Science.gov

Sample records for ocean environment based

  1. Model-Based Detection in a Shallow Water Ocean Environment

    SciTech Connect

    Candy, J V

    2001-07-30

    A model-based detector is developed to process shallow water ocean acoustic data. The function of the detector is to adaptively monitor the environment and decide whether or not a change from normal has occurred. Here we develop a processor incorporating both a normal-mode ocean acoustic model and a vertical hydrophone array. The detector is applied to data acquired from the Hudson Canyon experiments at various ranges and its performance is evaluated.

  2. Broadband model-based processing for shallow ocean environments

    SciTech Connect

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

    1998-07-01

    Most acoustic sources found in the ocean environment are spatially complex and broadband. In the case of shallow water propagation, these source characteristics complicate the analysis of received acoustic data considerably. A common approach to the broadband problem is to decompose the received signal into a set of narrow-band lines. This then allows the problem to be treated as a multiplicity of narrow-band problems. Here a model-based approach is developed for the processing of data received on a vertical array from a broadband source where it is assumed that the propagation is governed by the normal-mode model. The goal of the processor is to provide an enhanced (filtered) version of the pressure at the array and the modal functions. Thus a pre-processor is actually developed, since one could think of several applications for these enhanced quantities such as localization, modal estimation, etc. It is well-known that in normal-mode theory a different modal structure evolves for each temporal frequency; thus it is not surprising that the model-based solution to this problem results in a scheme that requires a {open_quotes}bank{close_quotes} of narrow-band model-based processors{emdash}each with its own underlying modal structure for the narrow frequency band it operates over. The {open_quotes}optimal{close_quotes} Bayesian solution to the broadband pressure field enhancement and modal function extraction problem is developed. It is shown how this broadband processor can be implemented (using a suboptimal scheme) in pseudo real time due to its inherent parallel structure. A set of noisy broadband data is synthesized to demonstrate how to construct the processor and achieve a minimum variance (optimal Bayesian) design. It is shown that both broadband pressure-field and modal function estimates can be extracted illustrating the feasibility of this approach. {copyright} {ital 1998 Acoustical Society of America.}

  3. 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.

  4. Monitoring the Ocean Acoustic Environment: A Model-Based Detection Approach

    SciTech Connect

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

    2000-03-13

    A model-based approach is applied in the development of a processor designed to passively monitor an ocean acoustic environment along with its associated variations. The technique employs an adaptive, model-based processor embedded in a sequential likelihood detection scheme. The trade-off between state-based and innovations-based monitor designs is discussed, conceptually. The underlying theory for the innovations-based design is briefly developed and applied to a simulated data set.

  5. 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.

  6. 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…

  7. 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…

  8. Broadband acoustic source processing in a noisy shallow ocean environment

    SciTech Connect

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

    1996-07-18

    Acoustic sources found in the ocean environment are spatially complex and broadband, complicating the analysis of received acoustic data considerably. A model-based approach is developed for a broadband source in a shallow ocean environment characterized by a normal-mode propagation model. Here we develop the optimal Bayesian solution to the broadband pressure-field enhancement and modal function extraction problem.

  9. 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

  10. Model-based ocean acoustic passive localization

    SciTech Connect

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

    1994-01-24

    The detection, localization and classification of acoustic sources (targets) in a hostile ocean environment is a difficult problem -- especially in light of the improved design of modern submarines and the continual improvement in quieting technology. Further the advent of more and more diesel-powered vessels makes the detection problem even more formidable than ever before. It has recently been recognized that the incorporation of a mathematical model that accurately represents the phenomenology under investigation can vastly improve the performance of any processor, assuming, of course, that the model is accurate. Therefore, it is necessary to incorporate more knowledge about the ocean environment into detection and localization algorithms in order to enhance the overall signal-to-noise ratios and improve performance. An alternative methodology to matched-field/matched-mode processing is the so-called model-based processor which is based on a state-space representation of the normal-mode propagation model. If state-space solutions can be accomplished, then many of the current ocean acoustic processing problems can be analyzed and solved using this framework to analyze performance results based on firm statistical and system theoretic grounds. The model-based approach, is (simply) ``incorporating mathematical models of both physical phenomenology and the measurement processes including noise into the processor to extract the desired information.`` In this application, we seek techniques to incorporate the: (1) ocean acoustic propagation model; (2) sensor array measurement model; and (3) noise models (ambient, shipping, surface and measurement) into a processor to solve the associated localization/detection problems.

  11. 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.

  12. Nitrogen recycling efficiency in steady-state oceanic environments

    NASA Astrophysics Data System (ADS)

    King, Frederick D.

    1987-06-01

    Nitrogen recycling in oceanic environments is considered on a cost to benefit basis; recycling efficiency ( R) defines the ratio of total heterotrophic nitrogen regeneration to the rate of phytoplankton grazed. A simple model is derived which demonstrates that R is a function of the excretion to ingestion ratios of organisms at each trophic level as well as the length of the food chain. R is discussed in relation to ecological efficiency, and model equations are solved for relative production, regeneration and egestion for 1-5 trophic levels using an ecological efficiency characteristic of an oceanic environment. Analysis of the microbial loop on the basis of recycling efficiency indicates that marine microheterotrophs may not contribute as much to nitrogen regeneration as previously suggested. Finally, the ecological role of nitrogen recycling is discussed in relation to the maintenance of nutrient-sufficient relatively high growing algal populations in oceanic waters depleted of inorganic nitrogen.

  13. 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.

  14. Optimal Localization of Ocean Acoustic Sources in AN Uncertain Environment

    NASA Astrophysics Data System (ADS)

    Richardson, Anthony Merle

    1990-01-01

    In this paper, a method for determining the position of an underwater acoustic source from observations of the associated acoustic field and information about the acoustic environment is presented. This algorithm, unlike matched field processing algorithms, does not require complete knowledge of the acoustic environment, but can determine source position even with uncertain or imprecise information about the environment. The algorithm is termed the optimum uncertain field processing algorithm. Parameter estimation theory is utilized to derive the new algorithm. This provides a systematic, optimal approach to the problem, and allows environmental uncertainty to be easily incorporated into the algorithm. In addition to estimating source position, estimates of parameters of the acoustic environment can also be calculated. This makes simultaneous source localization and acoustic tomographic estimation of ocean parameters possible. A detailed discussion of the acoustic propagation models used in the research is presented. The defining equation for the optimum uncertain field processor is then derived. It is shown that the algorithm reduces to a popular matched field processing technique for the special case in which the environment is completely known. A series of studies that illustrate the robust performance of the uncertain field processor, relative to the performance of matched field processing methods, is made. Estimation of ocean acoustic parameters is also illustrated. The affects of environmental uncertainty, source position, and frequency on localization performance are examined.

  15. 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

  16. Fiber Optic Cables in a Harsh Ocean Environment

    NASA Astrophysics Data System (ADS)

    Glavas, Xenophon G.

    1987-02-01

    Fiber optic cables have found widespread use in the ocean, but to fulfill its mission the cable must survive deployment and operation scenarios. Preservation of the manufactured strength and the optical transmission capacity of the optical fiber over its application lifetime are the primary system objectives. Other secondary objectives defined by system requirements include: fiber count, flexibility, weight, strength, lifetime, manufacturability, diameter, specific gravity, torsion stiffness, temperature influence, pressure effects, abrasion, cyclic flexure resistance, to name a few. This paper will discuss fiber optic cables, causes of failures, and their materials for use in the ocean for three general classes: a. Low cost, disposable cables. This requires the replacement rather than the repair of subject cables. Several applications fall into this category namely torpedo guidance, rapidly dispensible acoustic systems, and sonobuoy links. Life expectancy is months. b. Moderate cost, replaceable cables. This class of cables also requires the replacement of the cable; however, the system lifetime requires the cable be manufactured with the best materials for ocean service so once it is deployed, survival is ensured for many months or even years. Once the cable has failed, there will be no attempt to repair or recover the product, only replace it. Again, this type of cable would see an environment that spans the ocean depths. c. High cost, repairable cables. This class of cables constitutes the family of cables that generally require many years of service, extremely high cable bandwidth (high fiber count), span the major ocean depths and service continents or nations for their communications needs. The starting point for any cable design is defining the requirements the cable must meet. A systems approach is used to derive and impose on the design those requirements that influence cable function, life, cost and transmission capacity. A system analyses defines the

  17. 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. PMID:26515473

  18. Marine-acquired infections. Hazards of the ocean environment.

    PubMed

    Chang, W J; Pien, F D

    1986-09-15

    Numerous pathogenic bacteria are found in seawater. They can cause several environmental infections, such as conjunctivitis, otitis externa, wound infections, pneumonia, and gastrointestinal illness. The incidence of some of these infections could be lowered if people took care to avoid eating undercooked seafood, swimming in brackish water, or sustaining lacerations in a marine environment. However, such infections will probably increase in frequency as more people visit ocean resorts. Prompt elimination of the infective agent, adequate wound care, and avoidance of reexposure can minimize the severity of the condition. PMID:3763516

  19. 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.)

  20. 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)

  1. 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)

  2. Lidar description of the evaporative duct in ocean environments

    NASA Astrophysics Data System (ADS)

    Willitsford, Adam; Philbrick, C. R.

    2005-08-01

    The description of radar propagation in the presence of the evaporation duct has proven to be a difficult problem in both littoral and open ocean environments. To properly characterize the propagation of a radar beam at low elevation angles, the evaporation duct must be located and scattering properties quantified. The two key elements defining an evaporation duct are the gradients in density and specific humidity. The gradients of the neutral density are determined from the rotational Raman temperature profile. The profile of water vapor is measured directly from the vibrational Raman scattered returns. High spatial resolution and high temporal resolution measurements of water vapor and temperature are required to accurately describe the evaporation duct. Raman lidar techniques can provide these measurements continuously with high accuracy and high resolution so the development of the evaporation duct can be studied. A detailed simulation of a Raman lidar has been developed and applied to a near horizontal path, to examine the expected accuracy for high vertical resolution profiles. The simulation also allows various atmospheric scenarios to be investigated and analyzed. The evaporation duct is an atmospheric phenomenon that causes radar propagation to remain trapped in the surface layer. The duct can be thought of as a waveguide that bends and reflects the radar beam along a path effectively trapping it and guiding it over long distances. This is a major problem for radar propagation paths in both littoral and open ocean environments. Moreover, ducting skews details of radar returns such that radar objects are hidden, or are detected at unexpected distances, or may appear with apparent cross-sections and speeds much different than their actual values.

  3. 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. PMID:26457869

  4. 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.

  5. 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.

  6. Comparison of aerosol size distribution in coastal and oceanic environments

    NASA Astrophysics Data System (ADS)

    Kusmierczyk-Michulec, Jolanta; van Eijk, Alexander M.

    2006-08-01

    The results of applying the empirical orthogonal functions (EOF) method to decomposition and approximation of aerosol size distributions are presented. A comparison was made for two aerosol data sets, representing coastal and oceanic environments. The first data set includes measurements collected at the Irish Atlantic coast in 1994 and 1995, the second one data collected during the Rough Evaporation Duct (RED) experiment that took place off Oahu, Hawaii in 2001. The main finding is that aerosol size distributions can be represented by a superposition of the mean size distribution and the first eigenvector multiplied by an amplitude function. For the two aerosol data sets the mean size distribution is very similar in the range of small particles sizes (radius < 1μm) but the main difference appears for larger aerosols (radius > 1μm). It is also reflected by the spectral shape of the eigenvector. The differences can be related to the type of aerosols present at both locations, and the amplitude function can be associated to meteorological conditions. The amplitude function also indicates the episodes with the maximum/minimum continental influence. The results of this analysis will be used in upgrades of the ANAM model.

  7. 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

  8. Task performance under water. An evaluation of manual dexterity efficiency in the open ocean underwater environment.

    PubMed

    Hancock, P A; Miller, E K

    1986-06-01

    The present review examines studies which have reported on the performance of submerged operators on manual dexterity tasks in the practical arena of the open ocean underwater environment. The previous emphasis on the primacy of the factor situational anxiety, in degrading efficiency, is questioned. The case for environmentally-based factors and performer skill level as potent influences on performance is advanced. In postulating a potential linear relationship between depth of operation and performance decrement for air-breathing divers, the review seeks to stimulate further experimental examination of this important applied issue. PMID:15676579

  9. 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.

  10. 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.

  11. Real-time generation of infrared ocean scene based on GPU

    NASA Astrophysics Data System (ADS)

    Jiang, Zhaoyi; Wang, Xun; Lin, Yun; Jin, Jianqiu

    2007-12-01

    Infrared (IR) image synthesis for ocean scene has become more and more important nowadays, especially for remote sensing and military application. Although a number of works present ready-to-use simulations, those techniques cover only a few possible ways of water interacting with the environment. And the detail calculation of ocean temperature is rarely considered by previous investigators. With the advance of programmable features of graphic card, many algorithms previously limited to offline processing have become feasible for real-time usage. In this paper, we propose an efficient algorithm for real-time rendering of infrared ocean scene using the newest features of programmable graphics processors (GPU). It differs from previous works in three aspects: adaptive GPU-based ocean surface tessellation, sophisticated balance equation of thermal balance for ocean surface, and GPU-based rendering for infrared ocean scene. Finally some results of infrared image are shown, which are in good accordance with real images.

  12. 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. PMID:10097047

  13. 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

  14. 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. PMID:26808718

  15. Ocean Wave Simulation Based on Wind Field

    PubMed Central

    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. PMID:26808718

  16. Forecasting the ocean optical environment in support of Navy mine warfare operations

    NASA Astrophysics Data System (ADS)

    Ladner, S. D.; Arnone, R.; Jolliff, J.; Casey, B.; Matulewski, K.

    2012-06-01

    A 3D ocean optical forecast system called TODS (Tactical Ocean Data System) has been developed to determine the performance of underwater LIDAR detection/identification systems. TODS fuses optical measurements from gliders, surface satellite optical properties, and 3D ocean forecast circulation models to extend the 2-dimensional surface satellite optics into a 3-dimensional optical volume including subsurface optical layers of beam attenuation coefficient (c) and diver visibility. Optical 3D nowcast and forecasts are combined with electro-optical identification (EOID) models to determine the underwater LIDAR imaging performance field used to identify subsurface mine threats in rapidly changing coastal regions. TODS was validated during a recent mine warfare exercise with Helicopter Mine Countermeasures Squadron (HM-14). Results include the uncertainties in the optical forecast and lidar performance and sensor tow height predictions that are based on visual detection and identification metrics using actual mine target images from the EOID system. TODS is a new capability of coupling the 3D optical environment and EOID system performance and is proving important for the MIW community as both a tactical decision aid and for use in operational planning, improving timeliness and efficiency in clearance operations.

  17. 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

  18. Response to Comment on "Open-ocean fish reveal an omnidirectional solution to camouflage in polarized environments".

    PubMed

    Brady, Parrish; Gilerson, Alex; Kattawar, George; Sullivan, Jim; Twardowski, Mike; Dierssen, Heidi; Cummings, Molly

    2016-08-01

    Cronin et al take issue with our evidence for polarocryptic carangid fish based on concerns of pseudoreplication, our contrast metric, and habitat. We clarify (i) the importance of camouflage in near-surface open ocean environments and (ii) the use of a Stokes contrast metric and further (iii) conduct individual-based statistics on our data set to confirm the reported polarocrypsis patterns. PMID:27493177

  19. Ocean predictability studies in a parallel computing environment. Final report

    SciTech Connect

    Leary, R.H.

    1992-11-01

    The goal of the SDSC effort described here is to evaluate the performance potential of the Oberhuber isopycnal (OPYC) ocean global circulation model on the 64-node iPSC/860 parallel computer at SDSC and its near term successor, the Intel Paragon, relative to that of a single vector processor of a CRAY Y-MP and its near term successor, the CRAY C90. This effort is in support of a larger joint project with researchers at Scripps Institution of Oceanography to study the properties of long (10 to 100-year scale), computationally intensive integrations of ocean global circulation models. Generally, performance of the OPYC model on the iPSC/860 has proved quite disappointing, with a simplified version of the entire model running at approximately 1.4 Mflops on a single i860 node in its original form and after extensive optimization, including coding in assembler, at 3.2 Mflops. The author estimates overall performance to be limited to 75 Mflops or less on the 64-node machine, as compared to 180 Mflops for a single CRAY Y-MP processor and 500 Mflops for a single CRAY C90 processor. Similarly, he believes an implementation on an Intel Paragon, even with several hundred nodes, will not be competitive with a single processor C90 implementation. Additionally, the Hamburg Large Scale Geostrophic (LSG) model has been implemented on high-performance workstations and evaluated for its computational potential as an alternative to OPYC for the long term integrations.

  20. Iron Resources and Oceanic Nutrients: Advancement of Global Environment Simulations

    NASA Astrophysics Data System (ADS)

    Debaar, H. J.

    2002-12-01

    The concept of a single factor limiting plankton blooms, is presently giving way to co-limitation by light, and the nutrients 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 Biogeochemical Climate Models (OBCM's). Thus far OBCM's assume just one limiting nutrient (P) and one universal phytoplankton species, for C budgets and CO2 exchange. New realistic OBCM's are being developed for budgeting and exchanges of both CO2 and DMS, implementing (i) co-limitation by 4 nutrients of 5 major taxonomic classes of phytoplankton, (ii) DMS(P) pathways, (iii) global iron cycling, (iv) chemical forms of iron and (v) iron supply into surface waters. The new OBCM's will predict realistic climate scenario's, notably climatic feedbacks on oceanic biogeochemistry. IRONAGES is a European consortium of twelve institutes and is coordinated by Royal NIOZ. Input from below of iron from anoxic sediments of coastal margins has been assessed (March 2002) along a 2-D vertical section from Europe into the centre of the north Atlantic. Input from above of Fe(II) dissolved in rainwater from Sahara dust blown over the central Atlantic will be quantified at sea (October 2002), and related to observed plankton production. Different chemical forms of iron are being assessed and a certification excercise for Fe in seawater also under aegis of SCOR Working Group 109 is being completed (December 2002). For two major DMS-producing algal groups Phaeocystis sp. and Emiliania huxleyi the life cycle, Fe limitation, export production, CO2 uptake and DMS emissions have been synthesized from existing literature and laboratory experiments. This is being fed into ecosystem modeling, as well as into DMS(P) pathway modeling. Also know-how has been synthesized for three other major classes (diatoms, N2-fixing Trichodesmium and nano-pico-plankton) and fed into the ecosystem modeling. Pathways of DMS(P) in blooms are being

  1. 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

  2. 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.

  3. 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.)

  4. Compared chemistry of natural gas hydrates from different oceanic environments

    NASA Astrophysics Data System (ADS)

    Charlou, J.; Donval, J.; Ondreas, H.; Foucher, J.; Voisset, M.; Chazallon, B.; Jean-Baptiste, P.; Sauter, E.; Levache, D.

    2004-12-01

    Natural gas hydrates are generally associated with pockmarks or mud volcanoes on margins. They occurred both in deep sedimentary structures, and sometimes as outcrops on the seafloor. The gas hydrates studied here were collected from gravity sediment cores and occur as small fragments and massive crystal aggregates, mostly disseminated irregularly in the sediment. In most cases, they escape in the overlying deep seawater creating CH4-rich plumes which extend 100-150 m above the seafloor. These plumes are also enriched in particles, manganese, iron related to discharges of high turbid fluids issued from sediments and in all cases methane is rejected from sediment as free gas or as a consequence of the decomposition of gas hydrates. Specific equipments are necessary for collecting, and storing these gas hydrates in good conditions to avoid decomposition. The crystalline structure of solid gas hydrates is studied by Raman Spectrometry and Synchrotron techniques and show mainly methane gas hydrate of cubic Structure I. Analyses of hydrate water show variations (depletions or enrichments) of mineral elements compared to ambient deep seawater. Gas analysis shows that CH4 is the major component but CO2 and heavier gases (C2H4, C2H6, H2S) are also present as traces. In addition, many families of organic compounds detected by chromatography-mass spectrometry are present as traces. In most cases, the carbon and hydrogen isotopic data indicate a primarily microbial origin for the CH4 which is generated through bacterial CO2 reduction. All these chemical data contribute to understand the origin, formation and stability of gas hydrates trapped in sediments on oceanic margins. Specimens of natural gas hydrates recently collected on the African and Norvegian margins will be discussed.

  5. The upper ocean environment responses to typhoon Prapiroon (2012)

    NASA Astrophysics Data System (ADS)

    Li, Ying X.; Yang, Yuan J.; Sun, Liang; Fu, Yun F.

    2014-11-01

    Satellite-observed daily sea level anomaly (SLA), sea surface temperature (SST) and sea surface salinity (SSS) are used to determine the impact of the typhoon Prapiroon (2012) on the sea surface. The typhoon, Prapiroon, has a unique track when it went through the area (126°E-133°E, 17°N-25.5°N), where it influenced the sea greatly. For example, the lowest SST in this area was 25.2°C on October 8 before it entered, while the SST dropped to 20.7 °C on October 15. On the other hand, the lowest SLA dropped from -20 cm (on October 8) to -53 cm (on October 29). Accompanied with this, the SSS increased about 0.8-0.9 psu in some region. This is qualitative but quantitative agree with the Argo data of 0.2 psu SSS increase. One possible reason is the precipitation of typhoon, as the SSS data by Aquarius are easily affected by precipitation. And such significant SST cooling and SSS increasing were mainly due to vertical mixing, caused by longterm strong wind stirring brought by Parpiroon. We find that both the cold patch and eddies were transported westward. The horizontal advection took the cold water to 100 km away, this non-local effect could have notable impact on ocean dynamics and bio-physical processes. In addition we analyzed the possible factors of the temperature and salinity decreasing below the thermocline by calculating the Ekman pumping velocity due to the typhoon. It reveals that this is caused by Ekman pumping and upwelling in the cyclonic eddy, and Ekman pumping is the main factor.

  6. 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.)

  7. Core microbial functional activities in ocean environments revealed by global metagenomic profiling analyses.

    PubMed

    Ferreira, Ari J S; Siam, Rania; Setubal, João C; Moustafa, Ahmed; Sayed, Ahmed; Chambergo, Felipe S; Dawe, Adam S; Ghazy, Mohamed A; Sharaf, Hazem; Ouf, Amged; Alam, Intikhab; Abdel-Haleem, Alyaa M; Lehvaslaiho, Heikki; Ramadan, Eman; Antunes, André; Stingl, Ulrich; Archer, John A C; Jankovic, Boris R; Sogin, Mitchell; Bajic, Vladimir B; El-Dorry, Hamza

    2014-01-01

    Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world's oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs) of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light. PMID:24921648

  8. Core Microbial Functional Activities in Ocean Environments Revealed by Global Metagenomic Profiling Analyses

    PubMed Central

    Ferreira, Ari J. S.; Siam, Rania; Setubal, João C.; Moustafa, Ahmed; Sayed, Ahmed; Chambergo, Felipe S.; Dawe, Adam S.; Ghazy, Mohamed A.; Sharaf, Hazem; Ouf, Amged; Alam, Intikhab; Abdel-Haleem, Alyaa M.; Lehvaslaiho, Heikki; Ramadan, Eman; Antunes, André; Stingl, Ulrich; Archer, John A. C.; Jankovic, Boris R.; Sogin, Mitchell; Bajic, Vladimir B.; El-Dorry, Hamza

    2014-01-01

    Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world's oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs) of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light. PMID:24921648

  9. 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.

  10. 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.

  11. Ocean Model Analysis and Prediction System (Ocean Maps): Operational Ocean Forecasting Base on Near Real-Time Satellite Altimetry

    NASA Astrophysics Data System (ADS)

    Brassington, G. B.

    2006-07-01

    BLU Elink> is a join t Australian governmen t initiative to develop Austr alia's f irst operational ocean forecasting system called O cean MAPS. The project has transitioned to th e implemen tation and trial phase using the infrastructure of the Bureau of Meteorology. OceanMAPS has a g lobal grid with 1/10° by 1/10° resolution in the Australian region (90E-180E, 70S- 16N) and uses the Modular Ocean Model version 4 optimised for the NEC SX6. The analysis uses an ensemb le based multi-variate optimal interpolation scheme wh ere model error cov ariances ar e der ived from a 72-member ensemble of in tra-seasonal anomalies based on a 12-year ocean only model integration. The scheme has been formulated to assimilate near real- time sea level heigh t anomalies processed from Jason-1, ENVISAT and Geosat Follow-On and profile observations including Argo, X BT and the TAO array. The operation al configuration including the data manag emen t of the near real- time observ ations is review ed.

  12. 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.

  13. Ontology-Based Modelling of Ocean Satellite Images

    NASA Astrophysics Data System (ADS)

    Almendros-Jiménez, Jesús M.; Piedra, José A.; Cantón, Manuel

    In this paper we will define an ontology about the semantic content of ocean satellite images in which we are able to represent types of ocean structures, spatial and morphological concepts, and knowledge about measures of temperature, chrolophyll concentration, among others. Such ontology will provide the basis of a classification system based on the low-level features of images. We have tested our approach using the Protegé semantic web tool.

  14. 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.

  15. 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

    2016-01-01

    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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

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

    PubMed

    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

  3. 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

    2016-05-01

    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

  4. 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.

  5. 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.

  6. Passive localization in ocean acoustics: A model-based approach

    SciTech Connect

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

    1995-09-01

    A model-based approach is developed to solve the passive localization problem in ocean acoustics using the state-space formulation for the first time. It is shown that the inherent structure of the resulting processor consists of a parameter estimator coupled to a nonlinear optimization scheme. The parameter estimator is designed using the model-based approach in which an ocean acoustic propagation model is used in developing the model-based processor required for localization. Recall that model-based signal processing is a well-defined methodology enabling the inclusion of environmental (propagation) models, measurement (sensor arrays) models, and noise (shipping, measurement) models into a sophisticated processing algorithm. Here the parameter estimator is designed, or more appropriately the model-based identifier (MBID) for a propagation model developed from a shallow water ocean experiment. After simulation, it is then applied to a set of experimental data demonstrating the applicability of this approach. {copyright} {ital 1995} {ital Acoustical} {ital Society} {ital of} {ital America}.

  7. 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.)

  8. 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.

  9. 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.

  10. 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

  11. 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

    2013-01-01

    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

  12. 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

  13. Mean Upper-Ocean Circulation of the Southern Hemisphere Oceans Based on Goce Data

    NASA Astrophysics Data System (ADS)

    Menezes, V. V.; Bingham, R. J.; Vianna, M. L.; Phillips, H. E.

    2012-12-01

    One of the main goals of the Gravity and steady-state Ocean Circulation Explorer (GOCE) satellite mission launched in 2009 is to improve the previous estimates of the global ocean circulation structures determined from Mean Dynamic Topographies (MDTs). Recently published studies suggest that the GOCE-based MDTs and their respective mean geostrophic circulation fields (MGCs) are superior to those obtained from GRACE (Gravity Recovery and Climate Experiment)-only data. These studies focus mostly on the circulation of the North Atlantic and North Pacific oceans with emphasis on the strong western boundary current systems. In contrast, no detailed assessment has yet been made to determine the impact of the GOCE models in the southern hemisphere (SH) upper-ocean circulation especially in the subtropical region. It is generally recognized that the SH circulation is still not well established even at large scales, and the new GOCE and GRACE products can contribute to increase our understanding of the dominant currents in these regions, which may have even greater impact on the global climate than the NH counterparts. In the present work, we compute five global GOCE-derived MDTs with a 0.25 x 0.25 degree spatial grid based on three GOCE geoid models (TIM3, GOCO02S, GOCO3S) and three mean sea surfaces (CLS01, CLS11, DTU10) using the standard spectral approach (MSS minus Geoid). These MDTs do not have the well-known large-amplitude striation-type noise that plagued all of the GRACE-only MDTs with he same resolution, but still present commission errors which are filptered out with Singular Spectrum Analysis methods. Additionally, the MGCs were calculated by use of a Anderssen-Hegland averaging scheme for estimation of derivatives, which is able to filter out the well-known high amplitude noise caused by standard finite-difference methods. Comparisons with previous GRACE-only MGCs show that GOCE permits retrieval of currents with much higher intensities (e.g. the Agulhas

  14. Ray-based blind deconvolution in ocean sound channels.

    PubMed

    Sabra, Karim G; Song, Hee-Chun; Dowling, David R

    2010-02-01

    This letter describes a ray-based blind deconvolution technique for ocean sound channels that produces broadband estimates of the source-to-array impulse response and the original source waveform from array-measured signals corrupted by (unknown) multipath propagation. The technique merely requires elementary knowledge of array geometry and sound speed at the array location. It is based on identifying a ray arrival direction to separate source waveform and acoustic-propagation phase contributions to the received signals. This technique successfully decoded underwater telecommunication sequences in the bandwidth 3-4 kHz that were broadcast 4 km in a 120-m-deep ocean sound channel without a-priori knowledge of sound channel characteristics. PMID:20136177

  15. 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.

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

    DOE PAGESBeta

    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

  17. 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

  18. A Web-Based Climatology of Global Ocean Winds

    NASA Astrophysics Data System (ADS)

    Risien, C. M.; Chelton, D. B.; Hodges, M. K.

    2004-12-01

    A climatology of winds over the global ocean on a 0.5° x 0.5° grid is under development based on five-years of measurements from the SeaWinds scatterometer. The SeaWinds instrument was launched on 19 June 1999 onboard the QuikSCAT satellite. SeaWinds is an active microwave radar that, using electromagnetic backscatter from the wind roughened ocean surface, measures vector winds with an accuracy equivalent to well-calibrated buoy observations. This five-year climatology is a web-based interactive atlas from which users can retrieve wind statistics, both in tabular and graphic form, for any particular region of interest. The global coverage of the scatterometer data provides valuable information about the wind statistics in the many regions of the world ocean that are sparsely sampled by ships and buoys. One of the anticipated uses of this climatology will be presented via a case study of the NOAA/HAZMAT response to a 2001 oil spill that resulted from the grounding of the tanker "Jessica" at the entrance to Puerto Baquerizo Moreno, in Wreck Bay, on San Cristóbal island, Galápagos.

  19. 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

  20. 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.

  1. Fatigue crack growth of Ti-6Al-4V-0.1Ru (ELI grade) in ocean environments

    NASA Astrophysics Data System (ADS)

    Langoy, Morten Andre

    1999-11-01

    This study of fatigue crack growth rates found that Ti-6Al-4V-0.1Ru alloy seamless pipe in beta transformed/annealed condition is well suited for dynamically loaded risers, which transport the reservoir fluid (oil and gas) from the well to the vessel, and promises significant economic benefits can be realized by employing the material in this application. The tested ocean environments did not detrimentally affect crack growth rates. The material was studied in two conditions: as-received (i.e., the parent material) and cold rolled (simulating the effect of coiling and reeling). The effect of different combinations of loading and environment on fatigue crack growth rates of the parent and cold rolled materials were studied systematically using a design of experiments (DOE) approach. Different combinations of temperature, load frequency, R (sigmamin/sigmamax of the fatigue cycle), pre-strain (cold work), and environment (laboratory air and aerated and deaerated simulated ocean water) were used in the study. The observed fatigue crack growth rates ranged from 4 x 10 -10 to 1 x 10-6 m/cycle and the investigated DeltaK's (stress intensity ranges) ranged from 7 to 45 MPa√m. Fatigue crack growth rates are not substantially higher in ocean environments than in air, but the differences appear to be real. Cold work (5% reduction in thickness by rolling) reduces fatigue crack growth rates (compared to the parent material) at intermediate and high DeltaK by a factor of two. Microstructure, fracture surfaces, and crack path also were related to testing conditions. Fracture surfaces reveal a change of morphology from features associated with microstructure-sensitive crack propagation (cyclic cleavage) to features (striations) linked with structure-insensitive (continuum-mode) growth. Contrary to expectations based on anecdotal accounts, crack branching is observed at the center of the samples regardless of DeltaK or other parameters and also on the outer surfaces of the

  2. 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.

  3. Patterns of faulting and seismicity in the mid-ocean ridge environment

    NASA Astrophysics Data System (ADS)

    Bohnenstiehl, Delwayne Roger

    Abyssal hill faults within the slow-spreading (˜20 mm/yr) mid-ocean ridge environment exhibit displacement-length ratios that are systematically larger than those observed within the fast-spreading environment (˜100 mm/yr). This can be explained by considering the importance of fault linkage in the lateral growth of abyssal hill faults and the limits imposed on maximum fault displacement by the lithospheric thickness within each setting. Within the superfast spreading environment (>140 mm/yr) of the southern East Pacific Rise (EPR), a pattern of inward-dipping master faults is observed, with smaller outward-dipping faults clustered within their hanging walls. This pattern is distinct from the more classic horst and graben morphology described on the fast-spreading northern EPR. The pattern documented on the southern EPR suggests inward-dipping master faults are more sharply curved or listric relative to their abyssal hill equivalents at fast-spreading rates. Boundary element modeling is used to examine the role of axial magma chamber inflation in generating the pattern of faulting observed along the southern EPR. An earthquake catalog derived from the detection of seismically generated T-waves is used to study the decay rate and spatial distribution of mid-ocean ridge aftershock sequences. Generally, aftershock sequences in the mid-ocean ridge setting can be well described by a modified Omori law. Decay constants (p-values) are slightly higher than those previously estimated from stacked sequences derived from the teleseismic record. Three transform fault sequences and one microplate thrust sequence exhibit p-values consistent with the global median value. There is some evidence for higher p-values associated with normal faulting mainshocks along the spreading centers. Although the June 1999 Endeavour segment sequence has been suggested previously to be of tectonic origin, the timing and distribution of earthquakes are inconsistent with the aftershock process

  4. Estimating moisture transport over oceans using space-based observations

    NASA Technical Reports Server (NTRS)

    Liu, W. Timothy; Wenqing, Tang

    2005-01-01

    The moisture transport integrated over the depth of the atmosphere (0) is estimated over oceans using satellite data. The transport is the product of the precipitable water and an equivalent velocity (ue), which, by definition, is the depth-averaged wind velocity weighted by humidity. An artificial neural network is employed to construct a relation between the surface wind velocity measured by the spaceborne scatterometer and coincident ue derived using humidity and wind profiles measured by rawinsondes and produced by reanalysis of operational numerical weather prediction (NWP). On the basis of this relation, 0 fields are produced over global tropical and subtropical oceans (40_N- 40_S) at 0.25_ latitude-longitude and twice daily resolutions from August 1999 to December 2003 using surface wind vector from QuikSCAT and precipitable water from the Tropical Rain Measuring Mission. The derived ue were found to capture the major temporal variability when compared with radiosonde measurements. The average error over global oceans, when compared with NWP data, was comparable with the instrument accuracy specification of space-based scatterometers. The global distribution exhibits the known characteristics of, and reveals more detailed variability than in, previous data.

  5. 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. PMID:23129714

  6. 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

  7. A process-based analysis of ocean heat uptake in an AOGCM with an eddy-permitting ocean component

    NASA Astrophysics Data System (ADS)

    Kuhlbrodt, T.; Gregory, J. M.; Shaffrey, L. C.

    2015-12-01

    About 90 % of the anthropogenic increase in heat stored in the climate system is found in the oceans. Therefore it is relevant to understand the details of ocean heat uptake. Here we present a detailed, process-based analysis of ocean heat uptake (OHU) processes in HiGEM1.2, an atmosphere-ocean general circulation model with an eddy-permitting ocean component of 1/3° resolution. Similarly to various other models, HiGEM1.2 shows that the global heat budget is dominated by a downward advection of heat compensated by upward isopycnal diffusion. Only in the upper tropical ocean do we find the classical balance between downward diapycnal diffusion and upward advection of heat. The upward isopycnal diffusion of heat is located mostly in the Southern Ocean, which thus dominates the global heat budget. We compare the responses to a 4xCO2 forcing and an enhancement of the windstress forcing in the Southern Ocean. This highlights the importance of regional processes for the global ocean heat uptake. These are mainly surface fluxes and convection in the high latitudes, and advection in the Southern Ocean mid-latitudes. Changes in diffusion are less important. In line with the CMIP5 models, HiGEM1.2 shows a band of strong OHU in the mid-latitude Southern Ocean in the 4xCO2 run, which is mostly advective. By contrast, in the high-latitude Southern Ocean regions it is the suppression of convection that leads to OHU. In the enhanced windstress run, convection is strengthened at high Southern latitudes, leading to heat loss, while the magnitude of the OHU in the Southern mid-latitudes is very similar to the 4xCO2 results. Remarkably, there is only very small global OHU in the enhanced windstress run. The wind stress forcing just leads to a redistribution of heat. We relate the ocean changes at high Southern latitudes to the effect of climate change on the Antarctic Circumpolar Current (ACC). It weakens in the 4xCO2 run and strengthens in the wind stress run. The weakening is due

  8. Model-based ocean acoustic passive localization. Revision 1

    SciTech Connect

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

    1994-06-01

    A model-based approach is developed (theoretically) to solve the passive localization problem. Here the authors investigate the design of a model-based identifier for a shallow water ocean acoustic problem characterized by a normal-mode model. In this problem they show how the processor can be structured to estimate the vertical wave numbers directly from measured pressure-field and sound speed measurements thereby eliminating the need for synthetic aperture processing or even a propagation model solution. Finally, they investigate various special cases of the source localization problem, designing a model-based localizer for each and evaluating the underlying structure with the expectation of gaining more and more insight into the general problem.

  9. The Panthalassa—a cerium-rich Atlantic-type ocean: sedimentary environments of the Tamba Group, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Musashino, Makoto

    1990-09-01

    The oceanic sediments of the Tamba Group, a part of the Japanese Paleozoic-Mesozoic accretionary prism were studied geochemically. These oceanic sediments have various REE patterns, which correspond to specific ocean floor environments. The Type II suite of the Tamba Group contains the following changes in sedimentary environment; pelagic sedimentation under the influence of hydrothermal activity or diagenetic metal accumulation (negative Ce anomaly), pelagic sedimentation in Ce- poor seawater or diagenesis under less oxic conditions (LREE > HREE or MREE > LREE ⩾ HREE pattern) and slow pelagic sedimentation under oxic conditions where authigenic metal flux from seawater resulted in a positive Ce anomaly. Different from the Type II suite, lower pelagic sediments of the Type I suite show a LREE ⩽ HREE pattern, which indicates the inflow of very fine terrigenous or volcanic materials. Cherts and siliceous shales with positive Ce anomaly are exclusively present in the upper part of chert-siliceous shale sequences in all successions of the Tamba Group. This suggests that seawater of the Panthalassa Ocean was, at least partially, enriched in Ce, resembling the modern Atlantic more than the modern Pacific Ocean. The following reasons for this enrichment are considered: (1) fluvial input from surrounding continents was substantial; (2) reductive regeneration of Ce from continental shelves was active; or (3) Ce-depleted seawater did not enter from the other "ocean".

  10. 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.

  11. The role of ocean observatories in monitoring for potential effects of man-made sound on the marine environment

    NASA Astrophysics Data System (ADS)

    Bradley, David L.; D'Spain, Gerald L.; Miller, James H.; Frisk, George V.

    2005-04-01

    An important question is whether or not man-made sounds have an adverse long-term impact on the ocean environment. Clear evidence exists that an impact has occurred on some individual animals in a few cases. However, according to the 2003 National Academy of Sciences report, the degree of impact on any marine mammal population or on ocean ecosystems as a whole is unknown. An essential component of an approach to addressing this question is an ocean noise/marine ecosystem monitoring system. The monitoring regions should be global in extent and include biologically sensitive areas. The effort should be sustained so that long-term trends in ocean noise levels can be evaluated. An important aspect of the data collection effort is the type and quality of ancillary information. Ancillary data on the marine ecosystems allows determination of any impacts and data on the sources of marine noise and marine environmental properties which are required to develop metrics for evaluating and predicting the characteristics of the noise field. The ocean observatory system presently being contemplated could play an important role in establishing an ocean noise monitoring capability. [Work supported through the National Ocean Partnership Program, with sponsorship from ONR, NOAA, NSF, and USGS.

  12. 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…

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

    NASA Astrophysics Data System (ADS)

    Hellmer, Hartmut H.; Jacobs, Stanley S.

    1992-12-01

    Using a two-dimensional ocean thermohaline 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 seafloor 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. A freshwater flux across the grounding line, derived from melting beneath the grounded ice sheet, would have to be anomalously large to produce the basal marine ice layer and account for the Ice Shelf Water outflow. 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.

  14. 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.

  15. Enhancing Trust in SOA Based Collaborative Environments

    NASA Astrophysics Data System (ADS)

    Boursas, Latifa; Bourimi, Mohamed; Hommel, Wolfgang; Kesdogan, Dogan

    Considering trust and privacy requirements for online and collaborative distance learning environments, this paper discusses potential extensions of SOA based applications to simultaneously support authentication and authorization services, and offering mutual trust to both learners and service providers. This study shows that the security mechanisms integrated in the SOA platform can be effectively extended and correlated with a trust model.

  16. 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

  17. 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

  18. Investigating the impacts of deep ocean euxinia on continental shelf environments during the Great Ordovician Biodiversification Event: did changes in global oceanic redox have any effect?

    NASA Astrophysics Data System (ADS)

    Marenco, P. J.; Marenco, K. N.; Phillips, D. E.; Garcia, E.; Toure, N.; Fullem, A.

    2013-12-01

    The Great Ordovician Biodiversification Event was one of the most important radiations in the history of animal life. In particular, the GOBE was characterized by pronounced increases in diversity within the Paleozoic and Modern Evolutionary Faunas (e.g., Droser and Finnegan, 2003). Rather than being attributable to a singular cause, a number of tectonic, ecologic, and climate-related factors are thought to have contributed to this biodiversification event (e.g., Servais et al., 2009). For example, continental shelf area during the GOBE was more extensive than at any other time during the Phanerozoic, and the availability of these warm, shallow-water, well-oxygenated environments likely influenced the radiation (e.g., Servais et al., 2009). Despite this evidence for favorable conditions, recent geochemical studies suggest that the early Paleozoic, including the Ordovician, was a time of episodic deep ocean euxinia (e.g., Gill et al., 2011, Thompson and Kah, 2012). It remains unclear how the hypothesized deep ocean euxinia may have affected the GOBE. For example, it is possible that episodic incursions of euxinic deep water onto the continental shelves may have acted to slow down the GOBE or even dampen its magnitude. On the other hand, such incursions may have accelerated the radiation by adding additional selection pressures to communities that were already adapting to new predation and substrate conditions. Alternatively, the GOBE may have proceeded without any incursions of euxinic deep water onto the continental shelves. One way to address this issue is to investigate short-term, localized redox changes in shallow marine settings. Here we present results from our ongoing investigation of redox changes in shallow-water environments from the Lower and Middle Ordovician of Utah. Specifically, we use abundances of total organic carbon (TOC) and total sulfur (TS) as localized redox proxies. We use the isotopic composition of carbonate associated sulfate (δ34SCAS

  19. Measurements of Complex Oceanic Flows, from Turbulence in the Coastal Ocean to Interaction of Zooplankton with its Local Environment

    NASA Astrophysics Data System (ADS)

    Katz, J.

    2004-03-01

    The presentation has two parts, both dealing with flow structure, turbulence and flow-particle interactions in the ocean. The first part examines PIV data obtained in the bottom boundary layer of the coastal ocean in periods when the mean currents are higher, of the same order and weaker than the wave induced motions. The energy spectra display substantial anisotropy at all scales, and the flow consists of periods of "gusts" dominated by large vortical structures, separated by periods of quiescent flows. The frequency of these gusts increases with Reynolds number, and they disappear when the currents are weak. Conditional sampling shows that the Reynolds shear stress, and as a result the shear production, are generated only during periods of gusts. When the mean flow is weak and during quiescent periods of moderate flow the shear stresses are essentially zero. Dissipation, on the other hand, occurs continuously, and increases only slightly during gust periods. The second part focuses on interactions of zooplankton with the local flow. Digital in-line holographic cinematography is used for measuring the three-dimensional trajectory of a free-swimming copepod, and simultaneously the instantaneous 3-D velocity field around this copepod. The velocity field and trajectory of particles entrained by the copepod have a recirculating pattern in the copepod's frame of reference. This pattern is caused by the copepod sinking at a rate that is lower than its terminal sinking speed, due to the propulsive force generated by its feeding current. Consequently, the copepod has to hop periodically to scan different fluid for food. Using Stokeslets to model the velocity field, the measured velocity distributions enable us to estimate the excess weight of the copepod and the propulsive force generated by its feeding appendages. Sponsored in part by the Office of Naval Research and by the National Science Foundation.

  20. Ocean acoustic signal processing: A model-based approach

    SciTech Connect

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

    1992-12-01

    A model-based approach is proposed to solve the ocean acoustic signal processing problem that is based on a state-space representation of the normal-mode propagation model. It is shown that this representation can be utilized to spatially propagate both modal (depth) and range functions given the basic parameters (wave numbers, etc.) developed from the solution of the associated boundary value problem. This model is then generalized to the stochastic case where an approximate Gauss--Markov model evolves. The Gauss--Markov representation, in principle, allows the inclusion of stochastic phenomena such as noise and modeling errors in a consistent manner. Based on this framework, investigations are made of model-based solutions to the signal enhancement, detection and related parameter estimation problems. In particular, a modal/pressure field processor is designed that allows {ital in} {ital situ} recursive estimation of the sound velocity profile. Finally, it is shown that the associated residual or so-called innovation sequence that ensues from the recursive nature of this formulation can be employed to monitor the model's fit to the data and also form the basis of a sequential detector.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. Chitosan-based mucosal adjuvants: Sunrise on the ocean.

    PubMed

    Xia, Yufei; Fan, Qingze; Hao, Dongxia; Wu, Jie; Ma, Guanghui; Su, Zhiguo

    2015-11-01

    Mucosal vaccination, which is shown to elicit systemic and mucosal immune responses, serves as a non-invasive and convenient alternative to parenteral administration, with stronger capability in combatting diseases at the site of entry. The exploration of potent mucosal adjuvants is emerging as a significant area, based on the continued necessity to amplify the immune responses to a wide array of antigens that are poorly immunogenic at the mucosal sites. As one of the inspirations from the ocean, chitosan-based mucosal adjuvants have been developed with unique advantages, such as, ability of mucosal adhesion, distinct trait of opening the junctions to allow the paracellular transport of antigen, good tolerability and biocompatibility, which guaranteed the great potential in capitalizing on their application in human clinical trials. In this review, the state of art of chitosan and its derivatives as mucosal adjuvants, including thermo-sensitive chitosan system as mucosal adjuvant that were newly developed by author's group, was described, as well as the clinical application perspective. After a brief introduction of mucosal adjuvants, chitosan and its derivatives as robust immune potentiator were discussed in detail and depth, in regard to the metabolism, safety profile, mode of actions and preclinical and clinical applications, which may shed light on the massive clinical application of chitosan as mucosal adjuvant. PMID:26271831

  7. 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.

  8. 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

  9. 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.

  10. Feature Analysis of Ocean Waves in North Central Pacific Ocean Based ASAR Wave Spectral Data and Wave Model

    NASA Astrophysics Data System (ADS)

    Wang, Jichao; Zhang, Jie; Yang, Jungang; Meng, Junmin

    2013-01-01

    Directional Spectrum of the ocean waves could be obtained form Envisat advanced synthetic aperture radar (ASAR) wave spectral data. The wave model WAVEWATCH III (WW3) is applied to simulate the ocean wave field. Study area is 185°E-215°E and 15°N-30°N, time range is from 1 January 2008 to 31 December 2008. Based on ASAR and buoy data, the wave numerical simulation and assimilation of the north central Pacific Ocean is carried out. The validation and assessment of ASAR ocean wave spectra products is performed. The optimal interpolation (OI) algorithm is used in model WW3 for assimilating ASAR wave spectra data. Based on the result of the simulation and assimilation, mean waves direction (MWD), significant wave height (SWH) and mean wave period (MWP) are analysed. SWH and MWP are larger in winter and SWH reach to more than 2.5 meters. Seasonal change of SWH and MWP are significant.

  11. Model-based processor design for a shallow water ocean acoustic experiment

    SciTech Connect

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

    1994-04-01

    Model-based signal processing is a well-defined methodology enabling the inclusion of environmental (propagation) models, measurement (sensor arrays) models, and noise (shipping, measurement) models into a sophisticated processing algorithm. Depending on the class of model developed from the mathematical representation of the physical phenomenology, various processors can evolve. Here the design of a space-varying, nonstationary, model-based processor (MBP) is investigated and applied to the data from a well-controlled shallow water experiment performed at Hudson Canyon. This particular experiment is very attractive for the inaugural application of the MBP because it was performed in shallow water at low frequency requiring a small number of modes. In essence, the Hudson Canyon represents a well-known ocean environment, making it ideal for this investigation. In this shallow water application, a state-space representation of the normal-mode propagation model is used. The processor is designed such that it allows [ital in] [ital situ] recursive estimation of both the pressure-field and modal functions. It is shown that the MBP can be effectively utilized to validate'' the performance of the model on noisy ocean acoustic data. In fact, a set of processors is designed, one for each source range and the results are quite good---implying that the propagation model with measured parameters adequately represents the data.

  12. 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

  13. 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.

  14. 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.

  15. A VR-Ocean system for interactive geospatial analysis and 4D visualization of the marine environment around Antarctica

    NASA Astrophysics Data System (ADS)

    Li, Wenqing; Chen, Ge; Kong, Qianqian; Wang, Zhenzhen; Qian, Chengcheng

    2011-11-01

    The development of the VR-Ocean system coincides with the first availability of more than 15 years (1992-2009) of the merged altimeter data from up to four concurrent satellite missions (Topex/Poseidon, ERS-1 and 2, ENVISAT, Jason-1, and Geosat Follow-On) and ETOPO1 Ice Surface data (1 arc-minute global relief model of the Earth's surface that integrates land topography and ocean bathymetry). In the polar-region-oriented VR-Ocean system, the seabed and continental topography data south of 45°S were organized in a circular area and rendered in the form of geometry clipmaps. Maps of Sea-Level Anomalies (MSLA) data for the same district were extracted and streamlined in time order. A memory-mapped file was used to accelerate file loading speed, and sea surfaces of different times were rendered in turn as a vertex buffer object (VBO) and accelerated by the graphic processing unit (GPU). As a result, roaming anywhere at any angle of view and geospatial analysis are interactively obtained and dynamically presented in real-time using the 4D VR-Ocean system. As an attempt, we did a case study on ice melting and sea-level rise around the Antarctic. This system is expected to make a significant contribution to the description, understanding, prediction, and demonstration of 4D information and properties on both regional and hemispheric scales in a virtual environment.

  16. Properties of electromagnetic fields generated by tsunami first arrivals: Classification based on the ocean depth

    NASA Astrophysics Data System (ADS)

    Minami, Takuto; Toh, Hiroaki; Tyler, Robert H.

    2015-04-01

    Tsunami flow coupled with the geomagnetic field generates electric currents and associated magnetic fields. Although electromagnetic (EM) tsunami signals can be used for analysis and even forecasting tsunami propagation, the dynamically self-consistent effect of shoaling water depth on the fluid + electrodynamics has not been adequately clarified. In this study, we classify tsunami EM phenomena into three cases based on the ocean depth and find that the deeper ocean results in stronger self-induction due to the increase in both tsunami phase velocity and ocean conductance. In this deep-ocean case, the phase lead of the vertical magnetic variation relative to the sea surface elevation is smaller, while an initial rise in the horizontal magnetic component becomes observable prior to tsunami arrival. Furthermore, we confirm that the enhancement of tsunami height in shallower oceans shifts the ocean depth supplying maximum amplitudes of tsunami magnetic fields from approximately 2.0 km to 1.5 km.

  17. 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.

  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. 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.

  20. 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…

  1. Preliminary testing of turbulence and radionuclide transport modeling in deep ocean environment

    SciTech Connect

    Onishi, Y.; Dummuller, D.C.; Trent, D.S.; Washington State Univ., Pullman, WA; Pacific Northwest Lab., Richland, WA )

    1989-03-01

    Pacific Northwest Laboratory (PNL) performed a study for the US Environmental Protection Agency's Office of Radiation Programs to (1) identify candidate models for regional modeling of low-level waste ocean disposal sites in the mid-Atlantic ocean; (2) evaluate mathematical representation of the model's eddy viscosity/dispersion coefficients; and (3) evaluate the adequacy of the k-{epsilon} turbulence model and the feasibility of one of the candidate models, TEMPEST{copyright}/FLESCOT{copyright}, to deep-ocean applications on a preliminary basis. PNL identified the TEMPEST{copyright}/FLESCOT{copyright}, FLOWER, Blumberg's, and RMA 10 models as appropriate candidates for the regional radionuclide modeling. Among these models, TEMPEST/FLESCOT is currently the only model that solves distributions of flow, turbulence (with the k-{epsilon} model), salinity, water temperature, sediment, dissolved contaminants, and sediment-sorbed contaminants. Solving the Navier-Stokes equations using higher order correlations is not practical for regional modeling because of the prohibitive computational requirements; therefore, the turbulence modeling is a more practical approach. PNL applied the three-dimensional code, TEMPEST{copyright}/FLESCOT{copyright} with the k-{epsilon} model, to a very simple, hypothetical, two-dimensional, deep-ocean case, producing at least qualitatively appropriate results. However, more detailed testing should be performed for the further testing of the code. 46 refs., 39 figs., 6 tabs.

  2. 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.

  3. Atmosphere-ocean gas exchange based on radiocarbon data

    NASA Astrophysics Data System (ADS)

    Byalko, Alexey

    2014-05-01

    In recent decades, the intensity of global atmospheric convection has accelerated faster than climate warming; it is possible to judge this process from indirect data. Increasing ocean salinity contrasts provide evidence that evaporation has intensified [1]; sea surface wind velocities and wave heights have increased [2]. The CO2 gas exchange between the atmosphere and ocean must also simultaneously increase. Monthly measurements of atmospheric CO2 concentration have been published since 1958 [3], but directly measuring its fluxes from the atmosphere to the ocean and back is hardly possible. We show they can be reconstructed from 14C isotope concentration data. In the past century, two processes influenced the atmospheric 14C concentration in opposite directions: burning fossil fuels and testing nuclear weapons in the atmosphere. We compare the gas exchange theory with measurements of radiocarbon content in the atmosphere [4—6], which allows assessing the gas exchange quantitatively for the ocean to atmosphere and atmosphere to ocean fluxes separately for period 1960—2010 [7]. References 1. Durack P. J. and Wijffels S. E., J. Climate 23, 4342 (2010). 2. Young I. R., Sieger S., and Babanin A.V., Science 332, 451 (2011). 3. NOAA Earth System Research Laboratory Data: ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt. 4. Nydal R., Lövseth K. // J. Geophys. Res. 1983. V. 88. P. 3579. 5. Levin I., Kromer B. // Radiocarbon. 1997. V. 39. P. 205. 6. Miller J.B., Lehman S.J., Montzka S.A., et al. // J. Geophys. Res. 2012. V. 117. D08302. 7. Byalko A.V. Doklady Physics, 2013. V. 58, 267-271.

  4. 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

  5. 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,...

  6. 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... 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,...

  7. 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

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 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,...

  8. 33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 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,...

  9. 33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 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,...

  10. Deposition of organic carbon-rich sediments in narrow marine basins and open-marine upwelling environments - New results from the ocean drilling program

    SciTech Connect

    Stein, R. )

    1988-08-01

    Detailed sedimentological and organic geochemical investigations have been performed on Neogene sediments from ODP site 645 (Baffin Bay), ODP site 658 (upwelling area of northwest Africa), and ODP site 679 (upwelling area off Peru). The study is mainly based on (1) data derived from total organic carbon and nitrogen analyses, Rock-Eval pyrolysis, and kerogen microscopy (2) sedimentation rates, and (3) x-ray diffraction analyses. The main objective of this study was to point out the most important factors controlling the accumulation of organic carbon in the different sedimentary environments, such as supply of terrigenous organic matter, productivity of marine organic matter, and preservation of organic matter. These new results from the investigation of ODP sediments are compared with DSDP data from the Mesozoic Atlantic Ocean to characterize the depositional environments of Mesozoic black shales.

  11. Export Fluxes in Contrasting Environments of the South-East Pacific Ocean Derived From Drifting Sediment traps (BIOSOPE)

    NASA Astrophysics Data System (ADS)

    Miquel, J.; Gasser, B.; Claustre, H.

    2006-12-01

    The South-East Pacific presents contrasting oceanographic environments related to different oceanographic features such as High Nutrient Low Chlorophyl (HNLC) zones, upwelling of eastern boundaries or ultra- oligotrophy of the central gyre. This results in significant differences in particle production in surface waters and export to the deeper ocean. During the BIOSOPE (BIogeochemistry and Optics SOuth Pacific Experiment) cruise held in October-December 2004, particle flux in upper waters was assessed using drifting sediment traps. Traps were deployed at 2 depths (below the maximum chl.a and at the base of the euphotic layer) in six geographical areas, ranging from the oligotrophic central gyre through the mesotrophic area off Marquesas Islands to the eutrophic waters off the South-American coast. For all analyzed parameters fluxes were contrastingly different at the various sites, with lowest fluxes at the central gyre area and highest fluxes at the upwelling sites. Mass flux ranged from 2-7 mg m-2 d-1 to 410-630 mg m-2 d-1, POC flux from less than 1 mg POC m-2 d-1 up to 63 mg POC m^{- 2} d-1, and Th-234 from 35-47 dpm m-2 d-1 to >5000 dpm m-2 d-1. Fluxes were always lower at the deeper horizon except for Th-234 flux which was variable. Also, fluxes were very different at the two upwelling sites studied. The relation between the environmental and trophic characteristics of the sites visited and the two orders of magnitude in fluxes observed is discussed.

  12. 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.

  13. 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.

  14. 77 FR 19030 - Automated Commercial Environment Required for the Transmission of Advance Ocean and Rail Cargo...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... SECURITY U.S. Customs and Border Protection Automated Commercial Environment Required for the Transmission... recently completed the testing of the Automated Commercial Environment (ACE) for the transmission of..., rail or truck. See Required Advance Electronic ] Presentation of Cargo Information, 68 FR...

  15. 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.

  16. 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

  17. 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

    2015-07-01

    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

  18. 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. PMID:17746544

  19. Bet hedging in a warming ocean: predictability of maternal environment shapes offspring size variation in marine sticklebacks.

    PubMed

    Shama, Lisa N S

    2015-12-01

    Bet hedging at reproduction is expected to evolve when mothers are exposed to unpredictable cues for future environmental conditions, whereas transgenerational plasticity (TGP) should be favoured when cues reliably predict the environment offspring will experience. Since climate predictions forecast an increase in both temperature and climate variability, both TGP and bet hedging are likely to become important strategies to mediate climate change effects. Here, the potential to produce variably sized offspring in both warming and unpredictable environments was tested by investigating whether stickleback (Gasterosteus aculeatus) mothers adjusted mean offspring size and within-clutch variation in offspring size in response to experimental manipulation of maternal thermal environment and predictability (alternating between ambient and elevated water temperatures). Reproductive output traits of F1 females were influenced by both temperature and environmental predictability. Mothers that developed at ambient temperature (17 °C) produced larger, but fewer eggs than mothers that developed at elevated temperature (21 °C), implying selection for different-sized offspring in different environments. Mothers in unpredictable environments had smaller mean egg sizes and tended to have greater within-female egg size variability, especially at 21 °C, suggesting that mothers may have dynamically modified the variance in offspring size to spread the risk of incorrectly predicting future environmental conditions. Both TGP and diversification influenced F2 offspring body size. F2 offspring reared at 21 °C had larger mean body sizes if their mother developed at 21 °C, but this TGP benefit was not present for offspring of 17 °C mothers reared at 17 °C, indicating that maternal TGP will be highly relevant for ocean warming scenarios in this system. Offspring of variable environment mothers were smaller but more variable in size than offspring from constant environment

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

    SciTech Connect

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

    1983-01-01

    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, eight 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 simulated deep-ocean 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.

  1. Model-based localization for a shallow ocean experiment

    SciTech Connect

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

    1995-07-19

    In this paper a modern approach was developed to solve the passive localization problem in ocean acoustics using the state-space formulation. It is shown that the inherent structure of the resulting processor consists of a parameter estimator coupled to a nonlinear optimization scheme. The parameter estimator is design using an acoustic propagation model in developing the modern identifier required for localization. The detection and localization of an acoustic source has long been the motivation of early sonar systems. With the advent of quieter and quieter submarines due to new manufacturing technologies and the next proliferation of diesel powered vessels, the need for more sophisticated processing techniques has been apparent for quite some time.

  2. 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.

  3. 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

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

    PubMed

    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 to declines in the

  5. 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

  6. Noninvasive probing of the ocean surface using laser-based nonlinear optical methods

    SciTech Connect

    Korenowski, G.M.; Frysinger, G.S.; Asher, W.E. . Dept. of Chemistry)

    1992-06-01

    The laser-based nonlinear optical methods of second-harmonic generation and sum-frequency generation have been developed to study the chemical composition and concentration of natural surfactant materials present as slicks on the ocean surface. These noninvasive second-harmonic and sum-frequency generation methods produce signals which originate from only the top few molecular layers of the ocean surface, thereby producing an accurate picture of the ocean surface condition without interference from the bulk ocean chemistry. Chemical specificity of the methods is achieved by tuning the incident laser frequency to coincide with optical absorptions in the surface absorbed materials. We show that laser-based second-order nonlinear optical processes of SHG and SFG provide highly surface selective, noninvasive, in situ probes of the ocean surface. Although only preliminary experiments are reported in this paper, the probes provide important information about the nature of surfactants at the ocean surface and their behavior in response to dynamic forces at the sea/air interface. The future of the probes lies in their further development and use as in situ interfacial spectroscopic techniques.

  7. 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

  8. 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.

  9. 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. PMID:17532349

  10. 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. PMID:23039419

  11. 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.

  12. Persistence of Carbonate Platform Environments in Central Mexico during the Oceanic Anoxic Event 2: impact of the Carribean Plateau?

    NASA Astrophysics Data System (ADS)

    Bomou, Brahimsamba; Adatte, Thierry; Föllmi, Karl; Arnaud-Vanneau, Annie; Fleitmann, Dominik

    2010-05-01

    The Cenomanian-Turonian Oceanic Anoxic Event 2 is described as an interruption of normal pelagic sediment deposition by several distinct intervals of widespread oceanic anoxia (Schlanger & Jenkyns, 1976; Jenkyns, 1980; Arthur et al., 1990) characterized by black shales deposition coinciding with a positive shift in carbon isotope excursion. Some authors show a relationship between OAEs and massive volcanic events associated with the emplacement of large igneous provinces (LIPs) and sea floor spreading at mid-ocean ridges (Kuroda et al., 2007; Snow et al., 2005). High metal abundance anomalies recorded in pelagic sections (e.g. Pueblo, Colorado) coincide with the massive volcanism that built the Carribean plateau (around 93-94 Ma), associated with the onset of OAE 2 (Snow et al., 2005). Mort et al., (2007) demonstrate that the onset of the OAE 2 was triggered by a short-lived but significant increase in phosphorus burial. The bottom waters became anoxic and switched from being a P sink to a P source, sustaining the productivity in a positive feedback loop. However, the behaviour of phosphorus and trace metals at larger scale, in different paleogeography and paleodepht is still poorly known. The Axaxacualco and Baranca el Cañon sections, located at the Guerrero-Morelos carbonate platform in southern Mexico exhibit a fully correlateable d13C curves. In the distal part of the carbonate platform at Axaxacualco, the maximum d13C positive excursion coincides with oligotrophic carbonate platform environments supported by low concentrations in P and characterized by abundant and diversified benthic microfauna and rudists. The impact of OAE appears may be more significant in the proximal part of the carbonate platform at Barranca, characterized by the deposition of thick laminated microbialites indicative of mesotrophic conditions. The Morelos Carbonate platform with oligotrophic to mesotrophic conditions was persistent throughout the entire OAE2 in Central Mexico despite

  13. HOS-ocean: Open-source solver for nonlinear waves in open ocean based on High-Order Spectral method

    NASA Astrophysics Data System (ADS)

    Ducrozet, Guillaume; Bonnefoy, Félicien; Le Touzé, David; Ferrant, Pierre

    2016-06-01

    HOS-ocean is an efficient High-Order Spectral code developed to solve the deterministic propagation of nonlinear wavefields in open ocean. HOS-ocean is released as open-source, developed and distributed under the terms of GNU General Public License (GPLv3). Along with the source code, a documentation under wiki format is available which makes easy the compilation and execution of the source files. The code has been shown to be accurate and efficient.

  14. A Gegenbauer-based Shallow Water solver for a thick "ocean" over a rotating sphere

    NASA Astrophysics Data System (ADS)

    Shamir, Ofer; Paldor, Nathan

    2016-01-01

    Gegenbauer Harmonics which are the eigenfunctions of the Linearized Shallow Water Equations in spherical coordinates for a thick layer of ocean are examined as alternative basis functions for global-scale spectral models. The performance of this basis is compared to that of the traditional Spherical Harmonics basis by testing the accuracy and stability with which the two bases simulate a single, analytic, wave mode of the Linearized Shallow Water Equations. For the linear equations our results show that for low initial wavenumbers the Spherical Harmonics are able to conserve the single wave mode with comparable accuracy to that of the proposed Gegenbauer Harmonics basis while at high initial wavenumbers the simulation with the Spherical Harmonics is significantly less accurate than the simulation with the Gegenbauer Harmonics. By considering a range of ocean thicknesses it is found that, for thin oceans, the Spherical Harmonics become numerically unstable after about 150 days, whereas the proposed Gegenbauer Harmonics remain stable even though they too are not the eigenfunctions of the Linearized Shallow Water Equations in thin oceans. This numerical instability of the Spherical Harmonics is independent of the wave's period and was not observed in thick oceans where the simulation remained stable for at least 200 days. Our results suggest that the numerical instability of the Spherical Harmonics originates at the poles. For the non-linear equations our results show that the Spherical Harmonics solutions are less accurate than the Gegenbauer Harmonics even in a thick ocean.

  15. 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.

  16. Long period grating-based ocean pH sensor in an SMS fiber

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Klimov, Denis; Kolber, Zbigniew

    2008-03-01

    A long period grating-based pH sensor has been designed in order to measure the pH in the ocean. The pH-sensitive hydrogel, which is made through the thermal crosslink of poly vinyl alcohol and poly acrylic acid, can swell or contract in response to the pH change in the surrounding environment. The sensor is designed in a single mode-multimode-single mode (SMS) fiber structure. The long period grating is written into the multimode fiber of the SMS structure using a focused CO II laser at the critical period (1 mm) of this particular multimode fiber. The hydrogel is glued underneath the SMS structure and will physically stretch or compress the long period grating hence change the phase matching condition in the SMS structure. Because of the different core sizes of the single mode fiber and the multimode fiber, only energy coupled in and out of the fundamental mode in the multimode fiber will be detected directly. The SMS structure has a higher sensitivity than using just the multimode sensing fiber. This sensor has been utilized in the seawater pH sensing in the range of 6 ~ 8. Experiments show that the sensor has a pH resolution of 0.0042.

  17. 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.

  18. 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

  19. Understanding Social Presence in Text-Based Online Learning Environments

    ERIC Educational Resources Information Center

    Kehrwald, Benjamin

    2008-01-01

    This article reports on key aspects of a theory generative study into social presence in text-based online learning environments. The focus of the article is the nature of social presence as experienced by online learners in those environments. Employing a collective case study design, the study accessed online learners' experience-based heuristic…

  20. Observationally-Based Data/Model Metrics from the Southern Ocean Climate Model Atlas

    NASA Astrophysics Data System (ADS)

    Abell, J.; Russell, J. L.; Goodman, P. J.

    2015-12-01

    The Southern Ocean Climate Model Atlas makes available observationally-based standardized data/model metrics of the latest simulations of climate and projections of climate change from available climate models. Global climate model simulations differ greatly in the Southern Ocean, so the development of consistent, observationally-based metrics, by which to assess the fidelity of model simulations is essential. We will present metrics showing and quantifying the results of the modern day climate simulations over the Southern Ocean from models submitted as part of the CMIP5/IPCC-AR5 process. Our analysis will focus on the simulations of the temperature, salinity and carbon at various depths and along significant hydrographic sections. The models exhibit different skill levels with various metrics between models and also within individual models.

  1. 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.

  2. 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

  3. 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…

  4. A global ocean inventory of anthropogenic mercury based on water column measurements.

    PubMed

    Lamborg, Carl H; Hammerschmidt, Chad R; Bowman, Katlin L; Swarr, Gretchen J; Munson, Kathleen M; Ohnemus, Daniel C; Lam, Phoebe J; Heimbürger, Lars-Eric; Rijkenberg, Micha J A; Saito, Mak A

    2014-08-01

    Mercury is a toxic, bioaccumulating trace metal whose emissions to the environment have increased significantly as a result of anthropogenic activities such as mining and fossil fuel combustion. Several recent models have estimated that these emissions have increased the oceanic mercury inventory by 36-1,313 million moles since the 1500s. Such predictions have remained largely untested owing to a lack of appropriate historical data and natural archives. Here we report oceanographic measurements of total dissolved mercury and related parameters from several recent expeditions to the Atlantic, Pacific, Southern and Arctic oceans. We find that deep North Atlantic waters and most intermediate waters are anomalously enriched in mercury relative to the deep waters of the South Atlantic, Southern and Pacific oceans, probably as a result of the incorporation of anthropogenic mercury. We estimate the total amount of anthropogenic mercury present in the global ocean to be 290 ± 80 million moles, with almost two-thirds residing in water shallower than a thousand metres. Our findings suggest that anthropogenic perturbations to the global mercury cycle have led to an approximately 150 per cent increase in the amount of mercury in thermocline waters and have tripled the mercury content of surface waters compared to pre-anthropogenic conditions. This information may aid our understanding of the processes and the depths at which inorganic mercury species are converted into toxic methyl mercury and subsequently bioaccumulated in marine food webs. PMID:25100482

  5. 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…

  6. Laser-based display technology development at the Naval Ocean Systems Center

    NASA Astrophysics Data System (ADS)

    Phillips, Thomas E.; Trias, John A.; Lasher, Mark E.; Poirier, Peter M.; Dahlke, Weldon J.; Robinson, Waldo R.

    1991-02-01

    For several years, the Naval Ocean Systems Center (NOSC) has been working on the development of laser-based display systems with the goal of upgrading the image quality and ruggedness of shipboard displays. In this paper the authors report work on the major task of developing a full-color laser-addressed liquid crystal light valve (LCLV) projection system.

  7. Laser-based display technology development at the Naval Ocean Systems Center (NOSC)

    NASA Astrophysics Data System (ADS)

    Phillips, Thomas; Trias, John; Lasher, Mark; Poirier, Peter; Dahlke, Weldon

    1991-05-01

    For several years, the Naval Ocean Systems Center (NOSC) has been working on the development of laser-based display systems with the goal of upgrading the image quality and ruggedness of shipboard displays. In this paper we report work on our major task of developing a full-color laser-addressed liquid crystal light value (LCLV) projection system.

  8. 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.

  9. A comparative study of the particulate trace element geochemistry in two contrasting ocean margin environments in the Northeastern Atlantic

    NASA Astrophysics Data System (ADS)

    Chou, L.; Wollast, R.; Roevros, N.

    2003-04-01

    The present study was conducted during the Phases I and II of the Ocean Margin EXchange (OMEX) project, supported by the European Union in the framework of the MAST programme. The objective was to characterise the suspended matter by its composition with emphasis on trace elements in order to evaluate the sources, biogeochemical behaviour in the water column and fate of particulate material in two contrasting ocean margin environments: the Biscay margin and the Iberian margin. The Biscay margin is bordered by a wide continental plateau and a steep continental slope and rise, and is characterised by strong internal tides among many other physical processes with limited riverine input. In contrast, the Iberian margin is characterised by a narrow continental plateau receiving regularly continental input and by seasonal upwelling/downwelling that could influence significantly the chemical composition, transport and fluxes of particles in this region. Suspended matter in the water column along the two margins was sampled by various methods. These include 1) continuous centrifugation of surface waters, 2) in-situ filtration of large volumes of water at various depths using Stand Alone Pumps (SAPs), and 3) sediment traps. In addition to trace elements (Cr, Co, Ni, Cu, Zn Cd, Pb), the chemical composition of particulate matter collected was determined for major (Si, Al, Fe, Ca, POC/PN) and minor (Mg, Na, K, Mn) elements. Centrifugation samples allow the determination of the composition of surface suspended matter dominated by phytoplankton. SAP samples permit the assessment of the vertical evolution of suspended matter composition in the water column. Settling material intercepted by the sediment traps, are associated with large particles such as faecal pellets, marine snow and other aggregates. Trace metal geochemistry of the particulate matter in relation to the carbon cycle will be compared in the two margin environments investigated. Processes affecting the transfer

  10. Molecular and dissociation studies of natural gas hydrates collected from different oceanic environments

    NASA Astrophysics Data System (ADS)

    Bourry, C.; Charlou, J.; Donval, J.; Focsa, C.; Chazallon, B.

    2007-12-01

    is investigated by Raman spectroscopy at atmospheric pressure from 77 K to 260 K. Td shows to depend on the size of the hydrate particles. It is found to increase as the particle size increases. These results are consistent with previous data reported by Takeya et al. (2005). A "multi-layer" dissociation mechanism can be established for large hydrate particles thanks to the high spatial resolution of the micro-Raman technique. This effect will be discussed in the context of the stability of hydrates in natural environments. Takeya et al. (2005), Particle size effect of CH4 hydrate for self-preservation, Chem. Eng. Sci., 60, 1383-1387.

  11. 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.

  12. 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

  13. Mapping Arctic Ocean Coastline Change With Landsat Archive Data And Object-Based Image Analysis

    NASA Astrophysics Data System (ADS)

    Hulslander, D.

    2010-12-01

    The melting of arctic permafrost is a significant effect of climate change. The combination of rising sea level, longer periods of ice-free conditions in the Arctic Ocean and melting permafrost can greatly accelerate coastline changes in general and arctic coastal erosion in particular. Anderson et al. (2009; Geology News) have measured erosion rates of 15 m per year at sites along the Alaskan Arctic Ocean coastline dominated by ice-cemented peats and silt-rich permafrost. With over 45,000 km of Arctic Ocean coastline, it is important that coastline movement and transgressive oceanic regimes be mapped and tracked with accurate data. Determining historic coastal erosion rates for this region is as important as mapping the current extent of the phenomenon to create as complete a picture as possible and locate where rapid erosion is an emergent process. The extent of the area involved combined with its inaccessibility and inhospitable conditions makes geologic remote sensing an appropriate tool for characterizing Arctic Ocean coastal erosion. Traditional weaknesses associated with using remote sensing in the geosciences have included a lack of historical data or baseline information as well as difficulties in systematization of feature mapping. Using object-based image analysis on Landsat archive data can overcome these issues and may allow for a potential multi-decadal map of Arctic Ocean coastline changes. The Landsat family of sensors (MSS 1-3 and TM/ETM 4, 5, and 7) have been providing imagery as frequently as every 16 days since July 1972. The frequent revisits maximize the chance of getting cloud-free imagery at least once per year in most study areas. Also, Landsat data are well characterized, extensively studied, and freely available from the USGS EROS Data Center Archive, making it an ideal and stable source of data for mapping the Arctic Ocean coastline. Delineating large sections of coastline from imagery by hand digitization would be impractical due to the

  14. 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.

  15. A knowledge based software engineering environment testbed

    NASA Technical Reports Server (NTRS)

    Gill, C.; Reedy, A.; Baker, L.

    1985-01-01

    The Carnegie Group Incorporated and Boeing Computer Services Company are developing a testbed which will provide a framework for integrating conventional software engineering tools with Artifical Intelligence (AI) tools to promote automation and productivity. The emphasis is on the transfer of AI technology to the software development process. Experiments relate to AI issues such as scaling up, inference, and knowledge representation. In its first year, the project has created a model of software development by representing software activities; developed a module representation formalism to specify the behavior and structure of software objects; integrated the model with the formalism to identify shared representation and inheritance mechanisms; demonstrated object programming by writing procedures and applying them to software objects; used data-directed and goal-directed reasoning to, respectively, infer the cause of bugs and evaluate the appropriateness of a configuration; and demonstrated knowledge-based graphics. Future plans include introduction of knowledge-based systems for rapid prototyping or rescheduling; natural language interfaces; blackboard architecture; and distributed processing

  16. Ocean-generated magnetic field study based on satellite geomagnetic measurements: 2. Signal inference

    NASA Astrophysics Data System (ADS)

    Golubev, Yury

    2012-09-01

    The work presented here is the second part of an ocean-generated magnetic field study and provides a procedure for inferring the ocean-generated magnetic field from satellite geomagnetic measurements. The procedure was first tested on synthetic data. The simulation employed a hypothetical satellite measuring the magnetic field at an altitude of 400 km. The “measurements” (generated by the CM4 and CHAOS models) included the core field, the lithospheric field, the ionospheric and magnetospheric fields, the secular variation, and the ocean-generated magnetic field. The search algorithm, as proposed in part 1, converts irregular measurements into fields on a regular grid. The filtration procedure is based on the Savitzky-Golay algorithm. The procedure includes four steps providing seven unknown filter parameters. Parameter values were obtained by solving the problem of minimizing the spatially averaged squared residuals between the inferred field and the model field. Then, the parameters were used in the filter to infer the ocean-generated magnetic field that was initially added to the “measurements.” The inferred signal, although spatially corrupted and having a smaller magnitude (60% of the magnitude of the initial signal), indicated the presence of magnetic anomalies within the Southern Ocean. The technique was then applied to CHAMP geomagnetic measurements. The result of filtering was clear magnetic anomalies within the Southern Ocean with a spatial character that were close to what models of the ocean-generated magnetic field provided. The magnitude of the inferring signal was 5 nT, the corrected values were 7-8 nT, 1-2 nT larger than the modeled field magnitude. To compare the temporal variability of the inferred field with the variability of sea surface height, ten 10° by 10° areas were selected within the Southern Ocean and the root-mean-square of both SSH and the magnetic field were computed for each area. A comparison of the results indicated a

  17. 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)...

  18. 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)...

  19. 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)...

  20. 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)...

  1. 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)...

  2. 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)

  3. 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…

  4. 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…

  5. Using Design-Based Research in Informal Environments

    ERIC Educational Resources Information Center

    Reisman, Molly

    2008-01-01

    Design-Based Research (DBR) has been a tool of the learning sciences since the early 1990s, used as a way to improve and study learning environments. Using an iterative process of design with the goal of reining theories of learning, researchers and educators now use DBR seek to identify "how" to make a learning environment work. They then draw…

  6. 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 students. Three assessment…

  7. Global Ocean Surveillance With Electronic Intelligence Based Satellite System

    NASA Astrophysics Data System (ADS)

    Venkatramanan, Haritha

    2016-07-01

    The objective of this proposal is to design our own ELINT based satellite system to detect and locate the target by using satellite Trilateration Principle. The target position can be found by measuring the radio signals arrived at three satellites using Time Difference of Arrival(TDOA) technique. To locate a target it is necessary to determine the satellite position. The satellite motion and its position is obtained by using Simplified General Perturbation Model(SGP4) in MATLAB. This SGP4 accepts satellite Two Line Element(TLE) data and returns the position in the form of state vectors. These state vectors are then converted into observable parameters and then propagated in space. This calculations can be done for satellite constellation and non - visibility periods can be calculated. Satellite Trilateration consists of three satellites flying in formation with each other. The satellite constellation design consists of three satellites with an inclination of 61.3° maintained at equal distances between each other. The design is performed using MATLAB and simulated to obtain the necessary results. The target's position can be obtained using the three satellites ECEF Coordinate system and its position and velocity can be calculated in terms of Latitude and Longitude. The target's motion is simulated to obtain the Speed and Direction of Travel.

  8. 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.

  9. Toward a global ocean data assimilation system based on ensemble optimum interpolation: altimetry data assimilation experiment

    NASA Astrophysics Data System (ADS)

    Fu, Weiwei; Zhu, Jiang; Yan, Changxiang; Liu, Hailong

    2009-08-01

    A global ocean data assimilation system based on the ensemble optimum interpolation (EnOI) has been under development as the Chinese contribution to the Global Ocean Data Assimilation Experiment. The system uses a global ocean general circulation model, which is eddy permitting, developed by the Institute of Atmospheric Physics of the Chinese Academy of Sciences. In this paper, the implementation of the system is described in detail. We describe the sampling strategy to generate the stationary ensembles for EnOI. In addition, technical methods are introduced to deal with the requirement of massive memory space to hold the stationary ensembles of the global ocean. The system can assimilate observations such as satellite altimetry, sea surface temperature (SST), in situ temperature and salinity from Argo, XBT, Tropical Atmosphere Ocean (TAO), and other sources in a straightforward way. As a first step, an assimilation experiment from 1997 to 2001 is carried out by assimilating the sea level anomaly (SLA) data from TOPEX/Poseidon. We evaluate the performance of the system by comparing the results with various types of observations. We find that SLA assimilation shows very positive impact on the modeled fields. The SST and sea surface height fields are clearly improved in terms of both the standard deviation and the root mean square difference. In addition, the assimilation produces some improvements in regions where mesoscale processes cannot be resolved with the horizontal resolution of this model. Comparisons with TAO profiles in the Pacific show that the temperature and salinity fields have been improved to varying degrees in the upper ocean. The biases with respect to the independent TAO profiles are reduced with a maximum magnitude of about 0.25°C and 0.1 psu for the time-averaged temperature and salinity. The improvements on temperature and salinity also lead to positive impact on the subsurface currents. The equatorial under current is enhanced in the Pacific

  10. 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.

  11. Design-Based Research and Technology-Enhanced Learning Environments

    ERIC Educational Resources Information Center

    Wang, Feng; Hannafin, Michael J.

    2005-01-01

    During the past decade, design-based research has demonstrated its potential as a methodology suitable to both research and design of technology-enhanced learning environments (TELEs). In this paper, we define and identify characteristics of design-based research, describe the importance of design-based research for the development of TELEs,…

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

    NASA Astrophysics Data System (ADS)

    Luo, xiaowen

    2016-04-01

    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. This work is different to 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. NEMO-Nordic : A NEMO based ocean modelling configuration for Baltic & North Seas

    NASA Astrophysics Data System (ADS)

    Hordoir, Robinson; Schimanke, Semjon; Axell, Lars; Gröger, Matthias; Dieterich, Christian; Liu, Ye; Höglund, Anders; Kuznetsov, Ivan; Ljungemyr, Patrik; Nygren, Petter; Jönsson, Anette; Meier, Markus

    2015-04-01

    Based on the NEMO ocean engine, three regional setups for the North Sea and Baltic Sea domain have been developed : the NEMO-Nordic configuration is declined in an operational setup, a stand-alone version used for climate and process studies, and a NEMO-Nordic-RCA4 atmosphere/ocean coupled configuration used for downscalling climate scenarios. We give a brief overview of the options chosen within the NEMO engine to design the configurations. Based on the results provided by each of the three configurations, we also provide an assessment of the strengths and weaknesses of NEMO-Nordic. Finally, a validation of the configurations is provided based on an extensive comparison between in-situ measurements and model results for temperature, salinity, sea-ice extent, sea level and mean circulation.

  14. Oceanic Observations

    NASA Technical Reports Server (NTRS)

    Busalacchi, Antonio J.

    1997-01-01

    For many years, merchant ships and the naval fleets of various countries have been the major source of data over and in the open ocean. Oceanographic research experiments and process studies in the field have also contributed to the climatological data bases for the global ocean, but, for the most part, these have been limited in duration and extent. However, over the last 10 years under the auspices of the World Climate Research Program and the International Geosphere Biosphere Program the role of the oceans in global and climate change has taken on increased significance. This has created a need for a considerably improved understanding of the seasonal, interannual, decadal and longer time-scale variability of the physical and biogeochemical attributes of the global ocean. As a result, over the past 10 years several major international field programs have been implemented and have had a tremendous impact on the number of in situ observations obtained for the global ocean. The Tropical Ocean Global Atmosphere (TOGA) program, the World Ocean Circulation Experiment (WOCE), and the Joint Global Ocean Flux Study (JGOFS) were designed with observational, modelling, and process study components aimed at analyzing different aspects of the ocean's role in the coupled climate system. In parallel with the field programs, continuous space-based observations of sea surface temperature, sea surface topography, and sea surface winds spanning nearly a decade or longer have become a reality. During this same time period, numerical ocean models and computational power have advanced to the point where the oceanographic observations, both in situ and remotely sensed, can be assimilated into numerical ocean models in order to provide a four-dimensional (x-y-z-t) depiction of the evolving state of the global ocean.

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

    PubMed

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

    2016-09-01

    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

  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. 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.

  18. 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).

  19. 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.

  20. 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...

  1. 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...

  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, 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...

  4. 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...

  5. 75 FR 26100 - Danger Zone, Pacific Ocean, Naval Base Coronado, Coronado, California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ...The U.S. Army Corps of Engineers (Corps) is amending its regulations to establish a naval danger zone in the waters of the Pacific Ocean extending offshore from the small arms range at the Naval Base Coronado (NBC), in Coronado, San Diego County, California. The danger zone will provide an appropriate and enforceable zone in which the Navy may conduct small arms test firing to qualify military......

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

    PubMed

    Ward, Bess B; Eveillard, Damien; Kirshtein, Julie D; Nelson, Joshua D; Voytek, Mary A; Jackson, George A

    2007-10-01

    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. PMID:17803777

  7. 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.

  8. Analysis of Navigation in a Problem-Based Learning Environment.

    ERIC Educational Resources Information Center

    Williams, Douglas C.; Liu, Min; Benton, Denise

    Research has shown the potential of a problem-based approach to enhance students' learning. The interactive nature of hypermedia technology and its ability to deliver information in different media formats can provide unique capabilities for implementing problem-based learning (PBL) environments. Yet, little is known about the types of tools that…

  9. 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.

  10. 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

  11. Gradation from oceanic to estuarine beaches in a ría environment: A case study in the Ría de Vigo

    NASA Astrophysics Data System (ADS)

    Bernabeu, Ana M.; Lersundi-Kanpistegi, Aimar V.; Vilas, Federico

    2012-05-01

    Beaches are an important consideration in coastal management. Morphodynamic classification of sandy beaches is used for open-ocean, wave-dominated environments, but fails to describe the shape of natural sandy beaches located in low-energy environments. An important consequence of this is that these environments are excluded from current morphodynamic models, making the design of efficient coastal management plans difficult to achieve. Many of these types of beaches occur in quick succession along the coastline in protected environments such as estuaries, lagoons, fjords and rías, which are favourite sites for human settlements. These particular environments are of enormous economic importance and constitute the zones of greatest human impact on the coast. Correct management requires a good understanding of the physical factors that affect each type of beach and of the interactions between such factors. Fifteen beaches in the Ría de Vigo (NW Spain) were studied in order to determine how the gradational changes from oceanic to estuarine conditions affect the beach morphology and intertidal sediments. The balance between wave action and sedimentary supply was found to be the controlling factor in the ría. The results of this study provide useful information about a coastal ría environment, which will enable better design of a suitable integrated coastal plan for management of rías.

  12. 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

  13. 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

  14. 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

  15. 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. PMID:25214628

  16. Functional Dorsoventral Symmetry in Relation to Lift-Based Swimming in the Ocean Sunfish Mola mola

    PubMed Central

    Watanabe, Yuuki; Sato, Katsufumi

    2008-01-01

    The largest (up to 2 tons) and a globally distributed teleost—the ocean sunfish Mola mola—is commonly regarded as a planktonic fish because of its unusual shape including absence of caudal fin. This common view was recently questioned because the horizontal movements of the ocean sunfish tracked by acoustic telemetry were independent of ocean currents. However, direct information regarding their locomotor performance under natural conditions is still lacking. By using multi-sensor tags, we show that sunfish indeed swam continuously with frequent vertical movements at speeds of 0.4–0.7 m s–1, which is similar to the records of other large fishes such as salmons, marlins, and pelagic sharks. The acceleration data revealed that they stroked their dorsal and anal fins synchronously (dominant frequency, 0.3–0.6 Hz) to generate a lift-based thrust, as penguins do using two symmetrical flippers. Morphological studies of sunfish (mass, 2–959 kg) showed that the dorsal and anal fins had similar external (symmetrical shape and identical area) and internal (identical locomotory muscle mass) features; however, the muscle shape differed markedly. We conclude that ocean sunfish have functional dorsoventral symmetry with regards to the non-homologous dorsal and anal fins that act as a pair of vertical hydrofoils. Although sunfish lack a swimbladder, we found that they are neutrally buoyant independent of depth because of their subcutaneous gelatinous tissue that has low density and is incompressible. Efficient lift-based swimming in conjunction with neutral buoyancy enables sunfish to travel long distances both horizontally and vertically. PMID:18941510

  17. Chlorophyll a algorithms for oligotrophic oceans: A novel approach based on three-band reflectance difference

    NASA Astrophysics Data System (ADS)

    Hu, Chuanmin; Lee, Zhongping; Franz, Bryan

    2012-01-01

    A new empirical algorithm is proposed to estimate surface chlorophyll a (Chl) concentrations in the global ocean for Chl ≤ 0.25 mg m-3(˜78% of the global ocean area). The algorithm is based on a color index (CI), defined as the difference between remote-sensing reflectance (Rrs, sr-1) in the green and a reference formed linearly between Rrsin 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 Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua 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 nonphytoplankton 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 better 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 Medium-Resolution Imaging Spectrometer and Coastal Zone Color Scanner data indicate that the new approach should be generally applicable to all past, current, and future ocean color instruments.

  18. Three-dimensional ocean sensor networks: A survey

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Liu, Yingjian; Guo, Zhongwen

    2012-12-01

    The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research, oceanography, ocean monitoring, offshore exploration, and defense or homeland security. Ocean sensor networks are generally formed with various ocean sensors, autonomous underwater vehicles, surface stations, and research vessels. To make ocean sensor network applications viable, efficient communication among all devices and components is crucial. Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional (3D) ocean spaces, new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks. In this paper, we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks, with focuses on deployment, localization, topology design, and position-based routing in 3D ocean spaces.

  19. Hypercompetitive Environments: An Agent-based model approach

    NASA Astrophysics Data System (ADS)

    Dias, Manuel; Araújo, Tanya

    Information technology (IT) environments are characterized by complex changes and rapid evolution. Globalization and the spread of technological innovation have increased the need for new strategic information resources, both from individual firms and management environments. Improvements in multidisciplinary methods and, particularly, the availability of powerful computational tools, are giving researchers an increasing opportunity to investigate management environments in their true complex nature. The adoption of a complex systems approach allows for modeling business strategies from a bottom-up perspective — understood as resulting from repeated and local interaction of economic agents — without disregarding the consequences of the business strategies themselves to individual behavior of enterprises, emergence of interaction patterns between firms and management environments. Agent-based models are at the leading approach of this attempt.

  20. Data-based estimates of the ocean carbon sink variability - results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)

    NASA Astrophysics Data System (ADS)

    Rödenbeck, Christian; Bakker, Dorothee; Gruber, Nicolas; Iida, Yosuke; Jacobson, Andy; Jones, Steve; Landschützer, Peter; Metzl, Nicolas; Nakaoka, Shin-ichiro; Olsen, Are; Park, Geun-Ha; Peylin, Philippe; Rodgers, Keith; Sasse, Tristan; Schuster, Ute; Shutler, James; Valsala, Vinu; Wanninkhof, Rik; Zeng, Jiye

    2016-04-01

    Using measurements of the surface-ocean COtwo partial pressure (pCOtwo) from the SOCAT and LDEO data bases and 14 different pCOtwo mapping methods recently collated by the Surface Ocean pCOtwo Mapping intercomparison (SOCOM) initiative, variations in regional and global sea-air COtwo fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCOtwo seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the Eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types - taking variability either directly from the pCOtwo data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea-air COtwo flux of IAVampl (standard deviation over AnalysisPeriod), which is larger than simulated by biogeochemical process models. On a decadal perspective, the global ocean COtwo uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean COtwo sink estimated by the SOCOM ensemble is -1.75 UPgCyr (AnalysisPeriod), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends. Using data-based sea-air COtwo fluxes in atmospheric COtwo inversions also helps to better constrain land-atmosphere COtwo fluxes.

  1. Mooring-based long-term observation of oceanographic condition in the Chukchi Ses and Canada Basin of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takashi; Itoh, Motoyo; Nishino, Shigeto; Watanabe, Eiji

    2015-04-01

    Changes of the Arctic Ocean environment are well known as one of the most remarkable evidences of global warming, attracting social and public attentions as well as scientists'. However, to illustrate on-going changes and predict future condition of the Arctic marine environment, we still do not have enough knowledge of Arctic sea ice and marine environment. In particular, lack of observation data in winter, e.g., under sea ice, still remains a key issue for precise understanding of seasonal cycle on oceanographic condition in the Arctic Ocean. Mooring-based observation is one of the most useful methods to collect year-long data in the Arctic Ocean. We have been conducting long-term monitoring using mooring system in the Pacific sector of the Arctic Ocean. Volume, heat, and freshwater fluxes through Barrow Canyon where is a major conduit of Pacific-origin water-masses into the Canada Basin have been observed since 2000. We show from an analysis of the mooring results that volume flux through Barrow Canyon was about 60 % of Bering Strait volume flux. Averaged heat flux ranges from 0.9 to 3.07 TW, which could melt 88,000 to 300,000 km2 of 1m thick ice in the Canada Basin, which likely contributed to sea ice retreat in the Pacific sector of the Arctic Ocean. In winter, we found inter-annual variability in salinity related to coastal polynya activity in the Chukchi Sea. In collaboration with Distributed Biological Observatory (DBO) project, which is one of the tasks of Sustaining Arctic Observing Network (SAON), we also initiated year-long mooring observation in the Hope Valley of the southern Chukchi Sea since 2012. Interestingly, winter oceanographic conditions in the Hope Valley are greatly different between in 2012-2013 and in 2013-2014. We speculate that differences of sea ice freeze-up and coastal polynya activity in the southern Chukchi Sea cause significant difference of winter oceanographic condition. It suggests that recent sea ice reduction in the Pacific

  2. Scaffolding Diagnostic Reasoning in Case-Based Learning Environments.

    ERIC Educational Resources Information Center

    Jonassen, David H.

    1996-01-01

    Computer-delivered, case-based instruction can provide medical students with valuable clinical diagnostic experiences before encountering real patients. Diagnosis requires physicians to understand and use causal reasoning for prediction. Such reasoning may be scaffolded in the design of computerized learning environments. Scaffolding of causal…

  3. 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…

  4. Desktop Publishing in a PC-Based Environment.

    ERIC Educational Resources Information Center

    Sims, Harold A.

    1987-01-01

    Identifies, considers, and interrelates the functionality of hardware, firmware, and software types; discusses the relationship of input and output devices in the PC-based desktop publishing environment; and reports some of what has been experienced in three years of working intensively in/with desktop publishing devices and solutions. (MES)

  5. 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…

  6. A Case-Based Pharmacy Environment: Cognitive Flexibility + Social Constructivism.

    ERIC Educational Resources Information Center

    Oliver, Kevin M.

    The Internet Web Site on Virtual Clinical Applications and Disease Management is a hypermedia, case-based open learning environment that was designed to promote cognitive flexibility in college students at The University of Georgia College of Pharmacy. With a key objective of pharmacy education being patient problem-solving skills, this…

  7. Narrative-Based Interactive Learning Environments from Modelling Reasoning

    ERIC Educational Resources Information Center

    Yearwood, John; Stranieri, Andrew

    2007-01-01

    Narrative and story telling has a long history of use in structuring, organising and communicating human experience. This paper describes a narrative based interactive intelligent learning environment which aims to elucidate practical reasoning using interactive emergent narratives that can be used in training novices in decision making. Its…

  8. Instructionist versus Constructionist Web-Based Collaborative Learning Environments.

    ERIC Educational Resources Information Center

    Sherman, Greg

    This study investigated the effects of instructionist (navigational, functional) versus constructionist (adaptive) World Wide Web (WWW) site environments on collaboration, achievement, attitudes, and perceived level of learner controls reported by students after working in cooperative dyads within the different types of Web-based learning…

  9. Measuring Self-Regulation in Computer-Based Learning Environments

    ERIC Educational Resources Information Center

    Schraw, Gregory

    2010-01-01

    I provide a summary of the four invited articles in this special issue and compare and contrast different methods for measuring self-regulation in computer-based learning environments (CBLEs). I present a taxonomy that distinguishes between offline and online measures and further distinguishes subcategories within each of these categories. I…

  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 computer…

  11. 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)

  12. 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. PMID:26941092

  13. An approach to accidents modeling based on compounds road environments.

    PubMed

    Fernandes, Ana; Neves, Jose

    2013-04-01

    The most common approach to study the influence of certain road features on accidents has been the consideration of uniform road segments characterized by a unique feature. However, when an accident is related to the road infrastructure, its cause is usually not a single characteristic but rather a complex combination of several characteristics. The main objective of this paper is to describe a methodology developed in order to consider the road as a complete environment by using compound road environments, overcoming the limitations inherented in considering only uniform road segments. The methodology consists of: dividing a sample of roads into segments; grouping them into quite homogeneous road environments using cluster analysis; and identifying the influence of skid resistance and texture depth on road accidents in each environment by using generalized linear models. The application of this methodology is demonstrated for eight roads. Based on real data from accidents and road characteristics, three compound road environments were established where the pavement surface properties significantly influence the occurrence of accidents. Results have showed clearly that road environments where braking maneuvers are more common or those with small radii of curvature and high speeds require higher skid resistance and texture depth as an important contribution to the accident prevention. PMID:23376544

  14. Forecasting front displacements with a satellite based ocean forecasting (SOFT) system

    NASA Astrophysics Data System (ADS)

    Alvarez, A.; Orfila, A.; Basterretxea, G.; Tintoré, J.; Vizoso, G.; Fornes, A.

    2007-03-01

    Relatively long term time series of satellite data are nowadays available. These spatio-temporal time series of satellite observations can be employed to build empirical models, called satellite based ocean forecasting (SOFT) systems, to forecast certain aspects of future ocean states. The forecast skill of SOFT systems predicting the sea surface temperature (SST) at sub-basin spatial scale (from hundreds to thousand kilometres), has been extensively explored in previous works. Thus, these works were mostly focussed on predicting large scale patterns spatially stationary. At spatial scales smaller than sub-basin (from tens to hundred kilometres), spatio-temporal variability is more complex and propagating structures are frequently present. In this case, traditional SOFT systems based on Empirical Orthogonal Function (EOF) decompositions could not be optimal prediction systems. Instead, SOFT systems based on Complex Empirical Orthogonal Functions (CEOFs) are, a priori, better candidates to resolve these cases. In this work we study and compare the performance of an EOF and CEOF based SOFT systems forecasting the SST at weekly time scales of a propagating mesoscale structure. The SOFT system was implemented in an area of the Northern Balearic Sea (Western Mediterranean Sea) where a moving frontal structure is recurrently observed. Predictions from both SOFT systems are compared with observations and with the predictions obtained from persistence models. Results indicate that the implemented SOFT systems are superior in terms of predictability to persistence. No substantial differences have been found between the EOF and CEOF-SOFT systems.

  15. 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.

  16. 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. PMID:26357093

  17. Biomass of zooplankton in the eastern Arctic Ocean - A base line study

    NASA Astrophysics Data System (ADS)

    Kosobokova, Ksenia; Hirche, Hans-Jürgen

    2009-09-01

    Only a few historical assessments of the zooplankton biomass in the Arctic Ocean exist are difficult to compare due to methodological differences including incomplete sampling of the water column. We present assessments of the zooplankton biomass for 66 locations scattered over the Eurasian and Makarov Basins of the Arctic Ocean and analyze regional variability and factors affecting the biomass distribution. The study is based on material from several summer expeditions of RV Polarstern (1993-1998) that was collected and processed using consistent methods, i.e. stratified sampling of the entire water column from the bottom to the surface with very similar gear and standardized calculation of biomass. Total zooplankton biomass varied strongly from 1.9 to 23.9 g DW m -2 dry mass. Regional variability was mainly related to the circulation pattern, but local food availability was also important. A belt of elevated biomass along the Eurasian continental margin was associated with the advection of Atlantic pelagic populations within the Arctic Ocean Boundary Current along the Siberian shelves and returning branches along mid-ocean ridges. Biomass was highest in the core of the Atlantic inflow and remained rather stable along the continental margins, but species composition changed, pointing to different adaptation levels to local conditions by advected species. Biomass gradually decreased towards the shelves and basins and was lowest in the centers of the basins north of 85°N. In the slope region, three Calanus species ( C. hyperboreus, C. glacialis, C. finmarchicus) and Metridia longa contributed most to the biomass, chaetognaths ( Eukrohnia hamata) were also important. In the basins, C. hyperboreus was dominant, copepods made up to 97% of total biomass. Vertical distribution was similar at all stations with biomass maxima in the upper 50 m layer except for stations near Fram Strait and northern Kara Sea, the gateways of Atlantic water to the Arctic Ocean, where maxima

  18. 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.

  19. 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.

  20. An HLA based design of space system simulation environment

    NASA Astrophysics Data System (ADS)

    Li, Yinghua; Li, Yong; Liu, Jie

    2007-06-01

    Space system simulation is involved in many application fields, such as space remote sensing and space communication, etc. A simulation environment which can be shared by different space system simulation is needed. Two rules, called object template towing and hierarchical reusability, are proposed. Based on these two rules, the architecture, the network structure and the function structure of the simulation environment are designed. Then, the mechanism of utilizing data resources, inheriting object models and running simulation systems are also constructed. These mechanisms make the simulation objects defined in advance be easily inherited by different HLA federates, the fundamental simulation models be shared by different simulation systems. Therefore, the simulation environment is highly universal and reusable.

  1. 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)

  2. 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

    2016-06-01

    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.

  3. 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

  4. Investigating Effects of Problem-Based versus Lecture-Based Learning Environments on Student Motivation

    ERIC Educational Resources Information Center

    Wijnia, Lisette; Loyens, Sofie M. M.; Derous, Eva

    2011-01-01

    This study examines the effects of two learning environments (i.e., problem-based learning [PBL] versus lecture-based [LB] environments) on undergraduates' study motivation. Survey results demonstrated that PBL students scored higher on competence but did not differ from LB students on autonomous motivation. Analyses of focus groups further…

  5. Microflown based sound pressure microphone suitable for harsh environments

    NASA Astrophysics Data System (ADS)

    Yntema, D. R.; de Bree, Hans-Elias

    2005-09-01

    There are several cases where a sound field reconstruction or prediction is required under harsh conditions such as high temperature, humidity or chemical attack. A regular pressure microphone will not last long under these conditions. Electret based pressure microphones stop working well above 70 degrees centigrade and other type of pressure microphones often operate with a built in amplifier that does not function above 120 degrees centigrade. The functionality of a MEMS based Microflown acoustic particle velocity sensor in air lies in the use of two heated platinum wires that are resistant to high temperatures and chemical attack. The wires are supported by silicon that has no other function than provide support. A pressure microphone is made based upon the Microflown principle by putting it in the opening of an enclosure. In this paper a silicon and platinum based sound probe for harsh environments is created, combining particle velocity and pressure measurements in a harsh environment. Use of this sensor is possible up to 250 degrees centigrade, in humid and under most chemical environments. The probe realization as well as calibration measurements are presented.

  6. 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

  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 Cambrian

  8. 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

  9. A Time Series of Sea Surface Nitrate and Nitrate based New Production in the Global Oceans

    NASA Astrophysics Data System (ADS)

    Goes, J. I.; Fargion, G. S.; Gomes, H. R.; Franz, B. A.

    2014-12-01

    With support from NASA's MEaSUREs program, we are developing algorithms for two innovative satellite-based Earth Science Data Records (ESDRs), one Sea Surface Nitrate (SSN) and the other, Nitrate based new Production (NnP). Newly developed algorithms will be applied to mature ESDRs of Chlorophyll a and SST available from NASA, to generate maps of SSN and NnP. Our proposed ESDRs offer the potential of greatly improving our understanding of the role of the oceans in global carbon cycling, earth system processes and climate change, especially for regions and seasons which are inaccessible to traditional shipboard studies. They also provide an innovative means for validating and improving coupled ecosystem models that currently rely on global maps of nitrate generated from multi-year data sets. To aid in our algorithm development efforts and to ensure that our ESDRs are truly global in nature, we are currently in the process of assembling a large database of nutrients from oceanographic institutions all over the world. Once our products are developed and our algorithms are fine-tuned, large-scale data production will be undertaken in collaboration with NASA's Ocean Biology Processing Group (OPBG), who will make the data publicly available first as evaluation products and then as mature ESDRs.

  10. A first estimation of SMOS-based ocean surface T-S diagrams

    NASA Astrophysics Data System (ADS)

    Sabia, Roberto; Klockmann, Marlene; Fernández-Prieto, Diego; Donlon, Craig

    2014-10-01

    A first estimation of satellite-based ocean surface T-S diagrams is performed by using SMOS Sea Surface Salinity (SSS) and OSTIA Sea Surface Temperature (SST) and comparing them with in situ measurements interpolated fields obtained by the Argo-buoys for the North Atlantic and over the entire year 2011. The key objectives at the base of this study are: (1) To demonstrate the feasibility of generating routinely satellite-derived surface T-S diagrams, obviating the lack of extensive sampling of the surface open ocean, (2) To display the T-S diagrams variability and the distribution/dynamics of SSS, altogether with SST and the relative density with respect to in situ measurements, and (3) To assess the SMOS SSS data added value in detecting geophysical signals not sensed/resolved by the Argo measurements. To perform the latter analysis, the satellite-Argo mismatches have been overlapped with geophysical parameters of precipitation rates, surface heat and freshwater fluxes and wind speed data. Ongoing and future efforts focus on enlarging the study area and the temporal frame of the analysis and aim at developing a method for the systematic identification of surface water masses formation areas by remotely sensed data.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. Managers, leaders, and teams in a team-based environment.

    PubMed

    DeMent, J

    1996-08-01

    In order to succeed in today's dynamic environment, abundant with corporate restructuring and downsizing, into what must today's manager transform? Part of the answer lies in "leadership." Some managers are leaders, some leaders are managers, but the two are not synonymous. There are notable differences between managers and leaders, particularly in the role each plays in the transition towards organizations that are customer-focused, empowered, and team-based. The evolution towards team-based organizations begins with three different, concurrent transitions: of managers into leaders, of employees into teammates, and of functional hierarchical organizations into those of team empowerment. PMID:10159794

  16. Spring-Model-Based Wireless Localization in Cooperative User Environments

    NASA Astrophysics Data System (ADS)

    Ke, Wei; Wu, Lenan; Qi, Chenhao

    To overcome the shortcomings of conventional cellular positioning, a novel cooperative location algorithm that uses the available peer-to-peer communication between the mobile terminals (MTs) is proposed. The main idea behind the proposed approach is to incorporate the long- and short-range location information to improve the estimation of the MT's coordinates. Since short-range communications among MTs are characterized by high line-of-sight (LOS) probability, an improved spring-model-based cooperative location method can be exploited to provide low-cost improvement for cellular-based location in the non-line-of-sight (NLOS) environments.

  17. 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

  18. 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.

  19. Building simplification algorithms based on user cognition in mobile environment

    NASA Astrophysics Data System (ADS)

    Shen, Jie; Shi, Junfei; Wang, Meizhen; Wu, Chenyan

    2008-10-01

    With the development of LBS, mobile map should adaptively satisfy the cognitive requirement of user. User cognition in mobile environment is much more objective oriented and also seem to be a heavier burden than the user in static environment. The holistic idea and methods of map generalization can not fully suitable for the mobile map. This paper took the building simplification in habitation generalization as example, analyzed the characteristic of user cognition in mobile environment and the basic rules of building simplification, collected and studied the state-of-the-art of algorithms of building simplification in the static and mobile environment, put forward the idea of hierarchical building simplification based on user cognition. This paper took Hunan road business district of Nanjing as test area and took the building data with shapfile format of ESRI as test data and realized the simplification algorithm. The method took user as center, calculated the distance between user and the building which will be simplified and took the distance as the basis for choosing different simplification algorithm for different spaces. This contribution aimed to hierarchically present the building in different level of detail by real-time simplification.

  20. An improved simulation of the deep Pacific Ocean using optimally estimated vertical diffusivity based on the Green's function method

    NASA Astrophysics Data System (ADS)

    Toyoda, Takahiro; Sugiura, Nozomi; Masuda, Shuhei; Sasaki, Yuji; Igarashi, Hiromichi; Ishikawa, Yoichi; Hatayama, Takaki; Kawano, Takeshi; Kawai, Yoshimi; Kouketsu, Shinya; Katsumata, Katsuro; Uchida, Hiroshi; Doi, Toshimasa; Fukasawa, Masao; Awaji, Toshiyuki

    2015-11-01

    An improved vertical diffusivity scheme is introduced into an ocean general circulation model to better reproduce the observed features of water property distribution inherent in the deep Pacific Ocean structure. The scheme incorporates (a) a horizontally uniform background profile, (b) a parameterization depending on the local static stability, and (c) a parameterization depending on the bottom topography. Weighting factors for these parameterizations are optimally estimated based on the Green's function method. The optimized values indicate an important role of both the intense vertical diffusivity near rough topography and the background vertical diffusivity. This is consistent with recent reports that indicate the presence of significant vertical mixing associated with finite-amplitude internal wave breaking along the bottom slope and its remote effect. The robust simulation with less artificial trend of water properties in the deep Pacific Ocean illustrates that our approach offers a better modeling analysis for the deep ocean variability.

  1. 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.

  2. 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.

  3. Recent changes of Northern Indian Ocean summer rainfall based on CMIP5 multi-model

    NASA Astrophysics Data System (ADS)

    Yang, Yali; Du, Yan; Zhang, Yuhong; Cheng, Xuhua

    2013-06-01

    This study evaluates the simulation of summer rainfall changes in the Northern Indian Ocean (NIO) based on the fifth phase of Coupled Model Intercomparison Project (CMIP5). The historical runs of 20 CMIP5 coupled General Circulation Models (GCMs) are analyzed. The Multi-Model ensemble (MME) of the CMIP5 models well reproduces the general feature of NIO summer rainfall. For a short period 1979-2005, 14 out of 20 models show an increased trend in the mean rainfall and a similar spatial distribution to the Global Precipitation Climatology Project (GPCP) observations in MME. The increasing of the convergence in the equatorial IO results in the increase of rainfall significantly. The equatorial rainfall trend patterns seem modulated by the SST warming in the tropical Indian Ocean, which confirm the mechanism of `warmer-get-wetter' theory. For a long period 1950-2005, the trend of monsoon rainfall over India shows a decrease over the most parts of the India except an increase over the south corn er of the Indian Peninsula, due to a weakened summer monsoon circulation. The pattern is well simulated in half of the CMIP5 models. The rainfall over the north India is different for a short period, in which rainfall increases in 1979-2005, implying possible decadal variation in the NIO summer climate.

  4. 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

  5. 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.

  6. BIM based virtual environment for fire emergency evacuation.

    PubMed

    Wang, Bin; Li, Haijiang; Rezgui, Yacine; Bradley, Alex; 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

  7. Ocean-Atmosphere Environments of Antarctic-Region Cold-Air Mesocyclones: Evaluation of Reanalyses for Contrasting Adjacent 10-Day Periods ("Macro-Weather") in Winter.

    NASA Astrophysics Data System (ADS)

    Carleton, A. M.; Auger, J.; Birkel, S. D.; Maasch, K. A.; Mayewski, P. A.; Claud, C.

    2015-12-01

    Mesoscale cyclones in cold-air outbreaks (mesocyclones) feature in the weather and climate of the Antarctic (e.g., Ross Sea) and sub-antarctic (Drake Passage). They adversely impact field operations, and influence snowfall, the ice-sheet mass balance, and sea-air energy fluxes. Although individual mesocyclones are poorly represented on reanalyses, these datasets robustly depict the upper-ocean and troposphere environments in which multiple mesocyclones typically form. A spatial metric of mesocyclone activity—the Meso-Cyclogenesis Potential (MCP)—used ERA-40 anomaly fields of: sea surface temperature (SST) minus marine air temperature (MAT), near-surface winds, 500 hPa air temperature, and the sea-ice edge location. MCP maps composited by teleconnection phases for 1979-2001, broadly correspond to short-period satellite "climatologies" of mesocyclones. Here, we assess 3 reanalysis datasets (CFSR, ERA-I and MERRA) for their reliably to depict MCP patterns on weekly to sub-monthly periods marked by strong regional shifts in mesocyclone activity (frequencies, track densities) occurring during a La Niña winter: June 21-30, 1999 (SE Indian Ocean) and September 1-10, 1999 (Ross Sea sector). All reanalyses depict the marked variations in upper ocean and atmosphere variables between adjacent 10-day periods. Slight differences may owe to model resolution or internal components (land surface, coupled ocean models), and/or how the observations are assimilated. For June 21-30, positive SST-MAT, southerly winds, proximity to the ice edge, and negative T500, accompany increased meso-cyclogenesis. However, for September 1-10, surface forcing does not explain frequent comma cloud "polar lows" north-east of the Ross Sea. Inclusion of the upper-level diffluence (e.g., from Z300 field) in the MCP metric, better depicts the observed mesocyclone activity. MCP patterns on these "macro-weather" time scales appear relatively insensitive to the choice of reanalysis.

  8. Coupled mode transport theory for sound transmission through an ocean with random sound speed perturbations: coherence in deep water environments.

    PubMed

    Colosi, John A; Chandrayadula, Tarun K; Voronovich, Alexander G; Ostashev, Vladimir E

    2013-10-01

    Second moments of mode amplitudes at fixed frequency as a function of separations in mode number, time, and horizontal distance are investigated using mode-based transport equations and Monte Carlo simulation. These second moments are used to study full-field acoustic coherence, including depth separations. Calculations for low-order modes between 50 and 250 Hz are presented using a deep-water Philippine Sea environment. Comparisons between Monte Carlo simulations and transport theory for time and depth coherence at frequencies of 75 and 250 Hz and for ranges up to 500 km show good agreement. The theory is used to examine the accuracy of the adiabatic and quadratic lag approximations, and the range and frequency scaling of coherence. It is found that while temporal coherence has a dominant adiabatic component, horizontal and vertical coherence have more equal contributions from coupling and adiabatic effects. In addition, the quadratic lag approximation is shown to be most accurate at higher frequencies and longer ranges. Last the range and frequency scalings are found to be sensitive to the functional form of the exponential decay of coherence with lag, but temporal and horizontal coherence show scalings that fall quite close to the well-known inverse frequency and inverse square root range laws. PMID:24116510

  9. 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…

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Secure Biometrically Based Authentication Protocol for a Public Network Environment

    NASA Astrophysics Data System (ADS)

    Tait, Bobby; von Solms, Basie

    Biometric technology allows a computer system to identify and authenticate a person directly based on physical or behavioral traits [1]. However passwords and tokens that are currently widely used for authentication purposes do not directly authenticate a person; whenever a person offers a password or token the system only authenticates the presented password or token as authentic, but not the actual person presenting it [2], [8]. For this reason a lot of research went into developing a protocol that will allow a person to securely use a biometric token for personal authentication. Biometric technology is an attractive option for authenticating a person as there is a direct link between the person and a person's biometric token. This paper discusses a protocol, named BioVault. BioVault ensures safe transport of biometric tokens over un-secure networked environment without using any encryption technologies. The BioVault protocol also lays the foundation for biometrically based encryption, and biometrically based digital signatures.

  15. 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.

  16. Certificate-based authorization policy in a PKI environment

    SciTech Connect

    Thompson, Mary R.; Essiari, Abdelilah; Mudumbai, Srilekha

    2003-02-15

    The major emphasis of Public Key Infrastructure has been to provide acryptographically secure means of authenticating identities. However, procedures for authorizing the holders of these identities to perform specific actions still need additional research and development. While there are a number of proposed standards for authorization structures and protocols such as KeyNote, SPKI and SAML based on X.509 or other key-based identities, none have been widely adopted. As part of an effort to use X.509 identities to provide authorization in highly distributed environments, we have developed and deployed an authorization service based on X.509 identified users and access policy contained in certificates signed by X.509 identified stakeholders. The major goal of this system, called Akenti, is to produce a usable authorization system for an environment consisting of distributed resources used by geographically and administratively distributed users. Akenti assumes communication between user s and resources over a secure protocol such as Transport Layer Security(TLS) to provide mutual authentication with X.509 certificates. This paper explains the authorization model and policy language used by Akenti, and how we have implemented an Apache authorization module to provide Akenti authorization.

  17. 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.

  18. Virtual environment assessment for laser-based vision surface profiling

    NASA Astrophysics Data System (ADS)

    ElSoussi, Adnane; Al Alami, Abed ElRahman; Abu-Nabah, Bassam A.

    2015-03-01

    Oil and gas businesses have been raising the demand from original equipment manufacturers (OEMs) to implement a reliable metrology method in assessing surface profiles of welds before and after grinding. This certainly mandates the deviation from the commonly used surface measurement gauges, which are not only operator dependent, but also limited to discrete measurements along the weld. Due to its potential accuracy and speed, the use of laser-based vision surface profiling systems have been progressively rising as part of manufacturing quality control. This effort presents a virtual environment that lends itself for developing and evaluating existing laser vision sensor (LVS) calibration and measurement techniques. A combination of two known calibration techniques is implemented to deliver a calibrated LVS system. System calibration is implemented virtually and experimentally to scan simulated and 3D printed features of known profiles, respectively. Scanned data is inverted and compared with the input profiles to validate the virtual environment capability for LVS surface profiling and preliminary assess the measurement technique for weld profiling applications. Moreover, this effort brings 3D scanning capability a step closer towards robust quality control applications in a manufacturing environment.

  19. 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. PMID:26414378

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

    PubMed

    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

  1. 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

  2. CoP Sensing Framework on Web-Based Environment

    NASA Astrophysics Data System (ADS)

    Mustapha, S. M. F. D. Syed

    The Web technologies and Web applications have shown similar high growth rate in terms of daily usages and user acceptance. The Web applications have not only penetrated in the traditional domains such as education and business but have also encroached into areas such as politics, social, lifestyle, and culture. The emergence of Web technologies has enabled Web access even to the person on the move through PDAs or mobile phones that are connected using Wi-Fi, HSDPA, or other communication protocols. These two phenomena are the inducement factors toward the need of building Web-based systems as the supporting tools in fulfilling many mundane activities. In doing this, one of the many focuses in research has been to look at the implementation challenges in building Web-based support systems in different types of environment. This chapter describes the implementation issues in building the community learning framework that can be supported on the Web-based platform. The Community of Practice (CoP) has been chosen as the community learning theory to be the case study and analysis as it challenges the creativity of the architectural design of the Web system in order to capture the presence of learning activities. The details of this chapter describe the characteristics of the CoP to understand the inherent intricacies in modeling in the Web-based environment, the evidences of CoP that need to be traced automatically in a slick manner such that the evidence-capturing process is unobtrusive, and the technologies needed to embrace a full adoption of Web-based support system for the community learning framework.

  3. 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. PMID:15083656

  4. Regional Ocean Data Assimilation

    NASA Astrophysics Data System (ADS)

    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.

  5. Coherent reverberation model based on adiabatic normal mode theory in a range dependent shallow water environment

    NASA Astrophysics Data System (ADS)

    Li, Zhenglin; Zhang, Renhe; Li, Fenghua

    2010-09-01

    Ocean reverberation in shallow water is often the predominant background interference in active sonar applications. It is still an open problem in underwater acoustics. In recent years, an oscillation phenomenon of the reverberation intensity, due to the interference of the normal modes, has been observed in many experiments. A coherent reverberation theory has been developed and used to explain this oscillation phenomenon [F. Li et al., Journal of Sound and Vibration, 252(3), 457-468, 2002]. However, the published coherent reverberation theory is for the range independent environment. Following the derivations by F. Li and Ellis [D. D. Ellis, J. Acoust. Soc. Am., 97(5), 2804-2814, 1995], a general reverberation model based on the adiabatic normal mode theory in a range dependent shallow water environment is presented. From this theory the coherent or incoherent reverberation field caused by sediment inhomogeneity and surface roughness can be predicted. Observations of reverberation from the 2001 Asian Sea International Acoustic Experiment (ASIAEX) in the East China Sea are used to test the model. Model/data comparison shows that the coherent reverberation model can predict the experimental oscillation phenomenon of reverberation intensity and the vertical correlation of reverberation very well.

  6. 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.

  7. Reliability-based optimization under random vibration environment

    NASA Technical Reports Server (NTRS)

    Rao, S. S.

    1981-01-01

    A methodology of formulating the optimum design problem for structural systems with random parameters and subjected to random vibration as a mathematical programming problem is presented. The proposed method is applied to the optimum design of a cantilever beam with a tip mass and a truss structure supporting a water tank. The excitations are assumed to be Gaussian processes and the geometric and material properties are taken to be normally distributed random variables. The probabilistic constraints are specified for individual failure modes since it is easier to specify the reliability level for each failure mode keeping in view the consequences of failure in that particular mode. The time parameter appearing in the random vibration based constraints is eliminated by replacing the probabilities of failure by suitable upper bounds. The numerical results demonstrate the feasibility and effectiveness of applying the reliability-based design concepts to structures with random parameters and operating in random vibration environment.

  8. 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. PMID:23949845

  9. 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.

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

    DOE PAGESBeta

    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

  11. 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.

  12. 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

  13. A climate-based multivariate extreme emulator of met-ocean-hydrological events for coastal flooding

    NASA Astrophysics Data System (ADS)

    Camus, Paula; Rueda, Ana; Mendez, Fernando J.; Tomas, Antonio; Del Jesus, Manuel; Losada, Iñigo J.

    2015-04-01

    Atmosphere-ocean general circulation models (AOGCMs) are useful to analyze large-scale climate variability (long-term historical periods, future climate projections). However, applications such as coastal flood modeling require climate information at finer scale. Besides, flooding events depend on multiple climate conditions: waves, surge levels from the open-ocean and river discharge caused by precipitation. Therefore, a multivariate statistical downscaling approach is adopted to reproduce relationships between variables and due to its low computational cost. The proposed method can be considered as a hybrid approach which combines a probabilistic weather type downscaling model with a stochastic weather generator component. Predictand distributions are reproduced modeling the relationship with AOGCM predictors based on a physical division in weather types (Camus et al., 2012). The multivariate dependence structure of the predictand (extreme events) is introduced linking the independent marginal distributions of the variables by a probabilistic copula regression (Ben Ayala et al., 2014). This hybrid approach is applied for the downscaling of AOGCM data to daily precipitation and maximum significant wave height and storm-surge in different locations along the Spanish coast. Reanalysis data is used to assess the proposed method. A commonly predictor for the three variables involved is classified using a regression-guided clustering algorithm. The most appropriate statistical model (general extreme value distribution, pareto distribution) for daily conditions is fitted. Stochastic simulation of the present climate is performed obtaining the set of hydraulic boundary conditions needed for high resolution coastal flood modeling. References: Camus, P., Menéndez, M., Méndez, F.J., Izaguirre, C., Espejo, A., Cánovas, V., Pérez, J., Rueda, A., Losada, I.J., Medina, R. (2014b). A weather-type statistical downscaling framework for ocean wave climate. Journal of

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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…

  1. An Electronic Library-Based Learning Environment for Supporting Web-Based Problem-Solving Activities

    ERIC Educational Resources Information Center

    Tsai, Pei-Shan; Hwang, Gwo-Jen; Tsai, Chin-Chung; Hung, Chun-Ming; Huang, Iwen

    2012-01-01

    This study aims to develop an electronic library-based learning environment to support teachers in developing web-based problem-solving activities and analyzing the online problem-solving behaviors of students. Two experiments were performed in this study. In study 1, an experiment on 103 elementary and high school teachers (the learning activity…

  2. Response of benthic foraminifera to ocean acidification in their natural sediment environment: a long-term culturing experiment

    NASA Astrophysics Data System (ADS)

    Haynert, K.; Schönfeld, J.; Schiebel, R.; Wilson, B.; Thomsen, J.

    2014-03-01

    Calcifying foraminifera are expected to be endangered by ocean acidification; however, the response of a complete community kept in natural sediment and over multiple generations under controlled laboratory conditions has not been constrained to date. During 6 months of incubation, foraminiferal assemblages were kept and treated in natural sediment with pCO2-enriched seawater of 430, 907, 1865 and 3247 μatm pCO2. The fauna was dominated by Ammonia aomoriensis and Elphidium species, whereas agglutinated species were rare. After 6 months of incubation, pore water alkalinity was much higher in comparison to the overlying seawater. Consequently, the saturation state of Ωcalc was much higher in the sediment than in the water column in nearly all pCO2 treatments and remained close to saturation. As a result, the life cycle (population density, growth and reproduction) of living assemblages varied markedly during the experimental period, but was largely unaffected by the pCO2 treatments applied. According to the size-frequency distribution, we conclude that foraminifera start reproduction at a diameter of 250 μm. Mortality of living Ammonia aomoriensis was unaffected, whereas size of large and dead tests decreased with elevated pCO2 from 285 μm (pCO2 from 430 to 1865 μatm) to 258 μm (pCO2 3247 μatm). The total organic content of living Ammonia aomoriensis has been determined to be 4.3% of CaCO3 weight. Living individuals had a calcium carbonate production rate of 0.47 g m-2 a-1, whereas dead empty tests accumulated a rate of 0.27 g m-2 a-1. Although Ωcalc was close to 1, approximately 30% of the empty tests of Ammonia aomoriensis showed dissolution features at high pCO2 of 3247 μatm during the last 2 months of incubation. In contrast, tests of the subdominant species, Elphidium incertum, stayed intact. Our results emphasize that the sensitivity to ocean acidification of the endobenthic foraminifera Ammonia aomoriensis in their natural sediment habitat is much

  3. Response of benthic foraminifera to ocean acidification in their natural sediment environment: a long-term culturing experiment

    NASA Astrophysics Data System (ADS)

    Haynert, K.; Schönfeld, J.; Schiebel, R.; Wilson, B.; Thomsen, J.

    2013-06-01

    Calcifying foraminifera are expected to be endangered by ocean acidification, However, the response of a complete community kept in natural sediment and over multiple generations under controlled laboratory conditions has not been constrained to date. During six month incubation, foraminiferal assemblages were treated with pCO2 enriched seawater of 430, 907, 1865 and 3247 μatm pCO2. The fauna was dominated by Ammonia aomoriensis and Elphidium species, whereas agglutinated species were rare. After 6 months incubation, pore water alkalinity was much higher in comparison to the overlying seawater. Consequently, the saturation state of Ωcalc was much higher in the sediment than in the water column in all pCO2 treatments and remained close to saturation. As a result, the life cycle of living assemblages was largely unaffected by the tested pCO2 treatments. Growth rates, reproduction and mortality, and therefore population densities and size-frequency distribution of Ammonia aomoriensis varied markedly during the experimental period. Growth rates varied between 25 and 50 μm per month, which corresponds to an addition of 1 or 2 new chambers per month. According to the size-frequency distribution, foraminifera start reproduction at a diameter of 250 μm. Mortality of large foraminifera was recognized, commencing at a test size of 285 μm at a pCO2 ranging from 430 to 1865 μatm, and of 258 μm at 3247 μatm. The total organic content of living Ammonia aomoriensis has been determined to be 4.3% of dry weight. Living individuals had a calcium carbonate production rate of 0.47 g m-2 yr-1, whereas dead empty tests accumulated at a rate of 0.27 g m-2 a-1. Although Ωcalc was close to 1, some empty tests of Ammonia aomoriensis showed dissolution features at the end of incubation. In contrast, tests of the subdominant species, Elphidium incertum, stayed intact. This species specific response could be explained by differences in the elemental test composition, in particular the

  4. A Clustering-Based Approach to Enriching Code Foraging Environment.

    PubMed

    Niu, Nan; Jin, Xiaoyu; Niu, Zhendong; Cheng, Jing-Ru C; Li, Ling; Kataev, Mikhail Yu

    2016-09-01

    Developers often spend valuable time navigating and seeking relevant code in software maintenance. Currently, there is a lack of theoretical foundations to guide tool design and evaluation to best shape the code base to developers. This paper contributes a unified code navigation theory in light of the optimal food-foraging principles. We further develop a novel framework for automatically assessing the foraging mechanisms in the context of program investigation. We use the framework to examine to what extent the clustering of software entities affects code foraging. Our quantitative analysis of long-lived open-source projects suggests that clustering enriches the software environment and improves foraging efficiency. Our qualitative inquiry reveals concrete insights into real developer's behavior. Our research opens the avenue toward building a new set of ecologically valid code navigation tools. PMID:25910273

  5. ME: Multimodal Environment Based on Web Services Architecture

    NASA Astrophysics Data System (ADS)

    Chiara Caschera, Maria; D'Andrea, Alessia; D'Ulizia, Arianna; Ferri, Fernando; Grifoni, Patrizia; Guzzo, Tiziana

    Information, documents and knowledge for each person and for public and private organizations are fundamental in each activity, and they may be the products or services they provide or supply. The daily activities and decision-making processes are usually based on many different pieces of information, which could be handled on PDAs and mobile devices in general, or stored on laptop computers using a lot of different forms, such as spreadsheets, e-mail messages, Web information obtained as the result of a Google search or a query, and so on. Simulating and managing services and information in catastrophic events and emergencies does not represent an exception. This paper describes the Web Services architecture of the Multimodal collaborative knowledge oriented Environment (ME), a platform designed to manage data, information and services for catastrophic events such as earthquakes, floods and dangerous natural phenomena.

  6. 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.

  7. 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

  8. Ocean Science, 2nd ed

    SciTech Connect

    Stowe, K.

    1983-01-01

    An introductory treatment of all of the major areas of oceanographic studies including geological, physical, chemical, and biological aspects, ocean-atmosphere interactions, marine geology, and marine resources. Presents clear, concise explanations of ocean behavior and its properties. Explains the history behind specific aspects of the ocean environment. Includes considerably expanded sections on estuaries and marine biology, and chapters on marine ecology. Contents-The Earth. Plate Tectonics. The Ocean Bottom. Sediment Materials. Sediment Processes and Distributions. Properties of Ocean Waves. Waves and Tides. Beaches. The Components of Seawater--Part 1. The Components of Seawater--Part 2. The Ocean and Our Climate. The Earth's Rotation and Atmospheric Circulation. Ocean Surface Currents. Deep Ocean Currents and Water Masses. Seas and Estuaries. Biological Productivity in The Oceans. The Spectrum of Marine Organisms. Marine Ecology. Distributions and Lifestyles of Marine Organisms. Ocean Food Resources. Ocean Energy and Mineral Resources.

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

    PubMed

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

    2007-12-01

    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. PMID:18064010

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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. PMID:26887661

  15. 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. PMID:20617459

  16. Intracontinental accommodation of oceanic transform shear: an alternative geodynamic scenario for explaining seismicity, magmatism, and basin opening in passive margin environments

    NASA Astrophysics Data System (ADS)

    Salvini, F.; Storti, F.

    2003-04-01

    In the last years it has been recognised that one of the basic principles of Plate Tectonics i.e. the localisation of plate interactions at their boundaries whereas internal regions remain virtually undeformed, is an oversimplified assumption. Geological, geophysical and geodetic data indicate that plate interiors are associated to a much higher level of neotectonic activity than hitherto realised. Lithosphere buckle folding and intraplate strike-slip faulting during plate convergence, density imbalances produced by oceanic ridges, continental margins and plateau uplifts, and flexural unloading of the lithosphere, are geodynamic processes commonly used to explain the occurrence of significant deformations far from plate boundaries. In this contribution we propose that important intraplate deformations can be produced in passive margin environments by the post-rift activity of strike-slip deformation belts transferring differential spreading at constructional plate boundaries into the plate interiors. This despite the plate tectonics theory does not predict any strike-slip movement along fracture zones once they pass outboard of their associated ridge segments and away from the plate boundary. We illustrate the Cenozoic geodynamic framework at the northeastern edge of the Antarctic plate, where we believe there is strong evidence for the occurrence of post-rift strike-slip deformation belts including both the intraridge (transform) and out-of-ridge segments of fracture zones, and their collinear onshore strike-slip fault systems. Deep basins originated along the main traces of these impressively long strike-slip belts, where strong earthquakes have been recorded, including the 1998 Balleny event (8.2 Mw), which is one of the larger intraplate earthquake ever detected. The residual horizontal displacement at the tip of these intraplate strike-slip belts is accommodated by a lithosphere-scale horsetail array of transtensional basins, where subcrustal magmatism has

  17. Entrainment process at the base of the upper ocean layer in an upwelling filament area

    NASA Astrophysics Data System (ADS)

    Estrada-Allis, Sheila; Rodríguez-Santana, Ángel

    2014-05-01

    Entrainment is responsible for the deepening of the mixed layer and controls the transport of momentum, heat, salinity and nutrients across the interface between the turbulent mixed layer and non-turbulent layer below. This process, which is not yet well understood, can be mechanically forced by wind stirring and buoyancy forced through vertical heat fluxes. In strongly dynamical areas such as eastern boundary upwelling systems and their associated filaments, entrainment rates can also be influenced by vertical shear at the base of the mixed layer that may results from advected baroclinic instabilities. We investigate these processes in the Northwest African upwelling region and Cape Ghir filament using CTD, XBT, ADCP, a meteorological station on board for the wind data and heat flux measurements taken during October 2010, as well as one of the first microturbulent profile (TurboMAP) measurements taken in this area in order to obtain the TKE dissipation rate. We find that buoyancy production dominates over the wind induced mixing in the mixed layer of this region as indicate the Monin Obukhov length scale. To determine entrainment rates we compare four parameterizations based on the turbulent kinetic energy (TKE) balance and one based on the relation of the bulk Richardson number. Although there is no clear consensus between these four parameterizations, they provide evidence that vertical shear at the base of the mixed layer acts to enhance the entrainment rate, especially at stations effected by the upwelling filament or mesoscalar structures. We further compare the measured TKE dissipation rates to those parameterized of Gaspar (1988) and Deardorff (1983). Moreover, some relevant aspect relative to the study of turbulent process in the upper ocean layer, such as the choice of an algorithm or criteria to find the mixed layer depth and the difference between mixing and mixed layer are addressed. This work was funded by Spanish Government (PROMECA: CTM2008

  18. Designing a Web-Based Constructivist Learning Environment

    ERIC Educational Resources Information Center

    Wang, Qiyun

    2009-01-01

    The constructivist learning environment was designed on three perspectives: pedagogical, social and technological. A group of 24 trainee teachers used the environment and participated in the formative evaluation. Results showed that the trainee teachers liked the design specifications and perceived the learning environment to be useful. The…

  19. Environment.

    ERIC Educational Resources Information Center

    White, Gilbert F.

    1980-01-01

    Presented are perspectives on the emergence of environmental problems. Six major trends in scientific thinking are identified including: holistic approaches to examining environments, life support systems, resource management, risk assessment, streamlined methods for monitoring environmental change, and emphasis on the global framework. (Author/SA)

  20. A miniature fiber-optic sensor for high-resolution and high-speed temperature sensing in ocean environment

    NASA Astrophysics Data System (ADS)

    Liu, Guigen; Han, Ming; Hou, Weilin; Matt, Silvia; Goode, Wesley

    2015-05-01

    Temperature measurement is one of the key quantifies in ocean research. Temperature variations on small and large scales are key to air-sea interactions and climate change, and also regulate circulation patterns, and heat exchange. The influence from rapid temperature changes within microstructures are can have strong impacts to optical and acoustical sensor performance. In this paper, we present an optical fiber sensor for the high-resolution and high-speed temperature profiling. The developed sensor consists of a thin piece of silicon wafer which forms a Fabry-Pérot interferometer (FPI) on the end of fiber. Due to the unique properties of silicon, such as large thermal diffusivity, notable thermo-optic effects and thermal expansion coefficients of silicon, the proposed sensor exhibits excellent sensitivity and fast response to temperature variation. The small mass of the tiny probe also contributes to a fast response due to the large surface-tovolume ratio. The high reflective index at infrared wavelength range and surface flatness of silicon endow the FPI a spectrum with high visibilities, leading to a superior temperature resolution along with a new data processing method developed by us. Experimental results indicate that the fiber-optic temperature sensor can achieve a temperature resolution better than 0.001°C with a sampling frequency as high as 2 kHz. In addition, the miniature footprint of the senor provide high spatial resolutions. Using this high performance thermometer, excellent characterization of the realtime temperature profile within the flow of water turbulence has been realized.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Environment-based selection effects of Planck clusters

    NASA Astrophysics Data System (ADS)

    Kosyra, R.; Gruen, D.; Seitz, S.; Mana, A.; Rozo, E.; Rykoff, E.; Sanchez, A.; Bender, R.

    2015-09-01

    We investigate whether the large-scale structure environment of galaxy clusters imprints a selection bias on Sunyaev-Zel'dovich (SZ) catalogues. Such a selection effect might be caused by line of sight (LoS) structures that add to the SZ signal or contain point sources that disturb the signal extraction in the SZ survey. We use the Planck PSZ1 union catalogue in the Sloan Digital Sky Survey (SDSS) region as our sample of SZ-selected clusters. We calculate the angular two-point correlation function (2pcf) for physically correlated, foreground and background structure in the RedMaPPer SDSS DR8 catalogue with respect to each cluster. We compare our results with an optically selected comparison cluster sample and with theoretical predictions. In contrast to the hypothesis of no environment-based selection, we find a mean 2pcf for background structures of -0.049 on scales of ≲40 arcmin, significantly non-zero at ˜4σ, which means that Planck clusters are more likely to be detected in regions of low background density. We hypothesize this effect arises either from background estimation in the SZ survey or from radio sources in the background. We estimate the defect in SZ signal caused by this effect to be negligibly small, of the order of ˜10-4 of the signal of a typical Planck detection. Analogously, there are no implications on X-ray mass measurements. However, the environmental dependence has important consequences for weak lensing follow up of Planck galaxy clusters: we predict that projection effects account for half of the mass contained within a 15 arcmin radius of Planck galaxy clusters. We did not detect a background underdensity of CMASS LRGs, which also leaves a spatially varying redshift dependence of the Planck SZ selection function as a possible cause for our findings.

  7. 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.

  8. The Middle Eocene Paleoceanography of the Arctic Ocean Based on Silicoflagellates and Ebridians

    NASA Astrophysics Data System (ADS)

    Onodera, J.; Takahashi, K.

    2006-12-01

    The early middle Eocene Arctic samples, which were obtained by IODP Expedition 302 (ACEX), were studied for the siliceous microfossils of silicoflagellates and ebridians in order to decipher the paleoceanographic changes of the upper water column. The presence of low salinity waters in the Eocene Arctic is suggested from the co-occurrence of freshwater and blackish water microfossils. Changes of characteristic assemblages with age are probably due to the habitat modulation governed by the extent of mixing of significantly different water masses between the low salinity waters derived from the Arctic region and relatively high salinity waters supplied from the outside of the semi-closed paleo-Arctic basin. The freshwater is attributed to the rainfall and river influx during the rainy Eocene Arctic summers. According to the basin to basin fractionation model of Berger (1970), the Eocene Arctic Ocean probably corresponds to an estuarine type, which includes the Black Sea or the Baltic Sea today. The significantly high abundance of ebridians may reflect the presence of H2S boundary within the euphotic layer based on the extant ebridian ecology of Hermesinum adriaticum with symbiotic algae, which is present in the Black Sea today.

  9. 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).

  10. Giant robber crabs monitored from space: GPS-based telemetric studies on Christmas Island (Indian Ocean).

    PubMed

    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

  11. 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

  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. 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.

  14. 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.

  15. Estimating the global oceanic net freshwater flux from Argo and comparing it with satellite-based freshwater flux products

    NASA Astrophysics Data System (ADS)

    Ren, Li; Hackert, Eric; Arkin, Phillip; Busalacchi, Antonio J.

    2014-11-01

    Following the idea that analysis of in situ information in the salt budget could be used as a surrogate for global "ocean rain gauge," the annual mean oceanic net freshwater flux (E-P) was estimated from the Argo profiles and the wind stress data on a global scale. The comparison between the independent E-P estimation from Argo and the E-P product sets, including the combination of precipitation from TRMM, GPCP, CMAP and evaporation from OAFlux, GSSTF3 and IFREMER and E-P set from NEWS formed from satellite, generally show similar spatial patterns, particularly on the large scale. However, there are differences among the different satellite-based E-P estimates and between satellite estimates and independent in situ estimates. Based on the pattern correlation and the RMSD, the evaporation and precipitation from OAFlux and TRMM agrees best with the E-P estimated from the independent Argo-based estimates.

  16. 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.

  17. 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

  18. An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll-a based models

    NASA Astrophysics Data System (ADS)

    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.

  19. 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…

  20. 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.

  1. 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.

  2. 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.…

  3. 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.

  4. 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

  5. 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. PMID:26930874

  6. 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.

  7. A physical-based statistical method for modeling ocean wave heights

    NASA Astrophysics Data System (ADS)

    Casas-Prat, Mercè; Wang, Xiaolan L.; Sierra, Joan P.

    2014-01-01

    This study proposes a computationally inexpensive statistical method for modeling ocean wave heights, focusing particularly on modeling wave heights in near-shore areas. A multiple linear regression is used to predict significant wave heights (Hs) using predictors derived from the sea level pressure (SLP) field, including the use of squared SLP gradients to represent geostrophic winds. One time step lagged Hs is also included as a predictor, which could be interpreted as the first order derivative in the spectral energy balance governing equation. Further, based on the frequency/directional dispersion theory of waves, the swell component is accounted for by using a set of selected principal components derived from the squared SLP gradient vectors (including magnitudes and directions). The effect of non-Gaussian (non-negative) variables is also assessed by applying two types of transformation to the data. The proposed method is evaluated and shown to have good skills for the study area (Catalan coast). This method can be used to project possible future wave climate change for use in coastal impact assessment studies. It is used in this study to project the wave climate for the study area that corresponds to 5 sets of regional climate model (RCM) atmospheric projections, which were made by different RCMs forced by the same global circulation model (GCM), or by the same RCM forced by two GCMs. For the season analyzed (winter), the results show that the uncertainty due to using different GCMs to drive the same RCM is greater than that due to using different RCMs driven by the same GCM.

  8. Simulation-based study of wind loads on semi-submersed object in ocean wave field

    NASA Astrophysics Data System (ADS)

    Xie, Shengbai; Yang, Di; Liu, Yi; Shen, Lian

    2016-01-01

    Wind forcing makes a vital contribution to the hydrodynamic loads on structures at sea. The flow physics is complex, involving interactions among surface water waves, turbulent wind, and semi-submersed object. We perform a simulation-based study on a canonical problem of wind past a semi-submersed rectangular prism with the focus on the wave effect, which is an essential factor in wind loads at sea but has been elusive. To tackle this problem, we develop a hybrid simulation method consisting of two parts: a precursor simulation of coupled wind and wave motions in the far field upstream to provide physical inflow condition, and a near-field simulation of the air and water motions around the object. The simulation method is validated through numerical tests and comparisons with data from the literature for different aspects of the code. This hybrid simulation method is then applied to study the effect of surface wave motions on the wind load on the object. Various wave conditions are considered, including pure wind-sea satisfying the Joint North Sea Wave Project spectrum as well as wind-sea mixed with long-wavelength ocean swells. The simulation results exhibit significant oscillations in the wind load on the object. The oscillations are found to correlate well with the incident wave motions and are particularly strong in the presence of swells. The underlying mechanism is explained through analyses on variations of wind speed with different wave phases and wave-correlated flow patterns of the wind when it impinges on the object. Our simulations also indicate that waves have an appreciable effect on the wake behind the object.

  9. 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.

  10. Systematic Differences between Satellite-Based Presipitation Climatologies over the Tropical Oceans

    NASA Technical Reports Server (NTRS)

    Robertson, Frankin R.; Fitzjarrald, Dan; McCaul, Eugene W.

    1999-01-01

    Since the beginning of the World Climate Research Program's Global Precipitation Climatology Project (GPCP) satellite remote sensing of precipitation has made dramatic improvements, particularly for tropical regions. Data from microwave and infrared sensors now form the most critical input to precipitation data sets and can be calibrated with surface gauges to so that the strengths of each data source can be maximized in some statistically optimal sense. It is clear however that there still remain significant uncertainties with satellite precipitation retrievals which limit their usefulness for many purposes. Systematic differences i'A tropical precipitation estimates have been brought to light in comparison activities such as the GPCP Algorithm Intercomparison Project and more recent Wetnet Precipitation Intercomparison Project 3. These uncertainties are assuming more importance because of the demands for validation associated with global climate modeling and data assimilation methodologies. The objective of the present study is to determine the physical basis for systematic differences in spatial structure of tropical precipitation as portrayed by several different satellite-based data sets. The study is limited to oceanic regions only and deals primarily with aspects of spatial variability. We are specifically interested in why MSU channel 1 and GPI precipitation differences are so striking over the Eastern Pacific ITCZ and why they both differ from other microwave emission-based precipitation estimates from SSM/I and a scattering-based deep convective ice index from MSU channel 2. Our results to date have shown that MSU channel I precipitation estimates are biased high over the Eastern Pacific ITCZ because of two factors: (1) the hypersensitivity of this frequency to cloud water in contrast to falling rain drops, and (2) unaccounted for scattering effects by precipitation-size ice which depresses the signal of the liquid water emission. Likewise, cold cloud top

  11. Internet Project-Based Learning Environment: The Effects of Thinking Styles on Learning Transfer

    ERIC Educational Resources Information Center

    Lee, C.-I.; Tsai, F.-Y.

    2004-01-01

    The purpose of this study, in an environment of Internet project-based learning, is to undertake research on the effects of thinking styles on learning transfer. In this study, we establish an environment that incorporates project-based learning and Internet. Within this environment, we divide our sample of elementary school students into four…

  12. 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…

  13. Passive localization in the deep ocean based on cross-correlation function matching.

    PubMed

    Lei, Zhixiong; Yang, Kunde; Ma, Yuanliang

    2016-06-01

    Passive localization of a sound source in the deep ocean is investigated in this study. The source can be localized by taking advantage of a cross-correlation function matching technique. When a two-sensor vertical array is used in the deep ocean, two types of side lobe curves appear in the ambiguity surface of the localization. The side lobe curves are analytically expressed and they are then used as indicators of the localization result instead of the scanning point with the maximum power. Simulation and experiment demonstrate the performance of the proposed passive localization method. PMID:27369172

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Oceanic Plateaus

    NASA Astrophysics Data System (ADS)

    Kerr, A. C.

    2003-12-01

    al., 1992; Stein and Hofmann, 1994), as well as environmental effects on the global biosphere (e.g., Caldeira and Rampino, 1990; Courtillot et al., 1996; Kerr, 1998). Oceanic plateaus can also become accreted to continental margins, and it has been proposed that these plateaus have been significant contributors to the growth of continental crust (e.g., Abbott, 1996; Albarede, 1998).The most recent major phase of oceanic plateau formation was in the Cretaceous when the Ontong Java, Manihiki, Hess Rise, and the Caribbean-Colombian plateaus formed in the Pacific, while in the Indian Ocean the Kerguelen plateau was developing. The areas, volume maximum thicknesses and ages of the larger of these plateaus are given in Table 1. The Ontong Java is the largest of the Cretaceous plateaus. It covers an area of 1.9×106 km2, and has an estimated total volume of 4.4×107 km3 (Eldholm and Coffin, 2000). Although early seismic refraction data suggested that the OJP was as thick as 43 km ( Furomoto et al., 1976), a more recent synthesis based on existing seismic and new gravity data ( Gladczenko et al., 1997) has indicated the average thickness to be ˜32 km. Table 1. Ages and dimensions of Jurassic-Cretaceous oceanic plateaus Oceanic plateauMean age (Ma)Area (106 km2)Thickness range (km)Volume (106 km3) Hikurangiearly-mid Cretaceous0.710-152.7 Shatsky Rise1470.210-282.5 Magellan Rise1450.5101.8 Manihiki1230.8>208.8 Ontong Java121(90)1.915-3244.4 Hess Rise990.8>159.1 Caribbean881.18-204.4 South Kerguelen1101.0˜226.0 Central Kerguelen/Broken Ridge861.019-219.1 Sierra Leone Rise˜730.9>102.5 Maud Rise˜>730.2>101.2 After Eldholm and Coffin (2000).

  19. 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

  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. Carbon Solubility in Core Melts in Shallow Magma Ocean Environment and its bearing on Distribution of Carbon between Deep Earth Reservoirs

    NASA Astrophysics Data System (ADS)

    Dasgupta, R.; Walker, D.

    2007-12-01

    pressure, this may indicate the presence of a hidden carbon- rich mantle reservoir untapped by oceanic volcanism. For the entire range of possible bulk Earth carbon content from chondritic to subchondritic and for the mantle carbon content of 50-1000 ppm, DC of 10-4- 100 are derived. But for 1000 ppm bulk Earth carbon, DC is 10-2-100. Using the complete range of possible DC for a magma ocean at ~2200 °C, we predict maximum carbon content of the Earth's core to be 6-7 wt.% and a preferred value of 0.25 ± 0.15 wt.% carbon for a bulk Earth carbon concentration of 1000 ppm. Based on our estimate, the core is likely one of the most enriched terrestrial reservoirs of carbon with concentration as high as 0.4 wt.%, which likely is at least an order of magnitude higher than that of the average mantle. The higher carbon content of OIBs compared to MORBs thus may derive in part from core contributions to mantle plumes.[1] Dasgupta, R. and Hirschmann, M.M. 2006, Nature 440, 659- 662. [2] Wood, B.J. 1993, Earth Planet Sci Lett 117, 593-607.

  2. The Centers for Ocean Science Education Excellence: Partnering with Community Colleges to Enhance Ocean Education and Broaden Participation.

    NASA Astrophysics Data System (ADS)

    Hodder, J.

    2011-12-01

    The Centers for Ocean Science Education Excellence (COSEE) have developed collaborations between research scientists and educators to transform ocean sciences education. Several COSEE centers have worked with the two-year college (2YC) community to enhance the 2YC faculty's capacity to deliver high-quality educational programs in the ocean sciences, integrate ocean research into 2YC educational materials, and enable ocean researchers to gain a better understanding of the capacity and culture of the 2YC community. In addition, COSEE-Pacific Partnerships has developed the Promoting Research Investigations in the Marine Environment (PRIME) internship program, based at west coast marine laboratories, to provide community college students with opportunities to work with ocean research scientists. This presentation will highlight some of the programs developed by COSEE centers and discuss the impact of these activities on scientists, community college faculty and students.

  3. 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

  4. 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. PMID:26840066

  5. 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.

  6. 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).

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Plant growth chamber based on space proven controlled environment technology

    SciTech Connect

    Ignatius, R.W.; Ignatius, M.H.; Imberti, H.J.

    1997-01-01

    Quantum Devices, Inc., in conjunction with Percival Scientific, Inc., and the Wisconsin Center for Space Automation and Robotics (WCSAR) have developed a controlled environment plant growth chamber for terrestrial agricultural and scientific applications. This chamber incorporates controlled environment technology used in the WCSAR ASTROCULTURE{trademark} flight unit for conducting plant research on the Space Shuttle. The new chamber, termed CERES 2010, features air humidity, temperature, and carbon dioxide control, an atmospheric contaminant removal unit, an LED lighting system, and a water and nutrient delivery system. The advanced environment control technology used in this chamber will increase the reliability and repeatability of environmental physiology data derived from plant experiments conducted in this chamber. {copyright} {ital 1997 American Institute of Physics.}

  12. 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.

  13. 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.

  14. 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.

  15. Heterogeneity of the North Atlantic oceanic lithosphere based on integrated analysis of GOCE satellite gravity and geological data

    NASA Astrophysics Data System (ADS)

    Barantseva, Olga; Artemieva, Irina; Thybo, Hans; Herceg, Matija

    2015-04-01

    We present the results from modelling the gravity and density structure of the upper mantle for the off-shore area of the North Atlantic region. The crust and upper mantle of the region is expected to be anomalous: Part of the region affected by the Icelandic plume has an anomalously shallow bathymetry, whereas the northern part of the region is characterized by ultraslow spreading. In order to understand the links between deep geodynamical processes that control the spreading rate, on one hand, and their manifestations such as oceanic floor bathymetry and heat flow, on the other hand, we model the gravity and density structure of the upper mantle from satellite gravity data. The calculations are based on interpretation of GOCE gravity satellite data for the North Atlantics. To separate the gravity signal responsible for density anomalies within the crust and upper mantle, we subtract the lower harmonics caused by deep density structure of the Earth (the core and the lower mantle). The gravity effect of the upper mantle is calculated by subtracting the gravity effect of the crust for two crustal models. We use a recent regional seismic model for the crustal structure (Artemieva and Thybo, 2013) based om seismic data together with borehole data for sediments. For comparison, similar results are presented for the global CRUST 1.0 model as well (Laske, 2013). The conversion of seismic velocity data for the crustal structure to crustal density structure is crucial for the final results. We use a combination of Vp-to-density conversion based on published laboratory measurements for the crystalline basement (Ludwig, Nafe, Drake, 1970; Christensen and Mooney, 1995) and for oceanic sediments and oceanic crust based on laboratory measurements for serpentinites and gabbros from the Mid-Atlantic Ridge (Kelemen et al., 2004). Also, to overcome the high degree of uncertainty in Vp-to-density conversion, we account for regional tectonic variations in the Northern Atlantics as

  16. 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.

  17. 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.

  18. Cross-Cultural Considerations for Simulation-based Learning Environments.

    ERIC Educational Resources Information Center

    Morgan, Konrad

    2000-01-01

    Reviews some of the cross-cultural factors that should be considered in the design of interactive learning environments such as computer simulations and games. Highlights include cross-cultural differences in learning and the use of technology; cross-cultural attitudes toward technology; computer anxiety; and a methodology for culture-centered…

  19. 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…

  20. 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...

  1. 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.

  2. 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…

  3. 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.

  4. 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.

  5. 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

  6. Uncovering students' conceptions of the ocean: A critical first step to improving ocean literacy

    NASA Astrophysics Data System (ADS)

    Marrero, Meghan Elizabeth Conk

    Most Americans may view the ocean as a source of recreation and inspiration, or even of food and hurricanes, but do not recognize that the Earth's most significant feature is the one that controls our climate, provides our oxygen, is vital to our economy, and plays an important role in many other ways. This mixed methods study examines students' conceptions of the ocean and how these can change as a result of participation in an ocean literacy-focused curriculum entitled Signals of Spring -- ACES ("ACES"). The author utilized a questionnaire given to 941 students in two large coastal states, as well as conducted two case studies, to determine the ideas and perception of these students regarding ocean change over the course of an academic year. Results indicated that the prior knowledge of students on the subject matter was poor, but after participation in the ACES program, the students in the two classrooms under case study (n=64) were able to acknowledge the ocean as playing an important role in their lives and to recognize the potential impact it could have on the marine environment. Another aspect of the research was to examine students' decision making related to the ocean. The 7th grade students in this study were able to apply ocean concepts to personal and societal decision making related to pollution, food choice, and on a sample socioscientific issue-based (SSI) task. This study illustrated that programs such as ACES show promise for improving the ocean literacy of secondary students. These findings suggest that students are more aware of the ocean and its critical role in the earth system than are most adults and that students are empowered by the knowledge gained of the ocean and may use this knowledge when making decisions. The results are useful for teachers, curriculum developers, and policymakers interested in improving ocean literacy through K-12 education.

  7. A model-based assessment of the TrOCA approach for estimating oceanic anthropogenic carbon

    NASA Astrophysics Data System (ADS)

    Yool, A.; Oschlies, A.; Nurser, A. J. G.

    2009-07-01

    The future behaviour of the global ocean as a sink for CO2 is significant for climate change, but it is also important to understand its past by quantifying anthropogenic CO2 (Cant) in the ocean today. Unfortunately, this is complicated by the difficulty of deconvoluting Cant from the natural, unperturbed carbon cycle. Nonetheless, a range of techniques have been devised that perform this separation using the information implicit in other physical, biogeochemical and artificial ocean tracers. One such method is the TrOCA approach, whose parameterisation is derived from relationships between biogeochemical tracers within watermasses defined by age tracers such as CFC-11. TrOCA has a number of methodological advantages, and has been shown to be plausible, relative to other methods, in a number of studies. Here we examine the TrOCA approach by using it to deconvolute the known distribution of Cant from an ocean general circulation model (OGCM) simulation of the industrial period (1864-2004). TrOCA is evaluated at local, regional and global scales, with an emphasis on the wider applicability of the parameterisations derived at these scales. Our work finds that the published TrOCA parameterisation performs poorly when extrapolated beyond its calibration region, either with observational data or (especially) model output. Optimising TrOCA parameters using model output as a synthetic dataset leads to some small improvements, but the resulting TrOCA variants still perform poorly. Furthermore, there are large ranges on the optimised TrOCA parameters suggesting that a "universal" TrOCA parameterisation is not achieveable.

  8. Ocean products delivered by the Mercator Ocean Service Department

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    The newly created Service Department at Mercator Ocean is now offering various services for academic and private ocean applications. Mercator Ocean runs operationally ocean forecast systems for the Global and North Atlantic Ocean. These systems are based on an ocean general circulation model NEMO as well as on data assimilation of sea level anomalies, sea surface temperature and temperature and salinity vertical profiles. Three dimensional ocean fields of temperature, salinity and currents are updated and available weekly, including analysis and 2 weeks forecast fields. The Mercator Ocean service department is now offering a wide range of ocean derived products. This presentation will display some of the various products delivered in the framework of academic and private ocean applications: " Monitoring of the ocean current at the surface and at depth in several geographical areas for offshore oil platform, for offshore satellite launch platform, for transatlantic sailing or rowing boat races. " Monitoring of ocean climate indicators (Coral bleaching...) for marine reserve survey; " Monitoring of upwelling systems for fisheries; " Monitoring of the ocean heat content for tropical cyclone monitoring. " Monitoring of the ocean temperature/salinity and currents to guide research vessels during scientific cruises. The Mercator Ocean products catalogue will grow wider in the coming years, especially in the framework of the European GMES MyOcean project (FP7).

  9. 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

  10. 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…

  11. Mixed-Layer Salinity Budget in the Tropical Indian Ocean: Seasonal cycle based only on Observations

    NASA Astrophysics Data System (ADS)

    Casimir, Da-Allada; Fabienne, Gaillard; Nicolas, Kolodziejczyk

    2015-04-01

    The mixed-layer salinity (MLS) budget in the tropical Indian Ocean is estimated from a combination of satellite products, atmospheric reanalysis, and in situ observations over the 2004-2012 period, to investigate the mechanisms controlling the seasonal MLS variability. In contrast with previous studies in the Tropical Indian Ocean, our results reveal that the coverage, resolution and quality of available observations are now sufficient to approach a closed climatological seasonal salt budget. In the South-Central Arabian Sea and South-western Tropical Indian Ocean (SCAS and STIO, respectively), where seasonal variability of the MLS is pronounced, the monthly MLS tendency terms are well captured by the diagnostic. In the SCAS region, in agreement with previous results, the seasonal cycle of the MLS is mainly due to meridional advection driven by the monsoon winds. In the STIO, contrary to previous results which indicate that the MLS budget is dominated by meridional advection, our results reveal that freshwater flux due to precipitation plays an important role in the seasonal cycle of MLS.

  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. 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

  14. 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. PMID:15943340

  15. "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.

  16. 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.

  17. Tone-Mapped Mean-Shift Based Environment Map Sampling.

    PubMed

    Feng, Wei; Yang, Ying; Wan, Liang; Yu, Changguo

    2016-09-01

    In this paper, we present a novel approach for environment map sampling, which is an effective and pragmatic technique to reduce the computational cost of realistic rendering and get plausible rendering images. The proposed approach exploits the advantage of adaptive mean-shift image clustering with aid of tone-mapping, yielding oversegmented strata that have uniform intensities and capture shapes of light regions. The resulted strata, however, have unbalanced importance metric values for rendering, and the strata number is not user-controlled. To handle these issues, we develop an adaptive split-and-merge scheme that refines the strata and obtains a better balanced strata distribution. Compared to the state-of-the-art methods, our approach achieves comparable and even better rendering quality in terms of SSIM, RMSE and HDRVDP2 image quality metrics. Experimental results further show that our approach is more robust to the variation of viewpoint, environment rotation, and sample number. PMID:26584494

  18. Supporting Instance-Based Learning in Discovery Learning Environments.

    ERIC Educational Resources Information Center

    Reimann, Peter

    Recent research has demonstrated that knowledge about specific instances may be of more relevance to reasoning than has previously been assumed. Students can rely on principles they have learned, or they can recall something similar previously experienced, and base the new prediction on it in an instance-based approach. Instance-based (or…

  19. 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

  20. 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

  1. 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. PMID:22874268

  2. Anomaly transform methods based on total energy and ocean heat content norms for generating ocean dynamic disturbances for ensemble climate forecasts

    NASA Astrophysics Data System (ADS)

    Romanova, Vanya; Hense, Andreas

    2015-04-01

    In our study we use the anomaly transform, a special case of ensemble transform method, in which a selected set of initial oceanic anomalies in space, time and variables are defined and orthogonalized. The resulting orthogonal perturbation patterns are designed such that they pick up typical balanced anomaly structures in space and time and between variables. The metric used to set up the eigen problem is taken either as the weighted total energy with its zonal, meridional kinetic and available potential energy terms having equal contributions, or the weighted ocean heat content in which a disturbance is applied only to the initial temperature fields. The choices of a reference state for defining the initial anomalies are such that either perturbations on seasonal timescales and or on interannual timescales are constructed. These project a-priori only the slow modes of the ocean physical processes, such that the disturbances grow mainly in the Western Boundary Currents, in the Antarctic Circumpolar Current and the El Nino Southern Oscillation regions. An additional set of initial conditions is designed to fit in a least square sense data from global ocean reanalysis. Applying the AT produced sets of disturbances to oceanic initial conditions initialized by observations of the MPIOM-ESM coupled model on T63L47/GR15 resolution, four ensemble and one hind-cast experiments were performed. The weighted total energy norm is used to monitor the amplitudes and rates of the fastest growing error modes. The results showed minor dependence of the instabilities or error growth on the selected metric but considerable change due to the magnitude of the scaling amplitudes of the perturbation patterns. In contrast to similar atmospheric applications, we find an energy conversion from kinetic to available potential energy, which suggests a different source of uncertainty generation in the ocean than in the atmosphere mainly associated with changes in the density field.

  3. Corrosion of Silicon-Based Ceramics in Combustion Environments

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.

    1993-01-01

    The processes of passive oxidation, deposit-induced corrosion, active oxidation, scale/substance interactions, and scale volatility are presently studied in the case of high-purity SiC and Si3N4 in pure oxygen, giving attention to such secondary elements in the ceramics as water and CO2 oxidants, combustion environment impurities, and thermal cycling. Deposit-induced corrosion is discussed for the cases of NaSO4 as well as vanadate and oxide-slag deposits; issues associated with the active-to-passive oxidation transition are noted.

  4. Ocean microbial metagenomics

    NASA Astrophysics Data System (ADS)

    Kerkhof, Lee J.; Goodman, Robert M.

    2009-09-01

    Technology for accessing the genomic DNA of microorganisms, directly from environmental samples without prior cultivation, has opened new vistas to understanding microbial diversity and functions. Especially as applied to soils and the oceans, environments on Earth where microbial diversity is vast, metagenomics and its emergent approaches have the power to transform rapidly our understanding of environmental microbiology. Here we explore select recent applications of the metagenomic suite to ocean microbiology.

  5. 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

  6. Space-time variability of the Amazon River plume based on satellite ocean color

    NASA Astrophysics Data System (ADS)

    Molleri, Gustavo S. F.; Novo, Evlyn M. L. de M.; Kampel, Milton

    2010-02-01

    Satellite ocean color images were used to determine the space-time variability of the Amazon River plume from 2000-2004. The relationship between sea-surface salinity (SSS) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) absorption coefficient for dissolved and detrital material ( adg) ( r2=0.76, n=30, rmse=0.4) was used to identify the Amazon River plume low-salinity waters (<34 psu). The plume's spatial information was extracted from satellite bi-weekly time series using two metrics: plume area and plume shape. These metrics identified the seasonal variability of plume dimensions and dispersion patterns. During the study period, the plume showed the largest areas from July to August and the smallest from December to January. The mean annual amplitude and the mean, maximum and minimum plume areas were 1020×10 3 km 2, 680×10 3 km 2, 1506×10 3 km 2 and 268×10 3 km 2, respectively. Three main shapes and dispersion pattern periods were identified: (1) flow to the northeastern South American coast, in a narrow band adjacent to the continental shelf, from January to April; (2) flow to the Caribbean region, from April to July; and (3) flow to the Central Equatorial Atlantic Ocean, from August to December. Cross-correlation techniques were used to quantify the relationship between the plume's spatial variability and environmental forcing factors, including Amazon River discharge, wind field and ocean currents. The results showed that (1) river discharge is the main factor influencing plume area variability, (2) the wind field regulates the plume's northwestward flow velocity and residence time near the river mouth, and (3) surface currents have a strong influence over river plume dispersion patterns.

  7. 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.

  8. 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 &…

  9. VESTA: a system-level verification environment based on C++

    NASA Astrophysics Data System (ADS)

    Shahdadpuri, Mahendra V.; Sosa, Javier; Navarro, H. éctor; Montiel-Nelson, Juan A.; Sarmiento, Roberto

    2003-04-01

    System verification is an important issue to do at every design step to ensure the complete system correctness. The verification effort is becoming more time-consuming due to the increase in design complexity. New environments are necessary to reduce the complexity of this task and, most importantly, reduce the time to develop it. Among the languages used in verification, C++ is powerful enough for encapsulating the necessary concepts in a set of classes and templates. This work introduces a framework that allows describing and verifying highly complex systems in a user-friendly and speedy way with C++ classes. These encapsulate hardware description and verification concepts and can be reused throughout a project and also in various development projects. Furthermore, the resulting libraries provide an easy-to-use interface for describing systems and writing test benches in C++, with a transparent connection to an HDL simulator. VESTA includes an advanced memory management with an extremely versatile linked list. The linked list access mode can change on-fly to a FIFO, a LIFO or a memory array access mode, among others. Experimental results demonstrate that the basic types provided by our verification environment excel the features of non-commercial solutions as Openvera or TestBuilder and commercial solutions such as 'e' language. Besides, the results achieved have shown significant productivity gain in creating reusable testbenches and in debugging simulation runs.

  10. Environment influence on PSPL-based digital dental radiology systems

    NASA Astrophysics Data System (ADS)

    Costa, Eduardo T.; Albuquerque, Jorge A. G.; Neto, Francisco H.; Paganinni, Gisela A.; Boscolo, Frab N.; de Oliveira, Ana E. F.

    2001-06-01

    Photo-stimulable phosphor luminescence technology (PSPL) has been used in Digora (Soredex, Finland; Denoptix (CEDH Gendex, Italy) digital dental radiology imaging systems. PSPL plates store X-ray energy during exposition, being later processed by a laser reader and digitizer. Afterward they are erased and re-used. The large band of energy absorption provides PSPL systems with an extensive dynamic scale but at the same time a high sensibility to the incoming noise of environmental radiations. We have measured environment influences (electromagnetic radiation) for Digora and Denoptix plates after X-ray exposure and before digital processing. We have first compared the processing of PSPL plates 'in dark' against 'in light' environments. In another experiment, the exposed plates were also processed after being positioned 10 cm away from a 17 inches video monitor screen and to its laterals for 5, 10, 15, 20, 25 and 30 minutes (plates protected against light). The acquired images were used to calculate the noise power spectra (NPS) in each case. We have noticed that there was an increase in the noise spectra energy of 'in light' processing compared to 'in dark' processing. There was also an increment in the NPS energy when the images were processed after the exposition of the plates to the radiation emanated from video monitor.

  11. ULYSSES - an expert-system-based VLSI design environment

    SciTech Connect

    Bushnell, M.L.

    1987-01-01

    Ulysses is a VLSI computer-aided design (CAD) environment which effectively addresses the problems associated with CAD tool integration. Specifically, Ulysses allows the integration of CAD tools into a design automation (DA) system, the codification of a design methodology, and the representation of a design space. Ulysses keeps track of the progress of a design and allows exploration of the design space. The environment employs artificial intelligence techniques, functions as an interactive expert system, and interprets descriptions of design tasks encoded in the scripts language. An integrated-circuit silicon compilation task is presented as an example of the ability of Ulysses to automatically execute CAD tools to solve a problem where inferencing is required to obtain a viable VLSI layout. The inferencing mechanism, in the form of a controlled production system, allows Ulysses to recover when routing channel congestion or over-constrained leaf-cell boundary conditions make it impossible for CAD tools to complete layouts. Also, Ulysses allows the designer to intervene while design activities are being carried out. Consistency-maintenance rules encoded in the scripts language enforce geometric floor-plan consistency when CAD tools fail and when the designer makes adjustments to a VLSI chip layout.

  12. Analysis of the variability of temperature gradient in the ocean frontal zones based on satellite data

    NASA Astrophysics Data System (ADS)

    Kartushinsky, A. V.; Sidorenko, A. Y.

    2013-10-01

    AVHRR MCSST data for the periods 1982-2000 (mean weekly data) were used to calculate mean gradient fields in the ocean for different periods of time. Three-month averaged sea surface temperature gradients (SSTG) and their mean seasonal variations have been studied for 25 points in the large-scale oceanic fronts zones. Major oceanic fronts in the Atlantic and Pacific have been identified and compared in literature. In the North Atlantic and Pacific, the areas under study were the North Polar Front and Subpolar Fronts. In the South Atlantic and Pacific we studied the region of the Antarctic Circumpolar Current (ACC) and the fronts formed by this current, known as the South Polar Front, and the Subantarctic Front. SSTG were also calculated for El Niño (Southeast Pacific) and Benguela Current (Southeast Atlantic). In warm periods seasonal SSTG in the North Atlantic markedly increased and exhibit some interannual cycles. The correlation between the North Atlantic Oscillation index and seasonal SSTG for a single point in the Gulf Stream zone can be the key point for evaluation of heat transfer by the currents to the coast of East Europe. In the Southern Atlantic, the SSTG values are low during the cold period (summer in the southern hemisphere) in the ACC zone and increase in the warm season (winter in the southern hemisphere). It also exhibits interannual cycles. In the Northwest Pacific for some points in the Subpolar Front the SSTG values are high in the cold period (winter). Here at seven points in the spring of 1993 and 2000 the calculations disclosed significant increase of the gradient. In these years, the anomalous SSTG in Subpolar Front and South Polar Front were found to vary synchronously in both hemispheres, with maximum intensity in spring (North Pacific) and in summer (South Pacific). Mean annual SSTG in the El Niño zone and south oscillation index have been found to exhibit some correlation. Major jet currents periodically form high-gradient temperature

  13. Quaternary paleoceanography of the deep Arctic Ocean based on quantitative analysis of Ostracoda

    USGS Publications Warehouse

    Cronin, T. M.; Holtz, T.R., Jr.; 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. 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.

  15. 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…

  16. Scale Development of a Measure to Assess Community-Based and Clinical Intervention Group Environments

    ERIC Educational Resources Information Center

    Wilson, Patrick A.; Hansen, Nathan B.; Tarakeshwar, Nalini; Neufeld, Sharon; Kochman, Arlene; Sikkema, Kathleen J.

    2008-01-01

    Though group interventions are widely used in community-based and clinical settings, there are few brief instruments for assessing the group environment. Two studies on the development of a brief measure to assess intervention group environments are described, and psychometric properties of the new scale are presented. The new measure is based on…

  17. Study on the Teaching Model Based on Multimedia and Network Environment

    ERIC Educational Resources Information Center

    Zhang, Deju

    2010-01-01

    Based on the analysis of the advantages of teaching model in the network environment, three teaching models based on multimedia and network environment, i.e. the teaching model of giving priority of lecturing, the teaching model of giving priority of independent learning and the teaching model of group learning, are discussed in the article, and…

  18. Medium-Based Design: Extending a Medium to Create an Exploratory Learning Environment

    ERIC Educational Resources Information Center

    Rick, Jochen; Lamberty, K. K.

    2005-01-01

    This article introduces "medium-based" design -- an approach to creating "exploratory learning environments" using the method of "extending a medium". First, the characteristics of exploratory learning environments and medium-based design are described and grounded in related work. Particular attention is given to "extending a medium" --…

  19. The Design of an Analogical Encoding Tool for Game-Based Virtual Learning Environments

    ERIC Educational Resources Information Center

    Williams, Douglas; Ma, Yuxin; Feist, Steven; Richard, Charles E.; Prejean, Louise

    2007-01-01

    Game-based virtual learning environments have the potential to provide opportunities for engagement in authentic contexts while completing authentic tasks such as problem solving. However, research in problem-based learning indicates that scaffolding should be provided for learners to benefit from such learning environments. This paper describes…

  20. Data-based estimates of the ocean carbon sink variability - first results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)

    NASA Astrophysics Data System (ADS)

    Rödenbeck, C.; Bakker, D. C. E.; Gruber, N.; Iida, Y.; Jacobson, A. R.; Jones, S.; Landschützer, P.; Metzl, N.; Nakaoka, S.; Olsen, A.; Park, G.-H.; Peylin, P.; Rodgers, K. B.; Sasse, T. P.; Schuster, U.; Shutler, J. D.; Valsala, V.; Wanninkhof, R.; Zeng, J.

    2015-08-01

    Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global sea-air CO2 fluxes have been investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the Eastern equatorial Pacific. Despite considerable spead in the detailed variations, mapping methods with closer match to the data also tend to be more consistent with each other. Encouragingly, this includes mapping methods belonging to complementary types - taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea-air CO2 flux of 0.31 PgC yr-1 (standard deviation over 1992-2009), which is larger than simulated by biogeochemical process models. On a decadal perspective, the global CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to 2000. The weighted mean total ocean CO2 sink estimated by the SOCOM ensemble is consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends.

  1. 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.

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

    NASA Astrophysics Data System (ADS)

    Sun, Daner; Looi, Chee-Kit

    2013-02-01

    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 develop critical learning skills through model-based collaborative inquiry approach. It is intended to support collaborative inquiry, real-time social interaction, progressive modeling, and to provide multiple sources of scaffolding for students. We first discuss the theoretical underpinnings for synthesizing the WiMVT design framework, introduce the components and features of the system, and describe the proposed work flow of WiMVT instruction. We also elucidate our research approach that supports the development of the system. Finally, the findings of a pilot study are briefly presented to demonstrate of the potential for learning efficacy of the WiMVT implementation in science learning. Implications are drawn on how to improve the existing system, refine teaching strategies and provide feedback to researchers, designers and teachers. This pilot study informs designers like us on how to narrow the gap between the learning environment's intended design and its actual usage in the classroom.

  4. Data-based estimates of the ocean carbon sink variability - first results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)

    NASA Astrophysics Data System (ADS)

    Rödenbeck, C.; Bakker, D. C. E.; Gruber, N.; Iida, Y.; Jacobson, A. R.; Jones, S.; Landschützer, P.; Metzl, N.; Nakaoka, S.; Olsen, A.; Park, G.-H.; Peylin, P.; Rodgers, K. B.; Sasse, T. P.; Schuster, U.; Shutler, J. D.; Valsala, V.; Wanninkhof, R.; Zeng, J.

    2015-12-01

    Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global sea-air CO2 fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types - taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea-air CO2 flux of 0.31 PgC yr-1 (standard deviation over 1992-2009), which is larger than simulated by biogeochemical process models. From a decadal perspective, the global ocean CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean CO2 sink estimated by the SOCOM ensemble is -1.75 PgC yr-1 (1992-2009), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends.

  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. PMID:17066030

  7. Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions

    NASA Astrophysics Data System (ADS)

    Blaschek, M.; Renssen, H.; Kissel, C.; Thornalley, D.

    2015-11-01

    Climate and ocean circulation in the North Atlantic region changed over the course of the Holocene, partly because of disintegrating ice sheets and partly because of an orbital-induced insolation trend. In the Nordic Seas, this impact was accompanied by a rather small, but significant, amount of Greenland ice sheet melting. We have employed the EMIC LOVECLIM and compared our model simulations with proxy-based reconstructions of δ13C, sortable silt, and magnetic susceptibility (κ) used to infer changes in past ocean circulation over the last 9000 years. The various reconstructions exhibit different long-term evolutions suggesting changes in either the overturning of the Atlantic in total or of subcomponents of the ocean circulation, such as the overflow waters across the Greenland-Scotland ridge. Thus, the question arises whether these reconstructions are consistent with each other or not. A comparison with model results indicates that δ13C, employed as an indicator of overturning, agrees well with the long-term evolution of the modeled Atlantic meridional overturning circulation (AMOC). The model results suggest that different long-term trends in subcomponents of the AMOC, such as Iceland-Scotland overflow water, are consistent with proxy-based reconstructions and allow some of the reconstructions to be reconciled with the modeled and reconstructed (from δ13C) AMOC evolution. We find a weak early Holocene AMOC, which recovers by 7 kyr B.P. and shows a weak increasing trend of 88 ± 1 mSv/kyr toward present, with relatively low variability on centennial to millennial timescales.

  8. 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.

  9. 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.

  10. Simulation of anthropogenic CO2 uptake in the CCSM3.1 ocean circulation-biogeochemical model: comparison with data-based estimates

    NASA Astrophysics Data System (ADS)

    Wang, S.; Moore, J. K.; Primeau, F. W.; Khatiwala, S.

    2011-11-01

    The global ocean has taken up a large fraction of the CO2 released by human activities since the industrial revolution. Quantifying the oceanic anthropogenic carbon (Cant) inventory and its variability is important for predicting the future global carbon cycle. The detailed comparison of data-based and model-based estimates is essential for the validation and continued improvement of our prediction capabilities. So far, three global estimates of oceanic Cant inventory that are "data-based" and independent of global ocean circulation models have been produced: one based on the ΔC* method, and two are based on reconstructions of the Green function for the surface-to-interior transport, the TTD method and the maximum entropy inversion method (KPH). The KPH method, in particular, is capable of reconstructing the history of Cant inventory through the industrial era. In the present study we use forward model simulations of the Community Climate System Model (CCSM3.1) to estimate the Cant inventory and compare the results with the data-based estimates. We also use the simulations to test several assumptions of the KPH method, including the assumption of constant climate and circulation, which is common to all the data-based estimates. Though the integrated estimates of global Cant inventories are consistent with each other, the regional estimates show discrepancies up to 50 %. The CCSM3 model underestimates the total Cant inventory, in part due to weak mixing and ventilation in the North Atlantic and Southern Ocean. Analyses of different simulation results suggest that key assumptions about ocean circulation and air-sea disequilibrium in the KPH method are generally valid on the global scale, but may introduce significant errors in Cant estimates on regional scales. The KPH method should also be used with caution when predicting future oceanic anthropogenic carbon uptake.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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…

  16. 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…

  17. 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…

  18. Incorporating Computer-Based Learning in a Medical School Environment.

    ERIC Educational Resources Information Center

    Evans, Leonard,; And Others

    1994-01-01

    Presents the history and background for the use of computers in medical education at the Norris Medical School at the University of Southern California. Describes the current computer facilities and how computer-based learning is incorporated into the curriculum. (PR)

  19. Isotope-based evapotranspiration partition in semi-arid environments

    NASA Astrophysics Data System (ADS)

    Wang, Lixin; Parkes, Stephen; McCabe, Matthew; Azcurra, Cecilia; Wang, Jin; Graham, Peter

    2013-04-01

    Evapotranspiration (ET) partitioning is important for quantifying the water budget and understanding vegetation control on water cycles in various ecosystems. With the development of spectroscopy-based techniques for in-situ isotope measurements, the use of stable isotope based ET partition is rising rapidly. The sub-daily scale ET partition, however, is still rarely seen in the literature. In this study, we conducted an intensive field campaign measuring ET partition using laser-based isotope and chamber techniques in a pasture system between May and June 2012 in eastern Australia. Six soil collars were used, three of which had natural vegetation and the other three were bare soil collars where vegetation was artificially removed. The vegetated and bare soil collars were used to determine the isotopic composition of ET and evaporation, respectively. The isotopic composition of the transpiration flux was determined using a Licor leaf chamber for grasses inside the vegetated collars. The diurnal patterns in dET, dE and dT are observed. In the morning, they are depleted and became more enriched and level off during mid-day. Overall the total ET flux is dominated by evaporation, though transpiration contributions are relatively higher between 10am and 12pm. D-excess is a conservative tracer of ET components and may not be useful in ET partition. This study demonstrated the use of chamber-based measurements for direct partitioning of ET at sub-daily scale and showed a rarely observed diurnal pattern of ET partition.

  20. 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…

  1. 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…

  2. 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

  3. 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.

  4. A collaborative medical case authoring environment based on the UMLS.

    PubMed

    Suebnukarn, Siriwan; Haddawy, Peter; Rhienmora, Phattanapon

    2008-04-01

    In this paper, we present a novel collaborative authoring tool that was designed to allow medical teachers to formalize and visualize their knowledge for medical intelligent tutoring systems. Our goal is to increase the efficiency and effectiveness in creating the domain model representing the problem solution--often referred to as the bottleneck in developing intelligent tutoring systems. We incorporate the Unified Medical Language System (UMLS) knowledge base to assist the authors in creating the problem solution collaboratively via a videoconferencing platform. The system consists of a shared workspace gathering information visualization and tools necessary for collaborative problem-solving tasks. We found that the authoring tool can be used to effectively elicit the knowledge structure of the domain model. This was achieved in hours compared to months for the conventional paper-based approach. PMID:17920337

  5. RSSI-Based Smooth Localization for Indoor Environment

    PubMed Central

    2014-01-01

    Radio frequency (RF) technique, for its better penetrability over traditional techniques such as infrared or ultrasound, is widely used for indoor localization and tracking. In this paper, three novel measurements, point decision accuracy, path matching error and wrong jumping ratio, are firstly defined to express the localization efficiency. Then, a novel RSSI-based smooth localization (RSL) algorithm is designed, implemented, and evaluated on the WiFi networks. The tree-based mechanism determines the current position and track of the entity by assigning the weights and accumulative weights for all collected RSSI information of reference points so as to make the localization smooth. The evaluation results indicate that the proposed algorithm brings better localization smoothness of reducing 10% path matching error and 30% wrong jumping ratio over the RADAR system. PMID:25143988

  6. RSSI-based smooth localization for indoor environment.

    PubMed

    Wang, Yujian; Zhao, Bin; Jiang, Zhaohui

    2014-01-01

    Radio frequency (RF) technique, for its better penetrability over traditional techniques such as infrared or ultrasound, is widely used for indoor localization and tracking. In this paper, three novel measurements, point decision accuracy, path matching error and wrong jumping ratio, are firstly defined to express the localization efficiency. Then, a novel RSSI-based smooth localization (RSL) algorithm is designed, implemented, and evaluated on the WiFi networks. The tree-based mechanism determines the current position and track of the entity by assigning the weights and accumulative weights for all collected RSSI information of reference points so as to make the localization smooth. The evaluation results indicate that the proposed algorithm brings better localization smoothness of reducing 10% path matching error and 30% wrong jumping ratio over the RADAR system. PMID:25143988

  7. 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.

  8. 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...

  9. 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.

  10. Ground-based Measurement Of Saharan Dust In Marine Environment

    NASA Astrophysics Data System (ADS)

    Jeong, M. J.; Ji, Q.; Tsay, S.; Hsu, C.; Hansell, R. A.; Augustine, D.

    2007-12-01

    An extensive field experiment, named NASA African Monsoon Multidisciplinary Analyses (NAMMA) was conducted during August-September of 2006 to investigate the genesis and development of hurricanes. Two ground-based mobile laboratories, Surface-sensing Measurements for Atmospheric Radiative Transfer (SMART) and Chemical, Optical, Microphysical Measurements of In-situ Troposphere (COMMIT), were deployed at Sal Island, Cape Verde to continuously monitor the structure and composition of the atmosphere in the major path of the Saharan Air Layer and the African Easterly Waves. A Micro-Pulse Lidar in SMART, which measures the vertical profiles of backscatter from the atmospheric particulates continuously, caught several episodes of Saharan dust layers reached the surface site. Simultaneously, physical and optical properties of aerosols (e.g., mixture of the Saharan dust and maritime aerosols) were captured by several instruments in COMMIT. In this study, we propose a novel method to separate dust properties from those of marine background aerosols by utilizing the synergy of a suite of in-situ measurements. Derived parameters are mass scattering coefficients and single scattering albedo (SSA) for dust near the surface (~10m). As a crosscheck, the SSA based on the surface measurements is compared with the result of Deep Blue satellite-based aerosol retrievals, which is now incorporated in the operational MODIS aerosol product. The presented preliminary results will be useful in studying the properties of Saharan dust originated from various source regions, which, in turns, can be used as inputs to aerosol transport models to help better understand the interactions between aerosol and cloud water cycle.

  11. 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.

  12. Radium-based estimates of cesium isotope transport and total direct ocean discharges from the Fukushima Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Charette, M. A.; Breier, C. F.; Henderson, P. B.; Pike, S. M.; Rypina, I. I.; Jayne, S. R.; Buesseler, K. O.

    2013-03-01

    Radium has four naturally occurring isotopes that have proven useful in constraining water mass source, age, and mixing rates in the coastal and open ocean. In this study, we used radium isotopes to determine the fate and flux of runoff-derived cesium from the Fukushima Dai-ichi Nuclear Power Plant (FNPP). During a June 2011 cruise, the highest cesium (Cs) concentrations were found along the eastern shelf of northern Japan, from Fukushima south, to the edge of the Kuroshio Current, and in an eddy ~ 130 km from the FNPP site. Locations with the highest cesium also had some of the highest radium activities, suggesting much of the direct ocean discharges of Cs remained in the coastal zone 2-3 months after the accident. We used a short-lived Ra isotope (223Ra, t1/2 = 11.4 d) to derive an average water mass age (Tr) in the coastal zone of 32 days. To ground-truth the Ra age model, we conducted a direct, station-by-station comparison of water mass ages with a numerical oceanographic model and found them to be in excellent agreement (model avg. Tr = 27 days). From these independent Tr values and the inventory of Cs within the water column at the time of our cruise, we were able to calculate an offshore 134Cs flux of 3.9-4.6 × 1013 Bq d-1. Radium-228 (t1/2 = 5.75 yr) was used to derive a vertical eddy diffusivity (Kz) of 0.7 m2 d-1 (0.1 cm2 s-1); from this Kz and 134Cs inventory, we estimated a 134Cs flux across the pycnocline of 1.8 × 104 Bq d-1 for the same time period. On average, our results show that horizontal mixing loss of Cs from the coastal zone was ~ 109 greater than vertical exchange below the surface mixed layer. Finally, a mixing/dilution model that utilized our Ra-based and oceanographic model water mass ages produced a direct ocean discharge of 134Cs from the FNPP of 11-16 PBq at the time of the peak release in early April 2011. Our results can be used to calculate discharge of other water-soluble radionuclides that were released to the ocean directly

  13. Radium-based estimates of cesium isotope transport and total direct ocean discharges from the Fukushima Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Charette, M. A.; Breier, C. F.; Henderson, P. B.; Pike, S. M.; Rypina, I. I.; Jayne, S. R.; Buesseler, K. O.

    2012-11-01

    Radium has four naturally occurring isotopes that have proven useful in constraining water mass source, age, and mixing rates in the coastal and open ocean. In this study, we used radium isotopes to determine the fate and flux of runoff-derived cesium from the Fukushima Nuclear Power Plant (NPP). During a June 2011 cruise, the highest Cs concentrations were found along the eastern shelf of northern Japan, from Fukushima south, to the edge of the Kuroshio current, and in an eddy ∼ 130 km from the NPP site. Locations with the highest cesium also had some of the highest radium activities, suggesting much of the direct ocean discharges of Cs remained in the coastal zone 2-3 months after the accident. We used a short-lived Ra isotope (223Ra, t1/2 = 11.4 d) to derive an average water mass age (Tr) in the coastal zone of 32 days. To ground-truth the Ra age model, we conducted a direct, station-by-station comparison of water mass ages with a numerical oceanographic model and found them to be in excellent agreement (model avg. Tr = 27 days). From these independent Tr values and the inventory of Cs within the water column at the time of our cruise, we were able to calculate an offshore 134Cs flux of 3.9-4.6 × 1013 Bq d-1. Radium-228 (t1/2 = 5.75 yr) was used to derive a vertical eddy diffusivity (Kz) of 0.7 m2 d-1 (0.1 cm2 s-1); from this Kz and 134Cs inventory, we estimated a 134Cs flux across the pycnocline of 1.8 × 104 Bq d-1 for the same time period. On average, our results show that horizontal mixing loss of Cs from the coastal zone was ∼ 109 greater than vertical exchange below the surface mixed layer. Finally, a mixing/dilution model that utilized our Ra-based and oceanographic model water mass ages produced a direct ocean discharge of 134Cs from the FNPP of 11-16 PBq at the time of the peak release in early April 2011. Our results can be used to calculate discharge of other water-soluble radionuclides that were released to the ocean directly from the

  14. 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.

  15. Biomimetic Extracellular Environment Based on Natural Origin Polyelectrolyte Multilayers.

    PubMed

    Silva, Joana M; Reis, Rui L; Mano, João F

    2016-08-01

    Surface modification of biomaterials is a well-known approach to enable an adequate biointerface between the implant and the surrounding tissue, dictating the initial acceptance or rejection of the implantable device. Since its discovery in early 1990s layer-by-layer (LbL) approaches have become a popular and attractive technique to functionalize the biomaterials surface and also engineering various types of objects such as capsules, hollow tubes, and freestanding membranes in a controllable and versatile manner. Such versatility enables the incorporation of different nanostructured building blocks, including natural biopolymers, which appear as promising biomimetic multilayered systems due to their similarity to human tissues. In this review, the potential of natural origin polymer-based multilayers is highlighted in hopes of a better understanding of the mechanisms behind its use as building blocks of LbL assembly. A deep overview on the recent progresses achieved in the design, fabrication, and applications of natural origin multilayered films is provided. Such films may lead to novel biomimetic approaches for various biomedical applications, such as tissue engineering, regenerative medicine, implantable devices, cell-based biosensors, diagnostic systems, and basic cell biology. PMID:27435905

  16. 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).

  17. 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.

  18. A Modulation Transfer Function Compensation for the Geostationary Ocean Color Imager (GOCI) Based on the Wiener Filter

    NASA Astrophysics Data System (ADS)

    Oh, Eunsong; Ahn, Ki-Beom; Cho, Seongick; Ryu, Joo-Hyung

    2013-12-01

    The modulation transfer function (MTF) is a widely used indicator in assessments of remote-sensing image quality. This MTF method is also used to restore information to a standard value to compensate for image degradation caused by atmospheric or satellite jitter effects. In this study, we evaluated MTF values as an image quality indicator for the Geostationary Ocean Color Imager (GOCI). GOCI was launched in 2010 to monitor the ocean and coastal areas of the Korean peninsula. We evaluated in-orbit MTF value based on the GOCI image having a 500-m spatial resolution in the first time. The pulse method was selected to estimate a point spread function (PSF) with an optimal natural target such as a Seamangeum Seawall. Finally, image restoration was performed with a Wiener filter (WF) to calculate the PSF value required for the optimal regularization parameter. After application of the WF to the target image, MTF value is improved 35.06%, and the compensated image shows more sharpness comparing with the original image.

  19. 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.

  20. Ocean energy program summary

    SciTech Connect

    Not Available

    1990-01-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71% of the earth's surface, they collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the US 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. 13 figs.

  1. 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.

  2. Physics-Based and Statistical Forecasting in Slowly Stressed Environments

    NASA Astrophysics Data System (ADS)

    Segou, M.; Deschamps, A.

    2013-12-01

    We perform a retrospective forecasting experiment between 1995-2012, comparing the predictive power of physics-based and statistical models in Corinth Gulf (Central Greece), which is the fastest continental rift in the world with extension rates 11-15 mm/yr, but also at least three times lower than the motion accommodated by the San Andreas Fault System (~40 mm/yr). The seismicity of the western Corinth gulf has been characterized by significant historical events (1817 M6.6, 1861 M6.7, 1889 M7.0) whereas the modern instrumental catalog (post-1964) reveals one major event, the 1995 Aigio M6.4 (15/06/1995) together with several periods of increased microseismic activity, usually lasting few months and possibly related with fluid diffusion. We examine six predictive models, three based on the combination of Coulomb stress changes and rate-and-state theory (CRS), two epidemic type aftershock sequence (ETAS) models and one hybrid CRS-ETAS (h-ETAS) model. We investigate whether the above forecast models can adequately describe the episodic swarm activity within the gulf. Even though Corinth gulf has been studied extensively in the past there is still today a debate whether earthquake activity is related with the existence of either a shallow dipping structure or steeply dipping normal faults. In the light of the above statement, two CRS realization are based on resolving Coulomb stress changes on specified receiver faults, expressing the aforementioned structural models, whereas the third CRS model uses optimally-oriented for failure planes. In our CRS implementation we account for stress changes following all major ruptures within our testing phase with M greater than 4.5. We also estimate fault constitutive parameters from modeling the response to major earthquakes at the vicinity of the gulf (Ασ=0.2, stressing rate 0.02 bar/yr). The ETAS parameters are taken as the maximum likelihood estimates derived from stochastic declustering of the modern seismicity catalog

  3. 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.

  4. Magnetoelectric laminate composite based tachometer for harsh environment applications

    SciTech Connect

    Myers, Robert; Islam, Rashed Adnan; Karmarkar, Makarand; Priya, Shashank

    2007-09-17

    This study reports the design, fabrication, and characterization of a tachometer utilizing magnetoelectric (ME) laminate composites with sandwich structure consisting of Pb(Zr,Ti)O{sub 3} (PZT) and Galfenol. High temperature characterization of Galfenol shows that it can sustain the magnetic property over 500 deg. C. The Curie temperature of PZT compositions was in the range of 325-340 deg. C. The magnitude of the ME coefficient was found to scale with the dimensionless ratio (d g/S), where d is the piezoelectric strain constant, g is the piezoelectric voltage constant, and S is the elastic compliance. The tachometer design is based on the principle that when ME composite is exposed to oscillating magnetic field, it generates voltage with the same frequency.

  5. 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.

  6. 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.

  7. 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…

  8. Self-Regulation of Learning within Computer-Based Learning Environments: A Critical Analysis

    ERIC Educational Resources Information Center

    Winters, Fielding I.; Greene, Jeffrey A.; Costich, Claudine M.

    2008-01-01

    Computer-based learning environments (CBLEs) present important opportunities for fostering learning; however, studies have shown that students have difficulty when learning with these environments. Research has identified that students' self-regulatory learning (SRL) processes may mediate the hypothesized positive relations between CBLEs and…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. Learners' Perceptions and Learning Styles in the Integrated Mode of Web-Based Environment.

    ERIC Educational Resources Information Center

    Lee, In-Sook

    This research explores how learners perceive a Web-based learning environment integrated with a traditional classroom, as well as what learning styles are usually identified in this environment. Participants were 156 students at a university in Seoul, Korea, who were surveyed after the semester was over. The majority of them (89.1%) had…

  14. Learners' Perceptions and Illusions of Adaptivity in Computer-Based Learning Environments

    ERIC Educational Resources Information Center

    Vandewaetere, Mieke; Vandercruysse, Sylke; Clarebout, Geraldine

    2012-01-01

    Research on computer-based adaptive learning environments has shown exemplary growth. Although the mechanisms of effective adaptive instruction are unraveled systematically, little is known about the relative effect of learners' perceptions of adaptivity in adaptive learning environments. As previous research has demonstrated that the learners'…

  15. 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…

  16. 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…

  17. How To Create a Learning Environment on the Internet, Based on Constructivism and Sociocultural Approaches?

    ERIC Educational Resources Information Center

    Staupe, Arvid; Hernes, Margrethe Steen

    This paper discusses designing learning environments based on the Internet, as seen from a constructivist/situated learning point of view. First, some of the main principles of learning theory are examined. The structuring of virtual learning environments and integrated use of services on the Internet within the following five areas are addressed:…

  18. 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…

  19. 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…

  20. The built environment moderates effects of family-based childhood obesity treatment over two years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Research suggests the built environment can influence child activity and eating. Purpose: Test whether the built environment is related to effectiveness of standardized family-based behavioral treatments on overweight children’s weight loss. Method: zBMI changes for 212 children (8-...

  1. Supporting Self-Regulation in Student-Centered Web-Based Learning Environments

    ERIC Educational Resources Information Center

    Dabbagh, Nada; Kitsantas, Anastasia

    2004-01-01

    Numerous benefits of student-centered web-based learning environments have been documented in the literature; however the effects on student learning are questionable, particularly for low self-regulated learners primarily because these environments require students to exercise a high degree of self-regulation to succeed. Currently few guidelines…

  2. 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…

  3. Ocean optics IX

    SciTech Connect

    Blizard, M.A.

    1988-01-01

    These proceedings collect papers on optics and optical properties. Topics include: optical properties of water laser bathymetry, scattering from marine organisms, optically stimulated sound from bubbles, underwater laser-based imaging systems, and remote sensing of ocean physical properties.

  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. Smartphone-based hearing screening in noisy environments.

    PubMed

    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

  6. 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

  7. Tls Field Data Based Intensity Correction for Forest Environments

    NASA Astrophysics Data System (ADS)

    Heinzel, J.; Huber, M. O.

    2016-06-01

    Terrestrial laser scanning (TLS) is increasingly used for forestry applications. Besides the three dimensional point coordinates, the 'intensity' of the reflected signal plays an important role in forestry and vegetation studies. The benefit of the signal intensity is caused by the wavelength of the laser that is within the near infrared (NIR) for most scanners. The NIR is highly indicative for various vegetation characteristics. However, the intensity as recorded by most terrestrial scanners is distorted by both external and scanner specific factors. Since details about system internal alteration of the signal are often unknown to the user, model driven approaches are impractical. On the other hand, existing data driven calibration procedures require laborious acquisition of separate reference datasets or areas of homogenous reflection characteristics from the field data. In order to fill this gap, the present study introduces an approach to correct unwanted intensity variations directly from the point cloud of the field data. The focus is on the variation over range and sensor specific distortions. Instead of an absolute calibration of the values, a relative correction within the dataset is sufficient for most forestry applications. Finally, a method similar to time series detrending is presented with the only pre-condition of a relative equal distribution of forest objects and materials over range. Our test data covers 50 terrestrial scans captured with a FARO Focus 3D S120 scanner using a laser wavelength of 905 nm. Practical tests demonstrate that our correction method removes range and scanner based alterations of the intensity.

  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. PMID:21741207

  9. Sulfation of calcium based sorbents in a combustion environment

    SciTech Connect

    Newton, G.H.

    1987-01-01

    The capture of SO/sub 2/ by dry, calcium-based sorbents was examined in a three part research effort: (1) an experimental evaluation of sorbent materials under isothermal reaction conditions; (2) characterization of sulfation fundamentals through sulfation rate measurements with sized, precalcined sorbents and the development of a distributed pore sulfation model; and (3) experimental definition of reaction temperature effects and computer modeling of the simultaneous sintering and sulfation processes. The experimental sorbent evaluation examined calcitic and dolomitic carbonates and hydrates. High temperature, isothermal SO/sub 2/ capture data were obtained as a function of Ca/S molar ratio, temperature, and SO/sub 2/ concentration for each sorbent. SO/sub 2/ capture was found to be approximately linearly dependent on Ca/S ratio, relatively insensitive to SO/sub 2/ concentration above 2000 ppM, and a strong function of sorbent type. Time resolved sulfation data of sized, precalcined sorbents indicated that sulfation is initially rapid, but beyond approximately 300 ms the sulfation rate decreases dramatically. A distributed pore model, which viewed CaO particles as composed of nonintersecting, cylindrical pores with diameters determined from nitrogen porosimetry, particle boundary layer, pore, and CaSO/sub 4/ product layer diffusions in addition to the heterogeneous chemical reaction was developed. Temperature dependent sulfation data for precalcined sorbents suggest two types of sintering influence particle porosity: sintering associated with the combustion process and sintering promoted by the presence of sulfate ions in the particle crystal structure. Inclusion of both sintering mechanisms in the distributed pore model allowed predictions of the highest temperature experimental data from a variety of precalcines.

  10. 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...

  11. 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 ...

  12. 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…

  13. Oceanic emissions of ammonia

    NASA Astrophysics Data System (ADS)

    Paulot, F.; Jacob, D. J.; Johnson, M.; Bell, T. G.; Stock, C. A.; Doney, S. C.

    2013-12-01

    Half of natural ammonia (NH3) emissions is thought to originate from the oceans. Such large emissions have implications for the global budget of N and the acidity of marine aerosols. We develop two new inventories of oceanic NH3 emissions based on simulated monthly NH3 seawater concentrations from the GFDL-COBALT and the CESM-BEC ocean models. These new inventories explicitly account for the effect of temperature on the water-atmosphere exchange of NH3. We evaluate these inventory using cruise observations of gas-phase ammonia (AMT cruises) and ammonium (NOAA cruises) as well as seawater measurement of NHx. Implications of atmospheric NHx observations for the exchange of N between ocean and land and ocean N/P limitations are discussed.

  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. Redesigning Chat Forum for Critical Thinking in a Problem-Based Learning Environment

    ERIC Educational Resources Information Center

    Chiang, Akcell Chii-Chung; Fung, Isaac Pak-Wah

    2004-01-01

    Support is needed to promote problem-based learning (PBL) and to enhance critical thinking skills in discussion-based Internet forums. By advancing the capabilities of chat room and forum software, problem-based discussions for learning can be supported further in online learning environments. In this paper, the authors report on MALESAbrain, an…

  16. Potential for adaptive evolution at species range margins: contrasting interactions between red coral populations and their environment in a changing ocean

    PubMed Central

    Ledoux, Jean-Baptiste; Aurelle, Didier; Bensoussan, Nathaniel; Marschal, Christian; Féral, Jean-Pierre; Garrabou, Joaquim

    2015-01-01

    Studying population-by-environment interactions (PEIs) at species range margins offers the opportunity to characterize the responses of populations facing an extreme regime of selection, as expected due to global change. Nevertheless, the importance of these marginal populations as putative reservoirs of adaptive genetic variation has scarcely been considered in conservation biology. This is particularly true in marine ecosystems for which the deep refugia hypothesis proposes that disturbed shallow and marginal populations of a given species can be replenished by mesophotic ones. This hypothesis therefore assumes that identical PEIs exist between populations, neglecting the potential for adaptation at species range margins. Here, we combine reciprocal transplant and common garden experiments with population genetics analyses to decipher the PEIs in the red coral, Corallium rubrum. Our analyses reveal partially contrasting PEIs between shallow and mesophotic populations separated by approximately one hundred meters, suggesting that red coral populations may potentially be locally adapted to their environment. Based on the effective population size and connectivity analyses, we posit that genetic drift may be more important than gene flow in the adaptation of the red coral. We further investigate how adaptive divergence could impact population viability in the context of warming and demonstrate differential phenotypic buffering capacities against thermal stress. Our study questions the relevance of the deep refugia hypothesis and highlights the conservation value of marginal populations as a putative reservoir of adaptive genetic polymorphism. PMID:25859324

  17. The built environment moderates effects of family-based childhood obesity treatment over two years

    PubMed Central

    Epstein, Leonard H.; Raja, Samina; Daniel, Tinuke Oluyomi; Paluch, Rocco A.; Wilfley, Denise E.; Saelens, Brian E.; Roemmich, James N.

    2012-01-01

    Background Research suggests the neighborhood built environment is related to child physical activity and eating. Purpose Determine if characteristics of the neighborhood environment moderate the relationship between obesity treatment and weight loss, and if outcomes of particular treatments are moderated by built environment characteristics. Method The relationship between the built environment and zBMI changes for 191 8-12 year-old children who participated in one of four randomized, controlled trials of pediatric weight management was assessed using mixed models analysis of covariance. Results At 2 year follow-up, greater parkland, fewer convenience stores and fewer supermarkets were associated with greater zBMI reduction across all interventions. No treatments interacted with characteristics of the built environment. Conclusions Activity- and eating-related built neighborhood characteristics are associated with child success in behavioral obesity treatments. Efficacy may be improved by individualizing treatments based on built environment characteristics. PMID:22777879

  18. 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...

  19. 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...

  20. 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...