean tides from satellite altimetry data

    NASA Astrophysics Data System (ADS)

    Madzak, Matthias; Böhm, Sigrid; Böhm, Johannes; Bosch, Wolfgang; Schuh, Harald

    2013-04-01

    A new model for Earth rotation variations based on ocean tide models is highly desirable in order to close the gap between geophysical Earth rotation models and geodetic observations. We have started a project, SPOT (Short Period Ocean Tidal variations in Earth Rotation), with the goal to develop a new model of short period Earth rotation variations based on one of the best currently available empirical ocean tide models obtained from satellite altimetry. We employ the EOT11a model which is an upgrade of EOT08a, developed at DGFI, Munich. As EOT11a does not provide the tidal current velocities which are fundamental contributors to Earth rotation excitation, the calculation of current velocities from the tidal elevations is one of three main areas of research in project SPOT. The second key aspect is the conversion from ocean tidal angular momentum to the corresponding ERP variations using state-of-the-art transfer functions. A peculiar innovation at this step will be to consider the Earth's response to ocean tidal loading based on a realistic Earth model, including an anelastic mantle. The third part of the project deals with the introduction of the effect of minor tides. Ocean tide models usually only provide major semi-diurnal and diurnal tidal terms and the minor tides have to be inferred through admittance assumptions. Within the proposed project, selected minor tidal terms and the corresponding ERP variations shall be derived directly from satellite altimetry data. We determine ocean tidal angular momentum of four diurnal and five sub-daily tides from EOT11a and apply the angular momentum approach to derive a new model of ocean tidal Earth rotation variations. This poster gives a detailed description of project SPOT as well as the status of work progress. First results are presented as well.

  10. Ocean Science in a K-12 setting: Promoting Inquiry Based Science though Graduate Student and Teacher Collaboration

    NASA Astrophysics Data System (ADS)

    Lodico, J. M.; Greely, T.; Lodge, A.; Pyrtle, A.; Ivey, S.; Madeiros, A.; Saleem, S.

    2005-12-01

    The University of South Florida, College of Marine Science Oceans: GK-12 Teaching Fellowship Program is successfully enriching science learning via the oceans. Funded by the National Science Foundation, the program provides a unique opportunity among scientists and K-12 teachers to interact with the intention of bringing ocean science concepts and research to the classroom environment enhance the experience of learning and doing science, and to promote `citizen scientists' for the 21st century. The success of the program relies heavily on the extensive summer training program where graduate students develop teaching skills, create inquiry based science activities for a summer Oceanography Camp for Girls program and build a relationship with their mentor teacher. For the last year and a half, two graduate students from the College of Marine Science have worked in cooperation with teachers from the Pinellas county School District, Southside Fundamental Middle School. Successful lesson plans brought into a 6th grade Earth Science classroom include Weather and climate: Global warming, The Geologic timescale: It's all about time, Density: Layering liquids, and Erosion processes: What moves water and sediment. The school and students have benefited greatly from the program experiencing hands-on inquiry based science and the establishment of an after school science club providing opportunities for students to work on their science fair projects and pursuit other science interests. Students are provided scoring rubrics and their progress is creatively assessed through KWL worksheets, concept maps, surveys, oral one on one and classroom discussions and writing samples. The year culminated with a series of hands on lessons at the nearby beach, where students demonstrated their mastery of skills through practical application. Benefits to the graduate student include improved communication of current science research to a diverse audience, a better understanding of the

  11. Workflow-Based Software Development Environment

    NASA Technical Reports Server (NTRS)

    Izygon, Michel E.

    2013-01-01

    The Software Developer's Assistant (SDA) helps software teams more efficiently and accurately conduct or execute software processes associated with NASA mission-critical software. SDA is a process enactment platform that guides software teams through project-specific standards, processes, and procedures. Software projects are decomposed into all of their required process steps or tasks, and each task is assigned to project personnel. SDA orchestrates the performance of work required to complete all process tasks in the correct sequence. The software then notifies team members when they may begin work on their assigned tasks and provides the tools, instructions, reference materials, and supportive artifacts that allow users to compliantly perform the work. A combination of technology components captures and enacts any software process use to support the software lifecycle. It creates an adaptive workflow environment that can be modified as needed. SDA achieves software process automation through a Business Process Management (BPM) approach to managing the software lifecycle for mission-critical projects. It contains five main parts: TieFlow (workflow engine), Business Rules (rules to alter process flow), Common Repository (storage for project artifacts, versions, history, schedules, etc.), SOA (interface to allow internal, GFE, or COTS tools integration), and the Web Portal Interface (collaborative web environment

  12. Benefits of Informal Learning Environments: A Focused Examination of STEM-Based Program Environments

    ERIC Educational Resources Information Center

    Denson, Cameron D.; Austin Stallworth, Chandra; Hailey, Christine; Householder, Daniel L.

    2015-01-01

    This paper examines STEM-based informal learning environments for underrepresented students and reports on the aspects of these programs that are beneficial to students. This qualitative study provides a nuanced look into informal learning environments and determines what is unique about these experiences and makes them beneficial for students. We…

  13. Comparative analysis of Japanese three-spined stickleback clades reveals the Pacific Ocean lineage has adapted to freshwater environments while the Japan Sea has not.

    PubMed

    Ravinet, Mark; Takeuchi, Naoko; Kume, Manabu; Mori, Seiichi; Kitano, Jun

    2014-01-01

    Divergent selection and adaptive divergence can increase phenotypic diversification amongst populations and lineages. Yet adaptive divergence between different environments, habitats or niches does not occur in all lineages. For example, the colonization of freshwater environments by ancestral marine species has triggered adaptive radiation and phenotypic diversification in some taxa but not in others. Studying closely related lineages differing in their ability to diversify is an excellent means of understanding the factors promoting and constraining adaptive evolution. A well-known example of the evolution of increased phenotypic diversification following freshwater colonization is the three-spined stickleback. Two closely related stickleback lineages, the Pacific Ocean and the Japan Sea occur in Japan. However, Japanese freshwater stickleback populations are derived from the Pacific Ocean lineage only, suggesting the Japan Sea lineage is unable to colonize freshwater. Using stable isotope data and trophic morphology, we first show higher rates of phenotypic and ecological diversification between marine and freshwater populations within the Pacific Ocean lineage, confirming adaptive divergence has occurred between the two lineages and within the Pacific Ocean lineage but not in the Japan Sea lineage. We further identified consistent divergence in diet and foraging behaviour between marine forms from each lineage, confirming Pacific Ocean marine sticklebacks, from which all Japanese freshwater populations are derived, are better adapted to freshwater environments than Japan Sea sticklebacks. We suggest adaptive divergence between ancestral marine populations may have played a role in constraining phenotypic diversification and adaptive evolution in Japanese sticklebacks.

  14. Archean hydrothermal oceanic floor sedimentary environments: DXCL drilling project of the 3.2 Ga Dixon Island Formation, Pilbara, Australia

    NASA Astrophysics Data System (ADS)

    Kiyokawa, S.; Ito, T.; Ikehara, M.; Yamaguchi, K. E.; Naraoka, H.; Sakamoto, R.; Suganuma, Y.

    2009-12-01

    Many place in Archean greenstone belts have been reported of the black chert to Iron rich sediments above volcanic sequence. The chemical sedimentary sequence has been recognized to form by as hydrothermal siliceous sequence. These sediments contain the hint to understand the Archean ocean and earth surface environments. Here, we will focus the Dixon Island and Cleaverville formations, which are one of the best preserved Archean hydrothermal sedimentary sequence in the world, to recognized detail stratigraphy and restored deep ocean environment. We did scientific drilling, which is called ‘DXCL drilling project’, at 2007 summer. This drilling project had been selected two coastal sites; CL site at lower part of the Cleaverville Formation, and another is DX site at the upper Dixon Island Formation. A systematic combinations of geological, sedimentological, geochemical, and geobiological approaches will be applied to the fresh samples. Here we will show the recent result of this sequence, which will be key evidence to understand the nature of the middle Archean (3.2 Ga) marine environment influenced by hydrothermal activity. The 3.2 Ga Dixon Island -Cleaverville formations composed of volcanic rock units and chemical-volcanosedimentary sequence which are identified by accreted immature island arc setting. The ~350m-thick Dixon Island Formation which is overlie by pillow basalt consists mainly of highly silicified volcanic-siliceous sequences that contain apparent microbial mats and bacterial fossil-like structure within black chert and also includes a komatiite-rhyolite sequences bearing hydrothermal veins. The >300m-thick Cleaverville Formation, which conformably overlay pillow basalt, contains a thick unit of reddish shale, bedded red-white chert and banded iron formation. It partly contains chert fragments-bearing pyroclastic beds. In detail lithology from the drill cores, the CL and DX contain different type of organic rocks. The CL 1 and CL2 core samples

  15. Siderophore-based microbial adaptations to iron scarcity across the eastern Pacific Ocean

    PubMed Central

    Mende, Daniel R.; Hawco, Nicholas J.; McIlvin, Matthew R.; Fitzsimmons, Jessica N.; Saito, Mak A.; Sedwick, Peter N.; DeLong, Edward F.; Repeta, Daniel J.

    2016-01-01

    Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, amphiphilic siderophores with cell membrane affinity. Phylogenetic analysis of amphibactin biosynthetic genes suggests that the ability to produce amphibactins has transferred horizontally across multiple Gammaproteobacteria, potentially driven by pressures to compete for iron. In coastal and oligotrophic regions of the eastern Pacific Ocean, amphibactins were replaced with lower concentrations (1–2 pM) of hydrophilic ferrioxamine siderophores. Our results suggest that organic ligand composition changes across the surface ocean in response to environmental pressures. Hydrophilic siderophores are predominantly found across regions of the ocean where iron is not expected to be the limiting nutrient for the microbial community at large. However, in regions with intense competition for iron, some microbes optimize iron acquisition by producing siderophores that minimize diffusive losses to the environment. These siderophores affect iron bioavailability and thus may be an important component of the marine iron cycle. PMID:27911777

  16. Siderophore-based microbial adaptations to iron scarcity across the eastern Pacific Ocean.

    PubMed

    Boiteau, Rene M; Mende, Daniel R; Hawco, Nicholas J; McIlvin, Matthew R; Fitzsimmons, Jessica N; Saito, Mak A; Sedwick, Peter N; DeLong, Edward F; Repeta, Daniel J

    2016-12-13

    Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, amphiphilic siderophores with cell membrane affinity. Phylogenetic analysis of amphibactin biosynthetic genes suggests that the ability to produce amphibactins has transferred horizontally across multiple Gammaproteobacteria, potentially driven by pressures to compete for iron. In coastal and oligotrophic regions of the eastern Pacific Ocean, amphibactins were replaced with lower concentrations (1-2 pM) of hydrophilic ferrioxamine siderophores. Our results suggest that organic ligand composition changes across the surface ocean in response to environmental pressures. Hydrophilic siderophores are predominantly found across regions of the ocean where iron is not expected to be the limiting nutrient for the microbial community at large. However, in regions with intense competition for iron, some microbes optimize iron acquisition by producing siderophores that minimize diffusive losses to the environment. These siderophores affect iron bioavailability and thus may be an important component of the marine iron cycle.

  17. Siderophore-based microbial adaptations to iron scarcity across the eastern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Boiteau, Rene M.; Mende, Daniel R.; Hawco, Nicholas J.; McIlvin, Matthew R.; Fitzsimmons, Jessica N.; Saito, Mak A.; Sedwick, Peter N.; DeLong, Edward F.; Repeta, Daniel J.

    2016-12-01

    Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, amphiphilic siderophores with cell membrane affinity. Phylogenetic analysis of amphibactin biosynthetic genes suggests that the ability to produce amphibactins has transferred horizontally across multiple Gammaproteobacteria, potentially driven by pressures to compete for iron. In coastal and oligotrophic regions of the eastern Pacific Ocean, amphibactins were replaced with lower concentrations (1–2 pM) of hydrophilic ferrioxamine siderophores. Our results suggest that organic ligand composition changes across the surface ocean in response to environmental pressures. Hydrophilic siderophores are predominantly found across regions of the ocean where iron is not expected to be the limiting nutrient for the microbial community at large. However, in regions with intense competition for iron, some microbes optimize iron acquisition by producing siderophores that minimize diffusive losses to the environment. These siderophores affect iron bioavailability and thus may be an important component of the marine iron cycle.

  18. Paleoceanography Of The Middle Eocene Arctic Ocean Based On Geochemical Measurements Of Biogenic Matter

    NASA Astrophysics Data System (ADS)

    Ogawa, Y.; Takahashi, K.; Yamanaka, T.

    2007-12-01

    The IODP Expedition 302, Arctic Coring Expedition (ACEX), recovered 428 m long sediment cores on the Lomonosov Ridge in the central Arctic Ocean. Chemical analyses for biogenic opal, total organic carbon (TOC), total sulfur (TS), and stable sulfur isotopic composition were conducted on the middle Eocene section of the ACEX cores. The previous study for microfossil assemblages on this section indicated the presence of low- salinity water mass in the Arctic Ocean. However, % TS contents were high in all intervals, indicating that abundant sea water was present in the deep layer of the paleo Arctic Ocean in contrast with low salinity surface water. The light sulfur isotope composition indicates the microbial sulfate reduction in an open system. This supports the continuous supply of sea water from the outside of the Arctic Ocean. The euxinic condition of the bottom water is suggested by the TOC-TS diagram. The anoxic environment was brought about by salinity stratification like the modern Black Sea. The high values of the accumulation of biogenic opal and TOC indicate high productivity which continued for nine myr. The high productivity was related to the estuarine type circulation in the semi-closed Arctic Ocean.

  19. Android Based Mobile Environment for Moodle Users

    ERIC Educational Resources Information Center

    de Clunie, Gisela T.; Clunie, Clifton; Castillo, Aris; Rangel, Norman

    2013-01-01

    This paper is about the development of a platform that eases, throughout Android based mobile devices, mobility of users of virtual courses at Technological University of Panama. The platform deploys computational techniques such as "web services," design patterns, ontologies and mobile technologies to allow mobile devices communicate…

  20. Calcareous microfossil-based orbital cyclostratigraphy in the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Marzen, Rachel E.; DeNinno, Lauren H.; Cronin, Thomas M.

    2016-10-01

    Microfaunal and geochemical proxies from marine sediment records from central Arctic Ocean (CAO) submarine ridges suggest a close relationship over the last 550 thousand years (kyr) between orbital-scale climatic oscillations, sea-ice cover, marine biological productivity and other parameters. Multiple paleoclimate proxies record glacial to interglacial cycles. To understand the climate-cryosphere-productivity relationship, we examined the cyclostratigraphy of calcareous microfossils and constructed a composite Arctic Paleoclimate Index (API) "stack" from benthic foraminiferal and ostracode density from 14 sediment cores. Following the hypothesis that API is driven mainly by changes in sea-ice related productivity, the API stack shows the Arctic experienced a series of highly productive interglacials and interstadials every ∼20 kyr. These periods signify minimal ice shelf and sea-ice cover and maximum marine productivity. Rapid transitions in productivity are seen during shifts from interglacial to glacial climate states. Discrepancies between the Arctic API curves and various global climatic, sea-level and ice-volume curves suggest abrupt growth and decay of Arctic ice shelves related to climatic and sea level oscillations.

  1. Calcareous microfossil-based orbital cyclostratigraphy in the Arctic Ocean

    USGS Publications Warehouse

    Marzen, Rachel; DeNinno, Lauren H.; Cronin, Thomas M.

    2016-01-01

    Microfaunal and geochemical proxies from marine sediment records from central Arctic Ocean (CAO) submarine ridges suggest a close relationship over the last 550 thousand years (kyr) between orbital-scale climatic oscillations, sea-ice cover, marine biological productivity and other parameters. Multiple paleoclimate proxies record glacial to interglacial cycles. To understand the climate-cryosphere-productivity relationship, we examined the cyclostratigraphy of calcareous microfossils and constructed a composite Arctic Paleoclimate Index (API) "stack" from benthic foraminiferal and ostracode density from 14 sediment cores. Following the hypothesis that API is driven mainly by changes in sea-ice related productivity, the API stack shows the Arctic experienced a series of highly productive interglacials and interstadials every ∼20 kyr. These periods signify minimal ice shelf and sea-ice cover and maximum marine productivity. Rapid transitions in productivity are seen during shifts from interglacial to glacial climate states. Discrepancies between the Arctic API curves and various global climatic, sea-level and ice-volume curves suggest abrupt growth and decay of Arctic ice shelves related to climatic and sea level oscillations.

  2. Beyond the Water’s Edge: United States National Security & the Ocean Environment

    DTIC Science & Technology

    2006-12-01

    efficient fleet operations and makes go / no-go fleet sortie recommendations to the Commander in advance of tropical storms . CDR DiMento served as a...would relate to environmentally-based shocks to economies (droughts to agricultural economies for example, or floods and storm surges that...enough dust and eject it into the atmosphere and subsequently trigger atmospheric cooling through an effect similar to one observed during volcanic

  3. Acoustic Blind Deconvolution and Frequency-Difference Beamforming in Shallow Ocean Environments

    DTIC Science & Technology

    2012-01-01

    sparse-array measurements might be used for this task. The long term goals of this project are: i) to determine the effectiveness of synthetic time...focused on developing an acoustic-ray-based version of synthetic time reversal (STR), a fully-passive technique for recovering the original signal and...simulations, b) verify these findings with simple airborne- or water-borne acoustic laboratory experiments involving multiple receivers and multiple ray paths

  4. Transit Time Distribution based on the ECCO-JPL Ocean Data Assimilation

    NASA Astrophysics Data System (ADS)

    Ito, Takamitsu; Wang, Ou

    2017-03-01

    Oceanic water mass is a mixture of waters with varying ages, and the Transit Time Distribution (TTD) measures its age spectrum. We construct a model-based TTD using the data-constrained circulation fields from the ECCO-JPL Ocean Data Assimilation, and test it against the observed and directly simulated distribution of pCFC-11 from the Pacific and Atlantic basins. The ECCO-JPL circulation provides overall reliable estimates of the upper ocean ventilation rates suitable for biogeochemical studies. Observed distributions of pCFC-11 in the upper ocean thermocline are well reproduced by the convolution integral of the model-based TTD (mean bias < 6%, spatial correlation > 0.87) but there are significant regional biases in particular near the base of the thermocline and in the deep water formation regions. The model underestimates the deep pCFC-11 (> 2000 m) in the North Atlantic and in the Southern Ocean. The ratio between the mean and the spread of the age spectrum (Γ/Δ) is close to unity (mean = 1.04, median = 0.99) in the ventilated thermocline of the Pacific basin but there are significant regional variations of the ratio.

  5. A neural network-based method for merging ocean color and Argo data to extend surface bio-optical properties to depth: Retrieval of the particulate backscattering coefficient

    NASA Astrophysics Data System (ADS)

    Sauzède, R.; Claustre, H.; Uitz, J.; Jamet, C.; Dall'Olmo, G.; D'Ortenzio, F.; Gentili, B.; Poteau, A.; Schmechtig, C.

    2016-04-01

    The present study proposes a novel method that merges satellite ocean color bio-optical products with Argo temperature-salinity profiles to infer the vertical distribution of the particulate backscattering coefficient (bbp). This neural network-based method (SOCA-BBP for Satellite Ocean-Color merged with Argo data to infer the vertical distribution of the Particulate Backscattering coefficient) uses three main input components: (1) satellite-based surface estimates of bbp and chlorophyll a concentration matched up in space and time with (2) depth-resolved physical properties derived from temperature-salinity profiles measured by Argo profiling floats and (3) the day of the year of the considered satellite-Argo matchup. The neural network is trained and validated using a database including 4725 simultaneous profiles of temperature-salinity and bio-optical properties collected by Bio-Argo floats, with concomitant satellite-derived products. The Bio-Argo profiles are representative of the global open-ocean in terms of oceanographic conditions, making the proposed method applicable to most open-ocean environments. SOCA-BBP is validated using 20% of the entire database (global error of 21%). We present additional validation results based on two other independent data sets acquired (1) by four Bio-Argo floats deployed in major oceanic basins, not represented in the database used to train the method; and (2) during an AMT (Atlantic Meridional Transect) field cruise in 2009. These validation tests based on two fully independent data sets indicate the robustness of the predicted vertical distribution of bbp. To illustrate the potential of the method, we merged monthly climatological Argo profiles with ocean color products to produce a depth-resolved climatology of bbp for the global ocean.

  6. Adaptive User Model for Web-Based Learning Environment.

    ERIC Educational Resources Information Center

    Garofalakis, John; Sirmakessis, Spiros; Sakkopoulos, Evangelos; Tsakalidis, Athanasios

    This paper describes the design of an adaptive user model and its implementation in an advanced Web-based Virtual University environment that encompasses combined and synchronized adaptation between educational material and well-known communication facilities. The Virtual University environment has been implemented to support a postgraduate…

  7. EVA: Collaborative Distributed Learning Environment Based in Agents.

    ERIC Educational Resources Information Center

    Sheremetov, Leonid; Tellez, Rolando Quintero

    In this paper, a Web-based learning environment developed within the project called Virtual Learning Spaces (EVA, in Spanish) is presented. The environment is composed of knowledge, collaboration, consulting, experimentation, and personal spaces as a collection of agents and conventional software components working over the knowledge domains. All…

  8. Web-Based Interactive Writing Environment: Development and Evaluation

    ERIC Educational Resources Information Center

    Yang, Jie Chi; Ko, Hwa Wei; Chung, I. Ling

    2005-01-01

    This study reports the development and evaluation of a web-based interactive writing environment designed for elementary school students. The environment includes three writing themes, "story pass on", "story chameleon" and "thousand ideas", to encourage reading comprehension, creativity and problem-solving skills of…

  9. EVA: An Interactive Web-Based Collaborative Learning Environment

    ERIC Educational Resources Information Center

    Sheremetov, Leonid; Arenas, Adolfo Guzman

    2002-01-01

    In this paper, a Web-based learning environment developed within the project called Virtual Learning Spaces (EVA, in Spanish) is described. The environment is composed of knowledge, collaboration, consulting and experimentation spaces as a collection of agents and conventional software components working over the knowledge domains. All user…

  10. Applications of satellite and marine geodesy to operations in the ocean environment

    NASA Technical Reports Server (NTRS)

    Fubara, D. M.; Mourad, A. G.

    1975-01-01

    The requirements for marine and satellite geodesy technology are assessed with emphasis on the development of marine geodesy. Various programs and missions for identification of the satellite geodesy technology applicable to marine geodesy are analyzed along with national and international marine programs to identify the roles of satellite/marine geodesy techniques for meeting the objectives of the programs and other objectives of national interest effectively. The case for marine geodesy is developed based on the extraction of requirements documented by authoritative technical industrial people, professional geodesists, government agency personnel, and applicable technology reports.

  11. Assessment of Urbanization on the Integrated Land-Ocean-Atmosphere Environment in Coastal Metropolis in Preparation for HyspIRI

    NASA Technical Reports Server (NTRS)

    Sequera, Pedro; McDonald, Kyle C.; Gonzalez, Jorge; Arend, Mark; Krakauer, Nir; Bornstein, Robert; Luvll, Jeffrey

    2012-01-01

    The need for comprehensive studies of the relationships between past and projected changes of regional climate and human activity in comple x urban environments has been well established. The HyspIRI preparato ry airborne activities in California, associated science and applicat ions research, and eventually HyspIRI itself provide an unprecedented opportunity for development and implementation of an integrated data and modeling analysis system focused on coastal urban environments. We will utilize HyspIRI preparatory data collections in developing ne w remote sensing-based tools for investigating the integrated urban e nvironment, emphasizing weather, climate, and energy demands in compl ex coastal cities.

  12. A Design and Control Environment for Internet-Based Telerobotics

    NASA Technical Reports Server (NTRS)

    Oboe, Roberto; Fiorini, Paolo

    1997-01-01

    This paper describes an environment for the design, simulation and control of Internet-based force-relflecting telerobotc systems. We define these systems as using a segment of the computer network to connect the master to the slave.

  13. A Collaborative Environment for Knowledge Base Development

    NASA Astrophysics Data System (ADS)

    Li, W.; Yang, C.; Raskin, R.; Nebert, D. D.; Wu, H.

    2009-12-01

    Knowledge Base (KB) is an essential component for capturing, structuring and defining the meanings of domain knowledge. It’s important in enabling the sharing and interoperability of scientific data and services in a smart manner. It’s also the foundation for most the research in semantic field, such as semantic reasoning and ranking. In collaborating with ESIP, GMU is developing an online interface and supporting infrastructure to allow semantic registration of datasets and other web resources. The semantic description of data, services, and scientific content will be collected and transformed to the KB. As a case study, the harvest of web map services from by Nordic mapping agencies to build a virtual Arctic spatial data infrastructure will be used as the domain example. To automate the process, a controlled vocabulary of certain subjects, such as solid water, is created to filter from existing data and service repositories to obtain a collection of closely related document. Then latent semantic indexing is utilized to analyze semantic relationship among concepts that appears in service document. At last, semantic structure in plain text will be mapped and automatically populated to the specific presentation of knowledge in the KB.

  14. Studies of Ocean Predictability at Decade to Century Time Scales Using a Global Ocean General Circulation Model in a Parallel Computing Environment

    SciTech Connect

    Barnett, T.P.

    1998-11-30

    The objectives of this report are to determine the structure of oceanic natural variability at time scales of decades to centuries, characterize the physical mechanisms responsible for the variability; determine the relative importance of heat, fresh water, and moment fluxes on the variability; determine the predictability of the variability on these times scales. (B204)

  15. Reevaluation of plate motion models based on hotspot tracks in the Atlantic and Indian Oceans

    SciTech Connect

    Baksi, A.K.

    1999-01-01

    Plate motion models based on hotspot tracks in the Atlantic and Indian Oceans predict minimal movement (less than a few millimeters per year) between these hotspots and their counterparts in the Pacific Ocean for the past {approximately}100 m.yr., whereas plate circuit exercises indicate relative motions of {approximately}20 mm/yr. Hotspot-based models also suggest that the Rajmahal Traps, India, were located {approximately}1,000 km away from the Kerguelen hotspot at {approximately}115 Ma, and the Deccan Traps, India, were located a similar distance from the Reunion hotspot at {approximately}65 Ma; this is at odds with conclusions derived from paleomagnetism, plate circuits, and geochemical parameters that suggest a genetic link between flood basalt provinces in India and hotspots in the Indian Ocean. These divergent views may be explained by plume action {approximately}1,000 km from its center or errors in the hotspot motion models. The latter hypothesis is scrutinized in this article by examination of the radiometric ages for hotspot tracks in the Atlantic and Indian Oceans. The {sup 40}/{sup 39}Ar step-heating data for rocks defining the tracks of the Reunion and Kerguelen hotspots in the Indian Ocean and the Great Metero and Tristan da Cunha hotspots in the Atlantic Ocean are critically reexamined. Of {approximately}35 such ages utilized for deriving plate motion models for the past 130 m.yr., at best, only three ({approximately}32, {approximately}50, and {approximately}52 Ma) in the Indian Ocean and one ({approximately}65 Ma) for the Atlantic Ocean may be treated as crystallization ages. Conclusions based on hotspot track modeling for Late Cretaceous to Eocene time are suspect, and those for the Early to Late Cretaceous period are untenable. In the absence of precise age data for the tracks of hotspots in the Atlantic and Indian Oceans, and inconsistent age progressions noted within a single volcanic chain, plate circuit models serve as the superior technique

  16. Does the Defense Industrial Base Environment Create Strategic Risk?

    DTIC Science & Technology

    2013-03-01

    required of them to meet future DoD requirements. If an industry is struggling financially, money wasted on designing capabilities that DoD does not...Does the Defense Industrial Base Environment Create Strategic Risk? by Lieutenant Colonel Brandon L. Grubbs United States... Industrial Base Environment Create Strategic Risk? 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Lieutenant

  17. Terminal velocities of pure and hydrate coated CO 2 droplets and CH 4 bubbles rising in a simulated oceanic environment

    NASA Astrophysics Data System (ADS)

    Bigalke, N. K.; Enstad, L. I.; Rehder, G.; Alendal, G.

    2010-09-01

    Understanding the upward motion of CO 2 droplets or CH 4 bubbles in oceanic waters is prerequisite to predict the vertical distribution of the two most important greenhouse gases in the water column after these have been released from the seabed. One of the key parameters governing the fate of droplets or bubbles dissolving into the surrounding seawater as they rise, is the terminal velocity, uT. The latter is strongly influenced by the ability of both compounds to form skins of gas hydrate, if pressure and temperature satisfy thermodynamic framework conditions. Experimental efforts aiming to elucidate the rise properties of CO 2 droplets and CH 4 bubbles and specifically the influence of hydrate skins open the possibility to obtain a parameterization of uT applicable to both hydrate-coated and pure fluid particles of CH 4 and CO 2. With the present study, we report on experimentally determined terminal velocities of single CH 4 bubbles released to pressurized and temperature-regulated seawater. Hydrate skins were identified by high bubble sphericities and changed motion characteristics. Based on these experiments as well as published data on the rise of hydrate-coated and pure liquid CO 2 droplets and physical principles previously successfully used for clean bubbles near atmospheric pressures, a new parameterization of uT is proposed. Model predictions show a good agreement with the data base established from the laboratory-based measurements.

  18. Oceanic Flights and Airspace: Improving Efficiency by Trajectory-Based Operations

    NASA Technical Reports Server (NTRS)

    Fernandes, Alicia Borgman; Rebollo, Juan; Koch, Michael

    2016-01-01

    Oceanic operations suffer from multiple inefficiencies, including pre-departure planning that does not adequately consider uncertainty in the proposed trajectory, restrictions on the routes that a flight operator can choose for an oceanic crossing, time-consuming processes and procedures for amending en route trajectories, and difficulties exchanging data between Flight Information Regions (FIRs). These inefficiencies cause aircraft to fly suboptimal trajectories, burning fuel and time that could be conserved. A concept to support integration of existing and emerging capabilities and concepts is needed to transition to an airspace system that employs Trajectory Based Operations (TBO) to improve efficiency and safety in oceanic operations. This paper describes such a concept and the results of preliminary activities to evaluate the concept, including a stakeholder feedback activity, user needs analysis, and high level benefits analysis.

  19. IOCCG Report Number 16, 2015 Ocean Colour Remote Sensing in Polar Seas . Chapter 2; The Polar Environment: Sun, Clouds, and Ice

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.; Perovich, Don; Stamnes, Knut; Stuart, Venetia (Editor)

    2015-01-01

    The polar regions are places of extremes. There are months when the regions are enveloped in unending darkness, and months when they are in continuous daylight. During the daylight months the sun is low on the horizon and often obscured by clouds. In the dark winter months temperatures are brutally cold, and high winds and blowing snow are common. Even in summer, temperatures seldom rise above 0degC. The cold winter temperatures cause the ocean to freeze, forming sea ice. This sea ice cover acts as a barrier limiting the transfer of heat, moisture, and momentum between the atmosphere and the ocean. It also greatly complicates the optical signature of the surface. Taken together, these factors make the polar regions a highly challenging environment for optical remote sensing of the ocean.

  20. Teaching Sustainabilty in the Setting of a Field-based Class on the Oceans in Captivity

    NASA Astrophysics Data System (ADS)

    Macko, Stephen; Tuite, Michael; O'Connell, Matthew

    2013-04-01

    Sustainability awareness is increasingly a subject in educational settings. Marine science classes are perfect settings of establishing sustainability awareness owing to declining populations of organisms and perceived collapsenin fisheries worldwide. Students in oceanography classes often request more direct exposure to actual ocean situations or field trips. During regular session (13 week) or shorter term (4 week) summer classes such long trips are logistically difficult owing to large numbers of students involved or timing. This new approach to such a course supplement addresses the requests by utilizing local resources and short field trips for a limited number of students (20) to locations in which Ocean experiences are available, and are often supported through education and outreach components. The vision of the class was a mixture of classroom time, readings, along with paper and laboratories. In addition short day-long trips to locations where the ocean was "captured" were also used to supplement the experience as well as speakers involved with aquaculture ("cultivated") Central Virginia is a fortunate location for such a class, with close access for "day travel" to the Chesapeake Bay and numerous field stations, museums with ocean-based exhibits (the Smithsonian and National Zoo) that address both extant and extinct Earth history, as well as national/state aquaria in Baltimore, Washington and Virginia Beach. Furthermore, visits to local seafood markets at local grocery stores, or larger city markets) enhance the exposure to productivity in the ocean, and viability of the fisheries sustainability. The course could then address not only the particulars of the marine science, but also aspects of sustainability with discussions on ethics, including keeping animals in captivity or overfishing of particular species and the special difficulties that arise from captive or culturing ocean populations. In addition, the class was encouraged to post web-based

  1. 33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California; naval danger zone. 334.866 Section 334.866... AND RESTRICTED AREA REGULATIONS § 334.866 Pacific Ocean at Naval Base Coronado, in the City...

  2. 33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a)...

  3. 33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a)...

  4. 33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a)...

  5. 33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a)...

  6. 33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a)...

  7. Knowledge-based systems and NASA's software support environment

    NASA Technical Reports Server (NTRS)

    Dugan, Tim; Carmody, Cora; Lennington, Kent; Nelson, Bob

    1990-01-01

    A proposed role for knowledge-based systems within NASA's Software Support Environment (SSE) is described. The SSE is chartered to support all software development for the Space Station Freedom Program (SSFP). This includes support for development of knowledge-based systems and the integration of these systems with conventional software systems. In addition to the support of development of knowledge-based systems, various software development functions provided by the SSE will utilize knowledge-based systems technology.

  8. Life history and biogeography of Calanus copepods in the Arctic Ocean: An individual-based modeling study

    NASA Astrophysics Data System (ADS)

    Ji, Rubao; Ashjian, Carin J.; Campbell, Robert G.; Chen, Changsheng; Gao, Guoping; Davis, Cabell S.; Cowles, Geoffrey W.; Beardsley, Robert C.

    2012-04-01

    Calanus spp. copepods play a key role in the Arctic pelagic ecosystem. Among four congeneric species of Calanus found in the Arctic Ocean and its marginal seas, two are expatriates in the Arctic (Calanus finmarchicus and Calanus marshallae) and two are endemic (Calanus glacialis and Calanus hyperboreus). The biogeography of these species likely is controlled by the interactions of their life history traits and physical environment. A mechanistic understanding of these interactions is critical to predicting their future responses to a warming environment. Using a 3-D individual-based model that incorporates temperature-dependent and, for some cases, food-dependent development rates, we show that (1) C. finmarchicus and C. marshallae are unable to penetrate, survive, and colonize the Arctic Ocean under present conditions of temperature, food availability, and length of the growth season, mainly due to insufficient time to reach their diapausing stage and slow transport of the copepods into the Arctic Ocean during the growing season or even during the following winter at the depths the copepods are believed to diapause. (2) For the two endemic species, the model suggests that their capability of diapausing at earlier copepodite stages and utilizing ice-algae as a food source (thus prolonging the growth season length) contribute to the population sustainability in the Arctic Ocean. (3) The inability of C. hyperboreus to attain their first diapause stage in the central Arctic, as demonstrated by the model, suggests that the central Arctic population may be advected from the surrounding shelf regions along with multi-year successive development and diapausing, and/or our current estimation of the growth parameters and the growth season length (based on empirical assessment or literature) needs to be further evaluated. Increasing the length of the growth season or increasing water temperature by 2 °C, and therefore increasing development rates, greatly increased the area

  9. Ammonia-oxidizing bacterial community composition in estuarine and oceanic environments assessed using a functional gene microarray

    USGS Publications Warehouse

    Ward, B.B.; Eveillard, D.; Kirshtein, J.D.; Nelson, J.D.; Voytek, M.A.; Jackson, G.A.

    2007-01-01

    The relationship between environmental factors and functional gene diversity of ammonia-oxidizing bacteria (AOB) was investigated across a transect from the freshwater portions of the Chesapeake Bay and Choptank River out into the Sargasso Sea. Oligonucleotide probes (70-bp) designed to represent the diversity of ammonia monooxygenase (amoA) genes from Chesapeake Bay clone libraries and cultivated AOB were used to construct a glass slide microarray. Hybridization patterns among the probes in 14 samples along the transect showed clear variations in amoA community composition. Probes representing uncultivated members of the Nitrosospira-like AOB dominated the probe signal, especially in the more marine samples. Of the cultivated species, only Nitrosospira briensis was detected at appreciable levels. Discrimination analysis of hybridization signals detected two guilds. Guild 1 was dominated by the marine Nitrosospira-like probe signal, and Guild 2???s largest contribution was from upper bay (freshwater) sediment probes. Principal components analysis showed that Guild 1 was positively correlated with salinity, temperature and chlorophyll a concentration, while Guild 2 was positively correlated with concentrations of oxygen, dissolved organic carbon, and particulate nitrogen and carbon, suggesting that different amoA sequences represent organisms that occupy different ecological niches within the estuarine/marine environment. The trend from most diversity of AOB in the upper estuary towards dominance of a single type in the polyhaline region of the Bay is consistent with the declining importance of AOB with increasing salinity, and with the idea that AO-Archaea are the more important ammonia oxidizers in the ocean. ?? 2007 The Authors.

  10. Mooring system of ocean turbulence observation based on submerged buoy

    NASA Astrophysics Data System (ADS)

    Song, Da-lei; Sun, Jing-jing; Xue, Bing; Jiang, Qian-li; Wu, Bing-wei

    2013-06-01

    A comparison experiment has been taken in the Kiaochow Bay between a newly designed mooring turbulence observation instrument (MTOI) and microstructure profiler MSS60 made by Sea & Sun. The whole observing system is based on a submerged buoy, in which the turbulence observation instrument is embedded, with a streamline-shape floating body, which is made of buoyancy material of glass microsphere. For the movement of seawater and the cable shaking strongly anytime influence the behaviors of the floating body, the accelerate sensors are used for the vibration measurement in the instrument together with the shear probe sensor. Both the vibration data and the shear data are acquired by the instrument at the same time. During data processing, the vibration signals can be removed and leave the shear data which we really need. In order to prove the reliability of the new turbulence instrument MTOI, a comparison experiment was designed. The measuring conditions are the same both in time and space. By this way, the two groups of data are comparable. In this paper, the conclusion gives a good similarity of 0.93 for the two groups of shear data in dissipation rate. The processing of the data acquired by MTOI is based on the cross-spectrum analysis, and the dissipation rate of it matches the Nasmyth spectrum well.

  11. Multiple sensors-based kernel machine learning in smart environment

    NASA Astrophysics Data System (ADS)

    Li, Jun-Bao; Pan, Jeng-Shyang

    2017-01-01

    Sensor-based monitoring systems use multiple sensors to identify high-level information based on the events that take place in a monitored environment. Identification and health care are important tasks in the smart environment. This paper presents a framework for multisensory multimedia data analysis using a kernel optimization-based principal analysis for identification and health care in a smart environment. Images of faces, palmprints, and fingerprints are used to identify a person, and a wrist pulse signal is used to analyze the person's health condition. The recognition performance evaluations are implemented on the complex dataset of face, palmprint, fingerprint, and wrist pulse signals. The experimental results show that the proposed algorithms perform well for identification and heath analysis.

  12. Accuracy assessment of the global ionospheric model over the Southern Ocean based on dynamic observation

    NASA Astrophysics Data System (ADS)

    Luo, Xiaowen; Xu, Huajun; Li, Zishen; Zhang, Tao; Gao, Jinyao; Shen, Zhongyan; Yang, Chunguo; Wu, Ziyin

    2017-02-01

    The global ionospheric model based on the reference stations of the Global Navigation Satellite System (GNSS) of the International GNSS Services is presently the most commonly used products of the global ionosphere. It is very important to comprehensively analyze and evaluate the accuracy and reliability of the model for the reasonable use of this kind of ionospheric product. In terms of receiver station deployment, this work is different from the traditional performance evaluation of the global ionosphere model based on observation data of ground-based static reference stations. The preliminary evaluation and analysis of the the global ionospheric model was conducted with the dynamic observation data across different latitudes over the southern oceans. The validation results showed that the accuracy of the global ionospheric model over the southern oceans is about 5 TECu, which deviates from the measured ionospheric TEC by about -0.6 TECu.

  13. NIR- and SWIR-based on-orbit vicarious calibrations for satellite ocean color sensors.

    PubMed

    Wang, Menghua; Shi, Wei; Jiang, Lide; Voss, Kenneth

    2016-09-05

    The near-infrared (NIR) and shortwave infrared (SWIR)-based atmospheric correction algorithms are used in satellite ocean color data processing, with the SWIR-based algorithm particularly useful for turbid coastal and inland waters. In this study, we describe the NIR- and two SWIR-based on-orbit vicarious calibration approaches for satellite ocean color sensors, and compare results from these three on-orbit vicarious calibrations using satellite measurements from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP). Vicarious calibration gains for VIIRS spectral bands are derived using the in situ normalized water-leaving radiance nLw(λ) spectra from the Marine Optical Buoy (MOBY) in waters off Hawaii. The SWIR vicarious gains are determined using VIIRS measurements from the South Pacific Gyre region, where waters are the clearest and generally stable. Specifically, vicarious gain sets for VIIRS spectral bands of 410, 443, 486, 551, and 671 nm derived from the NIR method using the NIR 745 and 862 nm bands, the SWIR method using the SWIR 1238 and 1601 nm bands, and the SWIR method using the SWIR 1238 and 2257 nm bands are (0.979954, 0.974892, 0.974685, 0.965832, 0.979042), (0.980344, 0.975344, 0.975357, 0.965531, 0.979518), and (0.980820, 0.975609, 0.975761, 0.965888, 0.978576), respectively. Thus, the NIR-based vicarious calibration gains are consistent with those from the two SWIR-based approaches with discrepancies mostly within ~0.05% from three data processing methods. In addition, the NIR vicarious gains (745 and 862 nm) derived from the two SWIR methods are (0.982065, 1.00001) and (0.981811, 1.00000), respectively, with the difference ~0.03% at the NIR 745 nm band. This is the fundamental basis for the NIR-SWIR combined atmospheric correction algorithm, which has been used to derive improved satellite ocean color products over open oceans and turbid coastal/inland waters. Therefore, a unified

  14. A coordinated retrieval method for sea surface salinity based on SMOS and ocean color data

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Wang, Tianyu; Mao, Zhihua; Bai, Yan; Hao, Zengzhou

    2016-10-01

    A coordinated retrieval method for sea surface salinity based on SMOS and ocean color data was developed. The method retrieved sea surface salinity in open sea based on SMOS data, and those with much RFIs in the coastal area using ocean color data, aCDOM. Tight relationships between surface water salinity and in situ aCDOM were found during the cruises in the Yangtze River estuary on April 2013 and Hangzhou Bay in May 2014, distributions of aCDOM revealed gradual downward trends of magnitudes, as water flowed down the Yangtze River estuary into the ECS coast. A dilution process was detected as water flowed down the Yangtze River and into the ECS coast. Thus, a salinity inversion model from the negative relationship between salinity and aCDOM was developed firstly. Then we matched the SSS products with different spatial resolution retrieved based on SMOS and ocean color and combined them. In the end, we compared the SSS measurements between those based on only SMOS data and those based on method in this paper, and found that the method can make up the phenomenon of lack of data effectively.

  15. Microwave Propagation through Rain: Effects on Space based Radar Altimeter Measurements over Oceans

    NASA Astrophysics Data System (ADS)

    Bhandari, Satyendra

    2007-07-01

    Radar Altimetry from space, primarily developed for making precise cm level measurements of ocean surface height, has proved to be a highly versatile technique in providing valuable information about other enclosed water bodies like lakes, oceanic and polar ice surfaces as well as the Earth's ionosphere and the atmosphere. Sophisticated radar altimeters orbiting in space since 1992, make measurements of the pulse travel time, profile and energy backscattered from the ocean surface, simultaneously at two microwave frequencies. These pulse parameters are significantly affected by the presence of various ionospheric and atmospheric constituents, including the presence of rain in the propagation path. In this paper, we discuss the rain related effects on the radar altimeter measurements from space. Simultaneous availability of backscatter echo measurements at two widely separated frequencies in the C and Ku bands permit the estimation of rain induced attenuation of the microwave signal in its two-way journey through the raining column in the atmosphere. The application of differential C-Ku band attenuation in the development of algorithms for estimation over rainfall rate over the global oceans, pioneered by Bhandari and Varma (1995), is described and discussed. Over the last decade, the differential attenuation technique has been exploited extensively to map and study global oceanic rainfall in a comprehensive manner, based on dual frequency radar altimetric measurements from TOPEX/Poseidon, Jason and Envisat satellite missions. The paper would attempt to review the progress and accomplishments to date. Complementary and supplementary aspects of rainfall estimation from radar altimeters, in comparison to other space based methods, would also be highlighted. Attention would be focused on future radar altimeter missions addressing, in particular, the narrow-swath limitation of the present day radar altimeters.

  16. Local Observations, Global Connections: An Educational Program Using Ocean Networks Canada's Community-Based Observatories

    NASA Astrophysics Data System (ADS)

    Pelz, M.; Hoeberechts, M.; Ewing, N.; Davidson, E.; Riddell, D. J.

    2014-12-01

    Schools on Canada's west coast and in the Canadian Arctic are participating in the pilot year of a novel educational program based on analyzing, understanding and sharing ocean data collected by cabled observatories. The core of the program is "local observations, global connections." First, students develop an understanding of ocean conditions at their doorstep through the analysis of community-based observatory data. Then, they connect that knowledge with the health of the global ocean by engaging with students at other schools participating in the educational program and through supplemental educational resources. Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories which supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea. This Internet connectivity permits researchers, students and members of the public to download freely available data on their computers anywhere around the globe, in near real-time. In addition to the large NEPTUNE and VENUS cabled observatories off the coast of Vancouver Island, British Columbia, ONC has been installing smaller, community-based cabled observatories. Currently two are installed: one in Cambridge Bay, Nunavut and one at Brentwood College School, on Mill Bay in Saanich Inlet, BC. Several more community-based observatories are scheduled for installation within the next year. The observatories support a variety of subsea instruments, such as a video camera, hydrophone and water quality monitor and shore-based equipment including a weather station and a video camera. Schools in communities hosting an observatory are invited to participate in the program, alongside schools located in other coastal and inland communities. Students and teachers access educational material and data through a web portal, and use video conferencing and social media tools to communicate their findings. A series of lesson plans

  17. Oceanic loading monitored by ground-based tiltmeters at Cherbourg (France)

    NASA Astrophysics Data System (ADS)

    Florsch, Nicolas; Llubes, Muriel; Wöppelmann, Guy; Longuevergne, Laurent; Boy, Jean-Paul

    2009-12-01

    We installed two orthogonal Blum-Esnoult silica tiltmeters in an underground military facility close to the shore in Cherbourg (France). They have recorded the oceanic loading effects from March 2004 to July 2005. The signal to noise ratio is such that, within a period range from a few minutes to a few days, the main non-linear oceanic tides up to the M10 group can be observed. The modelling of the tidal tilt deformation has been carried out using oceanic models of the FES2004 family, with a stepwise refinement of the grid size based on the unstructured grid T-UGAm model leading to the NEA-2004 tidal solution. This improvement permits to reduce the discrepancy between the model and the data with respect to the use of FES2004 alone, and show that, although the misfit remains significant, one progresses toward an independent mean to validate the oceanic models and finally the whole modelling process. We also show that tiltmeters open new opportunities to explore loading of non-linear tides on a larger spectrum than gravimeters and GPS do.

  18. Event Detection and Visualization of Ocean Eddies based on SSH and Velocity Field

    NASA Astrophysics Data System (ADS)

    Matsuoka, Daisuke; Araki, Fumiaki; Inoue, Yumi; Sasaki, Hideharu

    2016-04-01

    Numerical studies of ocean eddies have been progressed using high-resolution ocean general circulation models. In order to understand ocean eddies from simulation results with large amount of information volume, it is necessary to visualize not only distribution of eddies of each time step, but also events or phenomena of eddies. However, previous methods cannot precisely detect eddies, especially, during the events such as eddies' amalgamation, bifurcation. In the present study, we propose a new approach of eddy's detection, tracking and event visualization based on sea surface height (SSH) and velocity field. The proposed method detects eddies region as well as streams and currents region, and classifies detected eddies into several types. By tracking the time-varying change of classified eddies, it is possible to detect not only eddies event such as amalgamation and bifurcation but also the interaction between eddy and ocean current. As a result of visualizing detected eddies and events, we succeeded in creating the movie which enables us to intuitively understand the region of interest.

  19. Web-based visualization of gridded dataset usings OceanBrowser

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Watelet, Sylvain; Troupin, Charles; Beckers, Jean-Marie

    2015-04-01

    OceanBrowser is a web-based visualization tool for gridded oceanographic data sets. Those data sets are typically four-dimensional (longitude, latitude, depth and time). OceanBrowser allows one to visualize horizontal sections at a given depth and time to examine the horizontal distribution of a given variable. It also offers the possibility to display the results on an arbitrary vertical section. To study the evolution of the variable in time, the horizontal and vertical sections can also be animated. Vertical section can be generated by using a fixed distance from coast or fixed ocean depth. The user can customize the plot by changing the color-map, the range of the color-bar, the type of the plot (linearly interpolated color, simple contours, filled contours) and download the current view as a simple image or as Keyhole Markup Language (KML) file for visualization in applications such as Google Earth. The data products can also be accessed as NetCDF files and through OPeNDAP. Third-party layers from a web map service can also be integrated. OceanBrowser is used in the frame of the SeaDataNet project (http://gher-diva.phys.ulg.ac.be/web-vis/) and EMODNET Chemistry (http://oceanbrowser.net/emodnet/) to distribute gridded data sets interpolated from in situ observation using DIVA (Data-Interpolating Variational Analysis).

  20. A deformation-based parametrization of ocean mesoscale eddy reynolds stresses

    NASA Astrophysics Data System (ADS)

    Anstey, James A.; Zanna, Laure

    2017-04-01

    Ocean mesoscale eddies strongly affect the strength and variability of large-scale ocean jets such as the Gulf Stream and Kuroshio Extension. Their spatial scales are too small to be fully resolved in many current climate models and hence their effects on the large-scale circulation need to be parametrized. Here we propose a parametrization of mesoscale eddy momentum fluxes based on large-scale flow deformation. The parametrization is argued to be suitable for use in eddy-permitting ocean general circulation models, and is motivated by an analogy between turbulence in Newtonian fluids (such as water) and laminar flow in non-Newtonian fluids. A primitive-equations model in an idealised double-gyre configuration at eddy-resolving horizontal resolution is used to diagnose the relationship between the proposed closure and the eddy fluxes resolved by the model. Favourable correlations suggest the closure could provide an appropriate deterministic parametrization of mesoscale eddies. The relationship between the closure and different representations of the Reynolds stress tensor is also described. The parametrized forcing possesses the key quasi-geostrophic turbulence properties of energy conservation and enstrophy dissipation, and allows for upgradient fluxes leading to the sharpening of vorticity gradients. The implementation of the closure for eddy-permitting ocean models requires only velocity derivatives and a single parameter that scales with model resolution.

  1. 33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine...

  2. 33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine...

  3. 33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine...

  4. 33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine...

  5. 33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine...

  6. Fine-Resolution Satellite-Based Daily Sea Surface Temperatures over the Global Ocean

    DTIC Science & Technology

    2007-05-01

    MODAS with latitudinal extent limited to ±80. Note that only the RTG product includes SST in the Caspian Sea and the Sea of Azov . The plot masks SST...Fine-resolution satellite-based daily sea surface temperatures over the global ocean A. B. Kara1 and C. N. Barron1 Received 18 November 2006; revised...13 February 2007; accepted 27 February 2007; published 22 May 2007. [1] The accuracy and relative merits of two sets of daily global sea surface

  7. Design and Application of Learning Environments Based on Integrative Problems

    ERIC Educational Resources Information Center

    Sanchez, Ivan; Neriz, Liliana; Ramis, Francisco

    2008-01-01

    This work reports on the results obtained from the application of learning environments on the basis of one integrative problem and a series of other smaller problems that limit the contents to be investigated and learned by the students. This methodology, which is a variation to traditional problem-based learning approaches, is here illustrated…

  8. Advances in Web-Based Education: Personalized Learning Environments

    ERIC Educational Resources Information Center

    Magoulas, George, Ed.; Chen, Sherry, Ed.

    2006-01-01

    Advances in technology are increasingly impacting the way in which curriculum is delivered and assessed. The emergence of the Internet has offered learners a new instructional delivery system that connects them with educational resources. "Advances in Web-Based Education: Personalized Learning Environments" covers a wide range of factors that…

  9. Challenges for Design of Computer-Based Learning Environments.

    ERIC Educational Resources Information Center

    Hakkinen, Paivi

    2002-01-01

    Presents a review of the basic foundations and recent challenges of the main instructional design traditions. Topics include learner characteristics; learner-controlled instruction; learning environments; the role of instructional interventions; computer-based instruction and other new technologies; and new theories of learning and design.…

  10. A Software Laboratory Environment for Computer-Based Problem Solving.

    ERIC Educational Resources Information Center

    Kurtz, Barry L.; O'Neal, Micheal B.

    This paper describes a National Science Foundation-sponsored project at Louisiana Technological University to develop computer-based laboratories for "hands-on" introductions to major topics of computer science. The underlying strategy is to develop structured laboratory environments that present abstract concepts through the use of…

  11. Web-based Learning Environments: Do Libraries Matter?

    ERIC Educational Resources Information Center

    Beagle, Donald

    2000-01-01

    Discussion of Web-based learning environments and asynchronous learning networks for on-campus and distance education focuses on the role of academic libraries. Topics include library involvement in courseware development decisions, integration with library systems, and librarian attitudes and observations compared to those of faculty. (Contains…

  12. Designing a Virtual-Reality-Based, Gamelike Math Learning Environment

    ERIC Educational Resources Information Center

    Xu, Xinhao; Ke, Fengfeng

    2016-01-01

    This exploratory study examined the design issues related to a virtual-reality-based, gamelike learning environment (VRGLE) developed via OpenSimulator, an open-source virtual reality server. The researchers collected qualitative data to examine the VRGLE's usability, playability, and content integration for math learning. They found it important…

  13. Novel two-stage piezoelectric-based ocean wave energy harvesters for moored or unmoored buoys

    NASA Astrophysics Data System (ADS)

    Murray, R.; Rastegar, J.

    2009-03-01

    Harvesting mechanical energy from ocean wave oscillations for conversion to electrical energy has long been pursued as an alternative or self-contained power source. The attraction to harvesting energy from ocean waves stems from the sheer power of the wave motion, which can easily exceed 50 kW per meter of wave front. The principal barrier to harvesting this power is the very low and varying frequency of ocean waves, which generally vary from 0.1Hz to 0.5Hz. In this paper the application of a novel class of two-stage electrical energy generators to buoyant structures is presented. The generators use the buoy's interaction with the ocean waves as a low-speed input to a primary system, which, in turn, successively excites an array of vibratory elements (secondary system) into resonance - like a musician strumming a guitar. The key advantage of the present system is that by having two decoupled systems, the low frequency and highly varying buoy motion is converted into constant and much higher frequency mechanical vibrations. Electrical energy may then be harvested from the vibrating elements of the secondary system with high efficiency using piezoelectric elements. The operating principles of the novel two-stage technique are presented, including analytical formulations describing the transfer of energy between the two systems. Also, prototypical design examples are offered, as well as an in-depth computer simulation of a prototypical heaving-based wave energy harvester which generates electrical energy from the up-and-down motion of a buoy riding on the ocean's surface.

  14. Atmospheric Nitrogen Deposition to the Oceans: Observation- and Model-Based Estimates

    NASA Astrophysics Data System (ADS)

    Baker, Alex

    2016-04-01

    The reactive nitrogen (Nr) burden of the atmosphere has been increased by a factor of 3-4 by anthropogenic activity since the Industrial Revolution. This has led to large increases in the deposition of nitrate and ammonium to the surface waters of the open ocean, particularly downwind of major human population centres, such as those in North America, Europe and Southeast Asia. In oligotrophic waters, this deposition has the potential to significantly impact marine productivity and the global carbon cycle. Global-scale understanding of N deposition to the oceans is reliant on our ability to produce effective models of reactive nitrogen emission, atmospheric chemistry, transport and deposition (including deposition to the land surface). Over land, N deposition models can be assessed using comparisons to regional monitoring networks of precipitation chemistry (notably those located in North America, Europe and Southeast Asia). No similar datasets exist which would allow observation - model comparisons of wet deposition for the open oceans, because long-term wet deposition records are available for only a handful of remote island sites and rain collection over the open ocean itself is logistically very difficult. In this work we attempt instead to use ~2800 observations of aerosol nitrate and ammonium concentrations, acquired from sampling aboard ships in the period 1995 - 2012, to assess the performance of modelled N deposition fields over the remote ocean. This database is non-uniformly distributed in time and space. We selected three ocean regions (the eastern tropical North Atlantic, the northern Indian Ocean and northwest Pacific) where we considered the density and distribution of observational data is sufficient to provide effective comparison to the model ensemble. Our presentation will focus on the eastern tropical North Atlantic region, which has the best data coverage of the three. We will compare dry deposition fluxes calculated from the observed nitrate

  15. Carbon-based phytoplankton size classes retrieved via ocean color estimates of the particle size distribution

    NASA Astrophysics Data System (ADS)

    Kostadinov, Tihomir S.; Milutinović, Svetlana; Marinov, Irina; Cabré, Anna

    2016-04-01

    Owing to their important roles in biogeochemical cycles, phytoplankton functional types (PFTs) have been the aim of an increasing number of ocean color algorithms. Yet, none of the existing methods are based on phytoplankton carbon (C) biomass, which is a fundamental biogeochemical and ecological variable and the "unit of accounting" in Earth system models. We present a novel bio-optical algorithm to retrieve size-partitioned phytoplankton carbon from ocean color satellite data. The algorithm is based on existing methods to estimate particle volume from a power-law particle size distribution (PSD). Volume is converted to carbon concentrations using a compilation of allometric relationships. We quantify absolute and fractional biomass in three PFTs based on size - picophytoplankton (0.5-2 µm in diameter), nanophytoplankton (2-20 µm) and microphytoplankton (20-50 µm). The mean spatial distributions of total phytoplankton C biomass and individual PFTs, derived from global SeaWiFS monthly ocean color data, are consistent with current understanding of oceanic ecosystems, i.e., oligotrophic regions are characterized by low biomass and dominance of picoplankton, whereas eutrophic regions have high biomass to which nanoplankton and microplankton contribute relatively larger fractions. Global climatological, spatially integrated phytoplankton carbon biomass standing stock estimates using our PSD-based approach yield ˜ 0.25 Gt of C, consistent with analogous estimates from two other ocean color algorithms and several state-of-the-art Earth system models. Satisfactory in situ closure observed between PSD and POC measurements lends support to the theoretical basis of the PSD-based algorithm. Uncertainty budget analyses indicate that absolute carbon concentration uncertainties are driven by the PSD parameter No which determines particle number concentration to first order, while uncertainties in PFTs' fractional contributions to total C biomass

  16. Carbon-based phytoplankton size classes retrieved via ocean color estimates of the particle size distribution

    NASA Astrophysics Data System (ADS)

    Kostadinov, T. S.; Milutinović, S.; Marinov, I.; Cabré, A.

    2015-05-01

    Owing to their important roles in biogeochemical cycles, phytoplankton functional types (PFTs) have been the aim of an increasing number of ocean color algorithms. Yet, none of the existing methods are based on phytoplankton carbon (C) biomass, which is a fundamental biogeochemical and ecological variable and the "unit of accounting" in Earth System models. We present a novel bio-optical algorithm to retrieve size-partitioned phytoplankton carbon from ocean color satellite data. The algorithm is based on existing algorithms to estimate particle volume from a power-law particle size distribution (PSD). Volume is converted to carbon concentrations using a compilation of allometric relationships. We quantify absolute and fractional biomass in three PFTs based on size - picophytoplankton (0.5-2 μm in diameter), nanophytoplankton (2-20 μm) and microphytoplankton (20-50 μm). The mean spatial distributions of total phytoplankton C biomass and individual PFTs, derived from global SeaWiFS monthly ocean color data, are consistent with current understanding of oceanic ecosystems, i.e. oligotrophic regions are characterized by low biomass and dominance of picoplankton, whereas eutrophic regions have large biomass to which nanoplankton and microplankton contribute relatively larger fractions. Global spatially integrated phytoplankton carbon biomass standing stock estimates using our PSD-based approach yield on average ~0.2-0.3 Gt of C, consistent with analogous estimates from two other ocean color algorithms, and several state-of-the-art Earth System models. However, the range of phytoplankton C biomass spatial variability globally is larger than estimated by any other models considered here, because the PSD-based algorithm is not a priori empirically constrained and introduces improvement over the assumptions of the other approaches. Satisfactory in situ closure observed between PSD and POC measurements lends support to the theoretical basis of the PSD-based algorithm

  17. Study concerning the utilization of the ocean spreading center environment for the conversion of biomass to a liquid fuel. (Includes Appendix A: hydrothermal petroleum genesis). [Supercritical water

    SciTech Connect

    Steverson, M.; Stormberg, G.

    1985-01-01

    This document contains a report on the feasibility of utilizing energy obtained from ocean spreading centers as process heat for the conversion of municipal solid wastes to liquid fuels. The appendix contains a paper describing hydrothermal petroleum genesis. Both have been indexed separately for inclusion in the Energy Data Base. (DMC)

  18. A real-time photo-realistic rendering algorithm of ocean color based on bio-optical model

    NASA Astrophysics Data System (ADS)

    Ma, Chunyong; Xu, Shu; Wang, Hongsong; Tian, Fenglin; Chen, Ge

    2016-12-01

    A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material (CDOM), inorganic suspended particle, etc., which have different contributions to absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We establish an ocean surface transmission model based on ocean bidirectional reflectance distribution function (BRDF) and the Fresnel law, and this model's outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the reflection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit (GPU). Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes.

  19. Three-dimensional elastic full waveform inversion in a marine environment using multicomponent ocean-bottom cables: a synthetic study

    NASA Astrophysics Data System (ADS)

    Borisov, Dmitry; Singh, Satish C.

    2015-06-01

    Full waveform inversion (FWI) is a powerful tool used to quantify the elastic properties of the subsurface from seismic data. Because of very high computational cost, the technique has so far been used for either 2-D full elastic or 3-D acoustic media while the extension to 3-D elastic media to a realistic model size is still a challenging task. However, the Earth being 3-D, elastic and highly heterogeneous, one would require a full 3-D elastic wave equation for accurate modelling of amplitudes and phases within the inversion process. The acoustic approximation could significantly impact the final waveform inversion results, mainly due to the amplitude variation with offset effect. This effect becomes extremely important in the presence of strong contrasts in S-wave velocity and density, specifically when long-offset reflection data are included for waveform inversion. Recent increase in computer power allows for more efficient parallel computing using thousands of processors simultaneously thus making 3-D elastic waveform inversion feasible today. In this paper we consider a synthetic study based on a 3-D elastic medium for inversion of both P- and S-wave velocities using multicomponent, ocean-bottom cable seismic data. Both the forward modelling part and the inversion part are carried out in the time domain. The inverse problem is parametrized in terms of P- and S-wave velocities, while the density, being difficult to reconstruct, is not inverted and is linked to the P-wave velocity. Among several synthetic examples, a successful experiment on a small part of a 3-D SEG/EAGE overthrust model is presented, demonstrating the feasibility of inverting and accurately quantifying both P- and S-wave velocities. The resolution analysis of the waveform inversion is tested using a checkerboard model. Our results show that 3-D elastic FWI of sparsely spaced sources can retrieve P- and S-wave velocities accurately.

  20. The Correlation Between Atmospheric Dust Deposition to the Surface Ocean and SeaWiFS Ocean Color: A Global Satellite-Based Analysis

    NASA Technical Reports Server (NTRS)

    Erickson, D. J., III; Hernandez, J.; Ginoux, P.; Gregg, W.; Kawa, R.; Behrenfeld, M.; Esaias, W.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Since the atmospheric deposition of iron has been linked to primary productivity in various oceanic regions, we have conducted an objective study of the correlation of dust deposition and satellite remotely sensed surface ocean chlorophyll concentrations. We present a global analysis of the correlation between atmospheric dust deposition derived from a satellite-based 3-D atmospheric transport model and SeaWiFs estimates of ocean color. We use the monthly mean dust deposition fields of Ginoux et al. which are based on a global model of dust generation and transport. This model is driven by atmospheric circulation from the Data Assimilation Office (DAO) for the period 1995-1998. This global dust model is constrained by several satellite estimates of standard circulation characteristics. We then perform an analysis of the correlation between the dust deposition and the 1998 SeaWIFS ocean color data for each 2.0 deg x 2.5 deg lat/long grid point, for each month of the year. The results are surprisingly robust. The region between 40 S and 60 S has correlation coefficients from 0.6 to 0.95, statistically significant at the 0.05 level. There are swaths of high correlation at the edges of some major ocean current systems. We interpret these correlations as reflecting areas that have shear related turbulence bringing nitrogen and phosphorus from depth into the surface ocean, and the atmospheric supply of iron provides the limiting nutrient and the correlation between iron deposition and surface ocean chlorophyll is high. There is a region in the western North Pacific with high correlation, reflecting the input of Asian dust to that region. The southern hemisphere has an average correlation coefficient of 0.72 compared that in the northern hemisphere of 0.42 consistent with present conceptual models of where atmospheric iron deposition may play a role in surface ocean biogeochemical cycles. The spatial structure of the correlation fields will be discussed within the context

  1. NLS cycle 1 and NLS 2 base heating technical notes. Appendix 3: Preliminary cycle 1 NLS base heating environments. Cycle 1 NLS base heating environments. NLS 2 650K STME base heating environments

    NASA Technical Reports Server (NTRS)

    Bender, Robert L.; Reardon, John E.; Prendergast, Maurice J.; Schmitz, Craig P.; Brown, John R.

    1992-01-01

    A preliminary analysis of National Launch System ascent plume induced base heating environments has been completed to support the Induced Environments Panel's objective to assist in maturing the NLS vehicle (1.5 stage and heavy launch lift vehicle) design. Environments during ascent have been determined from this analysis for a few selected locations on the engine nozzles and base heat shield for both vehicles. The environments reflect early summer 1991 configurations and performance data and conservative methodology. A more complete and thorough analysis is under way to update these environments for the cycle 1 review in January 1992.

  2. WAVE: Interactive Wave-based Sound Propagation for Virtual Environments.

    PubMed

    Mehra, Ravish; Rungta, Atul; Golas, Abhinav; Ming Lin; Manocha, Dinesh

    2015-04-01

    We present an interactive wave-based sound propagation system that generates accurate, realistic sound in virtual environments for dynamic (moving) sources and listeners. We propose a novel algorithm to accurately solve the wave equation for dynamic sources and listeners using a combination of precomputation techniques and GPU-based runtime evaluation. Our system can handle large environments typically used in VR applications, compute spatial sound corresponding to listener's motion (including head tracking) and handle both omnidirectional and directional sources, all at interactive rates. As compared to prior wave-based techniques applied to large scenes with moving sources, we observe significant improvement in runtime memory. The overall sound-propagation and rendering system has been integrated with the Half-Life 2 game engine, Oculus-Rift head-mounted display, and the Xbox game controller to enable users to experience high-quality acoustic effects (e.g., amplification, diffraction low-passing, high-order scattering) and spatial audio, based on their interactions in the VR application. We provide the results of preliminary user evaluations, conducted to study the impact of wave-based acoustic effects and spatial audio on users' navigation performance in virtual environments.

  3. Considering Affective Responses towards Environments for Enhancing Location Based Services

    NASA Astrophysics Data System (ADS)

    Huang, H.; Gartner, G.; Klettner, S.; Schmidt, M.

    2014-04-01

    A number of studies in the field of environmental psychology show that humans perceive and evaluate their surroundings affectively. Some places are experienced as unsafe, while some others as attractive and interesting. Experiences from daily life show that many of our daily behaviours and decision-making are often influenced by this kind of affective responses towards environments. Location based services (LBS) are often designed to assist and support people's behaviours and decision-making in space. In order to provide services with high usefulness (usability and utility), LBS should consider these kinds of affective responses towards environments. This paper reports on the results of a research project, which studies how people's affective responses towards environments can be modelled and acquired, as well as how LBS can benefit by considering these affective responses. As one of the most popular LBS applications, mobile pedestrian navigation systems are used as an example for illustration.

  4. Development of Web-based Virtual Training Environment for Machining

    NASA Astrophysics Data System (ADS)

    Yang, Zhixin; Wong, S. F.

    2010-05-01

    With the booming in the manufacturing sector of shoe, garments and toy, etc. in pearl region, training the usage of various facilities and design the facility layout become crucial for the success of industry companies. There is evidence that the use of virtual training may provide benefits in improving the effect of learning and reducing risk in the physical work environment. This paper proposed an advanced web-based training environment that could demonstrate the usage of a CNC machine in terms of working condition and parameters selection. The developed virtual environment could provide training at junior level and advanced level. Junior level training is to explain machining knowledge including safety factors, machine parameters (ex. material, speed, feed rate). Advanced level training enables interactive programming of NG coding and effect simulation. Operation sequence was used to assist the user to choose the appropriate machining condition. Several case studies were also carried out with animation of milling and turning operations.

  5. Biogeographic patterns in ocean microbes emerge in a neutral agent-based model.

    PubMed

    Hellweger, Ferdi L; van Sebille, Erik; Fredrick, Neil D

    2014-09-12

    A key question in ecology and evolution is the relative role of natural selection and neutral evolution in producing biogeographic patterns. We quantify the role of neutral processes by simulating division, mutation, and death of 100,000 individual marine bacteria cells with full 1 million-base-pair genomes in a global surface ocean circulation model. The model is run for up to 100,000 years and output is analyzed using BLAST (Basic Local Alignment Search Tool) alignment and metagenomics fragment recruitment. Simulations show the production and maintenance of biogeographic patterns, characterized by distinct provinces subject to mixing and periodic takeovers by neighbors (coalescence), after which neutral evolution reestablishes the province and the patterns reorganize. The emergent patterns are substantial (e.g., down to 99.5% DNA identity between North and Central Pacific provinces) and suggest that microbes evolve faster than ocean currents can disperse them. This approach can also be used to explore environmental selection.

  6. The Story of the Oceans and Salt. What We Take from Our Environment. Science and Technology Education in Philippine Society.

    ERIC Educational Resources Information Center

    Philippines Univ., Quezon City. Science Education Center.

    This module provides information on: (1) the origin of the oceans; (2) sources of minerals and salt found in the sea; and (3) the role and uses of salt in various cultures (stating, for example, that the expression "salt of the earth" describes a person who is considered one of the best). (JN)

  7. A highly redox-heterogeneous ocean in South China during the early Cambrian (˜529-514 Ma): Implications for biota-environment co-evolution

    NASA Astrophysics Data System (ADS)

    Jin, Chengsheng; Li, Chao; Algeo, Thomas J.; Planavsky, Noah J.; Cui, Hao; Yang, Xinglian; Zhao, Yuanlong; Zhang, Xingliang; Xie, Shucheng

    2016-05-01

    The ;Cambrian Explosion; is known for rapid increases in the morphological disparity and taxonomic diversity of metazoans. It has been widely proposed that this biological event was a consequence of oxygenation of the global ocean, but this hypothesis is still under debate. Here, we present high-resolution Fe-S-C-Al-trace element geochemical records from the Jinsha (outer shelf) and Weng'an (outer shelf) sections of the early Cambrian Yangtze Platform, integrating these results with previously published data from six correlative sections representing a range of water depths (Xiaotan, Shatan, Dingtai, Yangjiaping, Songtao, and Longbizui). The integrated iron chemistry and redox-sensitive trace element data suggest that euxinic mid-depth waters dynamically coexisted with oxic surface waters and ferruginous deep waters during the earliest Cambrian, but that stepwise expansion of oxic waters commenced during Cambrian Stage 3 (∼ 521- 514 Ma). Combined with data from lower Cambrian sections elsewhere, including Oman, Iran and Canada, we infer that the global ocean exhibited a high degree of redox heterogeneity during the early Cambrian, consistent with low atmospheric oxygen levels (∼ 10- 40% of present atmospheric level, or PAL). A large spatial gradient in pyrite sulfur isotopic compositions (δ34Spy), which vary from a mean of - 12.0 ‰ in nearshore areas to + 22.5 ‰ in distal deepwater sections in lower Cambrian marine units of South China imply low concentrations and spatial heterogeneity of seawater sulfate, which is consistent with a limited oceanic sulfate reservoir globally. By comparing our reconstructed redox chemistry with fossil records from the lower Cambrian of South China, we infer that a stepwise oxygenation of shelf and slope environments occurred concurrently with a gradual increase in ecosystem complexity. However, deep waters remained anoxic and ferruginous even as macrozooplankton and suspension-feeding mesozooplankton appeared during

  8. Place-based Learning Collaboration: Promoting climate, ocean and data literacy by hosting a CO2 buoy from NOAA's Pacific Marine Environmental Lab at the Exploratorium

    NASA Astrophysics Data System (ADS)

    Miller, M. K.; Sabine, C. L.; Maenner, S.; Sutton, A.; Raleigh, C.

    2015-12-01

    The Exploratorium's new museum site on the San Francisco waterfront is a unique location for place-based learning about climate impacts on the ocean. With access to the Bay and surrounding environment, and strong partnerships with a national network of NOAA scientists and local researchers, the museum can serve as an educational node for a variety of atmosphere and ocean observing networks. The most visible and iconic instrument at the museum's Pier 15 location is a CO2 buoy from NOAA's Pacific Marine Environmental Lab in Seattle. Part of an international network of real-time ocean acidification sensors, the NOAA buoy streams temperature, salinity, atmospheric and surface water CO2 data from the Exploratorium location to NOAA. Near real-time and archived ocean and atmosphere carbon data is displayed in the museum's Bay Observatory along with other water quality, weather, and air quality conditions. Displaying both the instruments and the data they provide gives the public a better understanding of where climate data comes from, how scientists make meaning from time series data, and the value of long-term observation in understanding climate change and the ways that humans impact the environment. However, creating interactive exhibits from environmental data presents many challenges, including interpreting complex earth systems and biological and human interactions. What is the impact of the adjacent urban center and the estuary on the Bay's carbon content? How do we tease out long-term trends from the local variability? How do we connect the place-based learning to global processes and impacts? We'll address some of these challenges in the presentation and include the importance of collaborative partnerships between informal education institutions and researchers in place-based education about climate and environmental change.

  9. Analysis of Aerospike Plume Induced Base-Heating Environment

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    1998-01-01

    Computational analysis is conducted to study the effect of an aerospike engine plume on X-33 base-heating environment during ascent flight. To properly account for the effect of forebody and aftbody flowfield such as shocks and to allow for potential plume-induced flow-separation, thermo-flowfield of trajectory points is computed. The computational methodology is based on a three-dimensional finite-difference, viscous flow, chemically reacting, pressure-base computational fluid dynamics formulation, and a three-dimensional, finite-volume, spectral-line based weighted-sum-of-gray-gases radiation absorption model computational heat transfer formulation. The predicted convective and radiative base-heat fluxes are presented.

  10. Validation of genetic algorithm-based optimal sampling for ocean data assimilation

    NASA Astrophysics Data System (ADS)

    Heaney, Kevin D.; Lermusiaux, Pierre F. J.; Duda, Timothy F.; Haley, Patrick J.

    2016-10-01

    Regional ocean models are capable of forecasting conditions for usefully long intervals of time (days) provided that initial and ongoing conditions can be measured. In resource-limited circumstances, the placement of sensors in optimal locations is essential. Here, a nonlinear optimization approach to determine optimal adaptive sampling that uses the genetic algorithm (GA) method is presented. The method determines sampling strategies that minimize a user-defined physics-based cost function. The method is evaluated using identical twin experiments, comparing hindcasts from an ensemble of simulations that assimilate data selected using the GA adaptive sampling and other methods. For skill metrics, we employ the reduction of the ensemble root mean square error (RMSE) between the "true" data-assimilative ocean simulation and the different ensembles of data-assimilative hindcasts. A five-glider optimal sampling study is set up for a 400 km × 400 km domain in the Middle Atlantic Bight region, along the New Jersey shelf-break. Results are compared for several ocean and atmospheric forcing conditions.

  11. Diatom Phytochromes Reveal the Existence of Far-Red-Light-Based Sensing in the Ocean.

    PubMed

    Fortunato, Antonio Emidio; Jaubert, Marianne; Enomoto, Gen; Bouly, Jean-Pierre; Raniello, Raffaella; Thaler, Michael; Malviya, Shruti; Bernardes, Juliana Silva; Rappaport, Fabrice; Gentili, Bernard; Huysman, Marie J J; Carbone, Alessandra; Bowler, Chris; d'Alcalà, Maurizio Ribera; Ikeuchi, Masahiko; Falciatore, Angela

    2016-03-01

    The absorption of visible light in aquatic environments has led to the common assumption that aquatic organisms sense and adapt to penetrative blue/green light wavelengths but show little or no response to the more attenuated red/far-red wavelengths. Here, we show that two marine diatom species, Phaeodactylum tricornutum and Thalassiosira pseudonana, possess a bona fide red/far-red light sensing phytochrome (DPH) that uses biliverdin as a chromophore and displays accentuated red-shifted absorbance peaks compared with other characterized plant and algal phytochromes. Exposure to both red and far-red light causes changes in gene expression in P. tricornutum, and the responses to far-red light disappear in DPH knockout cells, demonstrating that P. tricornutum DPH mediates far-red light signaling. The identification of DPH genes in diverse diatom species widely distributed along the water column further emphasizes the ecological significance of far-red light sensing, raising questions about the sources of far-red light. Our analyses indicate that, although far-red wavelengths from sunlight are only detectable at the ocean surface, chlorophyll fluorescence and Raman scattering can generate red/far-red photons in deeper layers. This study opens up novel perspectives on phytochrome-mediated far-red light signaling in the ocean and on the light sensing and adaptive capabilities of marine phototrophs.

  12. Changing the Environment Based on Empowerment as Intrinsic Motivation

    NASA Astrophysics Data System (ADS)

    Salge, Christoph; Glackin, Cornelius; Polani, Daniel

    2014-05-01

    One aspect of intelligence is the ability to restructure your own environment so that the world you live in becomes more beneficial to you. In this paper we investigate how the information-theoretic measure of agent empowerment can provide a task-independent, intrinsic motivation to restructure the world. We show how changes in embodiment and in the environment change the resulting behaviour of the agent and the artefacts left in the world. For this purpose, we introduce an approximation of the established empowerment formalism based on sparse sampling, which is simpler and significantly faster to compute for deterministic dynamics. Sparse sampling also introduces a degree of randomness into the decision making process, which turns out to beneficial for some cases. We then utilize the measure to generate agent behaviour for different agent embodiments in a Minecraft-inspired three dimensional block world. The paradigmatic results demonstrate that empowerment can be used as a suitable generic intrinsic motivation to not only generate actions in given static environments, as shown in the past, but also to modify existing environmental conditions. In doing so, the emerging strategies to modify an agent's environment turn out to be meaningful to the specific agent capabilities, i.e., de facto to its embodiment.

  13. National Science Foundation Division of Ocean Sciences: new opportunities for ocean research

    NASA Astrophysics Data System (ADS)

    Yoder, J. A.; Tenney, A. B.

    2003-04-01

    The mission of the NSF Division of Ocean Sciences (OCE) is to support basic, curiosity-driven research, using a competitive process based on peer-review to guide selection of grants for financial support. OCE is the leading U.S. government source of ocean science funding for academic institutions. OCE supports research in biological, chemical and physical oceanography, and marine geology and geophysics; ocean technology development; dedicated educational activities; large shipboard equipment and shared-use instruments; the U.S. academic research fleet, submersibles, and scientific ocean drilling (ODP/IODP). In our poster, we describe OCE plans for new infrastructure projects to support research, and some of the new research and education programs being developed. Two large ocean science infrastructure projects -- a drilling vessel conversion and the ocean observatories initiative -- have already been approved for possible inclusion in a future NSF budget request. The drilling vessel will contribute to a new international scientific ocean drilling program to replace the Ocean Drilling Program (ODP), which ends in 2003. We continue to refine our plan for the Ocean Observatories Initiative (OOI), another large infrastructure program that will provide a continuous ocean presence to advance research and education. We are also working closely with the Office of Naval Research and other agency partners to implement a federal plan to renew the academic fleet. We continue to initiate new research and education programs. Two recent examples are Centers for Ocean Science Education Excellence (COSEE) and Centers for Oceans and Human Health; the latter supported jointly with the National Institute for Environmental Health Sciences. COSEE is building a nationally coordinated effort in ocean science education designed to integrate ocean science research into delivery of high-quality education programs in the ocean sciences. The Centers for Oceans and Human Health program

  14. The oceanic budgets of nickel and zinc isotopes: the importance of sulfidic environments as illustrated by the Black Sea

    NASA Astrophysics Data System (ADS)

    Vance, Derek; Little, Susan H.; Archer, Corey; Cameron, Vyllinniskii; Andersen, Morten B.; Rijkenberg, Micha J. A.; Lyons, Timothy W.

    2016-11-01

    Isotopic data collected to date as part of the GEOTRACES and other programmes show that the oceanic dissolved pool is isotopically heavy relative to the inputs for zinc (Zn) and nickel (Ni). All Zn sinks measured until recently, and the only output yet measured for Ni, are isotopically heavier than the dissolved pool. This would require either a non-steady-state ocean or other unidentified sinks. Recently, isotopically light Zn has been measured in organic carbon-rich sediments from productive upwelling margins, providing a potential resolution of this issue, at least for Zn. However, the origin of the isotopically light sedimentary Zn signal is uncertain. Cellular uptake of isotopically light Zn followed by transfer to sediment does not appear to be a quantitatively important process. Here, we present Zn and Ni isotope data for the water column and sediments of the Black Sea. These data demonstrate that isotopically light Zn and Ni are extracted from the water column, probably through an equilibrium fractionation between different dissolved species followed by sequestration of light Zn and Ni in sulfide species to particulates and the sediment. We suggest that a similar, non-quantitative, process, operating in porewaters, explains the Zn data from organic carbon-rich sediments. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  15. BIM Based Virtual Environment for Fire Emergency Evacuation

    PubMed Central

    Rezgui, Yacine; Ong, Hoang N.

    2014-01-01

    Recent building emergency management research has highlighted the need for the effective utilization of dynamically changing building information. BIM (building information modelling) can play a significant role in this process due to its comprehensive and standardized data format and integrated process. This paper introduces a BIM based virtual environment supported by virtual reality (VR) and a serious game engine to address several key issues for building emergency management, for example, timely two-way information updating and better emergency awareness training. The focus of this paper lies on how to utilize BIM as a comprehensive building information provider to work with virtual reality technologies to build an adaptable immersive serious game environment to provide real-time fire evacuation guidance. The innovation lies on the seamless integration between BIM and a serious game based virtual reality (VR) environment aiming at practical problem solving by leveraging state-of-the-art computing technologies. The system has been tested for its robustness and functionality against the development requirements, and the results showed promising potential to support more effective emergency management. PMID:25197704

  16. Web-Based Environment for Maintaining Legacy Software

    NASA Technical Reports Server (NTRS)

    Tigges, Michael; Thompson, Nelson; Orr, Mark; Fox, Richard

    2007-01-01

    Advanced Tool Integration Environment (ATIE) is the name of both a software system and a Web-based environment created by the system for maintaining an archive of legacy software and expertise involved in developing the legacy software. ATIE can also be used in modifying legacy software and developing new software. The information that can be encapsulated in ATIE includes experts documentation, input and output data of tests cases, source code, and compilation scripts. All of this information is available within a common environment and retained in a database for ease of access and recovery by use of powerful search engines. ATIE also accommodates the embedment of supporting software that users require for their work, and even enables access to supporting commercial-off-the-shelf (COTS) software within the flow of the experts work. The flow of work can be captured by saving the sequence of computer programs that the expert uses. A user gains access to ATIE via a Web browser. A modern Web-based graphical user interface promotes efficiency in the retrieval, execution, and modification of legacy code. Thus, ATIE saves time and money in the support of new and pre-existing programs.

  17. Fine-Resolution Satellite-Based Sea Surface Temperatures over the Global Ocean

    DTIC Science & Technology

    2007-05-22

    sea -ice the Sea of Azov . The plot masks SST in the Great Lakes that coverage. may otherwise included in RTG. [7] These differences between MODAS and...and relative merits of two sets of daily global sea surface temperature (SST) analyses are examined and compared. The 1/81 Modular Ocean Data Analysis...10.1029/2006JC004021, 2007 ore FuN Awtle Fine-resolution satellite-based daily sea surface f!Tr7 1 UTION STATENT-T!T A temperatures over the global

  18. An interactive HTML ocean nowcast GUI based on Perl and JavaScript

    NASA Astrophysics Data System (ADS)

    Sakalaukus, Peter J.; Fox, Daniel N.; Louise Perkins, A.; Smedstad, Lucy F.

    1999-02-01

    We describe the use of Hyper Text Markup Language (HTML), JavaScript code, and Perl I/O to create and validate forms in an Internet-based graphical user interface (GUI) for the Naval Research Laboratory (NRL) Ocean models and Assimilation Demonstration System (NOMADS). The resulting nowcast system can be operated from any compatible browser across the Internet, for although the GUI was prepared in a Netscape browser, it used no Netscape extensions. Code available at: http://www.iamg.org/CGEditor/index.htm

  19. Planet Ocean

    NASA Astrophysics Data System (ADS)

    Afonso, Isabel

    2014-05-01

    A more adequate name for Planet Earth could be Planet Ocean, seeing that ocean water covers more than seventy percent of the planet's surface and plays a fundamental role in the survival of almost all living species. Actually, oceans are aqueous solutions of extraordinary importance due to its direct implications in the current living conditions of our planet and its potential role on the continuity of life as well, as long as we know how to respect the limits of its immense but finite capacities. We may therefore state that natural aqueous solutions are excellent contexts for the approach and further understanding of many important chemical concepts, whether they be of chemical equilibrium, acid-base reactions, solubility and oxidation-reduction reactions. The topic of the 2014 edition of GIFT ('Our Changing Planet') will explore some of the recent complex changes of our environment, subjects that have been lately included in Chemistry teaching programs. This is particularly relevant on high school programs, with themes such as 'Earth Atmosphere: radiation, matter and structure', 'From Atmosphere to the Ocean: solutions on Earth and to Earth', 'Spring Waters and Public Water Supply: Water acidity and alkalinity'. These are the subjects that I want to develop on my school project with my pupils. Geographically, our school is located near the sea in a region where a stream flows into the sea. Besides that, our school water comes from a borehole which shows that the quality of the water we use is of significant importance. This project will establish and implement several procedures that, supported by physical and chemical analysis, will monitor the quality of water - not only the water used in our school, but also the surrounding waters (stream and beach water). The samples will be collected in the borehole of the school, in the stream near the school and in the beach of Carcavelos. Several physical-chemical characteristics related to the quality of the water will

  20. A privacy authentication scheme based on cloud for medical environment.

    PubMed

    Chen, Chin-Ling; Yang, Tsai-Tung; Chiang, Mao-Lun; Shih, Tzay-Farn

    2014-11-01

    With the rapid development of the information technology, the health care technologies already became matured. Such as electronic medical records that can be easily stored. However, how to get medical resources more convenient is currently concerning issue. In spite of many literatures discussed about medical systems, these literatures should face many security challenges. The most important issue is patients' privacy. Therefore, we propose a privacy authentication scheme based on cloud environment. In our scheme, we use mobile device's characteristics, allowing peoples to use medical resources on the cloud environment to find medical advice conveniently. The digital signature is used to ensure the security of the medical information that is certified by the medical department in our proposed scheme.

  1. Cooperative Environment Scans Based on a Multi-Robot System

    PubMed Central

    Kwon, Ji-Wook

    2015-01-01

    This paper proposes a cooperative environment scan system (CESS) using multiple robots, where each robot has low-cost range finders and low processing power. To organize and maintain the CESS, a base robot monitors the positions of the child robots, controls them, and builds a map of the unknown environment, while the child robots with low performance range finders provide obstacle information. Even though each child robot provides approximated and limited information of the obstacles, CESS replaces the single LRF, which has a high cost, because much of the information is acquired and accumulated by a number of the child robots. Moreover, the proposed CESS extends the measurement boundaries and detects obstacles hidden behind others. To show the performance of the proposed system and compare this with the numerical models of the commercialized 2D and 3D laser scanners, simulation results are included. PMID:25789491

  2. Java-based communication in a High Performance Computing environment

    NASA Astrophysics Data System (ADS)

    Fries, A.; de Mora, J. Portell I.; Sirvent, R.

    2011-02-01

    Java is one of the most widely used computer programming languages, however its use in High Performance Computing (HPC) is relatively low. A typical HPC environment consists of a number of multi-core computing nodes, while a typical application running in such an environment will normally contain CPU intensive code that can be executed in parallel. Such an application may require inter-node as well as intra-node communication. Message Passing Interface (MPI) is a language independent specification of an API to allow such communication. MPJExpress (Baker et al. 2006) and F-MPJ (Taboada et al. 2009) are Java-based implementations of MPI, designed with the efficient performance of data transfers as a main objective. In this paper we discuss the scalability of one approach of distributing data to compute nodes in HPC and we propose the design of an alternative data transfer system, building upon MPI.

  3. Informatic infrastructure for Climatological and Oceanographic data based on THREDDS technology in a Grid environment

    NASA Astrophysics Data System (ADS)

    Tronconi, C.; Forneris, V.; Santoleri, R.

    2009-04-01

    CNR-ISAC-GOS is responsible for the Mediterranean Sea satellite operational system in the framework of MOON Patnership. This Observing System acquires satellite data and produces Near Real Time, Delayed Time and Re-analysis of Ocean Colour and Sea Surface Temperature products covering the Mediterranean and the Black Seas and regional basins. In the framework of several projects (MERSEA, PRIMI, Adricosm Star, SeaDataNet, MyOcean, ECOOP), GOS is producing Climatological/Satellite datasets based on optimal interpolation and specific Regional algorithm for chlorophyll, updated in Near Real Time and in Delayed mode. GOS has built • an informatic infrastructure data repository and delivery based on THREDDS technology The datasets are generated in NETCDF format, compliant with both the CF convention and the international satellite-oceanographic specification, as prescribed by GHRSST (for SST). All data produced, are made available to the users through a THREDDS server catalog. • A LAS has been installed in order to exploit the potential of NETCDF data and the OPENDAP URL. It provides flexible access to geo-referenced scientific data • a Grid Environment based on Globus Technologies (GT4) connecting more than one Institute; in particular exploiting CNR and ESA clusters makes possible to reprocess 12 years of Chlorophyll data in less than one month.(estimated processing time on a single core PC: 9months). In the poster we will give an overview of: • the features of the THREDDS catalogs, pointing out the powerful characteristics of this new middleware that has replaced the "old" OPENDAP Server; • the importance of adopting a common format (as NETCDF) for data exchange; • the tools (e.g. LAS) connected with THREDDS and NETCDF format use. • the Grid infrastructure on ISAC We will present also specific basin-scale High Resolution products and Ultra High Resolution regional/coastal products available on these catalogs.

  4. High-frequency Earth rotation variations deduced from altimetry-based ocean tides

    NASA Astrophysics Data System (ADS)

    Madzak, Matthias; Schindelegger, Michael; Böhm, Johannes; Bosch, Wolfgang; Hagedoorn, Jan

    2016-11-01

    A model of diurnal and semi-diurnal variations in Earth rotation parameters (ERP) is constructed based on altimetry-measured tidal heights from a multi-mission empirical ocean tide solution. Barotropic currents contributing to relative angular momentum changes are estimated for nine major tides in a global inversion algorithm that solves the two-dimensional momentum equations on a regular 0.5° grid with a heavily weighted continuity constraint. The influence of 19 minor tides is accounted for by linear admittance interpolation of ocean tidal angular momentum, although the assumption of smooth admittance variations with frequency appears to be a doubtful concept for semi-diurnal mass terms in particular. A validation of the newly derived model based on post-fit corrections to polar motion and universal time (Δ UT1) from the analysis of Very Long Baseline Interferometry (VLBI) observations shows a variance reduction for semi-diurnal Δ UT1 residuals that is significant at the 0.05 level with respect to the conventional ERP model. Improvements are also evident for the explicitly modeled K_1, Q_1, and K_2 tides in individual ERP components, but large residuals of more than 15 μ as remain at the principal lunar frequencies of O_1 and M_2. We attribute these shortcomings to uncertainties in the inverted relative angular momentum changes and, to a minor extent, to violation of mass conservation in the empirical ocean tide solution. Further dedicated hydrodynamic modeling efforts of these anomalous constituents are required to meet the accuracy standards of modern space geodesy.

  5. Ship-based remote sensing observations of clouds and aerosol over the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Pospichal, Bernhard; Wolf, Veronika; Pietsch, Alexandra; Engelmann, Ronny; Macke, Andreas

    2014-05-01

    Within the framework of the OCEANET project, ship-based remote sensing observations of the atmosphere above the Atlantic Ocean have been performed on board of the German research vessels Polarstern and Meteor. Since 2007, twelve cruises took place, mostly between Bremerhaven (Germany) and Cape Town (South Africa) or Punta Arenas (Chile), respectively. In 2014 and 2015, two additional cruises will be performed. The goal of these ship-based measurements is a better understanding of water vapor, cloud and aerosol interaction over the open sea where data are scarce. The project was designed to measure the full atmospheric energy budget in different climate zones, including exchange processes at the sea surface. The main instrumentation on all cruises consisted of a passive microwave radiometer, a full sky imager, sun photometer, lidar ceilometer and broadband solar and infrared radiation measurements. In addition a multi wavelength Raman lidar (PollyXT) was on board of six cruises. Spectral solar radiance and irradiance observations have been performed on four cruises. With this dataset, a variety of topics can be addressed. This presentation will focus on marine stratocumulus clouds which are widespread over oceans and still pose a large uncertainty for determining the Earth's energy budget. Detailed studies for the northern trade wind zone off the West African coast will be presented. The emphasis lies on stratocumulus cloud properties, such as frequency, size, variability, liquid water content as well as their impact on surface radiation. Additionally, the influence of Saharan dust on the cloud occurrence will be addressed. Dust outbreaks over the ship could be observed in several years, including also at a cruise from the Caribbean Sea to Cape Verde in 2013. Furthermore, we will give a statistical overview of the meridional distribution of atmospheric water vapour and clouds over the Atlantic Ocean. With six years of measurements, always at the same time of the

  6. The biological assessment of flora and fauna as standards for changes in the near-shore ocean environment: a study of Barbers Point Harbor.

    PubMed

    Hokama, Y; Wachi, K M; Shiraki, A; Goo, C; Ebesu, J S

    2001-02-01

    The biological assessments of the flora and fauna in the near-shore ocean environment, specifically Barbers Point Harbor (BPH), demonstrate the usefulness of these biological analyses for evaluation of the changes occurring following man-made excavation for expansion of the harbor. The study included identification and enumeration of macroalgae and dinoflagellates and analyses of herbivores and carnivores in four areas within the perimeter of the harbor and the north and south entrances into the harbor. Numbers of macroalgae varied between 1994 and 1999 surveys, with significant decrease in numbers in stations C, D and E. Stations A and B were similar between 1994 and 1999 with a slight increase in 1999. The significant differences were shown with the appearance of Gambierdiscus toxicus (G toxicus) in 1999 among the algae in stations A and B. Assessment of herbivores and carnivores with the immunological membrane immunobead assay using monoclonal antibody to ciguatoxin and related polyethers demonstrated an increase in fish toxicity among the herbivore from 1994-1999 (22% increase) with a decrease (22%) in non-toxic fish. This was also demonstrated in the carnivores, but to a lesser degree. It is suggested that the biological analyses of the flora and the fauna of the near-shore ocean environment are appropriate to assess the changes that occur from natural and man-made alterations.

  7. Late Quaternary environments on the western Lomonosov Ridge (Arctic Ocean) - first results from RV Polarstern expedition PS87 (2014)

    NASA Astrophysics Data System (ADS)

    Spielhagen, Robert F.; Stein, Rüdiger; Mackensen, Andreas; PS87 Shipboard Scientific Party

    2016-04-01

    The interior Arctic Ocean is still one of the least known parts of the earth's surface. In particular this holds true for the deep-sea area north of Greenland which has been reached by research ships only within the last decade. The region is of special interest for climate researchers because numerical climate models predict that under future global warming the shrinking summer sea ice cover will finde a place of refuge here until it totally disappears. In summer 2014 several short and long undisturbed large-volume sediment cores were obtained from the western Lomonosov Ridge between 86.5°N and the North Pole. Here we present first results from site PS87/030 situated at 88°40'N. The combined sedimentary record of a box core and a kasten core analyzed so far is interpreted to represent the environmental variability in the last ca. 200,000 years and can be correlated to comparable records from the eastern Lomonosov Ridge and the Morris Jesup Rise. The well-defined coarse layers with abundant ice-rafted detritus reflect the history of circum-Arctic ice sheets. Planktic foraminifers with a distinct dominance of the polar species were found in most of the analyzed samples and allow to reconstruct the water mass history for this part of the Arctic Ocean. Planktic oxygen and carbon isotope records allow to identify several freshwater events which can be correlated to the decay of ice sheets surrounding the Arctic Ocean. The results presented are, however, preliminary and will be refined by future work including an improved temporal resolution of the records and the addition of further proxy records.

  8. Sonobuoy-Based, 3-D Acoustic Characterization of Shallow-Water Environments

    DTIC Science & Technology

    2015-09-30

    Shallow- Water Environments George V. Frisk Department of Ocean and Mechanical Engineering Florida Atlantic University SeaTech Campus 101 North Beach...TERM GOALS The long-term goal of this research is to increase our understanding of shallow water acoustic propagation and its relationship to the...three-dimensionally varying seabed and water column environments. OBJECTIVES The scientific objectives of this research are: (1) to develop high

  9. Solutions Network Formulation Report. The Potential Contribution of the Ocean Surface Topography Mission to the General NOAA Oil Monitoring Environment

    NASA Technical Reports Server (NTRS)

    Hilbert, Kent; Anderson, Daniel; Lewis, David

    2007-01-01

    Data collected by the OSTM could be used to provide a solution for the GNOME DST. GNOME, developed by NOAA?s Office of Response and Restoration Hazardous Materials Response Division, geospatially models oil spill trajectories using wind, current, river flow, and tidal data. Data collected by the OSTM would supply information about ocean currents and wind speeds. This Candidate Solution is in alignment with the Coastal Management, Water Management, Disaster Management, Public Health, Ecological Forecasting, and Homeland Security National Applications and will benefit society by improving the capabilities of emergency responders who evaluate an oil spill?s probable threat.

  10. Network-based collaborative research environment LDRD final report

    SciTech Connect

    Davies, B.R.; McDonald, M.J.

    1997-09-01

    The Virtual Collaborative Environment (VCE) and Distributed Collaborative Workbench (DCW) are new technologies that make it possible for diverse users to synthesize and share mechatronic, sensor, and information resources. Using these technologies, university researchers, manufacturers, design firms, and others can directly access and reconfigure systems located throughout the world. The architecture for implementing VCE and DCW has been developed based on the proposed National Information Infrastructure or Information Highway and a tool kit of Sandia-developed software. Further enhancements to the VCE and DCW technologies will facilitate access to other mechatronic resources. This report describes characteristics of VCE and DCW and also includes background information about the evolution of these technologies.

  11. Part-based object retrieval in cluttered environment.

    PubMed

    Chi, Yanling; Leung, Maylor K H

    2007-05-01

    A novel local structural approach, which is a sequel to our previous work, is proposed in this paper for object retrieval in a cluttered and occluded environment without identifying the outlines of an object. It works by first extracting consistent and structurally unique local neighborhood from inputs or models and then voting on the optimal matches employing dynamic programming and a novel hypercube-based indexing structure. The proposed concepts have been tested on a database with thousands of images and compared with the six nearest-neighbors shape description with superior results.

  12. Holos: A collaborative environment for similarity-based holistic approaches.

    PubMed

    Lê, Tâm Minh; Brard, Margot; Lê, Sébastien

    2016-09-08

    Through this article, we aim to introduce Holos-a new collaborative environment that allows researchers to carry out experiments based on similarity assessments between stimuli, such as in projective-mapping and sorting tasks. An important feature of Holos is its capacity to assess real-time individual processes during the task. Within the Holos environment, researchers can design experiments on its platform, which can handle four kinds of stimuli: concepts, images, sounds, and videos. In addition, researchers can share their study resources within the scientific community, including stimuli, experimental protocols, and/or the data collected. With a dedicated Android application combined with a tactile human-machine interface, subjects can perform experiments using a tablet to obtain similarity measures between stimuli. On the tablet, the stimuli are displayed as icons that can be dragged with one finger to position them, depending on the ways they are perceived. By recording the x,y coordinates of the stimuli while subjects move the icons, the obtained data can reveal the cognitive processes of the subjects during the experiment. Such data, named digit-tracking data, can be analyzed with the SensoMineR package. In this article, we describe how researchers can design an experiment, how subjects can perform the experiment, and how digit-tracking data can be statistically analyzed within the Holos environment. At the end of the article, a short exemplary experiment is presented.

  13. A similarity-based data warehousing environment for medical images.

    PubMed

    Teixeira, Jefferson William; Annibal, Luana Peixoto; Felipe, Joaquim Cezar; Ciferri, Ricardo Rodrigues; Ciferri, Cristina Dutra de Aguiar

    2015-11-01

    A core issue of the decision-making process in the medical field is to support the execution of analytical (OLAP) similarity queries over images in data warehousing environments. In this paper, we focus on this issue. We propose imageDWE, a non-conventional data warehousing environment that enables the storage of intrinsic features taken from medical images in a data warehouse and supports OLAP similarity queries over them. To comply with this goal, we introduce the concept of perceptual layer, which is an abstraction used to represent an image dataset according to a given feature descriptor in order to enable similarity search. Based on this concept, we propose the imageDW, an extended data warehouse with dimension tables specifically designed to support one or more perceptual layers. We also detail how to build an imageDW and how to load image data into it. Furthermore, we show how to process OLAP similarity queries composed of a conventional predicate and a similarity search predicate that encompasses the specification of one or more perceptual layers. Moreover, we introduce an index technique to improve the OLAP query processing over images. We carried out performance tests over a data warehouse environment that consolidated medical images from exams of several modalities. The results demonstrated the feasibility and efficiency of our proposed imageDWE to manage images and to process OLAP similarity queries. The results also demonstrated that the use of the proposed index technique guaranteed a great improvement in query processing.

  14. Effect of Wind Speed on Aerosol Optical Depth over Remote Oceans, Based on Data from the Maritime Aerosol Network

    NASA Technical Reports Server (NTRS)

    Smirnov, A.; Sayer, A. M.; Holben, B. N.; Hsu, N. C.; Sakerin, S. M.; Macke, A.; Nelson, N. B.; Courcoux, Y.; Smyth, T. J.; Croot, P.; Quinn, P. K.; Sciare, J.; Gulev, S. K.; Piketh, S.; Losno, R.; Kinne, S.; Radionov, V. F.

    2012-01-01

    The Maritime Aerosol Network (MAN) has been collecting data over the oceans since November 2006. The MAN archive provides a valuable resource for aerosol studies in maritime environments. In the current paper we investigate correlations between ship-borne aerosol optical depth (AOD) and near-surface wind speed, either measured (onboard or from satellite) or modeled (NCEP). According to our analysis, wind speed influences columnar aerosol optical depth, although the slope of the linear regression between AOD and wind speed is not steep (approx. 0.004 - 0.005), even for strong winds over 10m/s. The relationships show significant scatter (correlation coefficients typically in the range 0.3 - 0.5); the majority of this scatter can be explained by the uncertainty on the input data. The various wind speed sources considered yield similar patterns. Results are in good agreement with the majority of previously published relationships between surface wind speed and ship-based or satellite-based AOD measurements. The basic relationships are similar for all the wind speed sources considered; however, the gradient of the relationship varies by around a factor of two depending on the wind data used

  15. Harvesting the Ocean: 1. The Ocean.

    ERIC Educational Resources Information Center

    Caton, Albert, Ed.; And Others

    This booklet is the first in a series of three interdisciplinary units which focus specifically on the Pacific Ocean and its surrounding countries. The booklet, designed for lower secondary students, provides an introduction to the ocean environment such that students can understand the physical factors underlying issues raised by the other two…

  16. Remote-sensing reflectance determinations in the coastal ocean environment: impact of instrumental characteristics and environmental variability.

    PubMed

    Toole, D A; Siegel, D A; Menzies, D W; Neumann, M J; Smith, R C

    2000-01-20

    Three independent ocean color sampling methodologies are compared to assess the potential impact of instrumental characteristics and environmental variability on shipboard remote-sensing reflectance observations from the Santa Barbara Channel, California. Results indicate that under typical field conditions, simultaneous determinations of incident irradiance can vary by 9-18%, upwelling radiance just above the sea surface by 8-18%, and remote-sensing reflectance by 12-24%. Variations in radiometric determinations can be attributed to a variety of environmental factors such as Sun angle, cloud cover, wind speed, and viewing geometry; however, wind speed is isolated as the major source of uncertainty. The above-water approach to estimating water-leaving radiance and remote-sensing reflectance is highly influenced by environmental factors. A model of the role of wind on the reflected sky radiance measured by an above-water sensor illustrates that, for clear-sky conditions and wind speeds greater than 5 m/s, determinations of water-leaving radiance at 490 nm are undercorrected by as much as 60%. A data merging procedure is presented to provide sky radiance correction parameters for above-water remote-sensing reflectance estimates. The merging results are consistent with statistical and model findings and highlight the importance of multiple field measurements in developing quality coastal oceanographic data sets for satellite ocean color algorithm development and validation.

  17. Occurrence, degradation, and effect of polymer-based materials in the environment.

    PubMed

    Lambert, Scott; Sinclair, Chris; Boxall, Alistair

    2014-01-01

    There is now a plethora of polymer-based materials (PBMs) on the market, because of the increasing demand for cheaper consumable goods, and light-weight industrial materials. Each PBM constitutes a mixture of their representative polymer/sand their various chemical additives. The major polymer types are polyethylene, polypropylene,and polyvinyl chloride, with natural rubber and biodegradable polymers becoming increasingly more important. The most important additives are those that are biologically active, because to be effective such chemicals often have properties that make them resistant to photo-degradation and biodegradation. During their lifecycle,PBMs can be released into the environment form a variety of sources. The principal introduction routes being general littering, dumping of unwanted waste materials,migration from landfills and emission during refuse collection. Once in the environment,PBMs are primarily broken down by photo-degradation processes, but due to the complex chemical makeup of PBMs, receiving environments are potentially exposed to a mixture of macro-, meso-, and micro-size polymer fragments, leached additives, and subsequent degradation products. In environments where sunlight is absent (i.e., soils and the deep sea) degradation for most PBMs is minimal .The majority of literature to date that has addressed the environmental contamination or disposition of PBMs has focused on the marine environment. This is because the oceans are identified as the major sink for macro PBMs, where they are known to present a hazard to wildlife via entanglement and ingestion. The published literature has established the occurrence of microplastics in marine environment and beach sediments, but is inadequate as regards contamination of soils and freshwater sediments. The uptake of microplastics for a limited range of aquatic organisms has also been established, but there is a lack of information regarding soil organisms, and the long-term effects of

  18. Diatom species abundance and morphologically-based dissolution proxies in coastal Southern Ocean assemblages

    NASA Astrophysics Data System (ADS)

    Warnock, Jonathan P.; Scherer, Reed P.

    2015-07-01

    Taphonomic processes alter diatom assemblages in sediments, thus potentially negatively impacting paleoclimate records at various rates across space, time, and taxa. However, quantitative taphonomic data is rarely included in diatom-based paleoenvironmental reconstructions and no objective standard exists for comparing diatom dissolution in sediments recovered from marine depositional settings, including the Southern Ocean's opal belt. Furthermore, identifying changes to diatom dissolution through time can provide insight into the efficiency of both upper water column nutrient recycling and the biological pump. This is significant in that reactive metal proxies (e.g. Al, Ti) in the sediments only account for post-depositional dissolution, not the water column where the majority of dissolution occurs. In order to assess the range of variability of responses to dissolution in a typical Southern Ocean diatom community and provide a quantitative guideline for assessing taphonomic variability in diatoms recovered from core material, a sediment trap sample was subjected to controlled, serial dissolution. By evaluating dissolution-induced changes to diatom species' relative abundance, three preservational categories of diatoms have been identified: gracile, intermediate, and robust. The relative abundances of these categories can be used to establish a preservation grade for diatom assemblages. However, changes to the relative abundances of diatom species in sediment samples may reflect taphonomic or ecological factors. In order to address this complication, relative abundance changes have been tied to dissolution-induced morphological change to the areolae of Fragilariopsis curta, a significant sea-ice indicator in Southern Ocean sediments. This correlation allows differentiation between gracile species loss to dissolution versus ecological factors or sediment winnowing. These results mirror a similar morphological dissolution index from a parallel study utilizing

  19. Satellite-based retrieval of desert dust deposition into the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Jaeger, Malte; Lelli, Luca; Vountas, Marco; Burrows, John P.

    2015-04-01

    Desert dust plays a prominent role in climate as it influences the radiation budget in the atmosphere and, if being transported to the ocean, affects the ecosystem, e.g. by acting as fertilizer. Measurements of dust deposition are usually performed using collectors on land and on buoys as well as sediment traps deployed across the Atlantic Ocean. However, regional to continental coverage can be only achieved with satellites. We present a new methodology for the assessment of desert dust deposition from top-of-atmosphere reflected solar irradiance measured by satellite. This methodology is based on the observation of changes in columnar aerosol optical thickness (AOT) along the transport path of dust outflows from the Sahara. The guiding idea is that, if transport orientation is correctly estimated, a decrease in AOT across the Atlantic can be linked to the deposition of aerosols onto the ocean surface. The Bremen Aerosol Retrieval (BAER), developed at the Institute of Environmental Physics of University of Bremen (IUP/U-Bre), serves as primary AOT retrieval algorithm. It uses multispectral measurements by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and MEdium Resolution Imaging Spectrometer (MERIS). Especially the correct implementation of the wind fields for trajectory prediction and the choice of comparison sites are of critical importance for deposition estimation. Therefore a two-step wind correction, including a simple implementation of vertical dust layer structure and wind variation, is performed, using ECMWF reanalysis data. First tests show that seasonal patterns of AOT are correctly reproduced, both in space and time. For example the largest peak in AOT mass loss is observed at summer. Moreover, intercomparisons with in-situ sedimentation measurements at various sites show good correlations.

  20. Road environment perception algorithm based on object semantic probabilistic model

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Wang, XinMei; Tian, Jinwen; Wang, Yong

    2015-12-01

    This article seeks to discover the object categories' semantic probabilistic model (OSPM) based on statistical test analysis method. We applied this model on road forward environment perception algorithm, including on-road object recognition and detection. First, the image was represented by a set composed of words (local feature regions). Then, found the probability distribution among image, local regions and object semantic category based on the new model. In training, the parameters of the object model are estimated. This is done by using expectation-maximization in a maximum likelihood setting. In recognition, this model is used to classify images by using a Bayesian manner. In detection, the posterios is calculated to detect the typical on-road objects. Experiments release the good performance on object recognition and detection in urban street background.

  1. Distributed collaborative environments for virtual capability-based planning

    NASA Astrophysics Data System (ADS)

    McQuay, William K.

    2003-09-01

    Distributed collaboration is an emerging technology that will significantly change how decisions are made in the 21st century. Collaboration involves two or more geographically dispersed individuals working together to share and exchange data, information, knowledge, and actions. The marriage of information, collaboration, and simulation technologies provides the decision maker with a collaborative virtual environment for planning and decision support. This paper reviews research that is focusing on the applying open standards agent-based framework with integrated modeling and simulation to a new Air Force initiative in capability-based planning and the ability to implement it in a distributed virtual environment. Virtual Capability Planning effort will provide decision-quality knowledge for Air Force resource allocation and investment planning including examining proposed capabilities and cost of alternative approaches, the impact of technologies, identification of primary risk drivers, and creation of executable acquisition strategies. The transformed Air Force business processes are enabled by iterative use of constructive and virtual modeling, simulation, and analysis together with information technology. These tools are applied collaboratively via a technical framework by all the affected stakeholders - warfighter, laboratory, product center, logistics center, test center, and primary contractor.

  2. Two RFID standard-based security protocols for healthcare environments.

    PubMed

    Picazo-Sanchez, Pablo; Bagheri, Nasour; Peris-Lopez, Pedro; Tapiador, Juan E

    2013-10-01

    Radio Frequency Identification (RFID) systems are widely used in access control, transportation, real-time inventory and asset management, automated payment systems, etc. Nevertheless, the use of this technology is almost unexplored in healthcare environments, where potential applications include patient monitoring, asset traceability and drug administration systems, to mention just a few. RFID technology can offer more intelligent systems and applications, but privacy and security issues have to be addressed before its adoption. This is even more dramatical in healthcare applications where very sensitive information is at stake and patient safety is paramount. In Wu et al. (J. Med. Syst. 37:19, 43) recently proposed a new RFID authentication protocol for healthcare environments. In this paper we show that this protocol puts location privacy of tag holders at risk, which is a matter of gravest concern and ruins the security of this proposal. To facilitate the implementation of secure RFID-based solutions in the medical sector, we suggest two new applications (authentication and secure messaging) and propose solutions that, in contrast to previous proposals in this field, are fully based on ISO Standards and NIST Security Recommendations.

  3. Simulation environment based on the Universal Verification Methodology

    NASA Astrophysics Data System (ADS)

    Fiergolski, A.

    2017-01-01

    Universal Verification Methodology (UVM) is a standardized approach of verifying integrated circuit designs, targeting a Coverage-Driven Verification (CDV). It combines automatic test generation, self-checking testbenches, and coverage metrics to indicate progress in the design verification. The flow of the CDV differs from the traditional directed-testing approach. With the CDV, a testbench developer, by setting the verification goals, starts with an structured plan. Those goals are targeted further by a developed testbench, which generates legal stimuli and sends them to a device under test (DUT). The progress is measured by coverage monitors added to the simulation environment. In this way, the non-exercised functionality can be identified. Moreover, the additional scoreboards indicate undesired DUT behaviour. Such verification environments were developed for three recent ASIC and FPGA projects which have successfully implemented the new work-flow: (1) the CLICpix2 65 nm CMOS hybrid pixel readout ASIC design; (2) the C3PD 180 nm HV-CMOS active sensor ASIC design; (3) the FPGA-based DAQ system of the CLICpix chip. This paper, based on the experience from the above projects, introduces briefly UVM and presents a set of tips and advices applicable at different stages of the verification process-cycle.

  4. Fabrication of diamond based sensors for use in extreme environments

    DOE PAGES

    Samudrala, Gopi K.; Moore, Samuel L.; Vohra, Yogesh K.

    2015-04-23

    Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This methodmore » can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. Here, we demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.« less

  5. Fabrication of diamond based sensors for use in extreme environments

    SciTech Connect

    Samudrala, Gopi K.; Moore, Samuel L.; Vohra, Yogesh K.

    2015-04-23

    Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. Here, we demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.

  6. System Design for Ocean Sensor Data Transmission Based on Inductive Coupling

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Liu, Fei; Zong, Yuan; Hong, Feng

    Ocean observation is the precondition to explore and utilize ocean. How to acquire ocean data in a precise, efficient and real-time way is the key question of ocean surveillance. Traditionally, there are three types of methods for ocean data transmission: underwater acoustic, GPRS via mobile network and satellite communication. However, none of them can meet the requirements of efficiency, accuracy, real-time and low cost at the same time. In this paper, we propose a new wireless transmission system for underwater sensors, which established on FGR wireless modules, combined with inductive coupling lab and offshore experiments confirmed the feasibility and effectiveness of the proposed wireless transmission system.

  7. Bridge-based sensing of NOx and SO2 emissions from ocean-going ships

    NASA Astrophysics Data System (ADS)

    Burgard, Daniel A.; Bria, Carmen R. M.

    2016-07-01

    As emissions from nonroad mobile sources face increased regulatory scrutiny, a surprisingly few number of real-world, in-use measurements exist for these sources. This paper reports the first use of an open-path Remote Sensing Device (RSD) to measure emissions from ocean-going ships, including cruise ships. This noninvasive technique measured NOx and SO2 emission factors from 16 individually identified ocean-going ships as they passed under the Lions Gate Bridge in Vancouver, B.C. and their exhaust plumes passed through the sensing beam of the RSD on a bridge directly above. Ship NOx emissions generally agreed with previous studies showing no emissions trends across vessel type. Ship SO2 emissions were reasonable based on expected Environmental Control Area fuel sulfur requirements and corresponded to 0.4-2.4% sulfur in the fuels. This method's specificity of individual vessel SO2 measurements suggests that this technique could be used as a tool to detect high sulfur fuel use in vessels.

  8. Sheltered coastal environments as archives of paleo-tsunami deposits: Observations from the 2004 Indian Ocean tsunami

    NASA Astrophysics Data System (ADS)

    Andrade, Vanessa; Rajendran, Kusala; Rajendran, C. P.

    2014-12-01

    The 2004 earthquake left several traces of coseismic land deformation and tsunami deposits, both on the islands along the plate boundary and distant shores of the Indian Ocean rim countries. Researchers are now exploring these sites to develop a chronology of past events. Where the coastal regions are also inundated by storm surges, there is an additional challenge to discriminate between the deposits formed by these two processes. Paleo-tsunami research relies largely on finding deposits where preservation potential is high and storm surge origin can be excluded. During the past decade of our work along the Andaman and Nicobar Islands and the east coast of India, we have observed that the 2004 tsunami deposits are best preserved in lagoons, inland streams and also on elevated terraces. Chronological evidence for older events obtained from such sites is better correlated with those from Thailand, Sri Lanka and Indonesia, reiterating their usefulness in tsunami geology studies.

  9. Role of depositional environments in the preservation and detection of past tsunamis: lessons from 2004 Indian Ocean tsunami

    NASA Astrophysics Data System (ADS)

    Rajendran, Kusala; Chittenipattu, Rajendran; Andrade, Vanessa

    2013-04-01

    Reconstructing the tsunamigenic earthquake history of a region aids hazard assessment, and in the absence of written records, tsunami geology is the only tool to constrain the chronology and magnitudes of previous tsunamis to have affected a region. Observations along the Andaman-Nicobar Islands and the east coast of India suggest that distant and geomorphologically sheltered sites provide more conducive environments for tsunami deposition and preservation. The 2004 deposits from the Andaman Islands are mainly organic debris, sand sheets, coral debris and boulder deposits. The 2004 coseismic deformational features include uplift and subsidence of land as well as soil liquefaction. We use sites of tsunami deposits and deformational features to obtain evidence leading to past tsunamigenic earthquakes. The study spans latitudes from 7-14° N, from Campbell Bay to East Island. We classify the ages into three grades, A, B and C, based on the stratigraphic context of the deposit and the material and the age uncertainties. The earliest of the tsunamis occurred between 2nd and 6th centuries AD, evidenced by the coastal boulder beds of the southern Car Nicobar Island. A subsequent tsunami probably in the age range AD 770-1040 is inferred from both the Andaman and Nicobar Islands and on the Indian subcontinent. It is the strongest candidate for a 2004-caliber earthquake in the past 1500 years or more. The A&N Islands also contain tsunami deposits from AD 1250-1450 that probably matches those previously reported from Sumatra and Thailand. Evidence from what we consider as protected inland sites as well as coseismic deformation and liquefaction fall in the same age brackets as AD 1250-1450 from Indonesia, Thailand and AD 770-1040, from Indonesia, Sri Lanka and the east coast of India. By using deposits from the inland locations within the rupture as well as transoceanic sites, and other proxies dated in the same age bracket, we suggest that the ~1000 year old earthquake best

  10. Image-Based Localization for Indoor Environment Using Mobile Phone

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Wang, H.; Zhan, K.; Zhao, J.; Gui, P.; Feng, T.

    2015-05-01

    Real-time indoor localization based on supporting infrastructures like wireless devices and QR codes are usually costly and labor intensive to implement. In this study, we explored a cheap alternative approach based on images for indoor localization. A user can localize him/herself by just shooting a photo of the surrounding indoor environment using the mobile phone. No any other equipment is required. This is achieved by employing image-matching and searching techniques with a dataset of pre-captured indoor images. In the beginning, a database of structured images of the indoor environment is constructed by using image matching and the bundle adjustment algorithm. Then each image's relative pose (its position and orientation) is estimated and the semantic locations of images are tagged. A user's location can then be determined by comparing a photo taken by the mobile phone to the database. This is done by combining quick image searching, matching and the relative orientation. This study also try to explore image acquisition plans and the processing capacity of off-the-shell mobile phones. During the whole pipeline, a collection of indoor images with both rich and poor textures are examined. Several feature detectors are used and compared. Pre-processing of complex indoor photo is also implemented on the mobile phone. The preliminary experimental results prove the feasibility of this method. In the future, we are trying to raise the efficiency of matching between indoor images and explore the fast 4G wireless communication to ensure the speed and accuracy of the localization based on a client-server framework.

  11. Navigation in GPS Challenged Environments Based Upon Ranging Imagery

    NASA Astrophysics Data System (ADS)

    Markiel, J. N. Nikki

    The ability of living creatures to navigate their environment is one of the great mysteries of life. Humans, even from an early age, can acquire data about their surroundings, determine whether objects are movable or fixed, and identify open space, separate static and non-static objects, and move towards another location with minimal effort, in infinitesimal time spans. Over extended time periods humans can recall the location of objects and duplicate navigation tasks based purely on relative positioning of landmarks. Our ability to emulate this complex process in autonomous vehicles remains incomplete, despite significant research efforts over the past half century. Autonomous vehicles rely on a variety of electronic sensors to acquire data about their environment; the challenge is to transform that data into information supporting the objective of navigation. Historically, much of the sensor data was limited to the two dimensional (2D) instance; recent technological developments such as Laser Ranging and 3D Sonar are extending data collection to full three dimensional (3D) acquisition. The objective of this dissertation is the development of an algorithm to support the transformation of 3D ranging data into a navigation solution within unknown environments, and in the presence of dynamically moving objects. The algorithm reflects one of the very first attempts to leverage the 3D ranging technology for the purpose of autonomous navigation, and provides a system which enables the ability to complete the following objectives: • Separation of static and non-static elements in the environment. • Navigation based upon the range measurements of static elements. This research extends the body of knowledge in three primary topics. 1) The first is the development of a general method to identify n features in an initial data set from m features in a subsequent data set, given that both data sets are acquired via 3D ranging sensors. Accomplishing this objective

  12. Simulation-Based Learning Environment for Assisting Error-Correction

    NASA Astrophysics Data System (ADS)

    Horiguchi, Tomoya; Hirashima, Tsukasa

    In simulation-based learning environments, 'unexpected' phenomena often work as counterexamples which promote a learner to reconsider the problem. It is important that counterexamples contain sufficient information which leads a learner to correct understanding. This paper proposes a method for creating such counterexamples. Error-Based Simulation (EBS) is used for this purpose, which simulates the erroneous motion in mechanics based on a learner's erroneous equation. Our framework is as follows: (1) to identify the cause of errors by comparing a learner's answer with the problem-solver's correct one, (2) to visualize the cause of errors by the unnatural motions in EBS. To perform (1), misconceptions are classified based on problem-solving model, and related to their appearance on a learner's answers (error-identification rules). To perform (2), objects' motions in EBS are classified and related to their suggesting misconceptions (error-visualization rules). A prototype system is implemented and evaluated through a preliminary test, to confirm the usefulness of the framework.

  13. Vision-based threat detection in dynamic environments.

    SciTech Connect

    Carlson, Jeffrey J.

    2007-08-01

    This report addresses the development of automated video-screening technology to assist security forces in protecting our homeland against terrorist threats. A prevailing threat is the covert placement of bombs inside crowded public facilities. Although video-surveillance systems are increasingly common, current systems cannot detect the placement of bombs. It is also unlikely that security personnel could detect a bomb or its placement by observing video from surveillance cameras. The problems lie in the large number of cameras required to monitor large areas, the limited number of security personnel employed to protect these areas, and the intense diligence required to effectively screen live video from even a single camera. Different from existing video-detection systems designed to operate in nearly static environments, we are developing technology to detect changes in the background of dynamic environments: environments where motion and human activities are persistent over long periods. Our goal is to quickly detect background changes, even if the background is visible to the camera less than 5 percent of the time and possibly never free from foreground activity. Our approach employs statistical scene models based on mixture densities. We hypothesized that the background component of the mixture has a small variance compared to foreground components. Experiments demonstrate this hypothesis is true under a wide variety of operating conditions. A major focus involved the development of robust background estimation techniques that exploit this property. We desire estimation algorithms that can rapidly produce accurate background estimates and detection algorithms that can reliably detect background changes with minimal nuisance alarms. Another goal is to recognize unusual activities or foreground conditions that could signal an attack (e.g., large numbers of running people, people falling to the floor, etc.). Detection of background changes and/or unusual

  14. An Anisotropic Ocean Surface Emissivity Model Based on WindSat Polarimetric Brightness Observations

    NASA Astrophysics Data System (ADS)

    Smith, D. F.; Gasiewski, A. J.; Sandeep, S.; Weber, B. L.

    2012-12-01

    The goal of this research has been to develop a standardized fast full-Stokes ocean surface emissivity model with Jacobian for a wind-driven ocean surface applicable at arbitrary microwave frequencies, polarizations, and incidence angles. The model is based on the Ohio State University (OSU) two-scale code for surface emission developed by Johnson (2006, IEEE TGRS, 44, 560) but modified as follows: (1) the Meissner-Wentz dielectric permittivity (2012, IEEE TGRS, 50, 3004) replaces the original permittivity, (2) the Elfouhaily sea surface spectrum (1997, JGR, 102, C7,15781) replaces the Durden-Vesecky spectrum (1985, IEEE TGRS, OE-10, 445), but the Durden-Vesecky angular spreading function is retained, (3) the high-frequency portion of the Elfouhaily spectrum is multiplied by the Pierson-Moskowitz shape spectrum to correct an error in the original paper, (4) the generalized Phillips-Kitaigorodskii equilibrium range parameter for short waves is modeled as a continuous function of the friction velocity at the water surface to eliminate a discontinuous jump in the original paper. A total of five physical tuning parameters were identified, including the spectral strength and the hydrodynamic modulation factor. The short wave part of the spectrum is also allowed to have an arbitrary ratio relative to the long wave part. The foam fraction is multiplied by a variable correction factor, and also modulated to allow an anisotropic foam fraction with more foam on the leeward side of a wave. The model is being tuned against multi-year sequences of WindSat and Special Sensor Microwave/Imager (SSMI) data as analyzed by Meissner and Wentz (2012, IEEE TGRS, 50, 3004) for up to four Stokes brightnesses and in all angular harmonics up to two in twenty five wind bins from 0.5-25.5 m/s and of 1 m/s width. As a result there are 40 brightnesses per wind bin, for a total of 1000 brightnesses used to constrain the modified model. A chi-squared tuning criterion based on error standard

  15. Regional ocean data assimilation.

    PubMed

    Edwards, Christopher A; Moore, Andrew M; Hoteit, Ibrahim; Cornuelle, Bruce D

    2015-01-01

    This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal regions. As in weather prediction, the accurate representation of physical, chemical, and/or biological properties in the ocean is challenging. Models and observations alone provide imperfect representations of the ocean state, but together they can offer improved estimates. Variational and sequential methods are among the most widely used in regional ocean systems, and there have been exciting recent advances in ensemble and four-dimensional variational approaches. These techniques are increasingly being tested and adapted for biogeochemical applications.

  16. 33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... westerly into the waters of the Pacific Ocean from a point on the beach of Naval Base Coronado, Coronado, California beginning at latitude 32°41′13″ N, longitude 117°12′45″ W; thence easterly, along the mean high..., landward, to the point of origin. (b) The regulations. (1) Range live firing on the Naval Base...

  17. Ocean acidification increases copper toxicity differentially in two key marine invertebrates with distinct acid-base responses

    PubMed Central

    Lewis, Ceri; Ellis, Robert P.; Vernon, Emily; Elliot, Katie; Newbatt, Sam; Wilson, Rod W.

    2016-01-01

    Ocean acidification (OA) is expected to indirectly impact biota living in contaminated coastal environments by altering the bioavailability and potentially toxicity of many pH-sensitive metals. Here, we show that OA (pH 7.71; pCO2 1480 μatm) significantly increases the toxicity responses to a global coastal contaminant (copper ~0.1 μM) in two keystone benthic species; mussels (Mytilus edulis) and purple sea urchins (Paracentrotus lividus). Mussels showed an extracellular acidosis in response to OA and copper individually which was enhanced during combined exposure. In contrast, urchins maintained extracellular fluid pH under OA by accumulating bicarbonate but exhibited a slight alkalosis in response to copper either alone or with OA. Importantly, copper-induced damage to DNA and lipids was significantly greater under OA compared to control conditions (pH 8.14; pCO2 470 μatm) for both species. However, this increase in DNA-damage was four times lower in urchins than mussels, suggesting that internal acid-base regulation in urchins may substantially moderate the magnitude of this OA-induced copper toxicity effect. Thus, changes in metal toxicity under OA may not purely be driven by metal speciation in seawater and may be far more diverse than either single-stressor or single-species studies indicate. This has important implications for future environmental management strategies. PMID:26899803

  18. Pesticides and the Marine Environment. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 237. [Project COAST].

    ERIC Educational Resources Information Center

    Delaware Univ., Newark. Coll. of Education.

    This document, for secondary school students, is designed to provide an introduction to the effects of pesticides in organisms and the environment. Included are background materials for the teacher, charts and graphs of the effect of chemicals on organisms, questions for discussion and study, and references. (RH)

  19. Energy transports by ocean and atmosphere based on an entropy extremum principle. Part I: Zonal averaged transports

    SciTech Connect

    Sohn, B.J.; Smith, E.A. )

    1993-05-01

    Required global energy transports determined from Nimbus-7 satellite net radiation measurements have been separated into atmospheric and oceanic components by applying a maximum entropy production principle to the atmospheric system. Strong poleward fluxes by the oceans in the Northern Hemisphere exhibit a maximum of 2.4 10[sup 15] W at 18[degrees]N, whereas maximum atmospheric transports are found at 37[degrees]N with a magnitude of 4.5 10[sup 15] W. These results are in good agreement with other published results. In the Southern Hemisphere, atmospheric transports are found to be considerably stronger than oceanic transports, and this finding corroborates findings based on other published direct estimates. Maximum atmospheric energy transports are found at 37[degrees]S with a magnitude of 4.7 x 10[sup 15]W; two local oceanic transport maxima are shown at 18[degrees]S and 45[degrees]S with magnitudes of 1.3 x 10[sup 15] W and 1.1 x 10[sup 15] W, respectively. There is also evidence of net cross-equatorial transport in which the Southern Hemisphere oceans give rise to a net transfer of heat northward across the equator that exceeds a net transfer from Northern to Southern Hemisphere by the atmosphere. Since Southern Hemisphere results in this study should have the same degree of accuracy as in the Northern Hemisphere, these findings suggest that Southern Ocean transports are weaker than previously reported. A main implication of the study is that a maximum entropy production principle can serve as a governing rule on macroscale global climate, and in conjunction with conventional satellite measurements of the net radiation balance, provides a means to decompose atmosphere and ocean transports from the total transport field. Furthermore, the modeling methodology provides a possible means to partition the transports in a two-dimensional framework; this approach is tested on the separate ocean basins with qualified success. 59 refs., 4 figs., 2 tabs.

  20. A Web Based Collaborative Design Environment for Spacecraft

    NASA Technical Reports Server (NTRS)

    Dunphy, Julia

    1998-01-01

    In this era of shrinking federal budgets in the USA we need to dramatically improve our efficiency in the spacecraft engineering design process. We have come up with a method which captures much of the experts' expertise in a dataflow design graph: Seamlessly connectable set of local and remote design tools; Seamlessly connectable web based design tools; and Web browser interface to the developing spacecraft design. We have recently completed our first web browser interface and demonstrated its utility in the design of an aeroshell using design tools located at web sites at three NASA facilities. Multiple design engineers and managers are now able to interrogate the design engine simultaneously and find out what the design looks like at any point in the design cycle, what its parameters are, and how it reacts to adverse space environments.

  1. Game Theory Based Trust Model for Cloud Environment

    PubMed Central

    Gokulnath, K.; Uthariaraj, Rhymend

    2015-01-01

    The aim of this work is to propose a method to establish trust at bootload level in cloud computing environment. This work proposes a game theoretic based approach for achieving trust at bootload level of both resources and users perception. Nash equilibrium (NE) enhances the trust evaluation of the first-time users and providers. It also restricts the service providers and the users to violate service level agreement (SLA). Significantly, the problem of cold start and whitewashing issues are addressed by the proposed method. In addition appropriate mapping of cloud user's application to cloud service provider for segregating trust level is achieved as a part of mapping. Thus, time complexity and space complexity are handled efficiently. Experiments were carried out to compare and contrast the performance of the conventional methods and the proposed method. Several metrics like execution time, accuracy, error identification, and undecidability of the resources were considered. PMID:26380365

  2. Student Engagement in Blended Learning Environments with Lecture-Based and Problem-Based Instructional Approaches

    ERIC Educational Resources Information Center

    Delialioglu, Omer

    2012-01-01

    This study investigates how blending of different instructional approaches with technology affects students' engagement. A computer networks course was designed and implemented for the first eight weeks of the semester as a lecture-based blended learning environment and for the second eight weeks of the semester as a problem-based blended learning…

  3. Track-based event recognition in a realistic crowded environment

    NASA Astrophysics Data System (ADS)

    van Huis, Jasper R.; Bouma, Henri; Baan, Jan; Burghouts, Gertjan J.; Eendebak, Pieter T.; den Hollander, Richard J. M.; Dijk, Judith; van Rest, Jeroen H.

    2014-10-01

    Automatic detection of abnormal behavior in CCTV cameras is important to improve the security in crowded environments, such as shopping malls, airports and railway stations. This behavior can be characterized at different time scales, e.g., by small-scale subtle and obvious actions or by large-scale walking patterns and interactions between people. For example, pickpocketing can be recognized by the actual snatch (small scale), when he follows the victim, or when he interacts with an accomplice before and after the incident (longer time scale). This paper focusses on event recognition by detecting large-scale track-based patterns. Our event recognition method consists of several steps: pedestrian detection, object tracking, track-based feature computation and rule-based event classification. In the experiment, we focused on single track actions (walk, run, loiter, stop, turn) and track interactions (pass, meet, merge, split). The experiment includes a controlled setup, where 10 actors perform these actions. The method is also applied to all tracks that are generated in a crowded shopping mall in a selected time frame. The results show that most of the actions can be detected reliably (on average 90%) at a low false positive rate (1.1%), and that the interactions obtain lower detection rates (70% at 0.3% FP). This method may become one of the components that assists operators to find threatening behavior and enrich the selection of videos that are to be observed.

  4. Ocean pollution from land-based sources: East China Sea, China.

    PubMed

    Li, Daoji; Daler, Dag

    2004-02-01

    The environment of East China Sea (ECS) has been faced by huge stresses from anthropogenic activities and population growth in the Yangtze River drainage basin and the areas along the coasts. Improper use of natural resources and short-term economic objectives have resulted in severe environmental degradation in a fairly short time frame and the degradation has now reached a level where the health and well being of the coastal populations are threatened. The main pollutants are inorganic nitrogen, phosphate, oil hydrocarbons, organic matters and heavy metals. Nutrients cause eutrophication of the coastal waters and the estuarine area and very often stimulate the occurrence of red tides. The environmental pollution of Yangtze River basin directly impact on the state of the marine environment in the ECS. The ecosystem stability is maintained by a steady water discharge from the river, that mixes with the marine salty water in the estuary, and the sediment loads from the river that balance ocean erosion in the delta and its adjacent coastal area. The large-scale water transfer and dam constructions in the Yangtze River basin will change this basis. For the ECS the challenge is to reverse the negative processes taking place and to restore ecosystem balance. The main challenge is to integrate socioeconomic and environmental decision making in order to promote sustainable development. A better understanding of the driving forces in society that cause these environmental pressures is required in order to overcome these obstacles. International cooperation may be an important contributor to the progress and in particular provide access to financial, technological, scientific and human resource assistance.

  5. Organochlorine pesticide residues in sediments from coastal environment of Cantabria (northern Spain) and evaluation of the Atlantic Ocean.

    PubMed

    Gómez, Sonia; Gorri, Daniel; Irabien, Angel

    2011-05-01

    This paper documents levels of organochlorine pesticides (OCs) in coastal surface sediments from selected reference sites on the northern Atlantic Spanish coast. One hundred eight samples covering three estuaries in the Cantabrian Coast were sampled in 2006 and analyzed in the finer fraction (<63 μm) for 19 OCs by gas chromatography with electron capture detector after confirmation by mass spectrometry. Detected organochlorine pesticides were endosulfan α, endosulfan β, endosulfan sulfate, hexachlorobenzene (HCB), aldrin, dieldrin, methoxychlor, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4'-DDE) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (4,4'-DDD). Total OCs concentrations ranged from 1.8 ng g(-1) dry weight (dw) to 3.9 ng g(-1) dw, showing a uniform distribution along the studied area, and being consistent with recorded levels in the literature for coastal sediments in other reference sites with low levels of pollution by OCs along the Atlantic Ocean. Endosulfan, 4,4'-DDD, HCB, aldrin, and dieldrin seemed to be ubiquitous as the legacy of past uses and deposition. OCs concentrations were significantly correlated to organic matter content and particle size distribution. No adverse biological effects derived from these pollutants are expected to take place as it can be concluded from the comparison with the existent marine sediment quality guidelines.

  6. Studies of Np and Pu in the marine environment of Swedish-Danish waters and the North Atlantic Ocean.

    PubMed

    Lindahl, Patric; Roos, Per; Holm, Elis; Dahlgaard, Henning

    2005-01-01

    The long-lived anthropogenic radionuclides (237)Np, (239)Pu and (240)Pu were determined in marine environmental samples (seaweed and seawater) collected from Swedish-Danish waters and the North Atlantic Ocean at various locations on different occasions during the period 1991-2001. The measurements were performed with sector field Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and conventional alpha spectrometry. The (237)Np activity concentrations in Fucus vesiculosus and surface seawater from the Swedish west coast and Danish waters ranged from 0.16+/-0.02 to 1.02+/-0.09 mBq kg(-1) (dry weight) and 0.65+/-0.02 to 1.69+/-0.02 mBq m(-3), respectively, depending on the location and sampling year. Most of the (237)Np in these waters is believed to originate from the Sellafield nuclear reprocessing plant, with some contribution from global fallout. The (240)Pu/(239)Pu atomic ratios in F. vesiculosus samples are reported in this study with an overall average of 0.17+/-0.03. The (237)Np and (239)Pu activity concentrations observed in surface seawater collected in North Atlantic waters ranged from 0.16+/-0.01 to 0.62+/-0.08 mBq m(-3) and from 0.64+/-0.05 to 4.27+/-0.08 mBq m(-3), respectively, and the (237)Np/(239)Pu atomic ratios were a good indicator of conservative behaviour of Np in marine waters.

  7. Quantification of the effects of ocean acidification on sediment microbial communities in the environment: the importance of ecosystem approaches

    PubMed Central

    Hassenrück, Christiane; Fink, Artur; Lichtschlag, Anna; Tegetmeyer, Halina E.; de Beer, Dirk; Ramette, Alban

    2016-01-01

    To understand how ocean acidification (OA) influences sediment microbial communities, naturally CO2-rich sites are increasingly being used as OA analogues. However, the characterization of these naturally CO2-rich sites is often limited to OA-related variables, neglecting additional environmental variables that may confound OA effects. Here, we used an extensive array of sediment and bottom water parameters to evaluate pH effects on sediment microbial communities at hydrothermal CO2 seeps in Papua New Guinea. The geochemical composition of the sediment pore water showed variations in the hydrothermal signature at seep sites with comparable pH, allowing the identification of sites that may better represent future OA scenarios. At these sites, we detected a 60% shift in the microbial community composition compared with reference sites, mostly related to increases in Chloroflexi sequences. pH was among the factors significantly, yet not mainly, explaining changes in microbial community composition. pH variation may therefore often not be the primary cause of microbial changes when sampling is done along complex environmental gradients. Thus, we recommend an ecosystem approach when assessing OA effects on sediment microbial communities under natural conditions. This will enable a more reliable quantification of OA effects via a reduction of potential confounding effects. PMID:26887661

  8. Quantification of the effects of ocean acidification on sediment microbial communities in the environment: the importance of ecosystem approaches.

    PubMed

    Hassenrück, Christiane; Fink, Artur; Lichtschlag, Anna; Tegetmeyer, Halina E; de Beer, Dirk; Ramette, Alban

    2016-05-01

    To understand how ocean acidification (OA) influences sediment microbial communities, naturally CO2-rich sites are increasingly being used as OA analogues. However, the characterization of these naturally CO2-rich sites is often limited to OA-related variables, neglecting additional environmental variables that may confound OA effects. Here, we used an extensive array of sediment and bottom water parameters to evaluate pH effects on sediment microbial communities at hydrothermal CO2 seeps in Papua New Guinea. The geochemical composition of the sediment pore water showed variations in the hydrothermal signature at seep sites with comparable pH, allowing the identification of sites that may better represent future OA scenarios. At these sites, we detected a 60% shift in the microbial community composition compared with reference sites, mostly related to increases in Chloroflexi sequences. pH was among the factors significantly, yet not mainly, explaining changes in microbial community composition. pH variation may therefore often not be the primary cause of microbial changes when sampling is done along complex environmental gradients. Thus, we recommend an ecosystem approach when assessing OA effects on sediment microbial communities under natural conditions. This will enable a more reliable quantification of OA effects via a reduction of potential confounding effects.

  9. Marine realms information bank: A distributed geolibrary for the ocean

    USGS Publications Warehouse

    Marincioni, F.; Lightsom, F.; ,

    2002-01-01

    The Marine Realms Information Bank (MRIB) is a prototype web-based distributed geolibrary that organizes, indexes, and delivers online information about the oceanic and coastal environments. It implements the distributed geolibrary concept to organize, index, and deliver online information about the oceanic and coastal environments. The significance of MRIB lies both in the utility of the information bank and in the implementation of the distributed geolibraries concept.

  10. Ocean, Land and Meteorology Studies Using Space-Based Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Hu,Yongxiang

    2009-01-01

    CALIPSO's main mission objective is studying the climate impact of clouds and aerosols in the atmosphere. CALIPSO also collects information about other components of the Earth's ecosystem, such as oceans and land. This paper introduces the physics concepts and presents preliminary results for the valueadded CALIPSO Earth system science products. These include ocean surface wind speeds, column atmospheric optical depths, ocean subsurface backscatter, land surface elevations, atmospheric temperature profiles, and A-train data fusion products.

  11. X ray based displacement measurement for hostile environments

    NASA Technical Reports Server (NTRS)

    Canistraro, Howard A.; Jordon, Eric H.; Pease, Douglas M.; Fralick, Gustave C.

    1992-01-01

    A new method on noncontacting, high temperature extensometry based on the focus and scanning of x rays is currently under development and shows great promise of overcoming limitations associated with available techniques. The chief advantage is the ability to make undisturbed measurements through stratified or flowing gases, smoke, and flame. The system is based on the ability to focus and scan low energy, hard x rays such as those emanating from copper or molybdenum sources. The x rays are focused into a narrow and intense line image which can be scanned onto targets that fluoresce secondary x ray radiation. The final goal of the system is the ability to conduct macroscopic strain measurements in hostile environments by utilizing two or more fluorescing targets. Current work is limited to displacement measurement of a single target with a resolution of 1.25 micro-m and a target temperature of 1200 C, directly through an open flame. The main advantage of the technique lies in the penetrating nature of x rays which are not affected by the presence of refracting gas layers, smoke, flame, or intense thermal radiation, all of which could render conventional extensometry methods inoperative or greatly compromise their performance.

  12. X-ray-based displacement measurement for hostile environments

    NASA Technical Reports Server (NTRS)

    Canistraro, H. A.; Jordan, E. H.; Pease, D. M.

    1992-01-01

    A new method on noncontacting, high temperature extensometry based on the focus and scanning of X-rays is currently under development and shows great promise of overcoming limitations associated with available techniques. The chief advantage is the ability to make undisturbed measurements through stratified or flowing gases, smoke, and flame. The system is based on the ability to focus and scan low energy, hard X-rays such as those emanating from copper or molybdenum sources. The X-rays are focused into a narrow and intense line image which can be scanned onto targets that fluoresce secondary X-ray radiation. The final goal of the system is the ability to conduct macroscopic strain measurements in hostile environments by utilizing two or more fluorescing targets. Current work is limited to displacement measurement of a single target with a resolution of 1.25 micro-m and a target temperature of 1200 C, directly through an open flame. The main advantage of the technique lies in the penetrating nature of X-rays which are not affected by the presence of refracting gas layers, smoke, flame, or intense thermal radiation, all of which could render conventional extensometry methods inoperative or greatly compromise their performance.

  13. Experiments with microcomputer-based artificial intelligence environments

    USGS Publications Warehouse

    Summers, E.G.; MacDonald, R.A.

    1988-01-01

    The U.S. Geological Survey (USGS) has been experimenting with the use of relatively inexpensive microcomputers as artificial intelligence (AI) development environments. Several AI languages are available that perform fairly well on desk-top personal computers, as are low-to-medium cost expert system packages. Although performance of these systems is respectable, their speed and capacity limitations are questionable for serious earth science applications foreseen by the USGS. The most capable artificial intelligence applications currently are concentrated on what is known as the "artificial intelligence computer," and include Xerox D-series, Tektronix 4400 series, Symbolics 3600, VAX, LMI, and Texas Instruments Explorer. The artificial intelligence computer runs expert system shells and Lisp, Prolog, and Smalltalk programming languages. However, these AI environments are expensive. Recently, inexpensive 32-bit hardware has become available for the IBM/AT microcomputer. USGS has acquired and recently completed Beta-testing of the Gold Hill Systems 80386 Hummingboard, which runs Common Lisp on an IBM/AT microcomputer. Hummingboard appears to have the potential to overcome many of the speed/capacity limitations observed with AI-applications on standard personal computers. USGS is a Beta-test site for the Gold Hill Systems GoldWorks expert system. GoldWorks combines some high-end expert system shell capabilities in a medium-cost package. This shell is developed in Common Lisp, runs on the 80386 Hummingboard, and provides some expert system features formerly available only on AI-computers including frame and rule-based reasoning, on-line tutorial, multiple inheritance, and object-programming. ?? 1988 International Association for Mathematical Geology.

  14. Experiments with microcomputer-based artificial intelligence environments

    SciTech Connect

    Summers, E.G.; MacDonald, R.A.

    1988-11-01

    The US Geological Survey (USGS) has been experimenting with the use of relatively inexpensive microcomputers as artificial intelligence (AI) development environments. Several AI languages are available that perform fairly well on desk-top personal computers, as are low-to-medium cost expert system packages. Although performance of these systems is respectable, their speed and capacity limitations are questionable for serious earth science applications foreseen by the USGS. The most capable artificial intelligence applications currently are concentrated on what is known as the artificial intelligence computer, and include Xerox D-series, Tektronix 4400 series, Symbolics 3600, VAX, LMI, and Texas Instruments Explorer. The artificial intelligence computer runs expert system shells and Lisp, Prolog, and Smalltalk programming languages. However, these AI environments are expensive. Recently inexpensive 32-bit hardware has become available for the IBM/AT microcomputer. USGS has acquired and recently completed Beta-testing of the Golf Hill Systems 80386 Hummingboard, which runs Common Lisp on an IBM/AT microcomputer. Hummingboard appears to have the potential to overcome many of the speed/capacity limitations observed with AI-applications on standard personal computers. USGS is a Beta-test site for the Gold Hill Systems GoldWorks expert system. GoldWorks combines some high-end expert system shell capabilities in a medium-cost package. This shell is developed in Common Lisp, runs on the 80386 Hummingboard, and provides some expert system features formerly available only on AI-computers including frame and rule-based reasoning, on-line tutorial, multiple inheritance, and object-programming.

  15. Genomic analysis of oceanic cyanobacterial myoviruses compared with T4-like myoviruses from diverse hosts and environments

    PubMed Central

    Sullivan, Matthew B; Huang, Katherine H; Ignacio-Espinoza, Julio C; Berlin, Aaron M; Kelly, Libusha; Weigele, Peter R; DeFrancesco, Alicia S; Kern, Suzanne E; Thompson, Luke R; Young, Sarah; Yandava, Chandri; Fu, Ross; Krastins, Bryan; Chase, Michael; Sarracino, David; Osburne, Marcia S; Henn, Matthew R; Chisholm, Sallie W

    2010-01-01

    T4-like myoviruses are ubiquitous, and their genes are among the most abundant documented in ocean systems. Here we compare 26 T4-like genomes, including 10 from non-cyanobacterial myoviruses, and 16 from marine cyanobacterial myoviruses (cyanophages) isolated on diverse Prochlorococcus or Synechococcus hosts. A core genome of 38 virion construction and DNA replication genes was observed in all 26 genomes, with 32 and 25 additional genes shared among the non-cyanophage and cyanophage subsets, respectively. These hierarchical cores are highly syntenic across the genomes, and sampled to saturation. The 25 cyanophage core genes include six previously described genes with putative functions (psbA, mazG, phoH, hsp20, hli03, cobS), a hypothetical protein with a potential phytanoyl-CoA dioxygenase domain, two virion structural genes, and 16 hypothetical genes. Beyond previously described cyanophage-encoded photosynthesis and phosphate stress genes, we observed core genes that may play a role in nitrogen metabolism during infection through modulation of 2-oxoglutarate. Patterns among non-core genes that may drive niche diversification revealed that phosphorus-related gene content reflects source waters rather than host strain used for isolation, and that carbon metabolism genes appear associated with putative mobile elements. As well, phages isolated on Synechococcus had higher genome-wide %G+C and often contained different gene subsets (e.g. petE, zwf, gnd, prnA, cpeT) than those isolated on Prochlorococcus. However, no clear diagnostic genes emerged to distinguish these phage groups, suggesting blurred boundaries possibly due to cross-infection. Finally, genome-wide comparisons of both diverse and closely related, co-isolated genomes provide a locus-to-locus variability metric that will prove valuable for interpreting metagenomic data sets. PMID:20662890

  16. Copepod response to ocean acidification in a low nutrient-low chlorophyll environment in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Zervoudaki, S.; Krasakopoulou, E.; Moutsopoulos, T.; Protopapa, M.; Marro, S.; Gazeau, F.

    2017-02-01

    In order to identify how ocean acidification will influence biological interactions and fluxes among planktonic organisms and across trophic levels, a large-scale mesocosm experiment was performed in the oligotrophic Northwestern Mediterranean Sea in the framework of the European MedSeA project. Nine mesocosms were deployed in the Bay of Calvi (Corsica, France) in summer 2012. Six mesocosms were subjected to different levels of CO2 partial pressures (pCO2; 550, 650, 750, 850, 1000 and 1250 μatm) covering the range of atmospheric pCO2 anticipated for the end of this century depending on future emission scenarios, and the last three mesocosms were unaltered (ambient pCO2 of ∼450 μatm). During this 21-day experiment, we monitored copepod egg and naupliar stocks, estimated copepod (Acartia clausi and Centropages typicus) feeding rates and determined the abundance and taxonomic composition of the mesozooplankton community at the start and at the completion of the experiment. This community was clearly dominated by copepods and its final composition slightly varied between mesocosms most likely due to natural and experimental variability that cannot be related to CO2 conditions. The abundances of eggs and nauplii as well as feeding rates of A. clausi and C. typicus on diatoms, dinoflagellates and ciliates showed no significant differences among CO2 levels. The above findings suggest that the experimental set-up especially for the specific trophic conditions and the short duration of the experiment did not provide the information on the effect of acidification that was expected. The acidification might have an effect on planktonic communities and even worsen the problems imposed by food limitation, therefore on this short time scale experiment and under the extreme ologotrophic conditions the signal that dominates was the food limitation.

  17. Active populations of rare microbes in oceanic environments as revealed by bromodeoxyuridine incorporation and 454 tag sequencing.

    PubMed

    Hamasaki, Koji; Taniguchi, Akito; Tada, Yuya; Kaneko, Ryo; Miki, Takeshi

    2016-02-01

    The "rare biosphere" consisting of thousands of low-abundance microbial taxa is important as a seed bank or a gene pool to maintain microbial functional redundancy and robustness of the ecosystem. Here we investigated contemporaneous growth of diverse microbial taxa including rare taxa and determined their variability in environmentally distinctive locations along a north-south transect in the Pacific Ocean in order to assess which taxa were actively growing and how environmental factors influenced bacterial community structures. A bromodeoxyuridine-labeling technique in combination with PCR amplicon pyrosequencing of 16S rRNA genes gave 215-793 OTUs from 1200 to 3500 unique sequences in the total communities and 175-299 OTUs nearly 860 to 1800 sequences in the active communities. Unexpectedly, many of the active OTUs were not detected in the total fractions. Among these active but rare OTUs, some taxa (2-4% of rare OTUs) showed much higher abundance (>0.10% of total reads) in the active fraction than in the total fraction, suggesting that their contribution to bacterial community productivity or growth was much larger than that expected from their standing stocks at each location. An ordination plot by the principal component analysis presented that bacterial community compositions among 4 sampling locations and between total and active fractions were distinctive with each other. A redundancy analysis revealed that the variability of community compositions significantly correlated to seawater temperature and dissolved oxygen concentration. Also, a variation partitioning analysis showed that the environmental factors explained 49% of the variability of community compositions and the distance only explained 4.0% of its variability. These results implied very dynamic change of community structures due to environmental filtering. The active bacterial populations are more diverse and spread further in rare biosphere than we have ever seen. This study implied that rare

  18. Design and implementation of a 3D ocean virtual reality and visualization engine

    NASA Astrophysics Data System (ADS)

    Chen, Ge; Li, Bo; Tian, Fenglin; Ji, Pengbo; Li, Wenqing

    2012-12-01

    In this study, a 3D virtual reality and visualization engine for rendering the ocean, named VV-Ocean, is designed for marine applications. The design goals of VV-Ocean aim at high fidelity simulation of ocean environment, visualization of massive and multidimensional marine data, and imitation of marine lives. VV-Ocean is composed of five modules, i.e. memory management module, resources management module, scene management module, rendering process management module and interaction management module. There are three core functions in VV-Ocean: reconstructing vivid virtual ocean scenes, visualizing real data dynamically in real time, imitating and simulating marine lives intuitively. Based on VV-Ocean, we establish a sea-land integration platform which can reproduce drifting and diffusion processes of oil spilling from sea bottom to surface. Environment factors such as ocean current and wind field have been considered in this simulation. On this platform oil spilling process can be abstracted as movements of abundant oil particles. The result shows that oil particles blend with water well and the platform meets the requirement for real-time and interactive rendering. VV-Ocean can be widely used in ocean applications such as demonstrating marine operations, facilitating maritime communications, developing ocean games, reducing marine hazards, forecasting the weather over oceans, serving marine tourism, and so on. Finally, further technological improvements of VV-Ocean are discussed.

  19. Places and Bases: The Chinese Navy’s Emerging Support Network in the Indian Ocean

    DTIC Science & Technology

    2011-01-01

    fleets that sailed the Indian Ocean between 1405 and 1433, during the Ming dy- nasty.38 Zheng He’s mariners traded silk and porcelain for Arab...Lanka served as a key nexus of China’s maritime trade in the Indian Ocean along the “ Porcelain Route” (as the maritime counterpart of the Central

  20. PREFACE: Ocean and climate changes in polar and sub-polar environments: proceedings from the 2010 IODP-Canada/ECORD summer school

    NASA Astrophysics Data System (ADS)

    St-Onge, Guillaume; Veiga-Pires, Cristina; Solignac, Sandrine

    2011-05-01

    IODP logoECORD logo The European Consortium for Ocean Drilling Program (ECORD), the Canadian Consortium for Ocean Drilling (CCOD), the Network of the Universités du Québec (UQ), the Université du Québec à Montréal (UQAM) and GEOTOP sponsored, in 2010, a summer school entitled 'Ocean and climate changes in polar and sub-polar environments'. This summer school took place from 27 June to 12 July in Rimouski, Québec city and Montréal (Quebec, Canada) and was attended by nineteen students and postdoctoral fellows from seven countries: Canada, France, Germany, UK, Serbia, Portugal and the USA. Lectures, hands-on laboratory exercises and laboratory visits were conducted at the Institut des Sciences de la Mer de Rimouski (ISMER), Institut National de la Recherche Scientifique - Centre Eau Terre Environnement (INRS-ETE) and UQAM, in addition to two field trips and a short geological and geophysical cruise on board the R/V Coriolis II in the St Lawrence Estuary and Saguenay Fjord. During the summer school, more than twenty researchers gave lectures on the use of several paleoceanographic and geophysical techniques to reconstruct ocean and climate changes in polar and sub-polar environments. Some of these lectures are presented as short review papers in this volume. They are intended to portray a brief, but state-of-the-art overview of an array of techniques applied to Arctic and sub-Arctic environments, as well as the geological background information needed by the summer school participants to put the scientific expedition and fieldwork into context. The volume begins with a view on the great challenges and key issues to be addressed in the Arctic Ocean (Stein) in the forthcoming years and is followed by a review (O'Regan) on Late Cenozoic paleoceanography of the Central Arctic. The two subsequent papers (St-Onge et al and de Vernal et al) deal with the oceanographic, paleoceanographic and geological context of the Saguenay Fjord, and St Lawrence Estuary and Gulf

  1. Sampling strategies based on singular vectors for assimilated models in ocean forecasting systems

    NASA Astrophysics Data System (ADS)

    Fattorini, Maria; Brandini, Carlo; Ortolani, Alberto

    2016-04-01

    Meteorological and oceanographic models do need observations, not only as a ground truth element to verify the quality of the models, but also to keep model forecast error acceptable: through data assimilation techniques which merge measured and modelled data, natural divergence of numerical solutions from reality can be reduced / controlled and a more reliable solution - called analysis - is computed. Although this concept is valid in general, its application, especially in oceanography, raises many problems due to three main reasons: the difficulties that have ocean models in reaching an acceptable state of equilibrium, the high measurements cost and the difficulties in realizing them. The performances of the data assimilation procedures depend on the particular observation networks in use, well beyond the background quality and the used assimilation method. In this study we will present some results concerning the great impact of the dataset configuration, in particular measurements position, on the evaluation of the overall forecasting reliability of an ocean model. The aim consists in identifying operational criteria to support the design of marine observation networks at regional scale. In order to identify the observation network able to minimize the forecast error, a methodology based on Singular Vectors Decomposition of the tangent linear model is proposed. Such a method can give strong indications on the local error dynamics. In addition, for the purpose of avoiding redundancy of information contained in the data, a minimal distance among data positions has been chosen on the base of a spatial correlation analysis of the hydrodynamic fields under investigation. This methodology has been applied for the choice of data positions starting from simplified models, like an ideal double-gyre model and a quasi-geostrophic one. Model configurations and data assimilation are based on available ROMS routines, where a variational assimilation algorithm (4D-var) is

  2. Space Launch System Base Heating Test: Environments and Base Flow Physics

    NASA Technical Reports Server (NTRS)

    Mehta, Manish; Knox, Kyle S.; Seaford, C. Mark; Dufrene, Aaron T.

    2016-01-01

    The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen-hydrogen rocket engines in the core-stage and two 5-segment solid rocket boosters and as a result six hot supersonic plumes interact within the aft section of the vehicle during flight. Due to the complex nature of rocket plume-induced flows within the launch vehicle base during ascent and a new vehicle configuration, sub-scale wind tunnel testing is required to reduce SLS base convective environment uncertainty and design risk levels. This hot-fire test program was conducted at the CUBRC Large Energy National Shock (LENS) II short-duration test facility to simulate flight from altitudes of 50 kft to 210 kft. The test program is a challenging and innovative effort that has not been attempted in 40+ years for a NASA vehicle. This paper discusses the various trends of base convective heat flux and pressure as a function of altitude at various locations within the core-stage and booster base regions of the two-percent SLS wind tunnel model. In-depth understanding of the base flow physics is presented using the test data, infrared high-speed imaging and theory. The normalized test design environments are compared to various NASA semi-empirical numerical models to determine exceedance and conservatism of the flight scaled test-derived base design environments. Brief discussion of thermal impact to the launch vehicle base components is also presented.

  3. Space Launch System Base Heating Test: Environments and Base Flow Physics

    NASA Technical Reports Server (NTRS)

    Mehta, Manish; Knox, Kyle S.; Seaford, C. Mark; Dufrene, Aaron T.

    2016-01-01

    The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen- hydrogen rocket engines in the core-stage and two 5-segment solid rocket boosters and as a result six hot supersonic plumes interact within the aft section of the vehicle during ight. Due to the complex nature of rocket plume-induced ows within the launch vehicle base during ascent and a new vehicle con guration, sub-scale wind tunnel testing is required to reduce SLS base convective environment uncertainty and design risk levels. This hot- re test program was conducted at the CUBRC Large Energy National Shock (LENS) II short-duration test facility to simulate ight from altitudes of 50 kft to 210 kft. The test program is a challenging and innovative e ort that has not been attempted in 40+ years for a NASA vehicle. This presentation discusses the various trends of base convective heat ux and pressure as a function of altitude at various locations within the core-stage and booster base regions of the two-percent SLS wind tunnel model. In-depth understanding of the base ow physics is presented using the test data, infrared high-speed imaging and theory. The normalized test design environments are compared to various NASA semi- empirical numerical models to determine exceedance and conservatism of the ight scaled test-derived base design environments. Brief discussion of thermal impact to the launch vehicle base components is also presented.

  4. A Web-Based Development Environment for Collaborative Data Analysis

    NASA Astrophysics Data System (ADS)

    Erdmann, M.; Fischer, R.; Glaser, C.; Klingebiel, D.; Komm, M.; Müller, G.; Rieger, M.; Steggemann, J.; Urban, M.; Winchen, T.

    2014-06-01

    Visual Physics Analysis (VISPA) is a web-based development environment addressing high energy and astroparticle physics. It covers the entire analysis spectrum from the design and validation phase to the execution of analyses and the visualization of results. VISPA provides a graphical steering of the analysis flow, which consists of self-written, re-usable Python and C++ modules for more demanding tasks. All common operating systems are supported since a standard internet browser is the only software requirement for users. Even access via mobile and touch-compatible devices is possible. In this contribution, we present the most recent developments of our web application concerning technical, state-of-the-art approaches as well as practical experiences. One of the key features is the use of workspaces, i.e. user-configurable connections to remote machines supplying resources and local file access. Thereby, workspaces enable the management of data, computing resources (e.g. remote clusters or computing grids), and additional software either centralized or individually. We further report on the results of an application with more than 100 third-year students using VISPA for their regular particle physics exercises during the winter term 2012/13. Besides the ambition to support and simplify the development cycle of physics analyses, new use cases such as fast, location-independent status queries, the validation of results, and the ability to share analyses within worldwide collaborations with a single click become conceivable.

  5. Web based remote monitoring and controlling system for vulnerable environments

    NASA Astrophysics Data System (ADS)

    Thomas, Aparna; George, Minu

    2016-03-01

    The two major areas of concern in industrial establishments are monitoring and security. The remote monitoring and controlling can be established with the help of Web technology. Managers can monitor and control the equipment in the remote area through a web browser. The targeted area includes all type of susceptible environment like gas filling station, research and development laboratories. The environmental parameters like temperature, light intensity, gas etc. can be monitored. Security is a very important factor in an industrial setup. So motion detection feature is added to the system to ensure the security. The remote monitoring and controlling system makes use of the latest, less power consumptive and fast working microcontroller like S3C2440. This system is based on ARM9 and Linux operating system. The ARM9 will collect the sensor data and establish real time video monitoring along with motion detection feature. These captured video data as well as environmental data is transmitted over internet using embedded web server which is integrated within the ARM9 board.

  6. Comparison of ocean surface solar irradiance in the GLA General Circulation Model and satellite-based calculations

    SciTech Connect

    Chertock, B. ); Sud, Y.C. )

    1993-03-01

    A global, 7-year satellite-based record of ocean surface solar irradiance (SSI) is used to assess the realism of ocean SSI simulated by the nine-layer Goddard Laboratory for Atmospheres (GLA) General Circulation Model (GCM). January and July climatologies of net SSI produced by the model are compared with corresponding satellite climatologies for the world oceans between 54[degrees]N and 54[degrees]S. This comparison of climatologies indicates areas of strengths and weaknesses in the GCM treatment of cloud-radiation interactions, the major source of model uncertainty. Realism of ocean SSI is also important for applications such as incorporating the GLA GCM into a coupled ocean-atmosphere GCM. The results show that the GLA GCM simulates too much SSI in the extratropics and too little in the tropics, especially in the summer hemisphere. These discrepancies reach magnitudes of 60 W m[sup [minus]2] and more. The discrepancies are particularly large in the July case off the western coast of North America. In this region of persistent marine stratus, the GCM climatological values exceed the satellite climatological values by as much as 131 W m[sup [minus]2]. Positive and negative discrepancies in SSI are shown to be consistent with discrepancies in planetary albedo.

  7. Comparison of ocean surface solar irradiance in the GLA General Circulation Model and satellite-based calculations

    NASA Technical Reports Server (NTRS)

    Chertock, Beth; Sud, Y. C.

    1993-01-01

    A global, 7-year satellite-based record of ocean surface solar irradiance (SSI) is used to assess the realism of ocean SSI simulated by the nine-layer Goddard Laboratory for Atmospheres (GLA) General Circulation Model (GCM). January and July climatologies of net SSI produced by the model are compared with corresponding satellite climatologies for the world oceans between 54 deg N and 54 deg S. This comparison of climatologies indicates areas of strengths and weaknesses in the GCM treatment of cloud-radiation interactions, the major source of model uncertainty. Realism of ocean SSI is also important for applications such as incorporating the GLA GCM into a coupled ocean-atmosphere GCM. The results show that the GLA GCM simulates too much SSI in the extratropics and too little in the tropics, especially in the summer hemisphere. These discrepancies reach magnitudes of 60 W/sq m and more. The discrepancies are particularly large in the July case off the western coast of North America. Positive and negative discrepancies in SSI are shown to be consistent with discrepancies in planetary albedo.

  8. The development of ecological environment in China based on the system dynamics method from the society, economy and environment perspective.

    PubMed

    Guang, Yang; Ge, Song; Han, Liu

    2016-01-01

    The harmonious development in society, economy and environment are crucial to regional sustained boom. However, the society, economy and environment are not respectively independent, but both mutually promotes one which, or restrict mutually complex to have the long-enduring overall process. The present study is an attempt to investigate the relationship and interaction of society, economy and environment in China based on the data from 2004 to 2013. The principal component analysis (PCA) model was employed to identify the main factors effecting the society, economy and environment subsystems, and SD (system dynamics) method used to carry out dynamic assessment for future state of sustainability from society, economy and environment perspective with future indicator values. Sustainable development in China was divided in the study into three phase from 2004 to 2013 based competitive values of these three subsystems. According to the results of PCA model, China is in third phase, and the economy growth is faster than the environment development, while the social development still maintained a steady and rapid growth, implying that the next step for sustainable development in China should focus on society development, especially the environment development.

  9. A crystallizing dense magma ocean at the base of the Earth's mantle.

    PubMed

    Labrosse, S; Hernlund, J W; Coltice, N

    2007-12-06

    The distribution of geochemical species in the Earth's interior is largely controlled by fractional melting and crystallization processes that are intimately linked to the thermal state and evolution of the mantle. The existence of patches of dense partial melt at the base of the Earth's mantle, together with estimates of melting temperatures for deep mantle phases and the amount of cooling of the underlying core required to maintain a geodynamo throughout much of the Earth's history, suggest that more extensive deep melting occurred in the past. Here we show that a stable layer of dense melt formed at the base of the mantle early in the Earth's history would have undergone slow fractional crystallization, and would be an ideal candidate for an unsampled geochemical reservoir hosting a variety of incompatible species (most notably the missing budget of heat-producing elements) for an initial basal magma ocean thickness of about 1,000 km. Differences in 142Nd/144Nd ratios between chondrites and terrestrial rocks can be explained by fractional crystallization with a decay timescale of the order of 1 Gyr. These combined constraints yield thermal evolution models in which radiogenic heat production and latent heat exchange prevent early cooling of the core and possibly delay the onset of the geodynamo to 3.4-4 Gyr ago.

  10. Numerical model of nonhydrostatic ocean dynamics based on methods of artificial compressibility and multicomponent splitting

    NASA Astrophysics Data System (ADS)

    Zalesny, V. B.; Gusev, A. V.; Fomin, V. V.

    2016-11-01

    An algorithm is proposed for solving three-dimensional ocean hydrodynamics equations without hydrostatic approximation and traditional simplification of Coriolis acceleration. It is based on multicomponent splitting of the modified model with artificial compressibility. The original system of equations is split into two subsystems describing the transport of three velocity components and adjustment of the density and velocity fields. At the adjustment stage, the horizontal velocity components are represented as a sum of the depth means and deviations; the two corresponding subsystems are derived. For barotropic dynamics, the compressibility effect is represented as the boundary condition at the free surface, while for the baroclinic subsystem, it is introduced as ɛ-regularization of the continuity equation. Then, the baroclinic equations are split into two subsystems describing the hydrostatic and nonhydrostatic dynamics. The nonhydrostatic dynamics is computed at a separate splitting stage. The algorithm is included into the Institute of Numerical Mathematics of the Russian Academy of Sciences model based on "primitive" equations and verified by solving the hydrodynamics problem for the Sea of Marmara.

  11. Making the Case for Play Policy: Research-Based Reasons to Support Play-Based Environments

    ERIC Educational Resources Information Center

    Stegelin, Dolores A.

    2005-01-01

    This article can help teachers and directors become eloquent and effective advocates of play-based early learning environments. It defines play and play policy and discusses distinct research areas that support play policy and practice for physical, cognitive, social, and emotional development within diverse early childhood settings. Also…

  12. Designing a Web-Based Science Learning Environment for Model-Based Collaborative Inquiry

    ERIC Educational Resources Information Center

    Sun, Daner; Looi, Chee-Kit

    2013-01-01

    The paper traces a research process in the design and development of a science learning environment called WiMVT (web-based inquirer with modeling and visualization technology). The WiMVT system is designed to help secondary school students build a sophisticated understanding of scientific conceptions, and the science inquiry process, as well as…

  13. Metacognition: Implications for Research in Hypermedia-Based Learning Environment.

    ERIC Educational Resources Information Center

    Lin, Xiaodong

    In learning environments which provide little structure (e.g., hypermedia systems) students have an especially strong need to regulate and control their own learning. However, a review of the literature indicates that merely providing learners with flexible learning environments does not necessarily mean that they will effectively explore and…

  14. Construction of a Digital Learning Environment Based on Cloud Computing

    ERIC Educational Resources Information Center

    Ding, Jihong; Xiong, Caiping; Liu, Huazhong

    2015-01-01

    Constructing the digital learning environment for ubiquitous learning and asynchronous distributed learning has opened up immense amounts of concrete research. However, current digital learning environments do not fully fulfill the expectations on supporting interactive group learning, shared understanding and social construction of knowledge.…

  15. Petrology and geochemistry of Abyssal Peridotites from the Manipur Ophiolite Complex, Indo-Myanmar Orogenic Belt, Northeast India: Implication for melt generation in mid-oceanic ridge environment

    NASA Astrophysics Data System (ADS)

    Krishnakanta Singh, A.

    2013-04-01

    The Manipur Ophiolite Complex (MOC) located in the Indo-Myanmar Orogenic Belt (IMOB) of Northeast India forms a section of the Tethyan Ophiolite Belt of the Alpine-Himalayan orogenic system. Whole rock compositions and mineral chemistry of mantle peridotites from the MOC show an affinity to the abyssal peridotites, characterized by high contents of Al2O3 (1.28-3.30 anhydrous wt.%); low Cr# of Cr-spinel (0.11-0.27); low Mg# of olivine (˜Fo90) and high Al2O3 in pyroxenes (3.71-6.35 wt.%). They have very low REE concentrations (∑REE = 0.48-2.14 ppb). Lherzolites display LREE-depleted patterns (LaN/SmN = 0.14-0.45) with a flat to slightly fractionated HREE segments (SmN/YbN = 0.30-0.65) whereas Cpx-harburgites have flat to upward-inflected LREE patterns (LaN/SmN = 0.13-1.23) with more fractionated HREE patterns (SmN/YbN = 0.13-0.65) than the lherzolite samples. Their platinum group elements (PGE) contents (<50 ppb) and distinct mantle-normalised PGE patterns with the Pd/Ir values (1.8-11.9) and Pt/Pt* values (0.2-1.1) show an affinity to the characteristic of the residual mantle material. Evaluation of mineralogical and petrological characteristics of these peridotites suggests that they represent the residues remaining after low degree of partial melting (˜2-12%) in the spinel stability field of a mid-oceanic ridge environment. The well-preserved mid-oceanic ridge characteristics of these peridotites further suggest that the mantle section was subsequently trapped in the forearc region of the subduction zone without undergoing significant modification in their chemistry by later subduction-related tectonic and petrological processes before its emplacement to the present crustal level.

  16. Creating a Realistic Weather Environment for Motion-Based Piloted Flight Simulation

    NASA Technical Reports Server (NTRS)

    Daniels, Taumi S.; Schaffner, Philip R.; Evans, Emory T.; Neece, Robert T.; Young, Steve D.

    2012-01-01

    A flight simulation environment is being enhanced to facilitate experiments that evaluate research prototypes of advanced onboard weather radar, hazard/integrity monitoring (HIM), and integrated alerting and notification (IAN) concepts in adverse weather conditions. The simulation environment uses weather data based on real weather events to support operational scenarios in a terminal area. A simulated atmospheric environment was realized by using numerical weather data sets. These were produced from the High-Resolution Rapid Refresh (HRRR) model hosted and run by the National Oceanic and Atmospheric Administration (NOAA). To align with the planned flight simulation experiment requirements, several HRRR data sets were acquired courtesy of NOAA. These data sets coincided with severe weather events at the Memphis International Airport (MEM) in Memphis, TN. In addition, representative flight tracks for approaches and departures at MEM were generated and used to develop and test simulations of (1) what onboard sensors such as the weather radar would observe; (2) what datalinks of weather information would provide; and (3) what atmospheric conditions the aircraft would experience (e.g. turbulence, winds, and icing). The simulation includes a weather radar display that provides weather and turbulence modes, derived from the modeled weather along the flight track. The radar capabilities and the pilots controls simulate current-generation commercial weather radar systems. Appropriate data-linked weather advisories (e.g., SIGMET) were derived from the HRRR weather models and provided to the pilot consistent with NextGen concepts of use for Aeronautical Information Service (AIS) and Meteorological (MET) data link products. The net result of this simulation development was the creation of an environment that supports investigations of new flight deck information systems, methods for incorporation of better weather information, and pilot interface and operational improvements

  17. Source mechanisms of earthquakes near mid-ocean ridges from body waveform inversion - Implications for the early evolution of oceanic lithosphere

    NASA Technical Reports Server (NTRS)

    Bergman, E. A.; Solomon, S. C.

    1984-01-01

    An evaluation is presented of the tectonics of the near-ridge environment based on the source mechanisms of earthquakes in young oceanic lithosphere. A catalog of near-ridge earthquakes is presented, and source parameters are determined from body waveform inversions. Source parameter-age relations are examined, and the near-ridge seismicity of the Indian Ocean is discussed. Deep normal faulting in young oceanic lithosphere is addressed, as is the relationship between thermoelastic stress and near-ridge earthquakes. The possibility of secondary convection beneath young oceanic lithosphere is considered. Finally, the broader tectonic implications of these results for the evolution of young oceanic lithosphere are discussed.

  18. Using Wikis as a Support and Assessment Tool in Collaborative Digital Game-Based Learning Environments

    ERIC Educational Resources Information Center

    Samur, Yavuz

    2011-01-01

    In computer-supported collaborative learning (CSCL) environments, there are many researches done on collaborative learning activities; however, in game-based learning environments, more research and literature on collaborative learning activities are required. Actually, both game-based learning environments and wikis enable us to use new chances…

  19. Ship accessibility predictions for the Arctic Ocean based on IPCC CO2 emission scenarios

    NASA Astrophysics Data System (ADS)

    Oh, Jai-Ho; Woo, Sumin; Yang, Sin-Il

    2017-02-01

    Changes in the extent of Arctic sea ice, which have resulted from climate change, offer new opportunities to use the Northern Sea Route (NSR) and Northwest Passage (NWP) for shipping. However, choosing to navigate the Arctic Ocean remains challenging due to the limited accessibility of ships and the balance between economic gain and potential risk. As a result, more precise and detailed information on both weather and sea ice change in the Arctic are required. In this study, a high-resolution global AGCM was used to provide detailed information on the extent and thickness of Arctic sea ice. For this simulation, we have simulated the AMIP-type simulation for the present-day climate during 31 years from 1979 to 2009 with observed SST and Sea Ice concentration. For the future climate projection, we have performed the historical climate during 1979-2005 and subsequently the future climate projection during 2010-2099 with mean of four CMIP5 models due to the two Representative Concentration Pathway scenarios (RCP 8.5 and RCP 4.5). First, the AMIP-type simulation was evaluated by comparison with observations from the Hadley Centre sea-ice and Sea Surface Temperature (HadlSST) dataset. The model reflects the maximum (in March) and minimum (in September) sea ice extent and annual cycle. Based on this validation, the future sea ice extents show the decreasing trend for both the maximum and minimum seasons and RCP 8.5 shows more sharply decreasing patterns of sea ice than RCP 4.5. Under both scenarios, ships classified as Polar Class (PC) 3 and Open-Water (OW) were predicted to have the largest and smallest number of ship-accessible days (in any given year) for the NSR and NWP, respectively. Based on the RCP 8.5 scenario, the projections suggest that after 2070, PC3 and PC6 vessels will have year-round access across to the Arctic Ocean. In contrast, OW vessels will continue to have a seasonal handicap, inhibiting their ability to pass through the NSR and NWP.

  20. Ocean Dumping: International Treaties

    EPA Pesticide Factsheets

    The London Convention and London Protocol are global treaties to protect the marine environment from pollution caused by the ocean dumping of wastes. The Marine, Protection, Research and Sanctuaries Act implements the requirements of the LC.

  1. Ocean Drilling Program Leg 112, Peru continental margin: Part 2, Sedimentary history and diagenesis in a coastal upwelling environment

    NASA Astrophysics Data System (ADS)

    Suess, E.; von Huene, R.

    1988-10-01

    On the shelf and upper slope off Peru the signal of coastal upwelling productivity and bottom-water oxygen is well preserved in alternately laminated and bioturbated diatomaceous Quaternary sediments. Global sea-level fluctuations are the ultimate cause for these cyclic facies changes. During late Miocene time, coastal upwelling was about 100 km west of the present centers, along the edge of an emergent structure that subsequently subsided to form the modern slope. The sediments are rich in organic carbon, and intense microbially mediated decomposition of organic matter is evident in sulfate reduction and methanogenesis. These processes are accompanied by the formation of diagenetic carbonates, mostly Ca-rich dolomites and Mg-calcites. The downhole isotopic signatures of these carbonate cements display distinct successions that reflect the vertical evolution of the pore fluid environment. From the association of methane gas hydrates, burial depth, and low-chloride interstitial fluids, we suggest an additional process that could contribute to the characteristic chloride depletion in pore fluids of active margins: release of interlayer water from clays without a mineral phase change. The shelf sediments also contain a subsurface brine that stretches for more than 500 km from north to south over the area drilled. The source of the brine remains uncertain, although the composition of the oxygen isotopes suggests dissolution of evaporites by seawater.

  2. Asymmetric Base-Bleed Effect on Aerospike Plume-Induced Base-Heating Environment

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Droege, Alan; DAgostino, Mark; Lee, Young-Ching; Williams, Robert

    2004-01-01

    A computational heat transfer design methodology was developed to study the dual-engine linear aerospike plume-induced base-heating environment during one power-pack out, in ascent flight. It includes a three-dimensional, finite volume, viscous, chemically reacting, and pressure-based computational fluid dynamics formulation, a special base-bleed boundary condition, and a three-dimensional, finite volume, and spectral-line-based weighted-sum-of-gray-gases absorption computational radiation heat transfer formulation. A separate radiation model was used for diagnostic purposes. The computational methodology was systematically benchmarked. In this study, near-base radiative heat fluxes were computed, and they compared well with those measured during static linear aerospike engine tests. The base-heating environment of 18 trajectory points selected from three power-pack out scenarios was computed. The computed asymmetric base-heating physics were analyzed. The power-pack out condition has the most impact on convective base heating when it happens early in flight. The source of its impact comes from the asymmetric and reduced base bleed.

  3. Epigenetics—DNA-Based Mirror of our Environment?

    PubMed Central

    Cooney, Craig A.

    2007-01-01

    Epigenetics affects health, appearance and behavior and propagates mammalian phenotypes across generations. Nutrients, drugs and behavior can all direct changes in epigenetics. In at least some cases, these directed changes are propagated across generations. This range of influences on epigenetics suggests that epigenetics is highly interactive with the environment. Changes in the environment may regularly change epigenetics and influence our future responses to the environment. The current research challenge is to understand these influences and use them to direct epigenetics toward improved health and longevity. PMID:17325432

  4. Investigation of GNSS Based ERP-series to Validate Atmospheric and Oceanic Contributions to High Frequency Earth Rotation

    NASA Astrophysics Data System (ADS)

    Weber, R.; Nastula, J.; Boehm, S.

    2009-12-01

    Over the past 25 years several authors have shown that polar motions and variations of Universal Time (UT1) or length of day (LOD), respectively, from seasonal time scales down to one week are forced to a great extent by atmospheric and oceanic angular momentum (AAM and OAM) changes (Barnes, 1983; Rosen and Salstein, 1983; Brzezinski, 1992, 1994; Nastula and Salstein, 1999; Kolaczek et al., 2000; Nastula et al., 2002; Ponte and Ali,2002) and by the solid Earth tides and ocean tides. Oceanic tides also cause variations in UT1/LOD and in polar motion in particular at shorter time scales with diurnal and semi-diurnal periods. Theoretical and semi-empirical models were published by e.g. Gross (1993), Ray et al. (1994). All studies were based on ocean tide models or were using ocean tidal measurements by satellite altimetry. The Ray et al. (1994) model based on TOPEX/Poseidon satellite altimetry data is still the model which is recommended in the IERS Conventions 2003. The high-frequency variations of the Earth rotation parameters due to ocean tides can also be empirically determined from time series derived by space geodetic techniques like Very Long Baseline Interferometry (VLBI) or the Global Positioning System (GPS). Within this investigation high-quality ERP (Earth Rotation Parameter) series, i.e. polar motion (PM), and UT1 or length of day (LOD) with a time resolution of one hour have been established by processing observation data from both active GNSS-systems (GPS+GLONASS). Their correlation with oceanic- (OAM) and atmospheric-induced angular momentum (AAM) acting on the Earth’s surface are investigated. The investigations concentrate on short period variations of Earth rotation with periods of a few days down to a few hours. The amplitudes and phases of these short period tidally and non-tidally induced variations are compared to recent semi-empirical models of the oceanic and atmospheric excitation. Contrary to the standard processing scheme an improved

  5. Diamond based detectors for high temperature, high radiation environments

    NASA Astrophysics Data System (ADS)

    Metcalfe, A.; Fern, G. R.; Hobson, P. R.; Smith, D. R.; Lefeuvre, G.; Saenger, R.

    2017-01-01

    Single crystal CVD diamond has many desirable properties as a radiation detector; exceptional radiation hardness and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry and transmission mode applications), wide bandgap (high temperature operation with low noise and solar blind), an intrinsic pathway to fast neutron detection through the 12C(n,α)9Be reaction. This combination of radiation hardness, temperature tolerance and ability to detect mixed radiation types with a single sensor makes diamond particularly attractive as a detector material for harsh environments such as nuclear power station monitoring (fission and fusion) and oil well logging. Effective exploitation of these properties requires the development of a metallisation scheme to give contacts that remain stable over extended periods at elevated temperatures (up to 250°C in this instance). Due to the cost of the primary detector material, computational modelling is essential to best utilise the available processing methods for optimising sensor response through geometry and conversion media configurations and to fully interpret experimental data. Monte Carlo simulations of our diamond based sensor have been developed, using MCNP6 and FLUKA2011, assessing the sensor performance in terms of spectral response and overall efficiency as a function of the detector and converter geometry. Sensors with varying metallisation schemes for high temperature operation have been fabricated at Brunel University London and by Micron Semiconductor Limited. These sensors have been tested under a varied set of conditions including irradiation with fast neutrons and alpha particles at high temperatures. The presented study indicates that viable metallisation schemes for high temperature contacts have been successfully developed and the modelling results, supported by preliminary experimental data from partners, indicate that the simulations provide a reasonable representation of

  6. 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

  7. Particle Swarm Based Collective Searching Model for Adaptive Environment

    SciTech Connect

    Cui, Xiaohui; Patton, Robert M; Potok, Thomas E; Treadwell, Jim N

    2008-01-01

    This report presents a pilot study of an integration of particle swarm algorithm, social knowledge adaptation and multi-agent approaches for modeling the collective search behavior of self-organized groups in an adaptive environment. The objective of this research is to apply the particle swarm metaphor as a model of social group adaptation for the dynamic environment and to provide insight and understanding of social group knowledge discovering and strategic searching. A new adaptive environment model, which dynamically reacts to the group collective searching behaviors, is proposed in this research. The simulations in the research indicate that effective communication between groups is not the necessary requirement for whole self-organized groups to achieve the efficient collective searching behavior in the adaptive environment.

  8. Particle Swarm Based Collective Searching Model for Adaptive Environment

    SciTech Connect

    Cui, Xiaohui; Patton, Robert M; Potok, Thomas E; Treadwell, Jim N

    2007-01-01

    This report presents a pilot study of an integration of particle swarm algorithm, social knowledge adaptation and multi-agent approaches for modeling the collective search behavior of self-organized groups in an adaptive environment. The objective of this research is to apply the particle swarm metaphor as a model of social group adaptation for the dynamic environment and to provide insight and understanding of social group knowledge discovering and strategic searching. A new adaptive environment model, which dynamically reacts to the group collective searching behaviors, is proposed in this research. The simulations in the research indicate that effective communication between groups is not the necessary requirement for whole self-organized groups to achieve the efficient collective searching behavior in the adaptive environment.

  9. Predicting the effects of ocean acidification on predator-prey interactions: a conceptual framework based on coastal molluscs.

    PubMed

    Kroeker, Kristy J; Sanford, Eric; Jellison, Brittany M; Gaylord, Brian

    2014-06-01

    The influence of environmental change on species interactions will affect population dynamics and community structure in the future, but our current understanding of the outcomes of species interactions in a high-CO2 world is limited. Here, we draw upon emerging experimental research examining the effects of ocean acidification on coastal molluscs to provide hypotheses of the potential impacts of high-CO2 on predator-prey interactions. Coastal molluscs, such as oysters, mussels, and snails, allocate energy among defenses, growth, and reproduction. Ocean acidification increases the energetic costs of physiological processes such as acid-base regulation and calcification. Impacted molluscs can display complex and divergent patterns of energy allocation to defenses and growth that may influence predator-prey interactions; these include changes in shell properties, body size, tissue mass, immune function, or reproductive output. Ocean acidification has also been shown to induce complex changes in chemoreception, behavior, and inducible defenses, including altered cue detection and predator avoidance behaviors. Each of these responses may ultimately alter the susceptibility of coastal molluscs to predation through effects on predator handling time, satiation, and search time. While many of these effects may manifest as increases in per capita predation rates on coastal molluscs, the ultimate outcome of predator-prey interactions will also depend on how ocean acidification affects the specified predators, which also exhibit complex responses to ocean acidification. Changes in predator-prey interactions could have profound and unexplored consequences for the population dynamics of coastal molluscs in a high-CO2 ocean.

  10. A new estimate of the global 3D geostrophic ocean circulation based on satellite data and in-situ measurements

    NASA Astrophysics Data System (ADS)

    Mulet, S.; Rio, M.-H.; Mignot, A.; Guinehut, S.; Morrow, R.

    2012-11-01

    A new estimate of the Global Ocean 3D geostrophic circulation from the surface down to 1500 m depth (Surcouf3D) has been computed for the 1993-2008 period using an observation-based approach that combines altimetry with temperature and salinity through the thermal wind equation. The validity of this simple approach was tested using a consistent dataset from a model reanalysis. Away from the boundary layers, errors are less than 10% in most places, which indicate that the thermal wind equation is a robust approximation to reconstruct the 3D oceanic circulation in the ocean interior. The Surcouf3D current field was validated in the Atlantic Ocean against in-situ observations. We considered the ANDRO current velocities deduced at 1000 m depth from Argo float displacements as well as velocity measurements at 26.5°N from the RAPID-MOCHA current meter array. The Surcouf3D currents show similar skill to the 3D velocities from the GLORYS Mercator Ocean reanalysis in reproducing the amplitude and variability of the ANDRO currents. In the upper 1000 m, high correlations are also found with in-situ velocities measured by the RAPID-MOCHA current meters. The Surcouf3D current field was then used to compute estimates of the Atlantic Meridional Overturning Circulation (AMOC) through the 25°N section, showing good comparisons with hydrographic sections from 1998 and 2004. Monthly averaged AMOC time series are also consistent with the RAPID-MOCHA array and with the GLORYS Mercator Ocean reanalysis over the April 2004-September 2007 period. Finally a 15 years long time series of monthly estimates of the AMOC was computed. The AMOC strength has a mean value of 16 Sv with an annual (resp. monthly) standard deviation of 2.4 Sv (resp. 7.1 Sv) over the 1993-2008 period. The time series, characterized by a strong variability, shows no significant trend.

  11. Simulation based study of the effect of ocean waves on floating wind farm

    NASA Astrophysics Data System (ADS)

    Yang, Di; Meneveau, Charles; Shen, Lian

    2012-11-01

    A hybrid numerical capability is developed for the simulation of floating wind farm offshore, in which large-eddy simulation is performed for wind turbulence, and a potential flow based method is used for the simulation of ocean wavefield. The wind and wave simulations are coupled through a two-way feedback scheme. The effect of wind turbines on the wind field is represented by an actuator disk model. A variety of fully-developed and fetch-limited wind-sea conditions are considered in the study. The simulation results indicate that the offshore wind farm obtains a higher wind power extraction rate under the fully-developed wind-sea condition compared with the fetch-limited condition. This higher extraction rate is caused by the faster propagating waves and the lower sea-surface resistance on the wind when the wind-seas are fully developed. Such wave effect becomes more prominent when the turbine density of the wind farm increases. DY and LS acknowledge the support of NSF-CBET-1133700. CM acknowledges the support of NSF-CBET-1133800 and NSF-AGS-1045189.

  12. Analysis of ocean in situ observations and web-based visualization

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Watelet, Sylvain; Troupin, Charles; Alvera Azcarate, Aida; Santinelli, Giorgio; Hendriksen, Gerrit; Giorgetti, Alessandra; Beckers, Jean-Marie

    2016-04-01

    The sparsity of observations poses a challenge common to various ocean science disciplines. Even for physical parameters where the spatial and temporal coverage is higher, current observational networks undersample a broad spectrum of scales. The situation is generally more severe for chemical and biological parameters because related sensors are less widely deployed. The analysis tool DIVA (Data-Interpolating Variational Analysis) is designed to generate gridded fields from in situ observations. DIVA has been applied to various physical (temperature and salinity), chemical (concentration of nitrate, nitrite and phosphate) and biological parameters (abundance of a species) in the context of different European projects (SeaDataNet, EMODnet Chemistry and EMODnet Biology). We show the technologies used to visualize the gridded fields based on the Web Map Services standard. Visualization of analyses from in situ observations provides a unique set of challenges since the accuracy of the analysed field is not spatially uniform as it strongly depends on the observations location. In addition, an adequate handling of depth and time dimensions is essential. Beside visualizing the gridded fields, access is also given to the underlying observations. It is thus also possible to view more detailed information about the variability of the observations. The in situ observation visualization service allows one to display vertical profiles and time series and it is built upon OGC standards (the Web Feature Service and Web Processing Services) and following recommendation from the INSPIRE directive.

  13. Detecting and tracking eddies in oceanic flows: A vorticity based Euler-Lagrangian method

    NASA Astrophysics Data System (ADS)

    Vortmeyer-Kley, Rahel; Gräwe, Ulf; Feudel, Ulrike

    2016-04-01

    Algae blooms as recurrent events in the Baltic Sea are an increasing natural hazard. Sandulescu et al. show in numerical simulation in [1] that eddies can play the role of an incubator for an algae bloom. Inside the eddy nutrients and plankton are trapped and can then be transported across rather long distances. To gain insight in mechanisms of algae bloom evolution detection and tracking of eddies is of interest. Based on the idea to interpret an eddy as a region that is bounded by manifolds and has an elliptic fixed point inside them, we develop an Euler-Lagrangian eddytracking tool using the idea of Lagrangian descriptors [2] and the vorticity. To test how well the tool detects eddy tracks and shapes, and estimates eddy lifetimes, the method is applied to a synthetic van Karman-Vortex Street. The results are compared to an eddytracking tool by Nencioli et al. [3]. Even velocity fields incorporated with different types of noise are taken into account to test the robustness of the tool. Finally, both methods are applied to velocity fields of the Baltic Sea. [1] M. Sandulescu, C. Lopez, E. Hernandez-Garcia and U. Feudel, Nonlinear Proc. Geophys., 14, 443-454, (2007). [2] J. Jimenez-Madrid and A. Mancho, Chaos, 19, 013111-1-18, (2009). [3] F. Nencioli, C. Dong, T. Dickey, L. Washburn, and J.C. McWilliams, J. Atmos. Ocean Tech., 27, 564-579, (2010).

  14. Giant Robber Crabs Monitored from Space: GPS-Based Telemetric Studies on Christmas Island (Indian Ocean)

    PubMed Central

    Krieger, Jakob; Grandy, Ronald; Drew, Michelle M.; Erland, Susanne; Stensmyr, Marcus C.; Harzsch, Steffen; Hansson, Bill S.

    2012-01-01

    We investigated the navigational capabilities of the world's largest land-living arthropod, the giant robber crab Birgus latro (Anomura, Coenobitidae); this crab reaches 4 kg in weight and can reach an age of up to 60 years. Populations are distributed over small Indo-Pacific islands of the tropics, including Christmas Island (Indian Ocean). Although this species has served as a crustacean model to explore anatomical, physiological, and ecological aspects of terrestrial adaptations, few behavioral analyses of it exist. We used a GPS-based telemetric system to analyze movements of freely roaming robber crabs, the first large-scale study of any arthropod using GPS technology to monitor behavior. Although female robber crabs are known to migrate to the coast for breeding, no such observations have been recorded for male animals. In total, we equipped 55 male robber crabs with GPS tags, successfully recording more than 1,500 crab days of activity, and followed some individual animals for as long as three months. Besides site fidelity with short-distance excursions, our data reveal long-distance movements (several kilometers) between the coast and the inland rainforest. These movements are likely related to mating, saltwater drinking and foraging. The tracking patterns indicate that crabs form route memories. Furthermore, translocation experiments show that robber crabs are capable of homing over large distances. We discuss if the search behavior induced in these experiments suggests path integration as another important navigation strategy. PMID:23166774

  15. Energy transports by ocean and atmosphere based on an entropy extremum principle. I - Zonal averaged transports

    NASA Technical Reports Server (NTRS)

    Sohn, Byung-Ju; Smith, Eric A.

    1993-01-01

    The maximum entropy production principle suggested by Paltridge (1975) is applied to separating the satellite-determined required total transports into atmospheric and oceanic components. Instead of using the excessively restrictive equal energy dissipation hypothesis as a deterministic tool for separating transports between the atmosphere and ocean fluids, the satellite-inferred required 2D energy transports are imposed on Paltridge's energy balance model, which is then solved as a variational problem using the equal energy dissipation hypothesis only to provide an initial guess field. It is suggested that Southern Ocean transports are weaker than previously reported. It is argued that a maximum entropy production principle can serve as a governing rule on macroscale global climate, and, in conjunction with conventional satellite measurements of the net radiation balance, provides a means to decompose atmosphere and ocean transports from the total transport field.

  16. Biogenic inputs to ocean mixing.

    PubMed

    Katija, Kakani

    2012-03-15

    Recent studies have evoked heated debate about whether biologically generated (or biogenic) fluid disturbances affect mixing in the ocean. Estimates of biogenic inputs have shown that their contribution to ocean mixing is of the same order as winds and tides. Although these estimates are intriguing, further study using theoretical, numerical and experimental techniques is required to obtain conclusive evidence of biogenic mixing in the ocean. Biogenic ocean mixing is a complex problem that requires detailed understanding of: (1) marine organism behavior and characteristics (i.e. swimming dynamics, abundance and migratory behavior), (2) mechanisms utilized by swimming animals that have the ability to mix stratified fluids (i.e. turbulence and fluid drift) and (3) knowledge of the physical environment to isolate contributions of marine organisms from other sources of mixing. In addition to summarizing prior work addressing the points above, observations on the effect of animal swimming mode and body morphology on biogenic fluid transport will also be presented. It is argued that to inform the debate on whether biogenic mixing can contribute to ocean mixing, our studies should focus on diel vertical migrators that traverse stratified waters of the upper pycnocline. Based on our understanding of mixing mechanisms, body morphologies, swimming modes and body orientation, combined with our knowledge of vertically migrating populations of animals, it is likely that copepods, krill and some species of gelatinous zooplankton and fish have the potential to be strong sources of biogenic mixing.

  17. A Direct Simulation-Based Study of Radiance in a Dynamic Ocean

    DTIC Science & Technology

    2010-01-01

    modeling of these hydrodynamic processes is coupled with the computation of radiative transport. (1) Radiative Transfer in CGW and FST: Monte Carlo ...JHU focuses on the study and development of (4) and (5). WORK COMPLETED • Development and validation of 3D Monte Carlo RT simulation for...atmosphere-ocean system: We developed a three-dimensional coupled atmosphere-ocean Monte Carlo radiative transfer (MIT-RT) simulation capability for both

  18. Modeling and Parameterization Study of Radiance in a Dynamic Ocean

    DTIC Science & Technology

    2012-09-30

    simulation of nonlinear capillary-gravity waves (CGW) • develop numerical capabilities for free-surface turbulence ( FST ) and the resultant surface...based simulations and modeling to solve the problem of ocean RT in a dynamic SBL environment that includes CGW and FST . The complex dynamic...processes of the ocean SBL, the nonlinear CGW interactions, and the development and transport of FST are modeled using physics-based computations. The

  19. An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll-a based models.

    PubMed

    Lee, Younjoo J; Matrai, Patricia A; Friedrichs, Marjorie A M; Saba, Vincent S; Antoine, David; Ardyna, Mathieu; Asanuma, Ichio; Babin, Marcel; Bélanger, Simon; Benoît-Gagné, Maxime; Devred, Emmanuel; Fernández-Méndez, Mar; Gentili, Bernard; Hirawake, Toru; Kang, Sung-Ho; Kameda, Takahiko; Katlein, Christian; Lee, Sang H; Lee, Zhongping; Mélin, Frédéric; Scardi, Michele; Smyth, Tim J; Tang, Shilin; Turpie, Kevin R; Waters, Kirk J; Westberry, Toby K

    2015-09-01

    We investigated 32 net primary productivity (NPP) models by assessing skills to reproduce integrated NPP in the Arctic Ocean. The models were provided with two sources each of surface chlorophyll-a concentration (chlorophyll), photosynthetically available radiation (PAR), sea surface temperature (SST), and mixed-layer depth (MLD). The models were most sensitive to uncertainties in surface chlorophyll, generally performing better with in situ chlorophyll than with satellite-derived values. They were much less sensitive to uncertainties in PAR, SST, and MLD, possibly due to relatively narrow ranges of input data and/or relatively little difference between input data sources. Regardless of type or complexity, most of the models were not able to fully reproduce the variability of in situ NPP, whereas some of them exhibited almost no bias (i.e., reproduced the mean of in situ NPP). The models performed relatively well in low-productivity seasons as well as in sea ice-covered/deep-water regions. Depth-resolved models correlated more with in situ NPP than other model types, but had a greater tendency to overestimate mean NPP whereas absorption-based models exhibited the lowest bias associated with weaker correlation. The models performed better when a subsurface chlorophyll-a maximum (SCM) was absent. As a group, the models overestimated mean NPP, however this was partly offset by some models underestimating NPP when a SCM was present. Our study suggests that NPP models need to be carefully tuned for the Arctic Ocean because most of the models performing relatively well were those that used Arctic-relevant parameters.

  20. An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll‐a based models

    PubMed Central

    Matrai, Patricia A.; Friedrichs, Marjorie A. M.; Saba, Vincent S.; Antoine, David; Ardyna, Mathieu; Asanuma, Ichio; Babin, Marcel; Bélanger, Simon; Benoît‐Gagné, Maxime; Devred, Emmanuel; Fernández‐Méndez, Mar; Gentili, Bernard; Hirawake, Toru; Kang, Sung‐Ho; Kameda, Takahiko; Katlein, Christian; Lee, Sang H.; Lee, Zhongping; Mélin, Frédéric; Scardi, Michele; Smyth, Tim J.; Tang, Shilin; Turpie, Kevin R.; Waters, Kirk J.; Westberry, Toby K.

    2015-01-01

    Abstract We investigated 32 net primary productivity (NPP) models by assessing skills to reproduce integrated NPP in the Arctic Ocean. The models were provided with two sources each of surface chlorophyll‐a concentration (chlorophyll), photosynthetically available radiation (PAR), sea surface temperature (SST), and mixed‐layer depth (MLD). The models were most sensitive to uncertainties in surface chlorophyll, generally performing better with in situ chlorophyll than with satellite‐derived values. They were much less sensitive to uncertainties in PAR, SST, and MLD, possibly due to relatively narrow ranges of input data and/or relatively little difference between input data sources. Regardless of type or complexity, most of the models were not able to fully reproduce the variability of in situ NPP, whereas some of them exhibited almost no bias (i.e., reproduced the mean of in situ NPP). The models performed relatively well in low‐productivity seasons as well as in sea ice‐covered/deep‐water regions. Depth‐resolved models correlated more with in situ NPP than other model types, but had a greater tendency to overestimate mean NPP whereas absorption‐based models exhibited the lowest bias associated with weaker correlation. The models performed better when a subsurface chlorophyll‐a maximum (SCM) was absent. As a group, the models overestimated mean NPP, however this was partly offset by some models underestimating NPP when a SCM was present. Our study suggests that NPP models need to be carefully tuned for the Arctic Ocean because most of the models performing relatively well were those that used Arctic‐relevant parameters. PMID:27668139

  1. Ocean acidification leads to counterproductive intestinal base loss in the gulf toadfish (Opsanus beta).

    PubMed

    Heuer, Rachael M; Esbaugh, Andrew J; Grosell, Martin

    2012-01-01

    Oceanic CO(2) has increased from 280 to 380 μatm since preindustrial times and is expected to reach 1,900 μatm by 2300. In addition, regional upwelling zones exhibit levels up to 2,300 μatm, making exploration at future global projected CO(2) levels ecologically relevant today. Recent work has demonstrated that CO(2) exposure as low as 1,000 μatm induces acidosis in toadfish (Opansus beta), leading to metabolic compensation by retention of blood HCO(3) in an effort to defend pH. Since increased serosal HCO(3) translates to increased HCO(3) rates in isolated intestinal tissue, we predicted that blood elevation of HCO(3) and Pco(2) during exposure to 1,900 μatm CO(2) would increase in vivo base secretion rates. Rectal fluid and CaCO(3) excretions were collected from toadfish exposed to 380 (control) and 1,900 μatm CO(2) for 72 h. Fluids were analyzed for pH, osmolality, ionic composition, and total CO(2). Precipitated CaCO(3) was analyzed for titratable alkalinity, Mg(2+), and Ca(2+) content. Fish exposed to 1,900 μatm CO(2) exhibited higher rectal base excretion rates, higher rectal fluid HCO(3) (mmol L(-1)), and lower fluid Cl(-) (mmol L(-1)) than controls, suggesting increased intestinal anion exchange as a result of the compensated respiratory acidosis. This study verifies that imminent projected CO(2) levels expected by the year 2300 lead to greater intestinal HCO(3) loss, a process that acts against compensation for a CO(2)-induced acidosis.

  2. An argo-based model for investigation of the Global Ocean (AMIGO)

    NASA Astrophysics Data System (ADS)

    Lebedev, K. V.

    2016-03-01

    We analyze the newly developed Argo-Based Model for Investigation of the Global Ocean (AMIGO), which consists of a block for variational interpolation of the profiles of drifting Argo floats to a regular grid and a block for model hydrodynamic adjustment of variationally interpolated fields. Such a method makes it possible to obtain a full set of oceanographic characteristics—temperature, salinity, density, and current velocity—using irregularly located Argo measurements. The resulting simulations are represented as monthly mean, seasonal, and annual means and climatological fields. The AMIGO oceanographic database developed at the Shirshov Institute of Oceanology from model simulations covers the 10-year period from 2005 to 2014. Analysis of transport variations in the propagation of North Atlantic Current jets to the Arctic based on the AMIGO data showed that during this period, anomalous winter transports were observed, which correlate with anomalous winter temperatures in regions of northwestern Europe, northern European Russia, and Iceland, which are subjected to the influence of these currents. Comparative analysis of variations in mass and heat transport by the currents and the North Atlantic Oscillation (NAO) index in the period of 2005-2014 shows a well pronounced correlation between them. The low winter values of the NAO index correspond to the low values of winter transports by the Faroe-Shetland branch of the North Atlantic current, and usually, to the high values of winter transports by the North Icelandic branch of the Irminger Current. High winter value of the NAO index results in a substantial increase in the winter transport by the Faroe-Shetland branch of the North Atlantic Current without notable influence on the transport of the North Icelandic branch of the Irminger Current.

  3. Estimating the impact of natural and anthropogenic changes on the transfer of elements from the continent to the ocean at the large watershed scale in a tropical environment

    NASA Astrophysics Data System (ADS)

    Godderis, Y.; Roelandt, C.; Bonnet, M.

    2007-12-01

    Continental weathering of silicate rocks has been recognized as a major driver of climatic changes at the geological timescale. New evidences and preliminary modelling works [1] show that the impact of continental weathering on the geochemical cycles and climate might be non negligible at shorter time scales, from 102 to 104 years, with for instance an increase in total continental weathering by 12 percent from the LGM towards the present day [2]. Continental weathering at large scale (106 km2) is generally described through parametric laws (see for instance [3]), linking weathering rates to mean annual air temperature and continental runoff. These laws are masking numerous other parameters, implicitly included, such as the role of vegetation and physical erosion, and limits the ability of those models to predict changes in weathering due to anthropogenic impacts. A coupled model of biospheric and weathering processes has been developped to estimate the transfer of elements to the ocean originating from tropical watersheds. The BERNI model is the result of the coupling of LPJ - dynamic global vegetation model [5] with the WITCH model [6] that estimates dissolution/precipitation of minerals in the soil environment from kinetic laboratory laws. Here we present results obtained for the Orinoco watershed. Output of the coupled model includes major ion concentrations that are compared to available data, and CO2 consumption through weathering for a tropical environment. The impact of land use changes is tested, as well as the response of weathering to climatic change at continental scale. [1] Aumont et al. (2001) GBC15, 393-405. [2] Burton K.W. et al. (2006) EGU General Assem., Vienna [3] Dessert C. et al. (2003) Chem. Geol.202, 257-273. [4] Edmond et al. (1995) GCA59, 3301-3325; Millot et al. (2002), EPSL196, 83-98. [5] Sitch S. et al. (2003) Global Change Biology 9, 161-185. [6] Goddéris et al. (2006) GCA70, 1228-1147.

  4. Ecogenomic characterization of a marine microorganism belonging to a Firmicutes lineage that is widespread in both terrestrial and oceanic subsurface environments

    NASA Astrophysics Data System (ADS)

    Jungbluth, S.; Glavina del Rio, T.; Tringe, S. G.; Stepanauskas, R.; Rappe, M. S.

    2015-12-01

    Large-volumes of basalt-hosted fluids from the sediment-covered subseafloor were collected in July 2011 from a horizon extending 29-117 meters below the sediment-rock interface at borehole 1362B, as well as from a deep horizon extending 193-292 meters below the sediment-rock interface at borehole 1362A, which are two of the latest generation of borehole observatories on the Juan de Fuca Ridge flank in the Northeast Pacific Ocean. Environmental DNA was sequenced from one fluid sample collected from each borehole, and a genomic bin related to the terrestrial Candidatus Desulforudis audaxviator lineage within the Firmicutes phylum of bacteria was identified. The near-complete bacterial genome, herein named Candidatus Desulfopertinax inferamarinus, is composed of six scaffolds totaling 1.78 Mbp in length. Despite vast differences in geography and environment of origin, phylogenomic analysis indicate that D. inferamarinus and D. audaxviator form a monophyletic clade to the exclusion of all other sequenced genomes. Similar to its terrestrial relative, the draft genome of the marine D. inferamarinus revealed a motile, sporulating, sulfate-reducing, chemoautotrophic thermophile that is capable of synthesizing all amino acids and fixing inorganic carbon via the Wood-Ljungdahl pathway. Unlike the terrestrial clade, relatively few integrases and transposases were identified. The marine genome described here provides evidence that a life-style adapted to the isolated deep subsurface environment is a general feature of the broader, globally-distributed Desulforudis/Desulfopertinax lineage and provides insight into the adaptations required for microbial life in the marine versus terrestrial deep biospheres.

  5. Robotic Vision-Based Localization in an Urban Environment

    NASA Technical Reports Server (NTRS)

    Mchenry, Michael; Cheng, Yang; Matthies

    2007-01-01

    A system of electronic hardware and software, now undergoing development, automatically estimates the location of a robotic land vehicle in an urban environment using a somewhat imprecise map, which has been generated in advance from aerial imagery. This system does not utilize the Global Positioning System and does not include any odometry, inertial measurement units, or any other sensors except a stereoscopic pair of black-and-white digital video cameras mounted on the vehicle. Of course, the system also includes a computer running software that processes the video image data. The software consists mostly of three components corresponding to the three major image-data-processing functions: Visual Odometry This component automatically tracks point features in the imagery and computes the relative motion of the cameras between sequential image frames. This component incorporates a modified version of a visual-odometry algorithm originally published in 1989. The algorithm selects point features, performs multiresolution area-correlation computations to match the features in stereoscopic images, tracks the features through the sequence of images, and uses the tracking results to estimate the six-degree-of-freedom motion of the camera between consecutive stereoscopic pairs of images (see figure). Urban Feature Detection and Ranging Using the same data as those processed by the visual-odometry component, this component strives to determine the three-dimensional (3D) coordinates of vertical and horizontal lines that are likely to be parts of, or close to, the exterior surfaces of buildings. The basic sequence of processes performed by this component is the following: 1. An edge-detection algorithm is applied, yielding a set of linked lists of edge pixels, a horizontal-gradient image, and a vertical-gradient image. 2. Straight-line segments of edges are extracted from the linked lists generated in step 1. Any straight-line segments longer than an arbitrary threshold (e

  6. Analysis of Indoor Environment in Classroom Based on Hygienic Requirements

    NASA Astrophysics Data System (ADS)

    Javorček, Miroslav; Sternová, Zuzana

    2016-06-01

    The article contains the analysis of experimental ventilation measurement in selected classrooms of the Elementary School Štrba. Mathematical model of selected classroom was prepared according to in-situ measurements and air exchange was calculated. Interior air temperature and quality influences the students ´ comfort. Evaluated data were compared to requirements of standard (STN EN 15251,2008) applicable to classroom indoor environment during lectures, highlighting the difference between required ambiance quality and actually measured values. CO2 concentration refers to one of the parameters indicating indoor environment quality.

  7. A Theoretical Analysis of Social Interactions in Computer-based Learning Environments: Evidence for Reciprocal Understandings.

    ERIC Educational Resources Information Center

    Jarvela, Sanna; Bonk, Curtis Jay; Lehtinen, Erno; Lehti, Sirpa

    1999-01-01

    Presents a theoretical and empirical analysis of social interactions in computer-based learning environments. Explores technology use to support reciprocal understanding between teachers and students based on three technology-based learning environments in Finland and the United States, and discusses situated learning, cognitive apprenticeships,…

  8. Agent-Based Learning Environments as a Research Tool for Investigating Teaching and Learning.

    ERIC Educational Resources Information Center

    Baylor, Amy L.

    2002-01-01

    Discusses intelligent learning environments for computer-based learning, such as agent-based learning environments, and their advantages over human-based instruction. Considers the effects of multiple agents; agents and research design; the use of Multiple Intelligent Mentors Instructing Collaboratively (MIMIC) for instructional design for…

  9. Ocean acidification and its impact on ocean noise: phenomenology and analysis.

    PubMed

    Reeder, D Benjamin; Chiu, Ching-Sang

    2010-09-01

    Ocean acidification has been observed since the beginning of the industrial era and is expected to further reduce ocean pH in the future. A significant increase in ocean noise has been suggested based upon the percentage change in acoustic absorption coefficient at low frequencies. Presented here is an analysis using transmission loss models of all relevant loss mechanisms for three environments experiencing a significant near-surface pH reduction of 8.1-7.4. Results show no observable change in the shallow water and surface duct environments, and a statistically insignificant change of less than 0.5 dB for all frequencies in the deep water environment.

  10. Ocean Tracks: Investigating Marine Migrations in a Changing Ocean

    NASA Astrophysics Data System (ADS)

    Krumhansl, R.; Kochevar, R. E.; Aluwihare, L.; Bardar, E. W.; Hirsch, L.; Hoyle, C.; Krumhansl, K.; Louie, J.; Madura, J.; Mueller-Northcott, J.; Peach, C. L.; Trujillo, A.; Winney, B.; Zetterlind, V.; Busey, A.

    2015-12-01

    The availability of scientific data sets online opens up exciting new opportunities to raise students' understanding of the worlds' oceans and the potential impacts of climate change. The Oceans of Data Institute at EDC; Stanford University; and the Scripps Institution of Oceanography have been collaborating, with the support of three National Science Foundation grants over the past 5 years, to bring marine science data sets into high school and undergraduate classrooms. These efforts have culminated in the development of a web-based student interface to data from the Tagging of Pacific Predators (TOPP) program, NOAA's Global Drifter Program, and NASA Earth-orbiting satellites through a student-friendly Web interface, customized data analysis tools, multimedia supports, and course modules. Ocean Tracks (http://oceantracks.org), which incorporates design principles based on a broad range of research findings in fields such as cognitive science, visual design, mathematics education and learning science, focuses on optimizing students' opportunities to focus their cognitive resources on viewing and comparing data to test hypotheses, while minimizing the time spent on downloading, filtering and creating displays. Ocean Tracks allows students to display the tracks of elephant seals, white sharks, Bluefin tuna, albatross, and drifting buoys along with sea surface temperature, chlorophyll-A, bathymetry, ocean currents, and human impacts overlays. A graphing tool allows students to dynamically display parameters associated with the track such as speed, deepest daily dive and track tortuosity (curviness). These interface features allow students to engage in investigations that mirror those currently being conducted by scientists to understand the broad-scale effects of changes in climate and other human activities on ocean ecosystems. In addition to supporting the teaching of the Ocean and Climate Literacy principles, high school curriculum modules facilitate the teaching

  11. Tropical cyclone-ocean interaction in Typhoon Megi (2010)—A synergy study based on ITOP observations and atmosphere-ocean coupled model simulations

    NASA Astrophysics Data System (ADS)

    Wu, Chun-Chieh; Tu, Wei-Tsung; Pun, Iam-Fei; Lin, I.-I.; Peng, Melinda S.

    2016-01-01

    A mesoscale model coupling the Weather Research and Forecasting model and the three-dimensional Price-Weller-Pinkel ocean model is used to investigate the dynamical ocean response to Megi (2010). It is found that Megi induces sea surface temperature (SST) cooling very differently in the Philippine Sea (PS) and the South China Sea (SCS). The results are compared to the in situ measurements from the Impact of Typhoons on the Ocean in the Pacific (ITOP) 2010 field experiment, satellite observations, and ocean analysis field from Eastern Asian Seas Ocean Nowcast/Forecast System of the U.S. Naval Research Laboratory. The uncoupled and coupled experiments simulate relatively accurately the track and intensity of Megi over PS; however, the simulated intensity of Megi over SCS varies significantly among the experiments. Only the experiment coupled with three-dimensional ocean processes, which generates rational SST cooling, reasonably simulates the storm intensity in SCS. Our results suggest that storm translation speed and upper ocean thermal structure are two main factors responsible for Megi's distinct different impact over PS and over SCS. In addition, it is shown that coupling with one-dimensional ocean process (i.e., only vertical mixing process) is not enough to provide sufficient ocean response, especially under slow translation speed (~2-3 m s-1), during which vertical advection (or upwelling) is significant. Therefore, coupling with three-dimensional ocean processes is necessary and crucial for tropical cyclone forecasting. Finally, the simulation results show that the stable boundary layer forms on top of the Megi-induced cold SST area and increases the inflow angle of the surface wind.

  12. School-Based Teams Help Improve School Learning Environments.

    ERIC Educational Resources Information Center

    Richardson, Ann

    1993-01-01

    Educators at a Connecticut middle school are creating programs to help students develop more positive self-images within a safe, supportive learning environment. Schoolwide restructuring efforts led to teams of professionals concerned with school learning climate, team teaching, monitoring of pupil progress, staff development, at-risk students,…

  13. Model-based description of environment interaction for mobile robots

    NASA Astrophysics Data System (ADS)

    Borghi, Giuseppe; Ferrari, Carlo; Pagello, Enrico; Vianello, Marco

    1999-01-01

    We consider a mobile robot that attempts to accomplish a task by reaching a given goal, and interacts with its environment through a finite set of actions and observations. The interaction between robot and environment is modeled by Partially Observable Markov Decision Processes (POMDP). The robot takes its decisions in presence of uncertainty about the current state, by maximizing its reward gained during interactions with the environment. It is able to self-locate into the environment by collecting actions and perception histories during the navigation. To make the state estimation more reliable, we introduce an additional information in the model without adding new states and without discretizing the considered measures. Thus, we associate to the state transition probabilities also a continuous metric given through the mean and the variance of some significant sensor measurements suitable to be kept under continuous form, such as odometric measurements, showing that also such unreliable data can supply a great deal of information to the robot. The overall control system of the robot is structured as a two-levels layered architecture, where the low level implements several collision avoidance algorithms, while the upper level takes care of the navigation problem. In this paper, we concentrate on how to use POMDP models at the upper level.

  14. Portal-based Knowledge Environment for Collaborative Science

    SciTech Connect

    Schuchardt, Karen L.; Pancerella, Carmen M.; Rahn, Larry; Didier, Brett T.; Kodeboyina, Deepti; Leahy, David; Myers, James D.; Oluwole, O.; Pitz, William; Ruscic, Branko; Song, Jing; Laszewski, Gregor V.; Yang, Christine

    2007-08-25

    The Knowledge Environment for Collaborative Science (KnECS) is an open source portal that integrates collaboration tools, data and metadata management, and scientific applications. We describe KnECS features, numerous science applications and their requirements, the benefits derived, and the integration approaches. Finally we discuss isues and challenges for the future.

  15. Students' Perceptions of a Problem-Based Learning Environment

    ERIC Educational Resources Information Center

    Dochy, Filip; Segers, Mien; Van Den Bossche, Piet; Struyven, Katrien

    2005-01-01

    During the last decades, traditional learning environments have been criticised for not developing the prerequisites for professional expertise (H. Mandl, H. Gruber & A. Renkl, "Interactive minds: Life-span perspectives on the social foundation of cognition," pp. 394-412, Cambridge, UK: Cambridge University Press, 1996; P. Tynjala, "International…

  16. Irrigation scheduling based on crop canopy temperature for humid environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of infrared thermometers (IR) to measure canopy temperatures for irrigation scheduling has been successfully applied in arid environments. Functionality of this technique in humid areas has been limited due to the presence of low vapor pressure deficits (VPD) and intermittent cloud cover. T...

  17. Space Launch System Base Heating Test: Environments and Base Flow Physics

    NASA Technical Reports Server (NTRS)

    Mehta, Manish; Knox, Kyle; Seaford, Mark; Dufrene, Aaron

    2016-01-01

    NASA MSFC and CUBRC designed and developed a 2% scale SLS propulsive wind tunnel test program to investigate base flow effects during flight from lift-off to MECO. This type of test program has not been conducted in 40+ years during the NASA Shuttle Program. Dufrene et al paper described the operation, instrumentation type and layout, facility and propulsion performance, test matrix and conditions and some raw results. This paper will focus on the SLS base flow physics and the generation and results of the design environments being used to design the thermal protection system.

  18. Online Resource-Based Learning Environment: Case Studies in Primary Classrooms

    ERIC Educational Resources Information Center

    So, Winnie Wing Mui; Ching, Fiona Ngai Ying

    2012-01-01

    This paper discusses the creation of learning environments with online resources by three primary school teachers for pupil's learning of science-related topics with reference to the resource-based e-learning environments (RBeLEs) framework. Teachers' choice of contexts, resources, tools, and scaffolds in designing the learning environments are…

  19. Use of coastal zone color scanner imagery to identify nearshore ocean areas affected by land-based pollutants. Final report

    SciTech Connect

    LaPointe, T.F.; Basta, D.J.

    1981-01-01

    The purpose of the analysis was to use remotely sensed satellite imagery to determine the spatial boundaries of nearshore areas or zones likely to be affected by pollutants from land-based sources, so that data collected on the presence or absence of living marine resources could be combined with information on land-based pollutant discharges in a preliminary relative assessment of potential risk. Ocean zones of impact related to East Coast estuaries and embayments were approximated using reflectance patterns from data transmitted from the Coastal Zone Color Scanner (CZCS) instrument mounted on the NASA Nimbus-7 satellite. Data were transformed from numerical measures of radiance to photographic images suitable for identifying and mapping ocean impact zones through a simple enhancement technique.

  20. Trace element bias in the use of CO2 vents as analogues for low pH environments: Implications for contamination levels in acidified oceans

    NASA Astrophysics Data System (ADS)

    Vizzini, S.; Di Leonardo, R.; Costa, V.; Tramati, C. D.; Luzzu, F.; Mazzola, A.

    2013-12-01

    analogues in ocean acidification research. They should be considered more appropriately as analogues for low pH environments with non-negligible trace element contamination which, in a scenario of continuous increase in anthropogenic pollution, may be very common.

  1. Monthly oceanic rainfall based on METH techniques: DMSP SSM/I V6 and SSMIS continuity

    NASA Astrophysics Data System (ADS)

    Chiu, L. S.; Gao, S.; Shin, D.-B.; Cho, Y.-J.; Adler, R. F.; Huffman, G.; Bolvin, D.; Nelkin, E.

    2012-04-01

    As part of the Global Precipitation Climatology Project (GPCP), our group have been producing oceanic rainfall over 2.5 and 5 degree boxes by applying the Microwave Emission brightness Temperature (Tb) Histogram, or METH technique to the Special Sensor Microwave Imager (SSM/I) data taken on board the Defense Meteorological Satellite Program (DMSP) satellite series. Recently, the rainfall series have been updated using the V6 SSM/I provided by RSS (Chiu and Chokngamwong., 2010). With the demise of the F15 SSM/I sensor, we examine the use of the SSMIS series to continue the DMSP time series. With its long duration, the DMSP satellite sensors constitute a unique data set capable of producing microwave-based products for climate studies. We compared the F13 SSM/I and F17 SSMIS for the period January 2008 - September 2009. The METH technique matches the histogram of Tb (twice 19V minus 22V) to a mixed-distribution of rain rates and estimates the parameters of the rain rate distribution. Mathematical convergence of the matching procedure is reached when a certain Chi-square threshold is reached. The important parameters are the Tb of the non-raining pixels (To) and the freezing level (FL) of the grid box considered. The sample size of the SSMIS is much larger than the SSM/I, hence the convergence criteria is relaxed by changing the Chi-square threshold. Preliminary results show a slight shift of the To (~0.8K). By adjusting To by a constant, the domain average SSMIS rain rates and FL are computed to within 2% and 1% of the SSM/I rain rates, respectively. Further investigation of the SSMIS METH rain rate will involve the comparison of the 19V and 22V and fine tuning the Chi-square parameter.

  2. Repulsive magnetic levitation-based ocean wave energy harvester with variable resonance: Modeling, simulation and experiment

    NASA Astrophysics Data System (ADS)

    Masoumi, Masoud; Wang, Ya

    2016-10-01

    This paper investigates a magnetic levitation characteristic used in a vibration based energy harvester, called repulsive magnetic scavenger (RMS). The RMS is capable of harvesting ocean wave energy with a unique repelling permanent magnet array, which provides a stronger and more uniform magnetic field, compared to its attracting magnetic counterparts. The levitating magnets are stacked together around a threaded rod so that the same pole is facing each other. Two fixed magnets placed with one at each end of the RMS provides a collocated harvesting and braking mechanism in the face of high amplitude vibrations. Magnets in the levitated magnet stack are separated by pole pieces which are made of metals to intensify the magnetic field strength. The effect of the thickness and the use of different materials with different permeability for pole pieces is also studied to obtain an optimal energy harvesting efficiency. Moreover, the procedure to find the restoring force applied to the levitating magnet stack is demonstrated. Then, the Duffing vibration equation of the harvester is solved and the frequency response function is calculated for various force amplitudes and electrical damping so as to investigate the effect of these parameters on the response of the system. Furthermore, the effect of the maximum displacement of the moving magnet stack on the natural frequency of the device is studied. And finally, Faraday's law is employed to estimate the output voltage and power of the system under the specified input excitation force. Experiments show that the output emf voltage of the manufactured prototype reaches up to 42 V for an excitation force with the frequency of 9 Hz and the maximum amplitude of 3.4 g.

  3. Application of a Hilbert transform based algorithm for parameter estimation of a nonlinear ocean system roll model

    SciTech Connect

    Gottlieb, O.; Feldman, M.

    1996-12-31

    The authors combine an averaging procedure with a Hilbert transform based algorithm for parameter estimation of a nonlinear ocean system roll model. System backbone curves obtained from data are compared to those obtained analytically and are found to be accurate. Sensitivity of the results is tested by introducing random noise to a nonlinear model describing roll response of a small boat. An example field calibration test of a small semisubmersible exhibiting nonlinear damping is also considered.

  4. Population-Level Transcriptomic Responses of the Southern Ocean Salp Salpa thompsoni to Environment Variability of the Western Antarctic Peninsula Region

    NASA Astrophysics Data System (ADS)

    Bucklin, A. C.; Batta Lona, P. G.; Maas, A. E.; O'Neill, R. J.; Wiebe, P. H.

    2015-12-01

    In response to the changing Antarctic climate, the Southern Ocean salp Salpa thompsoni has shown altered patterns of distribution and abundance that are anticipated to have profound impacts on pelagic food webs and ecosystem dynamics. The physiological and molecular processes that underlay ecological function and biogeographical distribution are key to understanding present-day dynamics and predicting future trajectories. This study examined transcriptome-wide patterns of gene expression in relation to biological and physical oceanographic conditions in coastal, shelf and offshore waters of the Western Antarctic Peninsula (WAP) region during austral spring and summer 2011. Based on field observations and collections, seasonal changes in the distribution and abundance of salps of different life stages were associated with differences in water mass structure of the WAP. Our observations are consistent with previous suggestions that bathymetry and currents in Bransfield Strait could generate a retentive cell for an overwintering population of S. thompsoni, which may generate the characteristic salp blooms found throughout the region later in summer. The statistical analysis of transcriptome-wide patterns of gene expression revealed differences among salps collected in different seasons and from different habitats (i.e., coastal versus offshore) in the WAP. Gene expression patterns also clustered by station in austral spring - but not summer - collections, suggesting stronger heterogeneity of environmental conditions. During the summer, differentially expressed genes covered a wider range of functions, including those associated with stress responses. Future research using novel molecular transcriptomic / genomic characterization of S. thompsoni will allow more complete understanding of individual-, population-, and species-level responses to environmental variability and prediction of future dynamics of Southern Ocean food webs and ecosystems.

  5. Islandora A Flexible Drupal-Based Virtual Research Environment

    NASA Astrophysics Data System (ADS)

    Leggott, M.; Pan, J.

    2011-12-01

    Research today exists in a landscape where data flood in, literature grows exponentially, and disciplinary boundaries are increasingly porous. Many of the greatest challenges facing researchers are related to managing the information produced during the research life cycle - from the discussion of new projects to the creation of funding proposals, the production and analysis of data, and the presentation of findings via conferences and scholarly publications. The Islandora framework provides a system that stewards digital data in any form (textual, numeric, scientific, multimedia) along the entire course of this research continuum, it facilitates collaboration not just among physically distant members of research groups but also among research groups and their associated support groups. Because Islandora accommodates both the project-specific, experiment-based context and the cross-project, interdisciplinary exploration context of data, the approach to the creation and discovery of data can be called 'discipline-agnostic.' UPEI's Virtual Research Environment (or VRE) has demonstrated the immense benefits of such an approach. In one example scientists collects samples, create detailed metadata for each sample, potentially generating thousands of data files of various kinds, which can all be loaded in one step. Software (some of it developed specifically for this project) then combines, recombines, and transforms these data into alternate formats for analysis -- thereby saving scientists hundreds of hours of manual labor. Wherever possible data are translated, converting them from proprietary file formats to standard XML, and stored -- thereby exposing the data to a larger audience that may bring them together with quite different samples or experiments in novel ways. The same computer processes and software work-flows brought to bear in the context of one research program can be re-used in other areas and across completely different disciplines, since the data are

  6. An assessment of the diversity in scenario-based tsunami forecasts for the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Greenslade, Diana J. M.; Annunziato, Alessandro; Babeyko, Andrey Y.; Burbidge, David R.; Ellguth, Enrico; Horspool, Nick; Srinivasa Kumar, T.; Kumar, Ch. Patanjali; Moore, Christopher W.; Rakowsky, Natalja; Riedlinger, Torsten; Ruangrassamee, Anat; Srivihok, Patchanok; Titov, Vasily V.

    2014-05-01

    This work examines the extent to which tsunami forecasts from different numerical forecast systems might be expected to differ under real-time conditions. This is done through comparing tsunami amplitudes from a number of existing tsunami scenario databases for eight different hypothetical tsunami events within the Indian Ocean. Forecasts of maximum tsunami amplitude are examined at 10 output points distributed throughout the Indian Ocean at a range of depths. The results show that there is considerable variability in the forecasts and on average, the standard deviation of the maximum amplitudes is approximately 62% of the mean value. It is also shown that a significant portion of this diversity can be attributed to the different lengths of the scenario time series. These results have implications for the interoperability of Regional Tsunami Service Providers in the Indian Ocean.

  7. Mean ocean temperature change over the last glacial transition based on atmospheric changes in heavy noble mixing ratios

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    On paleo-climatic timescales heavy noble gases (Krypton and Xenon) are passively cycled through the atmosphere-ocean system without seeing any significant sink or source. Since the solubility in water of each gas species is characterized by a specific temperature dependency, mixing ratios in the atmosphere change with changing ocean temperatures. In this study, we use this fact to reconstruct mean global ocean temperatures (MOT) over the course of the last glacial transition based on measurements of trapped air in the WAIS Divide ice core. We analyzed 70 ice samples with a recently developed method which determines the isotopic ratios of N2, Ar, Kr (and in some cases also of Xe, though with less precision) and the elemental ratios of Kr/N2, Xe/N2 and Xe/Kr. We use the isotope ratios to correct the elemental ratios for gravitational enrichment in the firn column. The corrected elemental ratios are then used in a simple box model to reconstruct MOT. The three elemental ratio pairs are first interpreted as independent measures of MOT and then combined to a single "best-estimate" MOT record with an average uncertainty of 0.27°C. We find a clear link to Antarctic temperatures and a LGM-Holocene change in MOT of 2.4°C. This value is in good agreement with results from marine sediment cores (which, however, have an uncertainty of 1°C). Our record provides an unprecedented constrain on ocean heat uptake over the last glacial transition and therefore gives new insights in the mechanisms underlying long term ocean heat fluxes. To our knowledge, this is the first time that MOT has been reconstructed in such great detail.

  8. Cruise-based Multi-factorial Investigation of the Impact of Ocean Acidification on the Pelagic Biosphere

    NASA Astrophysics Data System (ADS)

    Young, J. R.; Tyrell, T.

    2012-12-01

    The pelagic ecosystem is a critical component of the earth's biosphere and biogeochemistry. It is also, however, a complex and in many respects poorly understood system. In consequence predicting the likely impact of ocean acidification on the pelagic realm is problematic and predicting the possible secondary biogeochemical effects of these impacts is "challenging". Nonetheless there is a major societal need to predict these impacts and outcomes. Within the UK Ocean Acidification Programme our consortium is tasked with "improving the understanding of the impact of ocean acidification on surface ocean biology, community structure, biogeochemistry and on feedbacks to the climate." To ensure complimentarity with other programmes we have adopted a cruise-based approach. Two cruises have been undertaken; Cruise D366 in summer 2011 around the north west european shelf and Cruise JR271 summer 2012 to the Arctic Ocean. A final cruise, to the Antarctic will be undertaken in January/February 2013. On each cruise we are combining extensive environmental observations, with deck-board incubation experiments. The environmental observations are being made with both continuous sampling techniques and CTD sampling. The cruise tracks have been designed to cross environmental gradients in ocean chemistry and especially in carbonate chemistry. The objective here is to produce a high quality matrix of multiple environmental parameters including fully characterised carbonate chemistry (pH, CO2, DIC and alkalinity are all measured), nutrient chemistry, trace elements, climatically active gases, and TEP, phytoplankton and zooplankton composition and biocalcification. The biocalcification studies include microfabric study of pteropods, in situ calcification rates and integrated morphometric and assemblage composition analysis of coccolithophores. The incubation experiments are being conducted using a dedicated culture facility constructed in a shipping-container lab. This allows large

  9. Portal-based knowledge environment for collaborative science.

    SciTech Connect

    Schuchardt, K.; Pancerella, C.; Rahn, L. A.; Didier, B.; Kodeboyina, D.; Leahy, D.; Myers, J. D.; Oluwole, O. O.; Pitz, W.; Ruscic, B.; Song, J.; von Laszewski, G.; Yang, C.; PNNL; SNL; Stanford Univ.; National Center for Supercomputing Applications; MIT; LLNL

    2007-08-25

    The Knowledge Environment for Collaborative Science (KnECS) is an open-source informatics toolkit designed to enable knowledge Grids that interconnect science communities, unique facilities, data, and tools. KnECS features a Web portal with team and data collaboration tools, lightweight federation of data, provenance tracking, and multi-level support for application integration. We identify the capabilities of KnECS and discuss extensions from the Collaboratory for Multi-Scale Chemical Sciences (CMCS) which enable diverse combustion science communities to create and share verified, documented data sets and reference data, thereby demonstrating new methods of community interaction and data interoperability required by systems science approaches. Finally, we summarize the challenges we encountered and foresee for knowledge environments.

  10. Ship-based detection of glyoxal over the remote tropical Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Sinreich, R.; Coburn, S.; Dix, B.; Volkamer, R.

    2010-06-01

    We present the first detection of glyoxal (CHOCHO) over the remote tropical Pacific Ocean in the Marine Boundary Layer (MBL). The measurements were conducted by means of the University of Colorado Ship Multi-Axis Differential Optical Spectroscopy (CU SMAX-DOAS) instrument aboard the research vessel Ronald H. Brown. The research vessel was on a cruise in the framework of the VAMOS Ocean-Cloud-Atmosphere-Land Study - Regional Experiment (VOCALS-REx) and the Tropical Atmosphere Ocean (TAO) projects lasting from October 2008 through January 2009 (74 days at sea). The CU SMAX-DOAS instrument features a motion compensation system to characterize the pitch and roll of the ship and to compensate for ship movements in real time. We found elevated mixing ratios of up to 170 ppt CHOCHO located inside the MBL up to 3000 km from the continental coast over biologically active upwelling regions of the tropical Eastern Pacific Ocean. This is surprising since CHOCHO is very short lived (atmospheric life time ~2 h) and highly water soluble (Henry's Law constant H=4.2×105 M/atm). This CHOCHO cannot be explained by transport of it or its precursors from continental sources. Rather, the open ocean is a source for CHOCHO to the atmosphere. Dissolved Organic Matter (DOM) photochemistry in surface waters is a source for Volatile Organic Compounds (VOCs) to the atmosphere, e.g. acetaldehyde. The extension of this mechanism to very soluble gases, like CHOCHO, is not straightforward since the air-sea flux is directed from the atmosphere into the ocean. For CHOCHO, the dissolved concentrations would need to be extremely high in order to explain our gas-phase observations by this mechanism (40-70 μM CHOCHO, compared to ~0.01 μM acetaldehyde and 60-70 μM DOM). Further, while there is as yet no direct measurement of VOCs in our study area, measurements of the CHOCHO precursors isoprene, and/or acetylene over phytoplankton bloom areas in other parts of the oceans are too low (by a factor of

  11. Ship-based detection of glyoxal over the remote tropical Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Sinreich, R.; Coburn, S.; Dix, B.; Volkamer, R.

    2010-12-01

    We present the first detection of glyoxal (CHOCHO) over the remote tropical Pacific Ocean in the Marine Boundary Layer (MBL). The measurements were conducted by means of the University of Colorado Ship Multi-Axis Differential Optical Absorption Spectroscopy (CU SMAX-DOAS) instrument aboard the research vessel Ronald H. Brown. The research vessel was on a cruise in the framework of the VAMOS Ocean-Cloud-Atmosphere-Land Study - Regional Experiment (VOCALS-REx) and the Tropical Atmosphere Ocean (TAO) projects lasting from October 2008 through January 2009 (74 days at sea). The CU SMAX-DOAS instrument features a motion compensation system to characterize the pitch and roll of the ship and to compensate for ship movements in real time. We found elevated mixing ratios of up to 140 ppt CHOCHO located inside the MBL up to 3000 km from the continental coast over biologically active upwelling regions of the tropical Eastern Pacific Ocean. This is surprising since CHOCHO is very short lived (atmospheric life time ~2 h) and highly water soluble (Henry's Law constant H = 4.2 × 105 M/atm). This CHOCHO cannot be explained by transport of it or its precursors from continental sources. Rather, the open ocean must be a source for CHOCHO to the atmosphere. Dissolved Organic Matter (DOM) photochemistry in surface waters is a source for Volatile Organic Compounds (VOCs) to the atmosphere, e.g. acetaldehyde. The extension of this mechanism to very soluble gases, like CHOCHO, is not straightforward since the air-sea flux is directed from the atmosphere into the ocean. For CHOCHO, the dissolved concentrations would need to be extremely high in order to explain our gas-phase observations by this mechanism (40-70 μM CHOCHO, compared to ~0.01 μM acetaldehyde and 60-70 μM DOM). Further, while there is as yet no direct measurement of VOCs in our study area, measurements of the CHOCHO precursors isoprene, and/or acetylene over phytoplankton bloom areas in other parts of the oceans are too

  12. Enhanced ground-based vibration testing for aerodynamic environments

    NASA Astrophysics Data System (ADS)

    Daborn, P. M.; Ind, P. R.; Ewins, D. J.

    2014-12-01

    Typical methods of replicating aerodynamic environments in the laboratory are generally poor. A structure which flies "freely" in its normal operating environment, excited over its entire external surface by aerodynamic forces and in all directions simultaneously, is then subjected to a vibration test in the laboratory whilst rigidly attached to a high impedance shaker and excited by forces applied through a few attachment points and in one direction only. The two environments could hardly be more different. The majority of vibration testing is carried out at commercial establishments and it is understandable that little has been published which demonstrates the limitations with the status quo. The primary objective of this research is to do just that with a view to identifying significant improvements in vibration testing in light of modern technology. In this paper, case studies are presented which highlight some of the limitations with typical vibration tests showing that they can lead to significant overtests, sometimes by many orders of magnitude, with the level of overtest varying considerably across a wide range of frequencies. This research shows that substantial benefits can be gained by "freely" suspending the structure in the laboratory and exciting it with a relatively small number of electrodynamic shakers using Multi-Input-Multi-Output (MIMO) control technology. The shaker configuration can be designed to excite the modes within the bandwidth utilising the inherent amplification of the resonances to achieve the desired response levels. This free-free MIMO vibration test approach is shown to result in substantial benefits that include extremely good replication of the aerodynamic environment and significant savings in time as all axes are excited simultaneously instead of the sequential X, Y and Z testing required with traditional vibration tests. In addition, substantial cost savings can be achieved by replacing some expensive large shaker systems

  13. Reconstructing vanished ocean basins

    NASA Astrophysics Data System (ADS)

    Müller, D.; Sdrolias, M.; Gaina, C.

    2006-05-01

    The large-scale patterns of mantle convection are mainly dependent on the history of subduction. Therefore some of the primary constraints for subduction models are given by of the location of subduction zones through time, and of the convergence vectors and age of subducted lithosphere. This requires the complete reconstruction of ocean floor through time, including the main ocean basins, back-arc basins, and now subducted ocean crust, and tying these kinematic models to geodynamic simulations. We reconstruct paleo- oceans by creating "synthetic plates", the locations and geometry of which is established on the basis of preserved ocean crust (magnetic lineations and fracture zones), geological data, paleogeography, and the rules of plate tectonics. We use a merged moving hotspot (Late Cretaceous-present) and palaeomagnetic/fixed hotspot (Early Cretaceous) reference frame, coupled with reconstructed spreading histories of the Pacific, Phoenix and Farallon plates and the plates involved in the Tethys oceanic domain. Based on this approach we have created a set of global oceanic paleo-isochrons and paleo-oceanic age grids. The grids also provide the first complete global set of paleo-basement depth maps, including now subducted ocean floor, for the last 130 million years based on a depth-age relationship. We show that the mid-Cretaceous sealevel highstand was primarily caused by two main factors: (1) the "supercontinent breakup effect", which resulted in the creation of the mid-Atlantic and Indian Ocean ridges at the expense of subducting old ocean floor in the Tethys and (2) by a changing age-area distribution of Pacific ocean floor through time, resulting from the subduction of the Pacific-Izanagi, Pacific-Phoenix and Pacific-Farallon ridges. These grids provide model constraints for subduction dynamics through time and represent a framework for backtracking biogeographic and sediment data from ocean drilling and for constraining the opening/closing of oceanic

  14. Effect of age-based and environment-based cues on reproductive investment in Gambusia affinis

    PubMed Central

    Billman, Eric J; Belk, Mark C

    2014-01-01

    We examined the multivariate life-history trajectories of age 0 and age 1 female Gambusia affinis to determine relative effects of age-based and environment-based cues on reproductive investment. Age 0 females decreased reproductive investment prior to the onset of fall and winter months, while age 1 females increased reproductive investment as the summer progressed. The reproductive restraint and terminal investment patterns exhibited by age 0 and age 1 females, respectively, were consistent with the predictions from the cost of reproduction hypothesis. Age 0 females responded to environment-based cues, decreasing reproductive investment to increase the probability of overwinter survival and subsequent reproductive opportunities in the following summer. Age 1 females responded to age-based cues, or the proximity of death, increasing investment to current reproduction as future reproductive opportunities decreased late in life. Thus, individuals use multiple cues to determine the level of reproductive investment, and the response to each cue is dependent on the age of an individual. PMID:24967079

  15. Simple ocean carbon cycle models

    SciTech Connect

    Caldeira, K.; Hoffert, M.I.; Siegenthaler, U.

    1994-02-01

    Simple ocean carbon cycle models can be used to calculate the rate at which the oceans are likely to absorb CO{sub 2} from the atmosphere. For problems involving steady-state ocean circulation, well calibrated ocean models produce results that are very similar to results obtained using general circulation models. Hence, simple ocean carbon cycle models may be appropriate for use in studies in which the time or expense of running large scale general circulation models would be prohibitive. Simple ocean models have the advantage of being based on a small number of explicit assumptions. The simplicity of these ocean models facilitates the understanding of model results.

  16. Archetype based search in an IHE XDS environment.

    PubMed

    Rinner, Christoph; Kohler, Michael; Hübner-Bloder, Gudrun; Saboor, Samrend; Ammenwerth, Elske; Duftschmid, Georg

    2012-01-01

    To prevent information overload of physicians when accessing EHRs we introduce a method to extend the IHE XDS profile metadata-based search towards a content-based search. Detailed queries are created based on predefined information needs mapped to ISO/EN 13606 Archetypes. They are aggregated to a metadata-based query to retrieve all relevant documents, which are then analyzed for the desired contents. The results are presented in a tabular form. The content-based search in IHE-XDS could be implemented efficiently and was found helpful by the evaluating physicians.

  17. Advanced Physics-Based Modeling of Discrete Clutter and Diffuse Reverberation in the Littoral Environment

    DTIC Science & Technology

    2006-05-31

    ELEMENT NUMBER 6. AUTHOR(S) Peter Neumann (PSI), Charles Holland (ARL/PSU), Kevin LePage (NRL-DC), Greg Muncill (PSI) 5d. PROJECT NUMBER 5e. TASK NUMBER...monostatic or bistatic configurations, in range-varying ocean environments. The core propagation loss model with ASPM is ASTRAL , which is also an OAML...noted in the Software Design Document (Levin, SAIC-00/1032, 2000), the ASTRAL propagation loss model was selected to satisfy requirements 3.1-1, 3.1-4

  18. Norwegian Ocean Observatory Network (NOON)

    NASA Astrophysics Data System (ADS)

    Ferré, Bénédicte; Mienert, Jürgen; Winther, Svein; Hageberg, Anne; Rune Godoe, Olav; Partners, Noon

    2010-05-01

    The Norwegian Ocean Observatory Network (NOON) is led by the University of Tromsø and collaborates with the Universities of Oslo and Bergen, UniResearch, Institute of Marine Research, Christian Michelsen Research and SINTEF. It is supported by the Research Council of Norway and oil and gas (O&G) industries like Statoil to develop science, technology and new educational programs. Main topics relate to ocean climate and environment as well as marine resources offshore Norway from the northern North Atlantic to the Arctic Ocean. NOON's vision is to bring Norway to the international forefront in using cable based ocean observatory technology for marine science and management, by establishing an infrastructure that enables real-time and long term monitoring of processes and interactions between hydrosphere, geosphere and biosphere. This activity is in concert with the EU funded European Strategy Forum on Research Infrastructures (ESFRI) roadmap and European Multidisciplinary Seafloor Observation (EMSO) project to attract international leading research developments. NOON envisions developing towards a European Research Infrastructure Consortium (ERIC). Beside, the research community in Norway already possesses a considerable marine infrastructure that can expand towards an international focus for real-time multidisciplinary observations in times of rapid climate change. PIC The presently established cable-based fjord observatory, followed by the establishment of a cable-based ocean observatory network towards the Arctic from an O&G installation, will provide invaluable knowledge and experience necessary to make a successful larger cable-based observatory network at the Norwegian and Arctic margin (figure 1). Access to large quantities of real-time observation from the deep sea, including high definition video, could be used to provide the public and future recruits to science a fascinating insight into an almost unexplored part of the Earth beyond the Arctic Circle

  19. Ensemble-Based Estimates of the Predictability of Wind-Driven Coastal Ocean Flow Over Topography

    DTIC Science & Technology

    2008-01-01

    introduced in geophysi- cal fluid dynamics to quantify predictive information content in forecast ensembles (Kleeman 2002; Abramov et al. 2005). Here, we...National Ocean Partnership Program. 33 REFERENCES Abramov , R., A. Majda, and R. Kleeman, 2005: Information theory and predictability for low-frequency

  20. MERIS-based ocean colour classification with the discrete Forel-Ule scale

    NASA Astrophysics Data System (ADS)

    Wernand, M. R.; Hommersom, A.; van der Woerd, H. J.

    2012-08-01

    Multispectral information from satellite borne ocean colour sensors is at present used to characterize natural waters via the retrieval of concentration of the three dominant optical constituents; pigments of phytoplankton, non-algal particles and coloured dissolved organic matter. A limitation of this approach is that accurate retrieval of these constituents requires detailed local knowledge of the specific absorption and scattering properties. In addition, the retrieval algorithms generally use only a limited part of the collected spectral information. In this paper we present an additional new algorithm that has the merit to use the full spectral information in the visible domain to characterize natural waters in a simple and globally valid way. This Forel-Ule MERIS (FUME) algorithm converts the normalized multi-band reflectance information into a discrete set of numbers using uniform colourimetric functions. The Forel-Ule scale is a sea colour comparator scale that has been developed to cover all possible natural sea colours, ranging from indigo blue (the open ocean) to brownish-green (coastal water) and even brown (humic-acid dominated) waters. Data using this scale have been collected since the late nineteenth century, and therefore, this algorithm creates the possibility to compare historic ocean colour data with present-day satellite ocean colour observations. The FUME algorithm was tested by transforming a number of MERIS satellite images into Forel-Ule colour index images and comparing in situ observed FU numbers with FU numbers modelled from in situ radiometer measurements.

  1. Atmospheric Nitrogen Deposition to the Oceans: Observation- and Model-Based Estimates

    NASA Astrophysics Data System (ADS)

    Baker, Alex; Altieri, Katye; Okin, Greg; Dentener, Frank; Uematsu, Mitsuo; Kanakidou, Maria; Sarin, Manmohan; Duce, Robert; Galloway, Jim; Keene, Bill; Singh, Arvind; Zamora, Lauren; Lamarque, Jean-Francois; Hsu, Shih-Chieh

    2014-05-01

    The reactive nitrogen (Nr) burden of the atmosphere has been increased by a factor of 3-4 by anthropogenic activity since the industrial revolution. This has led to large increases in the deposition of nitrate and ammonium to the surface waters of the open ocean, particularly downwind of major human population centres, such as those in North America, Europe and Southeast Asia. In oligotrophic waters, this deposition has the potential to significantly impact marine productivity and the global carbon cycle. Global-scale understanding of N deposition to the oceans is reliant on our ability to produce effective models of reactive nitrogen emission, atmospheric chemistry, transport and deposition (including deposition to the land surface). The Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) recently completed a multi-model analysis of global N deposition, including comparisons to wet deposition observations from three regional networks in North America, Europe and Southeast Asia (Lamarque et al., Atmos. Chem. Phys., 13, 7977-8018, 2013). No similar datasets exist which would allow observation - model comparisons of wet deposition for the open oceans, because long-term wet deposition records are available for only a handful of remote island sites and rain collection over the open ocean itself is very difficult. In this work we attempt instead to use ~2600 observations of aerosol nitrate and ammonium concentrations, acquired chiefly from sampling aboard ships in the period 1995 - 2012, to assess the ACCMIP N deposition fields over the remote ocean. This database is non-uniformly distributed in time and space. We selected four ocean regions (the eastern North Atlantic, the South Atlantic, the northern Indian Ocean and northwest Pacific) where we considered the density and distribution of observational data is sufficient to provide effective comparison to the model ensemble. Two of these regions are adjacent to the land networks used in the ACCMIP

  2. Design of a Project-Based Study Environment on the World Wide Web.

    ERIC Educational Resources Information Center

    Grooters, Fiona; de Vries, Sjoerd

    This paper presents the design of a project-based study environment on the World Wide Web based upon the e-study concept, i.e., studying by means of Internet technologies. The first section discusses the e-study concept, including Interactive Study Environments (ISE), Interactive Study Systems, and online Study Services. Design guidelines for a…

  3. Bridging Theory and Practice: Developing Guidelines to Facilitate the Design of Computer-Based Learning Environments

    ERIC Educational Resources Information Center

    Young, Lisa D.

    2003-01-01

    The design of computer-­based learning environments has undergone a paradigm shift; moving students away from instruction that was considered to promote technical rationality grounded in objectivism, to the application of computers to create cognitive tools utilized in constructivist environments. The goal of the resulting computer-­based learning…

  4. Factors Associated with K-12 Teachers' Use of Environment-Based Education

    ERIC Educational Resources Information Center

    Ernst, Julie

    2007-01-01

    The term "environment-based education" describes a form of school-based environmental education in which an instructor uses the local environment as a context for integrating subjects and a source of real world learning experiences. Despite the growing body of evidence that supports the educational efficacy of this instructional approach and its…

  5. Influences on and Obstacles to K-12 Administrators' Support for Environment-Based Education

    ERIC Educational Resources Information Center

    Ernst, Julie

    2012-01-01

    The term environment-based education (EBE) describes a form of school-based environmental education that uses the environment as a context for integrating subjects and a source of real-world learning experiences. Because of the importance of administrator support in teachers' use of EBE (Ernst, 2009), survey research was conducted to explore…

  6. The Effectiveness of Worked Examples in a Game-Based Learning Environment

    ERIC Educational Resources Information Center

    Shen, Chun-Yi; O'Neil, Harold

    2006-01-01

    Researches indicate that worked examples could effectively facilitate problem solving by reducing cognitive load during learning. However, there is no study using worked examples in a game-based environment. The purpose of this study was to examine the effectiveness of worked examples on problem solving in a game-based environment. In this study,…

  7. A ventilation-based framework to explain the regeneration-scavenging balance of iron in the ocean

    NASA Astrophysics Data System (ADS)

    Tagliabue, Alessandro; Williams, Richard G.; Rogan, Nicholas; Achterberg, Eric P.; Boyd, Philip W.

    2014-10-01

    Our understanding of the processes driving the patterns of dissolved iron (DFe) in the ocean interior, either in observations or models, is complicated by the combined influences of subduction from the surface mixed layer, notable subsurface sources, regeneration, and scavenging loss. We describe a ventilation-based framework to quantify these processes in a global ocean biogeochemical model including diagnostics along potential density surfaces. There is a prevailing control of subsurface DFe by the subduction of surface DFe as preformed DFe augmented by benthic sources of DFe from hydrothermal activity and sediments. Unlike phosphate, there is often a first-order balance with a near cancelation between regeneration and scavenging with the remaining "net regeneration" controlled by the ventilation of surface excesses in Fe-binding ligands. This DFe framework provides a more stringent test of how the total DFe distribution is mechanistically controlled within a model and may be subsequently used to interpret observed DFe distributions.

  8. Observation-Based Assessment of PBDE Loads in Arctic Ocean Waters.

    PubMed

    Salvadó, Joan A; Sobek, Anna; Carrizo, Daniel; Gustafsson, Örjan

    2016-03-01

    Little is known about the distribution of polybrominated diphenyl ethers (PBDE) -also known as flame retardants- in major ocean compartments, with no reports yet for the large deep-water masses of the Arctic Ocean. Here, PBDE concentrations, congener patterns and inventories are presented for the different water masses of the pan-Arctic shelf seas and the interior basin. Seawater samples were collected onboard three cross-basin oceanographic campaigns in 2001, 2005, and 2008 following strict trace-clean protocols. ∑14PBDE concentrations in the Polar Mixed Layer (PML; a surface water mass) range from 0.3 to 11.2 pg·L(-1), with higher concentrations in the pan-Arctic shelf seas and lower levels in the interior basin. BDE-209 is the dominant congener in most of the pan-Arctic areas except for the ones close to North America, where penta-BDE and tetra-BDE congeners predominate. In deep-water masses, ∑14PBDE concentrations are up to 1 order of magnitude higher than in the PML. Whereas BDE-209 decreases with depth, the less-brominated congeners, particularly BDE-47 and BDE-99, increase down through the water column. Likewise, concentrations of BDE-71 -a congener not present in any PBDE commercial mixture- increase with depth, which potentially is the result of debromination of BDE-209. The inventories in the three water masses of the Central Arctic Basin (PML, intermediate Atlantic Water Layer, and the Arctic Deep Water Layer) are 158 ± 77 kg, 6320 ± 235 kg and 30800 ± 3100 kg, respectively. The total load of PBDEs in the entire Arctic Ocean shows that only a minor fraction of PBDEs emissions are transported to the Arctic Ocean. These findings represent the first PBDE data in the deep-water compartments of an ocean.

  9. MERIS-based ocean colour classification with the discrete Forel-Ule scale

    NASA Astrophysics Data System (ADS)

    Wernand, M. R.; Hommersom, A.; van der Woerd, H. J.

    2013-05-01

    Multispectral information from satellite borne ocean colour sensors is at present used to characterize natural waters via the retrieval of concentrations of the three dominant optical constituents; pigments of phytoplankton, non-algal particles and coloured dissolved organic matter. A limitation of this approach is that accurate retrieval of these constituents requires detailed local knowledge of the specific absorption and scattering properties. In addition, the retrieval algorithms generally use only a limited part of the collected spectral information. In this paper we present an additional new algorithm that has the merit of using the full spectral information in the visible domain to characterize natural waters in a simple and globally valid way. This Forel-Ule MERIS (FUME) algorithm converts the normalized multiband reflectance information into a discrete set of numbers using uniform colourimetric functions. The Forel-Ule (FU) scale is a sea colour comparator scale that has been developed to cover all possible natural sea colours, ranging from indigo blue (the open ocean) to brownish-green (coastal water) and even brown (humic-acid dominated) waters. Data using this scale have been collected since the late nineteenth century, and therefore, this algorithm creates the possibility to compare historic ocean colour data with present-day satellite ocean colour observations. The FUME algorithm was tested by transforming a number of MERIS satellite images into Forel-Ule colour index images and comparing in situ observed FU numbers with FU numbers modelled from in situ radiometer measurements. Similar patterns and FU numbers were observed when comparing MERIS ocean colour distribution maps with ground truth Forel-Ule observations. The FU numbers modelled from in situ radiometer measurements showed a good correlation with observed FU numbers (R2 = 0.81 when full spectra are used and R2 = 0.71 when MERIS bands are used).

  10. Remote-sensing-based measurement of phytoplankton size spectrum and cell diameter in the global oceans

    NASA Astrophysics Data System (ADS)

    Roy, S.; Sathyendranath, S.; Bouman, H. A.; Platt, T.

    2012-12-01

    Oceanic phytoplankton regulate the spectral quality of the submarine light field because light absorption by phytoplankton is spectrally structured, with a maximum in the blue and a secondary maximum in the red. The spectral characteristics of absorption are variable with phytoplankton taxa, and also with cell size and growth conditions. The intra-cellular concentration of light-absorbing pigments varies with phytoplankton size, which in turn modulates its specific absorption. The changes in phytoplankton cell size alter not only the bio-optical properties of the water column, but also the trophic interactions within the ecosystem. It is thus important to study the time evolution of phytoplankton size structure over the global ocean. We have developed a novel model that uses the light absorption coefficient of phytoplankton to retrieve quantitative information about phytoplankton size structure from satellite-derived ocean-colour data. The application of the method to satellite remote sensing at any given spatial location depends on the estimates of the concentration of chlorophyll-a, which is an operational index of phytoplankton biomass, and the remote sensing reflectance at different wavelengths in the visible domain. Using our method we have computed the equivalent spherical diameter of phytoplankton cells and the exponent of particle-size spectrum of phytoplankton, and thereby estimated the chlorophyll distribution in different phytoplankton size classes on a global scale. The spatial distribution of the size-spectrum exponent and the biomass fractions of pico-, nano- and micro-phytoplankton estimated are consistent with our current understanding of phytoplankton functional types in the global oceans. The study will enhance our understanding of the distribution and time evolution of phytoplankton size structure in the global oceans.

  11. The ``Adopt A Microbe'' project: Web-based interactive education connected with scientific ocean drilling

    NASA Astrophysics Data System (ADS)

    Orcutt, B. N.; Bowman, D.; Turner, A.; Inderbitzen, K. E.; Fisher, A. T.; Peart, L. W.; Iodp Expedition 327 Shipboard Party

    2010-12-01

    We launched the "Adopt a Microbe" project as part of Integrated Ocean Drilling Program (IODP) Expedition 327 in Summer 2010. This eight-week-long education and outreach effort was run by shipboard scientists and educators from the research vessel JOIDES Resolution, using a web site (https://sites.google.com/site/adoptamicrobe) to engage students of all ages in an exploration of the deep biosphere inhabiting the upper ocean crust. Participants were initially introduced to a cast of microbes (residing within an ‘Adoption Center’ on the project website) that live in the dark ocean and asked to select and virtually ‘adopt’ a microbe. A new educational activity was offered each week to encourage learning about microbiology, using the adopted microbe as a focal point. Activities included reading information and asking questions about the adopted microbes (with subsequent responses from shipboard scientists), writing haiku about the adopted microbes, making balloon and fabric models of the adopted microbes, answering math questions related to the study of microbes in the ocean, growing cultures of microbes, and examining the gases produced by microbes. In addition, the website featured regular text, photo and video updates about the science of the expedition using a toy microbe as narrator, as well as stories written by shipboard scientists from the perspective of deep ocean microbes accompanied by watercolor illustrations prepared by a shipboard artist. Assessment methods for evaluating the effectiveness of the Adopt a Microbe project included participant feedback via email and online surveys, website traffic monitoring, and online video viewing rates. Quantitative metrics suggest that the “Adope A Microbe” project was successful in reaching target audiences and helping to encourage and maintain interest in topics related to IODP Expedition 327. The “Adopt A Microbe” project mdel can be adapted for future oceanographic expeditions to help connect the

  12. Developing a Conceptual Architecture for a Generalized Agent-based Modeling Environment (GAME)

    DTIC Science & Technology

    2008-03-01

    possible. A conceptual architecture for a generalized agent- based modeling environment (GAME) based upon design principles from OR/MS systems was created...conceptual architecture for a generalized agent-based modeling environment (GAME) based upon design principles from OR/MS systems was created that...handle the event, and subsequently form the relevant plans. One of these plans will be selected, and either pushed to the top of the current

  13. A Design-Based Research Investigation of a Web-Based Learning Environment Designed to Support the Reading Process

    ERIC Educational Resources Information Center

    Kidwai, Khusro

    2009-01-01

    This research study had two purposes, (a) to design and develop a Web-based learning environment that supports the use of a set of reading strategies, and (b) to investigate the impact of this Web-based learning environment on readers' "memory" and "understanding" of an instructional unit on the human heart (Dwyer &…

  14. Chlorophyll-a Algorithms for Oligotrophic Oceans: A Novel Approach Based on Three-Band Reflectance Difference

    NASA Technical Reports Server (NTRS)

    Hu, Chuanmin; Lee, Zhongping; Franz, Bryan

    2011-01-01

    A new empirical algorithm is proposed to estimate surface chlorophyll-a concentrations (Chl) in the global ocean for Chl less than or equal to 0.25 milligrams per cubic meters (approximately 77% of the global ocean area). The algorithm is based on a color index (CI), defined as the difference between remote sensing reflectance (R(sub rs), sr(sup -1) in the green and a reference formed linearly between R(sub rs) in the blue and red. For low Chl waters, in situ data showed a tighter (and therefore better) relationship between CI and Chl than between traditional band-ratios and Chl, which was further validated using global data collected concurrently by ship-borne and SeaWiFS satellite instruments. Model simulations showed that for low Chl waters, compared with the band-ratio algorithm, the CI-based algorithm (CIA) was more tolerant to changes in chlorophyll-specific backscattering coefficient, and performed similarly for different relative contributions of non-phytoplankton absorption. Simulations using existing atmospheric correction approaches further demonstrated that the CIA was much less sensitive than band-ratio algorithms to various errors induced by instrument noise and imperfect atmospheric correction (including sun glint and whitecap corrections). Image and time-series analyses of SeaWiFS and MODIS/Aqua data also showed improved performance in terms of reduced image noise, more coherent spatial and temporal patterns, and consistency between the two sensors. The reduction in noise and other errors is particularly useful to improve the detection of various ocean features such as eddies. Preliminary tests over MERIS and CZCS data indicate that the new approach should be generally applicable to all existing and future ocean color instruments.

  15. Aquatic Environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic microbiology can be defined as the study of microorganisms and microbial communities in water environments. Aquatic environments occupy more than 70% of the earth’s surface including oceans, estuaries, rivers, lakes, wetlands, streams, springs, and aquifers. Water is essential for life and m...

  16. An u-Service Model Based on a Smart Phone for Urban Computing Environments

    NASA Astrophysics Data System (ADS)

    Cho, Yongyun; Yoe, Hyun

    In urban computing environments, all of services should be based on the interaction between humans and environments around them, which frequently and ordinarily in home and office. This paper propose an u-service model based on a smart phone for urban computing environments. The suggested service model includes a context-aware and personalized service scenario development environment that can instantly describe user's u-service demand or situation information with smart devices. To do this, the architecture of the suggested service model consists of a graphical service editing environment for smart devices, an u-service platform, and an infrastructure with sensors and WSN/USN. The graphic editor expresses contexts as execution conditions of a new service through a context model based on ontology. The service platform deals with the service scenario according to contexts. With the suggested service model, an user in urban computing environments can quickly and easily make u-service or new service using smart devices.

  17. Nanoparticles and Ocean Optics

    DTIC Science & Technology

    2008-09-30

    Nanoparticles and Ocean Optics William M. Balch Bigelow Laboratory for Ocean Sciences, POB 475, W. Boothbay Harbor, ME...Laboratory for Ocean Sciences, POB 475, W. Boothbay Harbor, ME 04575 phone: (207) 633-9600 fax: (207) 633-9641 email: jgoes@bigelow.org Award Number...characterization of virus/host assemblages for use in lab -based dilution experiments. We tested methods for the separation of naturally occurring virus and host

  18. Nanoparticles and Ocean Optics

    DTIC Science & Technology

    2007-09-30

    Nanoparticles and Ocean Optics William M. Balch Bigelow Laboratory for Ocean Sciences, POB 475 W. Boothbay Harbor, ME 04575 phone: (207) 633...Ocean Sciences, POB 475 W. Boothbay Harbor, ME 04575 phone: (207) 633-9600 fax: (207) 633-9641 email: jgoes@bigelow.org Award Number...and characterization of virus/host assemblages for use in lab -based dilution experiments. We tested methods for the separation of naturally occurring

  19. Nanoparticles and Ocean Optics

    DTIC Science & Technology

    2008-01-01

    Nanoparticles and Ocean Optics William M. Balch Bigelow Laboratory for Ocean Sciences, POB 475 W. Boothbay Harbor, ME 04575 phone: (207) 633...Ocean Sciences, POB 475 W. Boothbay Harbor, ME 04575 phone: (207) 633-9600 fax: (207) 633-9641 email: jgoes@bigelow.org Award Number...and characterization of virus/host assemblages for use in lab -based dilution experiments. We tested methods for the separation of naturally occurring

  20. Electromagnetic field pattern in the environment of GSM base stations.

    PubMed

    Aniołczyk, H

    1999-01-01

    Three mobile phone systems are used in Poland: analog, operated at the 450 MHz frequency range, and two digital systems operated at 900 MHz and 1800 MHz. The GSM--Global System for Mobile Communication meets all relevant requirements, and it is most widely used throughout the world. According to the mobile phone concept, the whole communication area is divided into sub-areas (cells) where base stations are located. The base stations are provided with the transmitter units mounted on free-standing masts, high chimneys and building roofs, including those of the residential buildings. The transmitter antennas of the base stations constitute a source of 935-960 EMF radiation. This work analyses the essential characteristics of the base station antennas from the point of view of radiation intensity. The analysis is based on the results of EMF measurements performed by experts of two relevant research institutes. For inaccessible antennas, the measurements were performed at the accredited laboratory.

  1. Neuroanatomical basis of concern-based altruism in virtual environment.

    PubMed

    Patil, Indrajeet; Zanon, Marco; Novembre, Giovanni; Zangrando, Nicola; Chittaro, Luca; Silani, Giorgia

    2017-02-22

    Costly altruism entails helping others at a cost to the self and prior work shows that empathic concern (EC) for the well-being of distressed and vulnerable individuals is one of the primary motivators of such behavior. However, extant work has investigated costly altruism with paradigms that did not feature self-relevant and severe costs for the altruist and have solely focused on neurofunctional, and not neuroanatomical, correlates. In the current study, we used a contextually-rich virtual reality environment to study costly altruism and found that individuals who risked their own lives in the virtual world to try to save someone in danger had enlarged right anterior insula and exhibited greater empathic concern than those who did not. These findings add to the growing literature showing the role of caring motivation in promoting altruism and prosociality and its neural correlates in the right anterior insula.

  2. ICBMs and the environment: Assessments at a base in Kazakhstan

    USGS Publications Warehouse

    Matzko, J.R.; Butler, B.

    1999-01-01

    A paper by two U.S. scientists explores the environmental/health hazard posed by abandoned missile launch sites and control facilities (dismantled by 1998 as part of the Nunn-Lugar Cooperative Threat Reduction Program) at an ICBM base in north-central Kazakhstan. It summarizes the findings of Environmental Site Assessment Reports based on a program of water and soil sampling at the sites, with a particular focus on testing for the presence of polychlorinated biphenyls, various toxic metals, and radiation. The study is important in that it documents levels of contamination (and describes abatement measures) at a former Soviet missile base.

  3. Quality and Behavior of Juvenile Salmonids in the Columbia River Estuary and Nearshore Ocean and Effects of the Ocean Environment on the Survival of Columbia River Juvenile Salmonids, 1989-1994 Technical Report.

    SciTech Connect

    Francis, R.C.; Schiewe, Michael H.; Fisher, J.P.

    1989-05-01

    In response to this limited understanding of the factors responsible for the continuing decline of spring chinook salmon in the Columbia River, this research plan was developed. The overall goal of the proposed research is to investigate and identify relationships among smolt quality (measured in the hatchery and after recovery in the estuary and nearshore ocean), environmental conditions in the estuary and nearshore ocean during smolt migration, and long-term survival (as measured by adult returns to the hatchery of origin and contributions to the recreational, commercial, and tribal fisheries). 16 refs., 15 figs., 3 tabs.

  4. SystemVerilog-Based Verification Environment Employing Multiple Inheritance of SystemC

    NASA Astrophysics Data System (ADS)

    You, Myoung-Keun; Song, Gi-Yong

    In this paper, we describe a verification environment which is based on a constrained random layered testbench using SystemVerilog OOP. As SystemVerilog OOP technique does not allow multiple inheritance, we adopt SystemC to design components of a verification environment which employ multiple inheritance. Then SystemC design unit is linked to a SystemVerilog-based verification environment using SystemVerilog DPI and ModelSim macro. Employing multiple inheritance of SystemC makes the design phase of verification environment simple and easy through source code reusability without corruption due to multi-level single inheritance.

  5. Virtualization, virtual environments, and content-based retrieval of three-dimensional information for cultural applications

    NASA Astrophysics Data System (ADS)

    Paquet, Eric; Peters, Shawn; Beraldin, J. A.; Valzano, Virginia; Bandiera, Adriana

    2003-01-01

    The present paper proposes a virtual environment for visualizing virtualized cultural and historical sites. The proposed environment is based on a distributed asynchronous architecture and supports stereo vision and tiled wall display. The system is mobile and can run from two laptops. This virtual environment addresses the problems of intellectual property protection and multimedia information retrieval through encryptation and content-based management respectively. Experimental results with a fully textured 3D model of the Crypt of Santa Cristina in Italy are presented, evaluating the performances of the proposed virtual environment.

  6. Assessment of the ultraviolet radiation field in ocean waters from space-based measurements and full radiative-transfer calculations.

    PubMed

    Vasilkov, Alexander P; Herman, Jay R; Ahmad, Ziauddin; Kahru, Mati; Mitchell, B Greg

    2005-05-10

    Quantitative assessment of the UV effects on aquatic ecosystems requires an estimate of the in-water radiation field. Actual ocean UV reflectances are needed for improving the total ozone retrievals from the total ozone mapping spectrometer (TOMS) and the ozone monitoring instrument (OMI) flown on NASA's Aura satellite. The estimate of underwater UV radiation can be done on the basis of measurements from the TOMS/OMI and full models of radiative transfer (RT) in the atmosphere-ocean system. The Hydrolight code, modified for extension to the UV, is used for the generation of look-up tables for in-water irradiances. A look-up table for surface radiances generated with a full RT code is input for the Hydrolight simulations. A model of seawater inherent optical properties (IOPs) is an extension of the Case 1 water model to the UV. A new element of the IOP model is parameterization of particulate matter absorption based on recent in situ data. A chlorophyll product from ocean color sensors is input for the IOP model. Verification of the in-water computational scheme shows that the calculated diffuse attenuation coefficient Kd is in good agreement with the measured Kd.

  7. In situ Raman-based measurements of high dissolved methane concentrations in hydrate-rich ocean sediments

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Hester, Keith C.; Ussler, William; Walz, Peter M.; Peltzer, Edward T.; Brewer, Peter G.

    2011-04-01

    Ocean sediment dissolved CH4 concentrations are of interest for possible climate-driven venting from sea floor hydrate decomposition, for supporting the large-scale microbial anaerobic oxidation of CH4 that holds the oceanic CH4 budget in balance, and for environmental issues of the oil and gas industry. Analyses of CH4 from recovered cores near vent locations typically show a maximum of ˜1 mM, close to the 1 atmosphere equilibrium value. We show from novel in situ measurement with a Raman-based probe that geochemically coherent profiles of dissolved CH4 occur rising to 30 mM (pCH4 = 3 MPa) or an excess pressure ˜3× greater than CO2 in a bottle of champagne. Normalization of the CH4 Raman ν1 peak to the ubiquitous water ν2 bending peak provides a fundamental internal calibration. Very large losses of CH4 and fractions of other gases (CO2, H2S) must typically occur from recovered cores at gas rich sites. The new data are consistent with observations of microbial biomass and observed CH4 oxidation rates at hydrate rich sites and support estimates of a greatly expanded near surface oceanic pore water CH4 reservoir.

  8. "Systems Education Experiences: Transforming high school science education through unique partnerships, inquiry based modules, and ocean systems studies"

    NASA Astrophysics Data System (ADS)

    Ludwig, C.; Orellana, M. V.; Baliga, N. S.

    2012-12-01

    Recent advances in experimental practice, accompanying computational techniques and systems thinking, have advanced biological inquiry. However, current scientific practices do not typically resemble the science taught in schools. As a result, students are missing out on significant opportunities to develop the critical thinking that is needed both in science and many professions. As a potential solution to this ongoing problem in science education, we are using current scientific practices to create classroom activities, packaged in easy-to-use curriculum modules, which promote conceptual development of standards based instructional outcomes. By bringing together students, teachers, researchers, engineers, and programmers we bring needed systems thinking and engaging inquiry experiences to schools throughout Washington State and the nation. Teachers are trained and continuously supported as they learn needed content and methods to bring this new science into their classrooms. Current research on ocean acidification, changing biogeochemical cycles, and the complexity and interdisciplinary nature of ocean systems studies have been translated through our newest curriculum module. Developing this module presented a significant challenge due to the urgency and importance of instilling understanding in high school students as they prepare to make decisions on the highly charged political, economic, and scientific issues of climate change and ocean acidification. Challenges have been overcome through partnerships and through infusing the habits of sustainability, high level thinking, systems modeling, scientific design, and communication. The Next Generation Standards have opened the door for nationwide dissemination of the module as we embark enabling students to think, understand, and contribute to scientific research.

  9. Five years of ship-based remote sensing observations of clouds, water vapor and radiation over the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Pospichal, B.; Wolf, V.; Zoll, Y.; Macke, A.

    2012-04-01

    Within the framework of the OCEANET project, ship-based observations have been performed since 2007 on board of the research vessel Polarstern on the Atlantic Ocean at ten cruises between Bremerhaven (Germany) and Cape Town (South Africa) or Punta Arenas (Chile), respectively. These observations were designated to measure the full energy budget and exchange processes at the sea surface as well as the state of the upper ocean and the troposphere in different climate zones. This presentation specifically analyzes the atmospheric water (clouds as well as vapour) and its influence on the energy balance. The main instrumentation on all cruises to infer the atmospheric composition consisted of a passive microwave radiometer, a full sky imager, sun photometer and additional lidar ceilometer and broadband solar and infrared radiation measurements. With five years of measurements, always at the same time of the year, it is possible now to assess the variability of the atmosphere, especially in subtropical and tropical regions. One focus is laid on marine stratocumulus clouds which are widespread over oceans and are therefore an important factor for the Earth's energy budget. To better quantify the effect of these clouds on the radiation balance, detailed studies on their structure and distribution are vital. In addition, statistics of the water vapor distribution, the liquid water content of clouds and their frequency will be presented, with a focus on the variability and annual differences.

  10. Seasonal cycle of plankton production in the Iberian margin based on a high resolution ocean model

    NASA Astrophysics Data System (ADS)

    Reboreda, Rosa; Nolasco, Rita; Castro, Carmen G.; Álvarez-Salgado, Xosé A.; Cordeiro, Nuno G. F.; Queiroga, Henrique; Dubert, Jesus

    2014-11-01

    The seasonal variability of plankton in the entire Iberian margin and the adjacent oceanic region was simulated by applying a NPZD-type biogeochemical model coupled to a physical high resolution configuration of the 3D Regional Ocean Modeling System (ROMS). The NPZD model simulated the time and space evolution of nitrate, phytoplankton/chlorophyll, zooplankton and detritus. Model results were compared to remotely sensed sea surface temperature from AVHRR, mixed layer depth from ARGO floats, and sea surface chlorophyll-a from a monthly SeaWiFS climatology. The model was able to reasonably reproduce the seasonal cycle of phytoplankton biomass in the Iberian Atlantic margin and the adjacent oceanic region. It allowed us to make a general characterization of the spatio-temporal patterns of phytoplankton and zooplankton biomass, as well as detritus and nitrate distribution. However, some limitations in the model were revealed by the Taylor Diagrams analysis. The model seemed to overestimate the offshore spring phytoplankton bloom and the upwelling-related coastal maxima of chlorophyll-a in the shelf. On the other hand, winter chlorophyll-a decrease simulated by the model over the shelf agreed with in situ samplings reported in the literature, contrasting with the high chlorophyll-a estimations of satellite data. This evidenced that care should be taken when validating model results in the Iberian coastal region using satellite chlorophyll-a products, particularly in winter.

  11. Data gateway for prognostic health monitoring of ocean-based power generation

    NASA Astrophysics Data System (ADS)

    Gundel, Joseph

    On August 5, 2010 the U.S. Department of Energy (DOE) has designated the Center for Ocean Energy Technology (COET) at Florida Atlantic University (FAU) as a national center for ocean energy research and development. Their focus is the research and development of open-ocean current systems and associated infrastructure needed to development and testing prototypes. The generation of power is achieved by using a specialized electric generator with a rotor called a turbine. As with all machines, the turbines will need maintenance and replacement as they near the end of their lifecycle. This prognostic health monitoring (PHM) requires data to be collected, stored, and analyzed in order to maximize the lifespan, reduce downtime and predict when failure is eminent. This thesis explores the use of a data gateway which will separate high level software with low level hardware including sensors and actuators. The gateway will standardize and store the data collected from various sensors with different speeds, formats, and interfaces allowing an easy and uniform transition to a database system for analysis.

  12. A global seasonal surface ocean climatology of phytoplankton types based on CHEMTAX analysis of HPLC pigments

    NASA Astrophysics Data System (ADS)

    Swan, Chantal M.; Vogt, Meike; Gruber, Nicolas; Laufkoetter, Charlotte

    2016-03-01

    Much advancement has been made in recent years in field data assimilation, remote sensing and ecosystem modeling, yet our global view of phytoplankton biogeography beyond chlorophyll biomass is still a cursory taxonomic picture with vast areas of the open ocean requiring field validations. High performance liquid chromatography (HPLC) pigment data combined with inverse methods offer an advantage over many other phytoplankton quantification measures by way of providing an immediate perspective of the whole phytoplankton community in a sample as a function of chlorophyll biomass. Historically, such chemotaxonomic analysis has been conducted mainly at local spatial and temporal scales in the ocean. Here, we apply a widely tested inverse approach, CHEMTAX, to a global climatology of pigment observations from HPLC. This study marks the first systematic and objective global application of CHEMTAX, yielding a seasonal climatology comprised of ~1500 1°×1° global grid points of the major phytoplankton pigment types in the ocean characterizing cyanobacteria, haptophytes, chlorophytes, cryptophytes, dinoflagellates, and diatoms, with results validated against prior regional studies where possible. Key findings from this new global view of specific phytoplankton abundances from pigments are a) the large global proportion of marine haptophytes (comprising 32±5% of total chlorophyll), whose biogeochemical functional roles are relatively unknown, and b) the contrasting spatial scales of complexity in global community structure that can be explained in part by regional oceanographic conditions. The results are publically accessible via

  13. Diatom Phytochromes Reveal the Existence of Far-Red-Light-Based Sensing in the Ocean[OPEN

    PubMed Central

    Enomoto, Gen; Bouly, Jean-Pierre; Thaler, Michael; Malviya, Shruti; Bernardes, Juliana Silva; Rappaport, Fabrice; Gentili, Bernard; Huysman, Marie J.J.; Carbone, Alessandra; Bowler, Chris; Ikeuchi, Masahiko; Falciatore, Angela

    2016-01-01

    The absorption of visible light in aquatic environments has led to the common assumption that aquatic organisms sense and adapt to penetrative blue/green light wavelengths but show little or no response to the more attenuated red/far-red wavelengths. Here, we show that two marine diatom species, Phaeodactylum tricornutum and Thalassiosira pseudonana, possess a bona fide red/far-red light sensing phytochrome (DPH) that uses biliverdin as a chromophore and displays accentuated red-shifted absorbance peaks compared with other characterized plant and algal phytochromes. Exposure to both red and far-red light causes changes in gene expression in P. tricornutum, and the responses to far-red light disappear in DPH knockout cells, demonstrating that P. tricornutum DPH mediates far-red light signaling. The identification of DPH genes in diverse diatom species widely distributed along the water column further emphasizes the ecological significance of far-red light sensing, raising questions about the sources of far-red light. Our analyses indicate that, although far-red wavelengths from sunlight are only detectable at the ocean surface, chlorophyll fluorescence and Raman scattering can generate red/far-red photons in deeper layers. This study opens up novel perspectives on phytochrome-mediated far-red light signaling in the ocean and on the light sensing and adaptive capabilities of marine phototrophs. PMID:26941092

  14. Simulation-based mask quality control in a production environment

    NASA Astrophysics Data System (ADS)

    Pang, Linyong; Chen, Jiunn-Hung; Cai, Lynn; Lee, Don; Chu, Brian; Huang, Vinsent; Fang, Te-Yang

    2004-05-01

    Traditionally, mask defect analysis has been done through a visual inspection review. As the semiconductor industry moves into smaller process generations and the complexity of mask exponentially increases, "Mask" issues have emerged as one of the main production problems due to their rising cost and long turn-around time. Mask-making specifications related to defects found on advanced masks also becomes more difficult to define due to the complex features involved [e.g. OPC (Optical Proximity Correction), SRAF (Sub Resolution Assist Features), etc.]. The Automatic Defect Severity Scoring (ADSS) module of i-Virtual Stepper System from Synopsys offers a fast and highly accurate software solution for defect printability analysis of advanced masks in a real production environment. In this paper, we present our case study of production pilot run in which the ADSS is used to automatically quantify the impact of a given defect on the surrounding features, basically filtering out killer defects and nuisance defects in terms of production viewpoints to reduce operators" intervention. In addition, an automation workflow is also tested, in which the production issues, such as the communication feasibility of mask quality control between mask house and wafer fab, are also considered.

  15. Final Report: Studies of Ocean Predictability at Decade to Century Time Scales Using a Global Ocean General Circulation Model in a Parallel Computing Environment (August 7, 1991-November 30, 1998)

    SciTech Connect

    Barnett, Tim P.

    1998-11-30

    Determine the structure of oceanic natural variability at time scales of decades to centuries; characterize the physical mechanisms responsible for the variability; determine the relative importance of heat, fresh water, and moment fluxes on the variability; determine the predictability of the variability on these times scales.

  16. Simulation of glacial ocean biogeochemical tracer and isotope distributions based on the PMIP3 suite of climate models

    NASA Astrophysics Data System (ADS)

    Khatiwala, Samar; Muglia, Juan; Kvale, Karin; Schmittner, Andreas

    2016-04-01

    In the present climate system, buoyancy forced convection at high-latitudes together with internal mixing results in a vigorous overturning circulation whose major component is North Atlantic Deep Water. One of the key questions of climate science is whether this "mode" of circulation persisted during glacial periods, and in particular at the Last Glacial Maximum (LGM; 21000 years before present). Resolving this question is both important for advancing our understanding of the climate system, as well as a critical test of numerical models' ability to reliably simulate different climates. The observational evidence, based on interpreting geochemical tracers archived in sediments, is conflicting, as are simulations carried out with state-of-the-art climate models (e.g., as part of the PMIP3 suite), which, due to the computational cost involved, do not by and large include biogeochemical and isotope tracers that can be directly compared with proxy data. Here, we apply geochemical observations to evaluate the ability of several realisations of an ocean model driven by atmospheric forcing from the PMIP3 suite of climate models to simulate global ocean circulation during the LGM. This results in a wide range of circulation states that are then used to simulate biogeochemical tracer and isotope (13C, 14C and Pa/Th) distributions using an efficient, "offline" computational scheme known as the transport matrix method (TMM). One of the key advantages of this approach is the use of a uniform set of biogeochemical and isotope parameterizations across all the different circulations based on the PMIP3 models. We compare these simulated distributions to both modern observations and data from LGM ocean sediments to identify similarities and discrepancies between model and data. We find, for example, that when the ocean model is forced with wind stress from the PMIP3 models the radiocarbon age of the deep ocean is systematically younger compared with reconstructions. Changes in

  17. Evidence for free oxygen in the Neoarchean ocean based on coupled iron-molybdenum isotope fractionation

    NASA Astrophysics Data System (ADS)

    Czaja, Andrew D.; Johnson, Clark M.; Roden, Eric E.; Beard, Brian L.; Voegelin, Andrea R.; Nägler, Thomas F.; Beukes, Nicolas J.; Wille, Martin

    2012-06-01

    Most geochemical proxies and models of atmospheric evolution suggest that the amount of free O2 in Earth’s atmosphere stayed below 10-5 present atmospheric level (PAL) until the Great Oxidation Event (GOE) that occurred between ∼2.2 and 2.4 Ga, at which time free O2 in the atmosphere increased to approximately 10-1 to 10-2 PAL. Although photosynthetically produced “O2 oases” have been proposed for the photic zone of the oceans prior to the GOE, it has been difficult to constrain absolute O2 concentrations and fluxes in such paleoenvironments. Here we constrain free O2 levels in the photic zone of a Late Archean marine basin by the combined use of Fe and Mo isotope systematics of Ca-Mg carbonates and shales from the 2.68 to 2.50 Ga Campbellrand-Malmani carbonate platform of the Kaapvaal Craton in South Africa. Correlated Fe and Mo isotope compositions require a key role for Fe oxide precipitation via oxidation of aqueous Fe(II) by photosynthetically-derived O2, followed by sorption of aqueous Mo to the newly formed Fe oxides. A dispersion/reaction model illustrates the effects of Fe oxide production and Mo sorption to Fe oxides, and suggests that a few to a few tens of μM free O2 was available in the photic zone of the Late Archean marine basin, consistent with some previous estimates. The coupling of Fe and Mo isotope systematics provides a unique view into the processes that occurred in the ancient shallow ocean after production of free O2 began, but prior to oxygenation of the deep ocean, or significant accumulation of free O2 in the atmosphere. These results require oxygenic photosynthesis to have evolved by at least 2.7 Ga and suggest that the Neoarchean ocean may have had a different oxygenation history than that of the atmosphere. The data also suggest that the extensive iron formation deposition that occurred during this time was unlikely to have been produced by anoxygenic photosynthetic Fe(II) oxidation. Finally, these data indicate that the ocean

  18. Ocean-Based Seismic Noise Sources Recorded by a Moderate Aperture Array in Antarctica

    NASA Astrophysics Data System (ADS)

    Pratt, M. J.; Winberry, J. P.; Wiens, D.; Anandakrishnan, S.; Euler, G. G.

    2015-12-01

    The deployment of a temporary, 60 km aperture, broadband seismic array on the Whillans Ice Stream (WIS), West Antarctica provides an opportunity to analyze ocean-derived seismic noise sources. The location of Antarctica, surrounded by the Southern Ocean and the seasonal effect of sea ice on shallow water noise production, allows for an intriguing experiment as to the production of primary and secondary microseisms. The WIS array was deployed for 2 months between December 2010-January 2011 with its primary objective to study WIS stick-slip events and glacial microseismicity. However, daylong stacks of station-to-station correlograms show directionality of the ambient noise field within the frequency bands of the primary and secondary microseisms. Although the WIS array is located close to the grounding line, it lies 700 km from the nearest open water at the end of the austral summer. The array consists of 17 broadband stations arranged in a series of offset concentric circles that minimizes spatial artifacts with regards to the array response. We use beamforming analysis to show that primary microseisms (~15 s) are sourced from three azimuthal directions with some ice-free coastline: Antarctic Peninsula, Victoria Land, and Dronning-Maude Land. Long-period secondary microseisms (~10 s) appear to be sourced in the deep Southern Ocean and track storm systems. Short-period secondary microseisms (~6 s) show much more dependence on the continental shelf and possibly coastal reflections. This is consistent with year-long noise spectra showing diminishment in the 15 s and 6 s bands [Grob et al. 2011]. Modeling of secondary microseism sources [Ardhuin et al. 2011] provides insight on the sources of surface wave noise at higher frequencies. We backproject daily P and PKPbc body wave microseism signals found at lower ray parameters sourced at distances of ~20-90° and ~145-155° respectively. The ocean sources for these arrivals remain fairly consistent, suggesting a

  19. Statistical Argumentation in Project-Based Learning Environments

    ERIC Educational Resources Information Center

    Hudson, Rick Alan

    2010-01-01

    Recent educational reform initiatives call for additional attention to be placed on data analysis and statistics in the K-12 school curriculum and an emphasis on mathematical processes such as reasoning and communication in mathematics classrooms. This study examines how small groups of middle grade students engaged during a project-based learning…

  20. A Computer Based Problem Solving Environment in Chemistry

    ERIC Educational Resources Information Center

    Bilgin, Ibrahim; Karakirik, Erol

    2005-01-01

    The purpose of this study was to introduce the Mole Solver, a computer based system that facilitates monitors and improves the students' problems solving skills on mole concept. The system has three distinct modes that: i) finds step by step solutions to the word problems on the mole concept ii) enable students' to solve word problems on their own…

  1. A Computer Based Problem Solving Environment in Chemistry

    ERIC Educational Resources Information Center

    Bilgin, Ibrahim; Karakirik, Erol

    2005-01-01

    The purpose of this study was to introduce the Mole Solver, a computer based system that facilitates monitors and improves students' problem solving skills on mole concept. The system has three distinct modes that: (1) find step by step solutions to the word problems on the mole concept; (2) enable students to solve word problems on their own by…

  2. Problem-Based Learning in Formal and Informal Learning Environments

    ERIC Educational Resources Information Center

    Shimic, Goran; Jevremovic, Aleksandar

    2012-01-01

    Problem-based learning (PBL) is a student-centered instructional strategy in which students solve problems and reflect on their experiences. Different domains need different approaches in the design of PBL systems. Therefore, we present one case study in this article: A Java Programming PBL. The application is developed as an additional module for…

  3. Collaborative Tasks in Wiki-Based Environment in EFL Learning

    ERIC Educational Resources Information Center

    Zou, Bin; Wang, Dongshuo; Xing, Minjie

    2016-01-01

    Wikis provide users with opportunities to post and edit messages to collaborate in the language learning process. Many studies have offered findings to show positive impact of Wiki-based language learning for learners. This paper explores the effect of collaborative task in error correction for English as a Foreign Language learning in an online…

  4. Leveraging Web-Based Environments for Mass Atrocity Prevention

    ERIC Educational Resources Information Center

    Harding, Tucker B.; Whitlock, Mark A.

    2013-01-01

    A growing literature exploring large-scale, identity-based political violence, including mass killing and genocide, debates the plausibility of, and prospects for, early warning and prevention. An extension of the debate involves the prospects for creating educational experiences that result in more sophisticated analytical products that enhance…

  5. Video-Based Affect Detection in Noninteractive Learning Environments

    ERIC Educational Resources Information Center

    Chen, Yuxuan; Bosch, Nigel; D'Mello, Sidney

    2015-01-01

    The current paper explores possible solutions to the problem of detecting affective states from facial expressions during text/diagram comprehension, a context devoid of interactive events that can be used to infer affect. These data present an interesting challenge for face-based affect detection because likely locations of affective facial…

  6. Towards an Intelligent Planning Knowledge Base Development Environment

    NASA Technical Reports Server (NTRS)

    Chien, S.

    1994-01-01

    ract describes work in developing knowledge base editing and debugging tools for the Multimission VICAR Planner (MVP) system. MVP uses artificial intelligence planning techniques to automatically construct executable complex image processing procedures (using models of the smaller constituent image processing requests made to the JPL Multimission Image Processing Laboratory.

  7. Vision-based traffic surveys in urban environments

    NASA Astrophysics Data System (ADS)

    Chen, Zezhi; Ellis, Tim; Velastin, Sergio A.

    2016-09-01

    This paper presents a state-of-the-art, vision-based vehicle detection and type classification to perform traffic surveys from a roadside closed-circuit television camera. Vehicles are detected using background subtraction based on a Gaussian mixture model that can cope with vehicles that become stationary over a significant period of time. Vehicle silhouettes are described using a combination of shape and appearance features using an intensity-based pyramid histogram of orientation gradients (HOG). Classification is performed using a support vector machine, which is trained on a small set of hand-labeled silhouette exemplars. These exemplars are identified using a model-based preclassifier that utilizes calibrated images mapped by Google Earth to provide accurately surveyed scene geometry matched to visible image landmarks. Kalman filters track the vehicles to enable classification by majority voting over several consecutive frames. The system counts vehicles and separates them into four categories: car, van, bus, and motorcycle (including bicycles). Experiments with real-world data have been undertaken to evaluate system performance and vehicle detection rates of 96.45% and classification accuracy of 95.70% have been achieved on this data.

  8. The Role of Ocean Currents in the Temperature Selection of Plankton: Insights from an Individual-Based Model.

    PubMed

    Hellweger, Ferdi L; van Sebille, Erik; Calfee, Benjamin C; Chandler, Jeremy W; Zinser, Erik R; Swan, Brandon K; Fredrick, Neil D

    2016-01-01

    Biogeography studies that correlate the observed distribution of organisms to environmental variables are typically based on local conditions. However, in cases with substantial translocation, like planktonic organisms carried by ocean currents, selection may happen upstream and local environmental factors may not be representative of those that shaped the local population. Here we use an individual-based model of microbes in the global surface ocean to explore this effect for temperature. We simulate up to 25 million individual cells belonging to up to 50 species with different temperature optima. Microbes are moved around the globe based on a hydrodynamic model, and grow and die based on local temperature. We quantify the role of currents using the "advective temperature differential" metric, which is the optimum temperature of the most abundant species from the model with advection minus that from the model without advection. This differential depends on the location and can be up to 4°C. Poleward-flowing currents, like the Gulf Stream, generally experience cooling and the differential is positive. We apply our results to three global datasets. For observations of optimum growth temperature of phytoplankton, accounting for the effect of currents leads to a slightly better agreement with observations, but there is large variability and the improvement is not statistically significant. For observed Prochlorococcus ecotype ratios and metagenome nucleotide divergence, accounting for advection improves the correlation significantly, especially in areas with relatively strong poleward or equatorward currents.

  9. The Role of Ocean Currents in the Temperature Selection of Plankton: Insights from an Individual-Based Model

    PubMed Central

    Hellweger, Ferdi L.; van Sebille, Erik; Calfee, Benjamin C.; Chandler, Jeremy W.; Zinser, Erik R.; Swan, Brandon K.; Fredrick, Neil D.

    2016-01-01

    Biogeography studies that correlate the observed distribution of organisms to environmental variables are typically based on local conditions. However, in cases with substantial translocation, like planktonic organisms carried by ocean currents, selection may happen upstream and local environmental factors may not be representative of those that shaped the local population. Here we use an individual-based model of microbes in the global surface ocean to explore this effect for temperature. We simulate up to 25 million individual cells belonging to up to 50 species with different temperature optima. Microbes are moved around the globe based on a hydrodynamic model, and grow and die based on local temperature. We quantify the role of currents using the “advective temperature differential” metric, which is the optimum temperature of the most abundant species from the model with advection minus that from the model without advection. This differential depends on the location and can be up to 4°C. Poleward-flowing currents, like the Gulf Stream, generally experience cooling and the differential is positive. We apply our results to three global datasets. For observations of optimum growth temperature of phytoplankton, accounting for the effect of currents leads to a slightly better agreement with observations, but there is large variability and the improvement is not statistically significant. For observed Prochlorococcus ecotype ratios and metagenome nucleotide divergence, accounting for advection improves the correlation significantly, especially in areas with relatively strong poleward or equatorward currents. PMID:27907181

  10. Evidence for free oxygen in the Neoarchean ocean based on coupled iron-molybdenum isotope fractionation

    NASA Astrophysics Data System (ADS)

    Czaja, A. D.; Johnson, C.; Roden, E. E.; Beard, B. L.; Voegelin, A. R.; Nagler, T. F.; Beukes, N. J.; Wille, M.

    2011-12-01

    Common estimates for the timing of surface oxidation and models of atmospheric evolution suggest that the amount of free oxygen in Earth's atmosphere stayed below 10-5 times present atmospheric level (PAL) until the Great Oxidation Event (GOE) that occurred between ~2.2 and 2.4 Ga, at which time free O2 in the atmosphere increased to approximately 10-1 to 10-2 times PAL. It is possible that the amount of photosynthetic O2 production was low to insignificant until the GOE, but some studies have suggested that photosynthetically-produced "oxygen oases", reflecting relatively high rates of O2 production, could have existed prior to this time. It has been difficult, however, to constrain absolute O2 concentrations and fluxes in such paleoenvironments. Here we show that free O2 levels in the photic zone of the Late Archean ocean can be constrained by the combined use of Fe and Mo isotope systematics of Ca-Mg carbonates from the 2.68 to 2.50 Ga Campbellrand-Malmani carbonate platform, Kaapvaal Craton, South Africa, and that O2 production is most easily explained by oxygenic photosynthesis. Correlated Fe and Mo isotope compositions of seawater in the photic zone, as sequestered into Ca-Mg carbonates, require a key role for Fe oxide precipitation via oxidation of aqueous Fe(II) by photosynthetically-derived O2, followed by sorption of aqueous Mo to the newly formed Fe oxides. Simulation of this process by use of a dispersion/reaction model illustrates the effects of Fe oxide precipitation and subsequent Mo sorption, and suggests that the balance of O2 production and loss could result in a Late Archean ocean with an oxic photic zone (~30 μM of free O2, which is ~10% of the modern value), an anoxic deep ocean, and an atmosphere that had ≤10-5 times PAL O2. The similarity of the temporal trends in Fe isotope compositions of these Ca-Mg carbonates to those of contemporaneously deposited carbonates from the Pilbara Craton in Western Australia suggests that photic zone

  11. Oceanic CO sub 2 measurements for the WOCE hydrographic survey in the Pacific Ocean, 1990--1991: Shore based analyses during Legs 1--3

    SciTech Connect

    Keeling, C.D.

    1992-01-01

    During the winter and spring of 1991 we made preparations for sampling on three legs of the US World Ocean Circulation Experiment in the Pacific Ocean. These transects, postponed from an original start date early in 1991, took place between May 31 to October 1. For the project, 1400 0.5 liter Pyrex sampling bottles were used for the collection of sea water. A second major pre-expedition task was the construction of a dual titration cell system of new design, as described in the original proposal and our previous semi-annual report.

  12. KAT: A Flexible XML-based Knowledge Authoring Environment

    PubMed Central

    Hulse, Nathan C.; Rocha, Roberto A.; Del Fiol, Guilherme; Bradshaw, Richard L.; Hanna, Timothy P.; Roemer, Lorrie K.

    2005-01-01

    As part of an enterprise effort to develop new clinical information systems at Intermountain Health Care, the authors have built a knowledge authoring tool that facilitates the development and refinement of medical knowledge content. At present, users of the application can compose order sets and an assortment of other structured clinical knowledge documents based on XML schemas. The flexible nature of the application allows the immediate authoring of new types of documents once an appropriate XML schema and accompanying Web form have been developed and stored in a shared repository. The need for a knowledge acquisition tool stems largely from the desire for medical practitioners to be able to write their own content for use within clinical applications. We hypothesize that medical knowledge content for clinical use can be successfully created and maintained through XML-based document frameworks containing structured and coded knowledge. PMID:15802477

  13. Reconstruction of the past 2000 years of ocean and glacier variability in Sermilik Fjord, SE Greenland, based on sediment archives

    NASA Astrophysics Data System (ADS)

    Stoican, Andreea; Andresen, Camilla; Seidenkrantz, Marit-Solveig; Kjaer, Kurt; Kuijpers, Antoon; Massé, Guillaume; Weckström, Kaarina

    2013-04-01

    Glaciomarine sediments represent valuable archives of climate and glacier variability in the arctic environment. Especially the fjords along Greenland's east coast represent a dynamic and complicated system, influenced by regional ocean circulation, local currents and by glacier terminations. Therefore, they represent appropriate locations for sedimentary core studies in order to detect the relative glacier and ocean variability. The aim of this project is to reconstruct the past 2000 years of glacier and ocean variability in Sermilik fjord, SE Greenland, into which Helheim glacier terminates. This is done by analysing two sedimentary cores (ER11 and ER07) and hereby reconstruct fluctuations in marine-terminating outlet glacier dynamics (including iceberg and to a lesser extent melt water production) and the interaction with oceanographic changes. The oceanographic variability is reconstructed on the basis of benthic and planktonic foraminiferal analysis and the content of the biomarker IP25 and these proxies are interpreted to reflect changes in the inflow of the warm Irminger Current and polar waters in association with the East Greenland Current. Interestingly, studies show that the onset of the Little Ice Age was characterised by intensified inflow of Irminger Current water masses to the Southeastern and Southwestern shelves of Greenland and that these may be associated with a contracted subpolar gyre. At the same time, the EGC Polar Water transport also intensified leading to a stratified water column on the shelf and this may have favoured entrainment of warm subsurface IC waters. Alternatively, the relatively warm rim of the eastern subpolar gyre may have promoted intense submarine melting of extended outlet glaciers at this time, producing enhanced melt water outflow which favoured estuarine circulation processes maintaining the inflow of IC water masses. Thus the aim of this study is to investigate in detail the circulation of these LIA warm waters from

  14. Dim waters: side effects of geoengineering using ocean albedo modification

    NASA Astrophysics Data System (ADS)

    Piskozub, J.; Neumann, T.

    2012-04-01

    We use a Monte Carlo radiative transfer code to check how the recently proposed geoengineering by injection of clean or coated microbubbles into the ocean mixed layer would impact in-water light fields. We show that due to massive multiscattering inside a bubble cloud, coating the bubbles with surfactant, needed to stabilize them, would not increase their albedo change effectiveness as much as expected basing on their backscattering coefficients. However, the bubble effect on reflectance is larger than estimated previously using a discrete ordinate method of solving the radiative transfer problem. We show significant side effects of ocean albedo change needed to counter global warming expected in this century and beyond (reduction of euphotic zone depth by respectively 20% and 50% in the case of global ocean albedo change corresponding to -1.25 K and -6 K global surface temperature change and irradiance decrease at 10 m depth by respectively 40% and over 80%) even if all ocean surface was "brightened". We discuss the possible negative side effect of such in-water light dimming on marine life. We conclude that the proposed "ocean brightening" is in fact "ocean dimming" as concerns the marine environment, on a scale that in any other circumstances would be called catastrophic. Finally, we briefly discuss other possible side effect of making the surface ocean waters turbid (both optically and acoustically), of adding large amounts of surfactants to the surface ocean layers and of surface cooling of the ocean, especially within the tropics.

  15. An Architecture and Supporting Environment of Service-Oriented Computing Based-On Context Awareness

    NASA Astrophysics Data System (ADS)

    Ma, Tianxiao; Wu, Gang; Huang, Jun

    Service-oriented computing (SOC) is emerging to be an important computing paradigm of the next future. Based on context awareness, this paper proposes an architecture of SOC. A definition of the context in open environments such as Internet is given, which is based on ontology. The paper also proposes a supporting environment for the context-aware SOC, which focus on services on-demand composition and context-awareness evolving. A reference implementation of the supporting environment based on OSGi[11] is given at last.

  16. Decreased calcification in the Southern Ocean over the satellite record

    NASA Astrophysics Data System (ADS)

    Freeman, Natalie M.; Lovenduski, Nicole S.

    2015-03-01

    Widespread ocean acidification is occurring as the ocean absorbs anthropogenic carbon dioxide from the atmosphere, threatening marine ecosystems, particularly the calcifying plankton that provide the base of the marine food chain and play a key role within the global carbon cycle. We use satellite estimates of particulate inorganic carbon (PIC), surface chlorophyll, and sea surface temperature to provide a first estimate of changing calcification rates throughout the Southern Ocean. From 1998 to 2014 we observe a 4% basin-wide reduction in summer calcification, with ˜9% reductions in large regions (˜1 × 106 km2) of the Pacific and Indian sectors. Southern Ocean trends are spatially heterogeneous and primarily driven by changes in PIC concentration (suspended calcite), which has declined by ˜24% in these regions. The observed decline in Southern Ocean calcification and PIC is suggestive of large-scale changes in the carbon cycle and provides insight into organism vulnerability in a changing environment.

  17. Homeostasis lighting control based on relationship between lighting environment and human behavior

    NASA Astrophysics Data System (ADS)

    Ueda, Risa; Mita, Akira

    2015-03-01

    Although each person has own preferences, living spaces which can respond to various preferences and needs have not become reality. Focusing on the lighting environments which influence on the impression of living spaces, this research aims to offer comfortable lighting environments for each resident by a flexible control. This research examines the relationship between lighting environments and human behaviors considering colored lights. In accord with the relationship, this research proposes an illuminance-color control system which flexibly changes spatial environments responding to human conditions. Firstly, the psychological evaluation was conducted in order to build human models for various environments. As a result, preferred lighting environments for each examinee were determined for particular behaviors. Moreover, satisfaction levels of lighting environments were calculated by using seven types of impression of the environments as parameters. The results were summarized as human models. Secondly, this research proposed "Homeostasis Lighting Control System", which employs the human models. Homeostasis lighting control system embodies the algorithm of homeostasis, which is one of the functions of the physiological adaptation. Human discomfort feelings are obtained automatically by the sensor agent robot. The system can offer comfortable lighting environments without controlling environments by residents autonomously based on the information from the robot. This research takes into accounts both illuminance and color. The robot communicates with the server which contains human models, then the system corresponds to individuals. Combining these three systems, the proposed system can effectively control the lighting environment. At last, the feasibility of the proposed system was verified by simulation experiments.

  18. Spreading and wandering of Gaussian-Schell model laser beams in an anisotropic turbulent ocean

    NASA Astrophysics Data System (ADS)

    Wu, Yuqian; Zhang, Yixin; Zhu, Yun; Hu, Zhengda

    2016-09-01

    The effect of anisotropic turbulence on the spreading and wandering of Gaussian-Schell model (GSM) laser beams propagating in an ocean is studied. The long-term spreading of a GSM beam propagating through the paraxial channel of a turbulent ocean is also developed. Expressions of random wander for such laser beams are derived in an anisotropic turbulent ocean based on the extended Huygens-Fresnel principle. We investigate the influence of parameters in a turbulent ocean on the beam wander and spreading. Our results indicate that beam spreading and random beam wandering are smaller without considering the anisotropy of turbulence in the oceanic channel. Salinity fluctuation has a greater contribution to both the beam spreading and beam wander than that of temperature fluctuations in a turbulent ocean. Our results could be helpful for designing a free-space optical wireless communication system in an oceanic environment.

  19. Capacitor-based isolation amplifiers for harsh radiation environments

    NASA Astrophysics Data System (ADS)

    Franco, Francisco J.; Zong, Yi; de Agapito, Juan A.

    2010-01-01

    Commercial-off-the-shelf (COTS) capacitor-based isolation amplifiers were irradiated at the Portuguese Research Reactor (PRR) in order to determine its tolerance to the displacement damage and total ionising dose (TID). The set of experimental data shows that some of these devices are suitable for zones inside future nuclear facilities where the expected total radiation damage would be below 2.2×1013 1-MeV neutron/cm2 and 230 Gy (Si). However, some drawbacks must be taken into account by the electronic designers such as the increase of the output offset voltage and the slight modification of the transmission gain.

  20. Sustaining Teacher Control in a Blog-Based Personal Learning Environment

    ERIC Educational Resources Information Center

    Tomberg, Vladimir; Laanpere, Mart; Ley, Tobias; Normak, Peeter

    2013-01-01

    Various tools and services based on Web 2.0 (mainly blogs, wikis, social networking tools) are increasingly used in formal education to create personal learning environments, providing self-directed learners with more freedom, choice, and control over their learning. In such distributed and personalized learning environments, the traditional role…

  1. Investigating Learners' Attitudes toward Virtual Reality Learning Environments: Based on a Constructivist Approach

    ERIC Educational Resources Information Center

    Huang, Hsiu-Mei; Rauch, Ulrich; Liaw, Shu-Sheng

    2010-01-01

    The use of animation and multimedia for learning is now further extended by the provision of entire Virtual Reality Learning Environments (VRLE). This highlights a shift in Web-based learning from a conventional multimedia to a more immersive, interactive, intuitive and exciting VR learning environment. VRLEs simulate the real world through the…

  2. Learning with Computer-Based Learning Environments: A Literature Review of Computer Self-Efficacy

    ERIC Educational Resources Information Center

    Moos, Daniel C.; Azevedo, Roger

    2009-01-01

    Although computer-based learning environments (CBLEs) are becoming more prevalent in the classroom, empirical research has demonstrated that some students have difficulty learning with these environments. The motivation construct of computer-self efficacy plays an integral role in learning with CBLEs. This literature review synthesizes research…

  3. Distributing vs. Blocking Learning Questions in a Web-Based Learning Environment

    ERIC Educational Resources Information Center

    Kapp, Felix; Proske, Antje; Narciss, Susanne; Körndle, Hermann

    2015-01-01

    Effective studying in web-based learning environments (web-LEs) requires cognitive engagement and demands learners to regulate their learning activities. One way to support learners in web-LEs is to provide interactive learning questions within the learning environment. Even though research on learning questions has a long tradition, there are…

  4. Learning How to Design a Technology Supported Inquiry-Based Learning Environment

    ERIC Educational Resources Information Center

    Hakverdi-Can, Meral; Sonmez, Duygu

    2012-01-01

    This paper describes a study focusing on pre-service teachers' experience of learning how to design a technology supported inquiry-based learning environment using the Internet. As part of their elective course, pre-service science teachers were asked to develop a WebQuest environment targeting middle school students. A WebQuest is an…

  5. RiBOMS: RFID-based object management system for home environments.

    PubMed

    Iraola, Hodei; Schafer, James; Yu, Xunyi; Mullett, Gary; Ganz, Aura

    2011-01-01

    In this paper we introduce a RFID-based object management system, RiBOMS, for home environments. The system has an easy to use pictorial user interface aimed at older adults with associative memory impairments. The system technical correctness was successfully tested in a lab environment.

  6. Permutations of Control: Cognitive Considerations for Agent-Based Learning Environments

    ERIC Educational Resources Information Center

    Baylor, Amy L.

    2004-01-01

    While there has been a significant amount of research on technical issues regarding the development of agent-based learning environments (e.g., see the special issue of Journal of "Interactive Learning Research," 10(3/4)), there is less information regarding cognitive foundations for these environments. The management of control is a prime issue…

  7. Permutations of Control: Cognitive Considerations for Agent-Based Learning Environments.

    ERIC Educational Resources Information Center

    Baylor, Amy L.

    2001-01-01

    Discussion of intelligent agents and their use in computer learning environments focuses on cognitive considerations. Presents four dimension of control that should be considered in designing agent-based learning environments: learner control, from constructivist to instructivist; feedback; relationship of learner to agent; and learner confidence…

  8. School-Level Environment and Outcomes-Based Education in South Africa

    ERIC Educational Resources Information Center

    Aldridge, Jill M.; Laugksch, Rudiger C.; Fraser, Barry J.

    2006-01-01

    In this study, we developed and validated a questionnaire to assess teachers' perceptions of their actual and preferred school-level environment, investigated whether teachers involved with Outcomes-Based Education (OBE) perceive the school-level environment differently from those who are not, and investigated factors in the school-level…

  9. Using a Cloud-Based Computing Environment to Support Teacher Training on Common Core Implementation

    ERIC Educational Resources Information Center

    Robertson, Cory

    2013-01-01

    A cloud-based computing environment, Google Apps for Education (GAFE), has provided the Anaheim City School District (ACSD) a comprehensive and collaborative avenue for creating, sharing, and editing documents, calendars, and social networking communities. With this environment, teachers and district staff at ACSD are able to utilize the deep…

  10. Exploring the Presentation and Format of Help in a Computer-Based Electrical Engineering Learning Environment

    ERIC Educational Resources Information Center

    Reisslein, Jana; Atkinson, Robert K.; Reisslein, Martin

    2004-01-01

    This study investigated whether it was more beneficial to provide the learners in computer-based learning environments access to on demand (self-regulated) help after they committed an error in problem solving or for the learning environment to externally regulate the presentation of instructional help. Furthermore, two different resentational…

  11. A ship-based methodology for high precision atmospheric oxygen measurements and its application in the Southern Ocean region

    NASA Astrophysics Data System (ADS)

    Thompson, Rona L.; Manning, Andrew C.; Lowe, David C.; Weatherburn, David C.

    2007-09-01

    A method for achieving continuous high precision measurements of atmospheric O2 is presented based on a commercially available fuel-cell instrument, (Sable Systems, Oxzilla FC-II) with a precision of 7 per meg (approximately equivalent to 1.2 ppm) for a 6-min measurement. The Oxzilla was deployed on two voyages in the Western Pacific sector of the Southern Ocean, in February 2003 and in April 2004, making these the second set of continuous O2 measurements ever made from a ship. The results show significant temporal variation in O2, in the order of +/-10 per meg over 6-hourly time intervals, and substantial spatial variation. Data from both voyages show an O2 maximum centred on 50°S, which is most likely to be the result of biologically driven O2 outgassing in the region of subtropical convergence around New Zealand, and a decreasing O2 trend towards Antarctica. O2 from the ship-based measurements is elevated compared with measurements from the Scripps Institution of Oceanography flask-sampling network, and the O2 maximum is also not captured in the network observations. This preliminary study shows that ship-based continuous measurements are a valuable addition to current fixed site sampling programmes for the understanding of ocean-atmosphere O2 exchange processes.

  12. Determination of the Ocean Tide Constituents Loading Based on GPS Measurements in the Chinese Offshore Islands

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Wu, Z.; He, X.; Peng, L.

    2015-12-01

    Ocean tide loading largely affects the accuracy of GPS positioning. In turn, GPS measurements could be used to monitor the ocean tide loading effect. In this paper, 67-days GPS observations from two island GPS stations, respectively located in the East China Sea and the South China Sea, were collected and calculated in 30s sampling rate using the Precise Point Positioning (PPP) algorithm. The variation of GPS observed position time series are 2cm in the horizontal and 7cm in the vertical generated by the ocean tide loading effect and other error sources. With the power spectra analysis by the Fast Fourier Transform (FFT), the eigenvalues of the semidiurnal constituents and the diurnal constituents are obtained from the GPS estimates time series. The calculated frequencies are well agreements to the known within the error less than 1.5% for K1,Q1, O1, K2,S2, M2,N2, but P1 within 4.2%. The calculated amplitudes are also well consistent with the results from the global tide models FES2004,NAO.99 and GOT4.7. Their difference in the amplitude are mostly less than 5mm in the horizontal and the vertical direction, except K1 and M2. The maximum amplitude difference occurs in K1 and M2 up to 1.5cm in the vertical direction. In additional, two islands locate at the different transmission Channel, but they give the same calculated frequency in the horizontal and the vertical directional, respectively for 8 tidal constituents. This exhibits they belongs to the same tide wave system as in fact.

  13. Quaternary paleoceanography of the deep Arctic Ocean based on quantitative analysis of Ostracoda

    USGS Publications Warehouse

    Cronin, T. M.; Holtz, T.R.; Whatley, R.C.

    1994-01-01

    Ostracodes were studied from deep Arctic Ocean cores obtained during the Arctic 91 expedition of the Polarstern to the Nansen, Amundsen and Makarov Basins, the Lomonosov Ridge, Morris Jesup Rise and Yermak Plateau, in order to investigate their distribution in Arctic Ocean deep water (AODW) and apply these data to paleoceanographic reconstruction of bottom water masses during the Quaternary. Analyses of coretop assemblages from Arctic 91 boxcores indicate the following: ostracodes are common at all depths between 1000 and 4500 m, and species distribution is strongly influenced by water mass characteristics and bathymetry; quantitative analyses comparing Eurasian and Canada Basin assemblages indicate that distinct assemblages inhabit regions east and west of the Lomonosov Ridge, a barrier especially important to species living in lower AODW; deep Eurasian Basin assemblages are more similar to those living in Greenland Sea deep water (GSDW) than those in Canada Basin deep water; two upper AODW assemblages were recognized throughout the Arctic Ocean, one living between 1000 and 1500 m, and the other, having high species diversity, at 1500-3000 m. Downcore quantitative analyses of species' abundances and the squared chord distance coefficient of similarity reveals a distinct series of abundance peaks in key indicator taxa interpreted to signify the following late Quaternary deep water history of the Eurasian Basin. During the Last Glacial Maximum (LGM), a GSDW/AODW assemblage, characteristic of cold, well oxygenated deep water > 3000 m today, inhabited the Lomonosov Ridge to depths as shallow as 1000 m, perhaps indicating the influence of GSDW at mid-depths in the central Arctic Ocean. During Termination 1, a period of high organic productivity associated with a strong inflowing warm North Atlantic layer occurred. During the mid-Holocene, several key faunal events indicate a period of warming and/or enhanced flow between the Canada and Eurasian Basins. A long

  14. Oceanic CO{sub 2} measurements for the WOCE hydrographic survey in the Pacific Ocean, 1990--1991: Shore based analyses. Technical data report

    SciTech Connect

    Guenther, P.R.; Keeling, C.D.; Emanuele, G. III

    1991-12-31

    The Office of Health and Environmental Research, of the US Department of Energy (DOE), actively supports global survey investigations of carbon dioxide in the oceans. This large scale study is in conjunction with the hydrographic program of the World Ocean Circulation Experiment (WOCE/HP). On ocean cruises operated by WOCE/HP, carbon dioxide analysis groups, from various oceanographic institutions, perform shipboard chemical measurements of the inorganic carbon system in the ocean. Measurements of total dissolved inorganic carbon (DIC) are of central importance to this carbon survey. Shipboard measurements of DIC were made by employing a coulometric technique. The majority of coulometric measurements were made on an integrated automatic device, the Single Operator Multi-Parameter Metabolic Analyzer (SOMMA). In addition to DIC determinations, shipboard analytical groups measured at least one additional parameter of sea water carbon chemistry. This was done to more fully characterize the inorganic carbon system of the sea water sample. This thechnical data report presents DIC and ALK measurements performed in the SIO laboratory on replicate samples collected on the five expedition legs of the WOCE/HP cruises.

  15. PC CLIN-SIM: a toolbook based clinical simulation environment.

    PubMed Central

    Pincetl, P.; Cobbs, E.; Hubshman, J.; Liao, R. L.; Baranano, S.; Heller, R.; Fry, E.; Piemme, T.

    1992-01-01

    The Departments of Computer Medicine, Health Care Sciences, Medicine, and Electrical Engineering & Computer Science at the George Washington University have joined forces to create a clinical simulation program. The purpose of this program is to provide experience in the management of complex patient populations (eg geriatrics). A number of simulation programs are available commercially, however none provide adequate geriatric content, or were deemed to lack functionality important to the developers. The immediate goal of this effort was to create a computer-based, core curriculum in geriatric medicine for medical and allied health students. The curriculum includes case simulations linked to a comprehensive reference database. The development objectives were to create an intuitive, friendly, consistent user interface which could serve as a shell for additional content areas. In order to increase fidelity, free text entry and time simulation were included. PMID:1482984

  16. Flow dynamic environment data base development for the SSME

    NASA Technical Reports Server (NTRS)

    Sundaram, C. V.

    1985-01-01

    The fluid flow-induced vibration of the Space Shuttle main engine (SSME) components are being studied with a view to correlating the frequency characteristics of the pressure fluctuations in a rocket engine to its operating conditions and geometry. An overview of the data base development for SSME test firing results and the interactive computer software used to access, retrieve, and plot or print the results selectively for given thrust levels, engine numbers, etc., is presented. The various statistical methods available in the computer code for data analysis are discussed. Plots of test data, nondimensionalized using parameters such as fluid flow velocities, densities, and pressures, are presented. Results are compared with those available in the literature. Correlations between the resonant peaks observed at higher frequencies in power spectral density plots with pump geometry and operating conditions are discussed. An overview of the status of the investigation is presented and future directions are discussed.

  17. Developing Personal Learning Environments Based on Calm Technologies

    NASA Astrophysics Data System (ADS)

    Fiaidhi, Jinan

    Educational technology is constantly evolving and growing, and it is inevitable that this progression will continually offer new and interesting advances in our world. The instigation of calm technologies for the delivery of education is another new approach now emerging. Calm technology aims to reduce the "excitement" of information overload by letting the learner select what information is at the center of their attention and what information need to be at the peripheral. In this paper we report on the adaptation of calm technologies in an educational setting with emphasis on the needs to cater the preferences of the individual learner to respond to the challenge of providing truly learner-centered, accessible, personalized and flexible learning. Central to calm computing vision is the notion of representing learning objects as widgets, harvesting widgets from the periphery based on semantic wikis as well as widgets garbage collection from the virtual/central learning memory.

  18. Toward a multivariate reanalysis of the North Atlantic Ocean biogeochemistry during 1998-2006 based on the assimilation of SeaWiFS chlorophyll data

    NASA Astrophysics Data System (ADS)

    Fontana, C.; Brasseur, P.; Brankart, J.-M.

    2013-01-01

    Today, the routine assimilation of satellite data into operational models of ocean circulation is mature enough to enable the production of global reanalyses describing the ocean circulation variability during the past decades. The expansion of the "reanalysis" concept from ocean physics to biogeochemistry is a timely challenge that motivates the present study. The objective of this paper is to investigate the potential benefits of assimilating satellite-estimated chlorophyll data into a basin-scale three-dimensional coupled physical-biogeochemical model of the North Atlantic. The aim is on the one hand to improve forecasts of ocean biogeochemical properties and on the other hand to define a methodology for producing data-driven climatologies based on coupled physical-biogeochemical modeling. A simplified variant of the Kalman filter is used to assimilate ocean color data during a 9-year period. In this frame, two experiments are carried out, with and without anamorphic transformations of the state vector variables. Data assimilation efficiency is assessed with respect to the assimilated data set, nitrate of the World Ocean Atlas database and a derived climatology. Along the simulation period, the non-linear assimilation scheme clearly improves the surface analysis and forecast chlorophyll concentrations, especially in the North Atlantic bloom region. Nitrate concentration forecasts are also improved thanks to the assimilation of ocean color data while this improvement is limited to the upper layer of the water column, in agreement with recent related literature. This feature is explained by the weak correlation taken into account by the assimilation between surface phytoplankton and nitrate concentrations deeper than 50 meters. The assessment of the non-linear assimilation experiments indicates that the proposed methodology provides the skeleton of an assimilative system suitable for reanalyzing the ocean biogeochemistry based on ocean color data.

  19. Toward a multivariate reanalysis of the North Atlantic ocean biogeochemistry during 1998-2006 based on the assimilation of SeaWiFS chlorophyll data

    NASA Astrophysics Data System (ADS)

    Fontana, C.; Brasseur, P.; Brankart, J.-M.

    2012-04-01

    Today, the routine assimilation of satellite data into operational models of the ocean circulation is mature enough to enable the production of global reanalyses describing the ocean circulation variability during the past decades. The expansion of the "reanalysis" concept from ocean physics to biogeochemistry is a timely challenge that motivates the present study. The objective of this paper is to investigate the potential benefits of assimilating satellite-estimated chlorophyll data into a basin-scale three-dimensional coupled physical-biogeochemical model of the North-Atlantic. The aim is on one hand to improve forecasts of ocean biogeochemical properties and on the other hand to define a methodology for producing data-driven climatologies based on coupled physical-biogeochemical modelling. A simplified variant of the Kalman filter is used to assimilate ocean color data during a 9 year-long period. In this frame, two experiences are carried out, with and without anamorphic transformations of the state vector variables. Data assimilation efficiency is assessed with respect to the assimilated data set, the nitrate World Ocean Atlas database and a derived climatology. Along the simulation period, the non-linear assimilation scheme clearly improves the surface chlorophyll concentrations analysis and forecast, especially in the North Atlantic bloom region. Nitrate concentration forecasts are also improved thanks to the assimilation of ocean color data while this improvement is limited to the upper layer of the water column, in agreement with recent related litterature. This feature is explained by the weak correlation taken into account by the assimilation between surface phytoplankton and nitrate concentration deeper than 50 m. The assessement of the non-linear assimilation experiments indicates that the proposed methodology provides the skeleton of an assimilative system suitable for reanalysing the ocean biogeochemistry based on ocean color data.

  20. Mechanistic site-based emulation of a global ocean biogeochemical model (MEDUSA 1.0) for parametric analysis and calibration: an application of the Marine Model Optimization Testbed (MarMOT 1.1)

    NASA Astrophysics Data System (ADS)

    Hemmings, J. C. P.; Challenor, P. G.; Yool, A.

    2015-03-01

    Biogeochemical ocean circulation models used to investigate the role of plankton ecosystems in global change rely on adjustable parameters to capture the dominant biogeochemical dynamics of a complex biological system. In principle, optimal parameter values can be estimated by fitting models to observational data, including satellite ocean colour products such as chlorophyll that achieve good spatial and temporal coverage of the surface ocean. However, comprehensive parametric analyses require large ensemble experiments that are computationally infeasible with global 3-D simulations. Site-based simulations provide an efficient alternative but can only be used to make reliable inferences about global model performance if robust quantitative descriptions of their relationships with the corresponding 3-D simulations can be established. The feasibility of establishing such a relationship is investigated for an intermediate complexity biogeochemistry model (MEDUSA) coupled with a widely used global ocean model (NEMO). A site-based mechanistic emulator is constructed for surface chlorophyll output from this target model as a function of model parameters. The emulator comprises an array of 1-D simulators and a statistical quantification of the uncertainty in their predictions. The unknown parameter-dependent biogeochemical environment, in terms of initial tracer concentrations and lateral flux information required by the simulators, is a significant source of uncertainty. It is approximated by a mean environment derived from a small ensemble of 3-D simulations representing variability of the target model behaviour over the parameter space of interest. The performance of two alternative uncertainty quantification schemes is examined: a direct method based on comparisons between simulator output and a sample of known target model "truths" and an indirect method that is only partially reliant on knowledge of the target model output. In general, chlorophyll records at a

  1. Sunlight-induced Transformations of Graphene-based Nanomaterials in Aquatic Environments

    EPA Science Inventory

    Graphene-based nanomaterials and other related carbon nanomaterials (CNMs) can be released from products during their life cycles. Upon entry into aquatic environments, they are potentially transformed by photochemical reactions, oxidation reactions and biological processes, all ...

  2. From molecules to management: adopting DNA-based methods for monitoring biological invasions in aquatic environments

    EPA Science Inventory

    Recent technological advances have driven rapid development of DNA-based methods designed to facilitate detection and monitoring of invasive species in aquatic environments. These tools promise to significantly alleviate difficulties associated with traditional monitoring approac...

  3. Computer Support for Learning Mathematics: A Learning Environment Based on Recreational Learning Objects

    ERIC Educational Resources Information Center

    Lopez-Morteo, Gabriel; Lopez, Gilberto

    2007-01-01

    In this paper, we introduce an electronic collaborative learning environment based on Interactive Instructors of Recreational Mathematics (IIRM), establishing an alternative approach for motivating students towards mathematics. The IIRM are educational software components, specializing in mathematical concepts, presented through recreational…

  4. A national knowledge-based crop recognition in Mediterranean environment

    NASA Astrophysics Data System (ADS)

    Cohen, Yafit; Shoshany, Maxim

    2002-08-01

    Population growth, urban expansion, land degradation, civil strife and war may place plant natural resources for food and agriculture at risk. Crop and yield monitoring is basic information necessary for wise management of these resources. Satellite remote sensing techniques have proven to be cost-effective in widespread agricultural lands in Africa, America, Europe and Australia. However, they have had limited success in Mediterranean regions that are characterized by a high rate of spatio-temporal ecological heterogeneity and high fragmentation of farming lands. An integrative knowledge-based approach is needed for this purpose, which combines imagery and geographical data within the framework of an intelligent recognition system. This paper describes the development of such a crop recognition methodology and its application to an area that comprises approximately 40% of the cropland in Israel. This area contains eight crop types that represent 70% of Israeli agricultural production. Multi-date Landsat TM images representing seasonal vegetation cover variations were converted to normalized difference vegetation index (NDVI) layers. Field boundaries were delineated by merging Landsat data with SPOT-panchromatic images. Crop recognition was then achieved in two-phases, by clustering multi-temporal NDVI layers using unsupervised classification, and then applying 'split-and-merge' rules to these clusters. These rules were formalized through comprehensive learning of relationships between crop types, imagery properties (spectral and NDVI) and auxiliary data including agricultural knowledge, precipitation and soil types. Assessment of the recognition results using ground data from the Israeli Agriculture Ministry indicated an average recognition accuracy exceeding 85% which accounts for both omission and commission errors. The two-phase strategy implemented in this study is apparently successful for heterogeneous regions. This is due to the fact that it allows

  5. Climatic Analysis of Oceanic Water Vapor Transports Based on Satellite E-P Datasets

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Sohn, Byung-Ju; Mehta, Vikram

    2004-01-01

    Understanding the climatically varying properties of water vapor transports from a robust observational perspective is an essential step in calibrating climate models. This is tantamount to measuring year-to-year changes of monthly- or seasonally-averaged, divergent water vapor transport distributions. This cannot be done effectively with conventional radiosonde data over ocean regions where sounding data are generally sparse. This talk describes how a methodology designed to derive atmospheric water vapor transports over the world oceans from satellite-retrieved precipitation (P) and evaporation (E) datasets circumvents the problem of inadequate sampling. Ultimately, the method is intended to take advantage of the relatively complete and consistent coverage, as well as continuity in sampling, associated with E and P datasets obtained from satellite measurements. Independent P and E retrievals from Special Sensor Microwave Imager (SSM/I) measurements, along with P retrievals from Tropical Rainfall Measuring Mission (TRMM) measurements, are used to obtain transports by solving a potential function for the divergence of water vapor transport as balanced by large scale E - P conditions.

  6. A palaeotemperature curve for the Precambrian oceans based on silicon isotopes in cherts.

    PubMed

    Robert, François; Chaussidon, Marc

    2006-10-26

    The terrestrial sediment record indicates that the Earth's climate varied drastically in the Precambrian era (before 550 million years ago), ranging from surface temperatures similar to or higher than today's to global glaciation events. The most continuous record of sea surface temperatures of that time has been derived from variations in oxygen isotope ratios of cherts (siliceous sediments), but the long-term cooling of the oceans inferred from those data has been questioned because the oxygen isotope signature could have been reset through the exchange with hydrothermal fluids after deposition of the sediments. Here we show that the silicon isotopic composition of cherts more than 550 million years old shows systematic variations with age that support the earlier conclusion of long-term ocean cooling and exclude post-depositional exchange as the main source of the isotopic variations. In agreement with other lines of evidence, a model of the silicon cycle in the Precambrian era shows that the observed silicon isotope variations imply seawater temperature changes from about 70 degrees C 3,500 million years ago to about 20 degrees C 800 million years ago.

  7. Onshore propagation of a buoyant ocean front observed using a shore-based marine radar

    NASA Astrophysics Data System (ADS)

    Marmorino, G. O.; Cooper, A. L.; Mied, R. P.; Lindemann, G. J.; Trizna, D. B.; Porter, D. L.

    2004-06-01

    An analysis is presented of a 2-h-long time series of X-band marine radar images, collected at Duck, North Carolina (USA), that captured the evolution of a buoyant ocean front as it propagated onshore, following a period of upwelling-favorable winds. In plan view, the front exhibits a scallop-shaped structure similar to that previously observed along strongly convergent fronts. This alongshore structure consists of broad frontal crests (a few hundred meters in length) alternating with sharply angled troughs, or frontal cusps. The evolution of these frontal shapes is explored using a reduced-gravity model (Cooper et al., J. Geophys. Res.-Oceans 106 (2001) 16887) that allows for nonlinear self-interaction of a propagating front. A model simulation shows cusps that develop quickly from initially broad troughs and that point toward the buoyant water, features resembling the observations. However, the simulation also shows a continuous oscillation of frontal shapes, while the observed front reaches a quasi-steady plan form. We attribute this difference in behavior to the gradual shoaling of the observed front as it steadily advances, ultimately reaching water depths of less than 2 m, which is comparable to the thickness of the buoyant layer. As a consequence of the shoaling, we suggest the cusps become sites of enhanced mixing, where water inshore of the front is also accelerated seaward.

  8. Simulation Platform: a cloud-based online simulation environment.

    PubMed

    Yamazaki, Tadashi; Ikeno, Hidetoshi; Okumura, Yoshihiro; Satoh, Shunji; Kamiyama, Yoshimi; Hirata, Yutaka; Inagaki, Keiichiro; Ishihara, Akito; Kannon, Takayuki; Usui, Shiro

    2011-09-01

    For multi-scale and multi-modal neural modeling, it is needed to handle multiple neural models described at different levels seamlessly. Database technology will become more important for these studies, specifically for downloading and handling the neural models seamlessly and effortlessly. To date, conventional neuroinformatics databases have solely been designed to archive model files, but the databases should provide a chance for users to validate the models before downloading them. In this paper, we report our on-going project to develop a cloud-based web service for online simulation called "Simulation Platform". Simulation Platform is a cloud of virtual machines running GNU/Linux. On a virtual machine, various software including developer tools such as compilers and libraries, popular neural simulators such as GENESIS, NEURON and NEST, and scientific software such as Gnuplot, R and Octave, are pre-installed. When a user posts a request, a virtual machine is assigned to the user, and the simulation starts on that machine. The user remotely accesses to the machine through a web browser and carries out the simulation, without the need to install any software but a web browser on the user's own computer. Therefore, Simulation Platform is expected to eliminate impediments to handle multiple neural models that require multiple software.

  9. Environment-protected solid-state-based distributed charge qubit

    NASA Astrophysics Data System (ADS)

    Tayebi, Amin; Hoatson, Tanya Nicole; Wang, Joie; Zelevinsky, Vladimir

    2016-12-01

    A solid-state-based charge qubit is presented. The system consists of a one-dimensional wire with a pair of qubits embedded at its center. It is shown that the system supports collective states localized in the left and right sides of the wire and therefore, as a whole, performs as a single qubit. The couplings between the ground and excited states of the two central qubits are inversely proportional making them fully asynchronized and allowing for coherent manipulation and gate operations. Initialization and measurement devices, such as leads and charge detectors, connected to the edges of the wire are modeled by a continuum of energy states. The coupling to the continuum is discussed using the effective non-Hermitian Hamiltonian. At weak continuum coupling, all internal states uniformly acquire small decay widths. This changes dramatically as the coupling strength increases: the width distribution undergoes a sharp restructuring and is no longer uniformly divided among the eigenstates. Two broad resonances localized at the ends of the wire are formed. These superradiant states (analogous to Dicke states in quantum optics) effectively protect the remaining internal states from decaying into the continuum and hence increase the lifetime of the qubit. Environmental noise is introduced by considering random Gaussian fluctuations of electronic energies. The interplay between decoherence and superradiance is studied by solving the stochastic Liouville equation. In addition to increasing the lifetime, the emergence of the superradiant states increases the qubit coherence.

  10. Smartphone-Based Hearing Screening in Noisy Environments

    PubMed Central

    Na, Youngmin; Joo, Hyo Sung; Yang, Hyejin; Kang, Soojin; Hong, Sung Hwa; Woo, Jihwan

    2014-01-01

    It is important and recommended to detect hearing loss as soon as possible. If it is found early, proper treatment may help improve hearing and reduce the negative consequences of hearing loss. In this study, we developed smartphone-based hearing screening methods that can ubiquitously test hearing. However, environmental noise generally results in the loss of ear sensitivity, which causes a hearing threshold shift (HTS). To overcome this limitation in the hearing screening location, we developed a correction algorithm to reduce the HTS effect. A built-in microphone and headphone were calibrated to provide the standard units of measure. The HTSs in the presence of either white or babble noise were systematically investigated to determine the mean HTS as a function of noise level. When the hearing screening application runs, the smartphone automatically measures the environmental noise and provides the HTS value to correct the hearing threshold. A comparison to pure tone audiometry shows that this hearing screening method in the presence of noise could closely estimate the hearing threshold. We expect that the proposed ubiquitous hearing test method could be used as a simple hearing screening tool and could alert the user if they suffer from hearing loss. PMID:24926692

  11. Design of a Problem-Based Online Learning Environment and Evaluation of Its Effectiveness

    ERIC Educational Resources Information Center

    Gündüz, Abdullah Yasin; Alemdag, Ecenaz; Yasar, Sevil; Erdem, Mukaddes

    2016-01-01

    Problem-based learning approach presents several advantages such as improving students' engagement in learning and fostering their higher-order thinking skills. Although there is a plethora of research regarding implementation of problem-based learning in classrooms, its design and application process for web-based environments need further…

  12. Ocean Fertilization and Ocean Acidification

    NASA Astrophysics Data System (ADS)

    Cao, L.; Caldeira, K.

    2008-12-01

    It has been suggested that ocean fertilization could help diminish ocean acidification. Here, we quantitatively evaluate this suggestion. Ocean fertilization is one of several ocean methods proposed to mitigate atmospheric CO2 concentrations. The basic idea of this method is to enhance the biological uptake of atmospheric CO2 by stimulating net phytoplankton growth through the addition of iron to the surface ocean. Concern has been expressed that ocean fertilization may not be very effective at reducing atmospheric CO2 concentrations and may produce unintended environmental consequences. The rationale for thinking that ocean fertilization might help diminish ocean acidification is that dissolved inorganic carbon concentrations in the near-surface equilibrate with the atmosphere in about a year. If ocean fertilization could reduce atmospheric CO2 concentrations, it would also reduce surface ocean dissolved inorganic carbon concentrations, and thus diminish the degree of ocean acidification. To evaluate this line of thinking, we use a global ocean carbon cycle model with a simple representation of marine biology and investigate the maximum potential effect of ocean fertilization on ocean carbonate chemistry. We find that the effect of ocean fertilization on ocean acidification depends, in part, on the context in which ocean fertilization is performed. With fixed emissions of CO2 to the atmosphere, ocean fertilization moderately mitigates changes in ocean carbonate chemistry near the ocean surface, but at the expense of further acidifying the deep ocean. Under the SRES A2 CO2 emission scenario, by year 2100 simulated atmospheric CO2, global mean surface pH, and saturation state of aragonite is 965 ppm, 7.74, and 1.55 for the scenario without fertilization and 833 ppm, 7.80, and 1.71 for the scenario with 100-year (between 2000 and 2100) continuous fertilization for the global ocean (For comparison, pre-industrial global mean surface pH and saturation state of

  13. Genetic algorithms with memory- and elitism-based immigrants in dynamic environments.

    PubMed

    Yang, Shengxiang

    2008-01-01

    In recent years the genetic algorithm community has shown a growing interest in studying dynamic optimization problems. Several approaches have been devised. The random immigrants and memory schemes are two major ones. The random immigrants scheme addresses dynamic environments by maintaining the population diversity while the memory scheme aims to adapt genetic algorithms quickly to new environments by reusing historical information. This paper investigates a hybrid memory and random immigrants scheme, called memory-based immigrants, and a hybrid elitism and random immigrants scheme, called elitism-based immigrants, for genetic algorithms in dynamic environments. In these schemes, the best individual from memory or the elite from the previous generation is retrieved as the base to create immigrants into the population by mutation. This way, not only can diversity be maintained but it is done more efficiently to adapt genetic algorithms to the current environment. Based on a series of systematically constructed dynamic problems, experiments are carried out to compare genetic algorithms with the memory-based and elitism-based immigrants schemes against genetic algorithms with traditional memory and random immigrants schemes and a hybrid memory and multi-population scheme. The sensitivity analysis regarding some key parameters is also carried out. Experimental results show that the memory-based and elitism-based immigrants schemes efficiently improve the performance of genetic algorithms in dynamic environments.

  14. Adjusting thresholds of satellite-based convective initiation interest fields based on the cloud environment

    NASA Astrophysics Data System (ADS)

    Jewett, Christopher P.; Mecikalski, John R.

    2013-11-01

    The Time-Space Exchangeability (TSE) concept states that similar characteristics of a given property are closely related statistically for objects or features within close proximity. In this exercise, the objects considered are growing cumulus clouds, and the data sets to be considered in a statistical sense are geostationary satellite infrared (IR) fields that help describe cloud growth rates, cloud top heights, and whether cloud tops contain significant amounts of frozen hydrometeors. In this exercise, the TSE concept is applied to alter otherwise static thresholds of IR fields of interest used within a satellite-based convective initiation (CI) nowcasting algorithm. The convective environment in which the clouds develop dictate growth rate and precipitation processes, and cumuli growing within similar mesoscale environments should have similar growth characteristics. Using environmental information provided by regional statistics of the interest fields, the thresholds are examined for adjustment toward improving the accuracy of 0-1 h CI nowcasts. Growing cumulus clouds are observed within a CI algorithm through IR fields for many 1000 s of cumulus cloud objects, from which statistics are generated on mesoscales. Initial results show a reduction in the number of false alarms of ~50%, yet at the cost of eliminating approximately ~20% of the correct CI forecasts. For comparison, static thresholds (i.e., with the same threshold values applied across the entire satellite domain) within the CI algorithm often produce a relatively high probability of detection, with false alarms being a significant problem. In addition to increased algorithm performance, a benefit of using a method like TSE is that a variety of unknown variables that influence cumulus cloud growth can be accounted for without need for explicit near-cloud observations that can be difficult to obtain.

  15. Ocean energy program summary

    NASA Astrophysics Data System (ADS)

    1990-01-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71 percent of the earth's surface, they collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the U.S. Department of Energy's (DOE) Ocean Energy Technology (OET) Program is to develop techniques that harness this ocean energy cost effectively and in a way that does not harm the environment. The program seeks to develop ocean energy technology to a point where industry can accurately assess whether the technology is a viable energy conversion alternative, or supplement, to current power generating systems. In past studies, DOE identified ocean thermal energy conversion (OTEC), which uses the temperature difference between warm surface water and cold deep water, as the most promising of the ocean energy technologies. As a result, the OET Program is concentrating on research that advances the OTEC technology. The program also continues to monitor and study developments in wave energy, ocean current, and salinity gradient concepts; but it is not actively developing these technologies now.

  16. Atmospheric Torques on the Solid Earth and Oceans Based on the GEOS-1 General Circulation Model

    NASA Technical Reports Server (NTRS)

    Sanchez, Braulio V.; Au, Andrew Y.

    1998-01-01

    The GEOS-1 general circulation model has been used to compute atmospheric torques on the oceans and solid Earth for the period 1980-1995. The time series for the various torque components have been analyzed by means of Fourier transform techniques. It was determined that the wind stress torque over land is more powerful than the wind stress torque over water by 55%, 42%, and 80% for the x, y, and z components respectively. This is mainly the result of power in the high frequency range. The pressure torques due to polar flattening, equatorial ellipticity, marine geoid, and continental orography were computed. The orographic or "mountain torque" components are more powerful than their wind stress counterparts (land plus ocean) by 231% (x), 191% (y), and 77% (z). The marine pressure torques due to geoidal undulations are much smaller than the orographic ones, as expected. They are only 3% (x), 4% (y), and 5% (z) of the corresponding mountain torques. The geoidal pressure torques are approximately equal in magnitude to those produced by the equatorial ellipticity of the Earth. The pressure torque due to polar flattening makes the largest contributions to the atmospheric torque budget. It has no zonal component, only equatorial ones. Most of the power of the latter, between 68% and 69%, is found in modes with periods under 15 days. The single most powerful mode has a period of 361 days. The gravitational torque ranks second in power only to the polar flattening pressure torque. Unlike the former, it does produce a zonal component, albeit much smaller (1%) than the equatorial ones. The gravitational and pressure torques have opposite signs, therefore, the gravitational torque nullifies 42% of the total pressure torque. Zonally, however, the gravitational torque amounts to only 6% of the total pressure torque. The power budget for the total atmospheric torque yields 7595 and 7120 Hadleys for the equatorial components and 966 Hadleys for the zonal. The x-component exhibits

  17. Atmospheric Torques on the Solid Earth and Oceans Based on the GEOS-1 General Circulation Model

    NASA Technical Reports Server (NTRS)

    Sanchez, Braulio

    1999-01-01

    The GEOS-1 general circulation model has been used to compute atmospheric torques on the oceans and solid Earth for the period 1980-1995. The time series for the various torque components have been analyzed by means of Fourier transform techniques. It was determined that the wind stress torque over land is more powerful than the wind stress torque over water by 55\\%, 42\\%, and 80\\t for the x, y, and z components respectively. This is mainly the result of power in the high frequency range. The pressure torques due to polar flattening, equatorial ellipticity, marine geoid, and continental orography were computed. The orographic or "mountain torque" components are more powerful than their wind stress counterparts (land plus ocean) by 231\\% (x), 191\\% (y), and 77\\% (z). The marine pressure torques due to geoidal undulations are much smaller than the orographic ones, as expected. They are only 3\\% (x), 4\\% (y), and 5\\% (z) of the corresponding mountain torques. The geoidal pressure torques are approximately equal in magnitude to those produced by the equatorial ellipticity of the Earth. The pressure torque due to polar flattening makes the largest contributions to the atmospheric'torque budget. It has no zonal component, only equatorial ones. Most of the power of the latter, between 68\\% and 69 %, is found in modes with periods under 15 days. The single most powerful mode has a period of 361 days. The gravitational torque ranks second in power only to the polar flattening pressure torque. Unlike the former, it does produce a zonal component, albeit much smaller (1\\ ) than the equatorial ones. The gravitational and pressure torques have opposite signs, therefore, the gravitational torque nullifies 42\\% of the total pressure torque. Zonally, however, the gravitational torque amounts to only 6\\% of the total pressure torque. The power budget for the total atmospheric torque yields 7595 and 7120 Hadleys for the equatorial components and 966 Hadleys for the

  18. Ubiquitous cyanobacterial podoviruses in the global oceans unveiled through viral DNA polymerase gene sequences.

    PubMed

    Huang, Sijun; Wilhelm, Steven W; Jiao, Nianzhi; Chen, Feng

    2010-10-01

    As a major cyanophage group, cyanobacterial podoviruses are important in regulating the biomass and population structure of picocyanobacteria in the ocean. However, little is known about their biogeography in the open ocean. This study represents the first survey of the biodiversity of cyanopodoviruses in the global oceans based on the viral encoded DNA polymerase (pol) gene. A total of 303 DNA pol sequences were amplified by PCR from 10 virus communities collected in the Atlantic and Pacific oceans and the South China Sea. At least five subclusters of cyanopodoviruses were identified in these samples, and one subcluster (subcluster VIII) was found in all sampling sites and comprised approximately 50% of total sequences. The diversity index based on the DNA pol gene sequences recovered through PCR suggests that cyanopodoviruses are less diverse in these oceanic samples than in a previously studied estuarine environment. Although diverse podoviruses were present in the global ocean, each sample was dominated by one major group of cyanopodoviruses. No clear biogeographic patterns were observed using statistical analysis. A metagenomic analysis based on the Global Ocean Sampling database indicates that other types of cyanopodovirus-like DNA pol sequences were present in the global ocean. Together, our study results suggest that cyanopodoviruses are widely distributed in the ocean but their community composition varies with local environments.

  19. Using evidence-based leadership initiatives to create a healthy nursing work environment.

    PubMed

    Nayback-Beebe, Ann M; Forsythe, Tanya; Funari, Tamara; Mayfield, Marie; Thoms, William; Smith, Kimberly K; Bradstreet, Harry; Scott, Pamela

    2013-01-01

    In an effort to create a healthy nursing work environment in a military hospital Intermediate Care Unit (IMCU), a facility-level Evidence Based Practice working group composed of nursing.Stakeholders brainstormed and piloted several unit-level evidence-based leadership initiatives to improve the IMCU nursing work environment. These initiatives were guided by the American Association of Critical Care Nurses Standards for Establishing and Sustaining Healthy Work Environments which encompass: (1) skilled communication, (2) true collaboration, (3) effective decision making, (4) appropriate staffing, (5) meaningful recognition, and (6) authentic leadership. Interim findings suggest implementation of these six evidence-based, relationship-centered principals, when combined with IMCU nurses' clinical expertise, management experience, and personal values and preferences, improved staff morale, decreased staff absenteeism, promoted a healthy nursing work environment, and improved patient care.

  20. The use of computer vision techniques to augment home based sensorised environments.

    PubMed

    Uhríková, Zdenka; Nugent, Chris D; Hlavác, Václav

    2008-01-01

    Technology within the home environment is becoming widely accepted as a means to facilitate independent living. Nevertheless, practical issues of detecting different tasks between multiple persons within the same environment along with managing instances of uncertainty associated with recorded sensor data are two key challenges yet to be fully solved. This work presents details of how computer vision techniques can be used as both alternative and complementary means in the assessment of behaviour in home based sensorised environments. Within our work we assessed the ability of vision processing techniques in conjunction with sensor based data to deal with instances of multiple occupancy. Our Results indicate that the inclusion of the video data improved the overall process of task identification by detecting and recognizing multiple people in the environment using color based tracking algorithm.

  1. POM.gpu-v1.0: a GPU-based Princeton Ocean Model

    NASA Astrophysics Data System (ADS)

    Xu, S.; Huang, X.; Oey, L.-Y.; Xu, F.; Fu, H.; Zhang, Y.; Yang, G.

    2015-09-01

    Graphics processing units (GPUs) are an attractive solution in many scientific applications due to their high performance. However, most existing GPU conversions of climate models use GPUs for only a few computationally intensive regions. In the present study, we redesign the mpiPOM (a parallel version of the Princeton Ocean Model) with GPUs. Specifically, we first convert the model from its original Fortran form to a new Compute Unified Device Architecture C (CUDA-C) code, then we optimize the code on each of the GPUs, the communications between the GPUs, and the I / O between the GPUs and the central processing units (CPUs). We show that the performance of the new model on a workstation containing four GPUs is comparable to that on a powerful cluster with 408 standard CPU cores, and it reduces the energy consumption by a factor of 6.8.

  2. 40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for...

  3. 40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for...

  4. 40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for...

  5. 40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for...

  6. 40 CFR 227.14 - Criteria for evaluating the need for ocean dumping and alternatives to ocean dumping.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ocean dumping and alternatives to ocean dumping. 227.14 Section 227.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Need for Ocean Dumping § 227.14 Criteria for evaluating the need for...

  7. Quaternary history of sea ice in the western Arctic Ocean based on foraminifera

    NASA Astrophysics Data System (ADS)

    Polyak, Leonid; Best, Kelly M.; Crawford, Kevin A.; Council, Edward A.; St-Onge, Guillaume

    2013-11-01

    Sediment cores from the Northwind Ridge, western Arctic Ocean, including uniquely preserved calcareous microfossils, provide the first continuous proxy record of sea ice in the Arctic Ocean encompassing more than half of the Quaternary. The cores were investigated for foraminiferal assemblages along with coarse grain size and bulk chemical composition. By combination of glacial cycles and unique events reflected in the stratigraphy, the age of the foraminiferal record was estimated as ca 1.5 Ma. Foraminiferal abundances, diversity, and composition of benthic assemblages, especially phytodetritus and polar species, were used as proxies for sea-ice conditions. Foraminiferal Assemblage Zone 2 in the Lower Pleistocene indicates diminished, mostly seasonal sea ice, probably facilitated by enhanced inflow of Pacific waters. A gradual decrease in ice-free season with episodes of abrupt ice expansion is interpreted for the Mid-Pleistocene Transition, consistent with climatic cooling and ice-sheet growth in the Northern Hemisphere. A principal faunal and sedimentary turnover occurred near the Early-Middle Pleistocene boundary ca 0.75 Ma, with mostly perennial sea ice indicated by the overlying Assemblage Zone 1. Two steps of further increase in sea-ice coverage are inferred from foraminiferal assemblage changes in the "Glacial" Pleistocene by ca 0.4 and 0.24 Ma, possibly related to hemispheric (Mid-Brunhes Event) and Laurentide ice sheet growth, respectively. These results suggest that year-round ice in the western Arctic was a norm for the last several 100 ka, in contrast to rapidly disappearing summer ice today.

  8. Development of a High-Stability Microstrip-based L-band Radiometer for Ocean Salinity Measurements

    NASA Technical Reports Server (NTRS)

    Pellerano, Fernando A.; Horgan, Kevin A.; Wilson, William J.; Tanner, Alan B.

    2004-01-01

    The development of a microstrip-based L-band Dicke radiometer with the long-term stability required for future ocean salinity measurements to an accuracy of 0.1 psu is presented. This measurement requires the L-band radiometers to have calibration stabilities of less than or equal to 0.05 K over 2 days. This research has focused on determining the optimum radiometer requirements and configuration to achieve this objective. System configuration and component performance have been evaluated with radiometer test beds at both JPL and GSFC. The GSFC testbed uses a cryogenic chamber that allows long-term characterization at radiometric temperatures in the range of 70 - 120 K. The research has addressed several areas including component characterization as a function of temperature and DC bias, system linearity, optimum noise diode injection calibration, and precision temperature control of components. A breadboard radiometer, utilizing microstrip-based technologies, has been built to demonstrate this long-term stability.

  9. PAME Proceedings, Pattern Analysis in the Marine Environment, an Ocean Science and Technology Workshop Held at the Naval Ocean Research and Development Activity, NSTL, MS. on 24-26 March 1982.

    DTIC Science & Technology

    1983-10-01

    2//,, 6 AA A Hii "Al6 M A iViV ’ .A ~~~~~ ,’V ?’ N * V ZV . , N t: .. tiGG Ot :: +iooo~ : t’ 5iWp C*- %,.!:4’iv. V VO O"v, +a v vV$ NCd 3 0t $ 133 I...Catalina Island . The *sonar subsystems described are employed on five sonars: port side looking, starboard side looking, down or altitude, up or depth...PROCESSING OF ZOOPLANKTON SAMPLES....Arthur D. Poularikas, University of Rhode Island , Luther E. Bivins, Office of Ocean Technology and Engineering

  10. Oceanic processes in marine pollution

    SciTech Connect

    Champ, M.A. ); Park, P.K. )

    1989-01-01

    This book covers the following areas: disposal of low-level radioactive wastes in oceans; disposal of coal wastes in marine environments; the role of pollution conventions and regulation of oil disposal; and monitoring of high-level radioactive waste disposal sites in oceans.

  11. Preface to special issue (Impacts of surface ocean acidification in polar seas and globally: A field-based approach)

    NASA Astrophysics Data System (ADS)

    Tyrrell, Toby; Tarling, Geraint A.; Leakey, Raymond J. G.; Cripps, Gemma; Thorpe, Sally; Richier, Sophie; Mark Moore, C.

    2016-05-01

    Both ocean acidification and global warming are consequences of the rise in atmospheric CO2. Ocean acidification is not itself a consequence of global warming, but rather of the invasion of atmospheric CO2 into the ocean. Time-series of carbonate chemistry measurements in different locations around the world all document the continuous and ongoing increase in the amount of CO2 in the ocean, and the consequential accompanying decrease in surface ocean seawater pH at all sites over the last years (Bates et al., 2014).

  12. Analysis of 2012 M8.6 Indian Ocean earthquake coseismic slip model based on GPS data

    NASA Astrophysics Data System (ADS)

    Maulida, Putra; Meilano, Irwan; Gunawan, Endra; Efendi, Joni

    2016-05-01

    The CGPS (Continuous Global Position System) data of Sumatran GPS Array (CGPS) and Indonesian Geospatial Agency (BIG) in Sumatra are processed to estimate the best fit coseismic model of 2012 M8.6 Indian Ocean earthquake. For GPS data processing, we used the GPS Analysis at Massachusetts Institute of Technology (GAMIT) 10.5 software and Global Kalman Filter (GLOBK) to generate position time series of each GPS stations and estimate the coseismic offset due to the Earthquake. The result from GPS processing indicates that the earthquake caused displacement northeast ward up to 25 cm in northern Sumatra. Results also show subsidence at the northern Sumatran while the central part of Sumatra show northwest direction displacement, but we cannot find whether the subsidence or the uplift signal associated to the earthquake due to the vertical data quality. Based on the GPS coseismic data, we evaluate the coseismic slip model of Indian Ocean Earthquake produced by previous study [1], [2], [3]. We calculated coseismic displacement using half-space with earthquake slip model input and compare it with the displacement produced form GPS data.

  13. Ship-based Aerosol Optical Depth Measurements in the Atlantic Ocean, Comparison with Satellite Retrievals and GOCART Model

    NASA Astrophysics Data System (ADS)

    Smirnov, A.; Holben, B. N.; Sakerin, S.; Kabanov, D.; Slutsker, I.; Remer, L. A.; Kahn, R.; Ignatov, A.; Chin, M.; Diehl, T. L.; Mishchenko, M.; Liu, L.; Kucsera, T. L.; Giles, D.; Eck, T. F.; Torres, O.; Kopelevich, O.

    2005-12-01

    Aerosol optical depth measurements were made in October -December 2004 aboard of R/V Akademik Sergey Vavilov. The cruise area included the Atlantic transect from North Sea to Cape Town and then a crossing in the South Atlantic to Ushuaia, Argentina. The hand-held Microtops II sunphotometer was used to acquire 314 series of measurements spanning 38 days. The sunphotometer was pre-calibrated at the NASA Goddard Space Flight Center against a master sun/sky radiometer instrument of the Aerosol Robotic Network (AERONET). The direct sun measurements were acquired in five spectral channels: 340, 440, 675, 870 and 940 nm. To retrieve aerosol optical depths we applied AERONET processing algorithm (Version 2) to the raw data. Aerosol optical depth values were close to background oceanic conditions (0.04-0.08) in the open oceanic areas not influenced by continental sources. Spectral dependence can be described as almost neutral (Angstrom parameter was less than 0.6), especially in the Southern Atlantic. A notable latitudinal variability of optical depth was observed between 15N and 21S, which was associated with the aerosol transport from Africa. Correlations between optical depth and meteorological parameters were considered and comparison between ship-based measurements and AERONET sites along the cruise track was made. Aerosol optical depths were compared to the global transport model (GOCART) simulations and satellite retrievals from MODIS, MISR, and AVHRR.

  14. Environment-based pin-power reconstruction method for homogeneous core calculations

    SciTech Connect

    Leroyer, H.; Brosselard, C.; Girardi, E.

    2012-07-01

    Core calculation schemes are usually based on a classical two-step approach associated with assembly and core calculations. During the first step, infinite lattice assemblies calculations relying on a fundamental mode approach are used to generate cross-sections libraries for PWRs core calculations. This fundamental mode hypothesis may be questioned when dealing with loading patterns involving several types of assemblies (UOX, MOX), burnable poisons, control rods and burn-up gradients. This paper proposes a calculation method able to take into account the heterogeneous environment of the assemblies when using homogeneous core calculations and an appropriate pin-power reconstruction. This methodology is applied to MOX assemblies, computed within an environment of UOX assemblies. The new environment-based pin-power reconstruction is then used on various clusters of 3x3 assemblies showing burn-up gradients and UOX/MOX interfaces, and compared to reference calculations performed with APOLLO-2. The results show that UOX/MOX interfaces are much better calculated with the environment-based calculation scheme when compared to the usual pin-power reconstruction method. The power peak is always better located and calculated with the environment-based pin-power reconstruction method on every cluster configuration studied. This study shows that taking into account the environment in transport calculations can significantly improve the pin-power reconstruction so far as it is consistent with the core loading pattern. (authors)

  15. Ocean thermal plant

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1979-01-01

    Modular Ocean Thermal-Energy Conversion (OTEC) plant permits vital component research and testing and serves as operational generator for 100 megawatts of electric power. Construction permits evaporators and condensers to be tested in same environment in which they will be used, and could result in design specifications for most efficient plant facilities in future.

  16. Diving into Oceans.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1992-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Diving Into Oceans." Contents are organized into the following…

  17. A Neuro-Fuzzy System for Extracting Environment Features Based on Ultrasonic Sensors

    PubMed Central

    Marichal, Graciliano Nicolás; Hernández, Angela; Acosta, Leopoldo; González, Evelio José

    2009-01-01

    In this paper, a method to extract features of the environment based on ultrasonic sensors is presented. A 3D model of a set of sonar systems and a workplace has been developed. The target of this approach is to extract in a short time, while the vehicle is moving, features of the environment. Particularly, the approach shown in this paper has been focused on determining walls and corners, which are very common environment features. In order to prove the viability of the devised approach, a 3D simulated environment has been built. A Neuro-Fuzzy strategy has been used in order to extract environment features from this simulated model. Several trials have been carried out, obtaining satisfactory results in this context. After that, some experimental tests have been conducted using a real vehicle with a set of sonar systems. The obtained results reveal the satisfactory generalization properties of the approach in this case. PMID:22303160

  18. A neuro-fuzzy system for extracting environment features based on ultrasonic sensors.

    PubMed

    Marichal, Graciliano Nicolás; Hernández, Angela; Acosta, Leopoldo; González, Evelio José

    2009-01-01

    In this paper, a method to extract features of the environment based on ultrasonic sensors is presented. A 3D model of a set of sonar systems and a workplace has been developed. The target of this approach is to extract in a short time, while the vehicle is moving, features of the environment. Particularly, the approach shown in this paper has been focused on determining walls and corners, which are very common environment features. In order to prove the viability of the devised approach, a 3D simulated environment has been built. A Neuro-Fuzzy strategy has been used in order to extract environment features from this simulated model. Several trials have been carried out, obtaining satisfactory results in this context. After that, some experimental tests have been conducted using a real vehicle with a set of sonar systems. The obtained results reveal the satisfactory generalization properties of the approach in this case.

  19. Calculation of Shuttle Base Heating Environments and Comparison with Flight Data

    NASA Technical Reports Server (NTRS)

    Greenwood, T. F.; Lee, Y. C.; Bender, R. L.; Carter, R. E.

    1983-01-01

    The techniques, analytical tools, and experimental programs used initially to generate and later to improve and validate the Shuttle base heating design environments are discussed. In general, the measured base heating environments for STS-1 through STS-5 were in good agreement with the preflight predictions. However, some changes were made in the methodology after reviewing the flight data. The flight data is described, preflight predictions are compared with the flight data, and improvements in the prediction methodology based on the data are discussed.

  20. Enriching Project-Based Learning Environments with Virtual Manipulatives: A Comparative Study

    ERIC Educational Resources Information Center

    Çakiroglu, Ünal

    2014-01-01

    Problem statement: Although there is agreement on the potential of project based learning (PBL) and virtual manipulatives (VMs), their positive impact depends on how they are used. This study was based on supporting the use of online PBL environments and improving the efficacy of the instructional practices in PBL by combining the potentials of…