Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6106946
B. Thornton, T. Masamura, Tomoko Takahashi, T. Ura, T. Sakka, K. Ohki
The application of laser-induced breakdown spectroscopy for analysis of the chemical composition of solids immersed in water at oceanic pressures has been investigated. Well defined emission spectra were observed from plumes generated from underwater solids after excitation using a single laser pulse of duration less than 10 ns. It is demonstrated that an increase in water pressure from 0.1 to 30MPa (300 atm) does not have a significant effect on the intensity and broadness of the observed spectral lines. Shadowgraph images demonstrate that even at pressures of 30MPa, beyond the critical pressure of water, cavitation occurs around the ablated region. Furthermore, it is demonstrated that during the early stages, less than 1 µs, after irradiation the size of the cavity is largely independent of the external fluid pressure for pressures up to 30MPa. It is suggested that the high pressure shock wave induced by the focused laser dominates the local pressure regime for close to 1 µs after irradiation and generates a transient low pressure region in which a cavity can form for the plume to expand into. Measurements of craters formed in the solids after ablation at different pressures demonstrate that the amount of material ablated by the laser stays within the same order for all hydrostatic pressures tested. The results of this study suggest that laser-induced breakdown spectroscopy is, in principle, a technique suitable for in situ elemental analysis of both shallow water sediments and deep sea minerals.
{"title":"A study of laser-induced breakdown spectroscopy for analysis of the composition of solids submerged at oceanic pressures","authors":"B. Thornton, T. Masamura, Tomoko Takahashi, T. Ura, T. Sakka, K. Ohki","doi":"10.23919/OCEANS.2011.6106946","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6106946","url":null,"abstract":"The application of laser-induced breakdown spectroscopy for analysis of the chemical composition of solids immersed in water at oceanic pressures has been investigated. Well defined emission spectra were observed from plumes generated from underwater solids after excitation using a single laser pulse of duration less than 10 ns. It is demonstrated that an increase in water pressure from 0.1 to 30MPa (300 atm) does not have a significant effect on the intensity and broadness of the observed spectral lines. Shadowgraph images demonstrate that even at pressures of 30MPa, beyond the critical pressure of water, cavitation occurs around the ablated region. Furthermore, it is demonstrated that during the early stages, less than 1 µs, after irradiation the size of the cavity is largely independent of the external fluid pressure for pressures up to 30MPa. It is suggested that the high pressure shock wave induced by the focused laser dominates the local pressure regime for close to 1 µs after irradiation and generates a transient low pressure region in which a cavity can form for the plume to expand into. Measurements of craters formed in the solids after ablation at different pressures demonstrate that the amount of material ablated by the laser stays within the same order for all hydrostatic pressures tested. The results of this study suggest that laser-induced breakdown spectroscopy is, in principle, a technique suitable for in situ elemental analysis of both shallow water sediments and deep sea minerals.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"61 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83689130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6107221
S. Morey, D. Dukhovskoy
This paper describes a nesting approach for ocean models that is useful when the numerical model for the inner nest differs from the that used for the outer model. The typical use of nested grids in ocean modeling is to refine the horizontal resolution in a certain region, and often the same numerical model is employed for the outer and inner nests. In the application described here, a refinement of the vertical as well as the horizontal resolution is desired, and the structure of the vertical grid for the inner nest is necessarily different than that used in the outer model. In particular, this study is focused on simulation of bottom-intensified small-scale intense currents traveling along the Sigsbee Escarpment, a steep topographic feature found between roughly 1500–3000m depth in the northern Gulf of Mexico. The HYbrid Coordinate Ocean Model (HYCOM) is used to simulate large-scale upper ocean circulation features in the Gulf of Mexico, and a very-high resolution nest is applied using the Navy Coastal Ocean Model (NCOM) with a new quasi-vanishing sigma vertical coordinate over the Sigsbee Escarpment region.
{"title":"A multi-model nesting approach for simulating deep ocean dynamics and topographic interactions","authors":"S. Morey, D. Dukhovskoy","doi":"10.23919/OCEANS.2011.6107221","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6107221","url":null,"abstract":"This paper describes a nesting approach for ocean models that is useful when the numerical model for the inner nest differs from the that used for the outer model. The typical use of nested grids in ocean modeling is to refine the horizontal resolution in a certain region, and often the same numerical model is employed for the outer and inner nests. In the application described here, a refinement of the vertical as well as the horizontal resolution is desired, and the structure of the vertical grid for the inner nest is necessarily different than that used in the outer model. In particular, this study is focused on simulation of bottom-intensified small-scale intense currents traveling along the Sigsbee Escarpment, a steep topographic feature found between roughly 1500–3000m depth in the northern Gulf of Mexico. The HYbrid Coordinate Ocean Model (HYCOM) is used to simulate large-scale upper ocean circulation features in the Gulf of Mexico, and a very-high resolution nest is applied using the Navy Coastal Ocean Model (NCOM) with a new quasi-vanishing sigma vertical coordinate over the Sigsbee Escarpment region.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"36 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88339037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6107095
C. Kecy, E. Peltzer, P. Walz, K. Headley, B. Herlien, W. Kirkwood, T. O 'reilly, K. Salamy, F. Shane, J. Schofield, P. Brewer
The kinetics of the reaction that occurs when CO2 and seawater are in contact is a complex function of temperature, alkalinity, final pH and TCO2 which taken together determine the time required for complete equilibrium. This reaction is extremely important to the study of Ocean Acidification (OA) and is the critical technical driver in the Monterey Bay Aquarium Research Institute's (MBARI) Free Ocean CO2 Enrichment (FOCE) experiments. The deep water FOCE science experiments are conducted at depths beyond scuba diver reach and demand that a valid perturbation experiment operate at a stable yet naturally fluctuating lower pH condition and avoid large or rapid pH variation as well as incomplete reactions, when we expose an experimental region or sample. Therefore, the technical requirement is to create a CO2 source in situ that is stable and well controlled. After extensive research and experimentation MBARI has developed the ability to create an in situ source of CO2 enriched seawater (ESW) for distribution and subsequent use in an ocean acidification experiment. The system mates with FOCE, but can be used in conjunction with other CO2 experimental applications in deep water. The ESW system is completely standalone from FOCE.
{"title":"Design and development of the CO2 enriched Seawater Distribution System","authors":"C. Kecy, E. Peltzer, P. Walz, K. Headley, B. Herlien, W. Kirkwood, T. O 'reilly, K. Salamy, F. Shane, J. Schofield, P. Brewer","doi":"10.23919/OCEANS.2011.6107095","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6107095","url":null,"abstract":"The kinetics of the reaction that occurs when CO2 and seawater are in contact is a complex function of temperature, alkalinity, final pH and TCO2 which taken together determine the time required for complete equilibrium. This reaction is extremely important to the study of Ocean Acidification (OA) and is the critical technical driver in the Monterey Bay Aquarium Research Institute's (MBARI) Free Ocean CO2 Enrichment (FOCE) experiments. The deep water FOCE science experiments are conducted at depths beyond scuba diver reach and demand that a valid perturbation experiment operate at a stable yet naturally fluctuating lower pH condition and avoid large or rapid pH variation as well as incomplete reactions, when we expose an experimental region or sample. Therefore, the technical requirement is to create a CO2 source in situ that is stable and well controlled. After extensive research and experimentation MBARI has developed the ability to create an in situ source of CO2 enriched seawater (ESW) for distribution and subsequent use in an ocean acidification experiment. The system mates with FOCE, but can be used in conjunction with other CO2 experimental applications in deep water. The ESW system is completely standalone from FOCE.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"1 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88640665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6106964
W. Keith, A. Foley, K. Cipolla
Measurements of the autospectra and coherence of turbulent wall pressure fluctuations were made in the circular test section of the Quiet Water Tunnel Facility at the Naval Undersea Warfare Center in Newport, Rhode Island. The pipe diameter Reynolds numbers varied from 2.09 × 105 to 1.85 × 106. The coherence measurements are shown to collapse well with the similarity scaling over the entire range of Reynolds numbers. Wavenumber-frequency spectra are estimated by computing the spatial Fourier transform of the measured coherence, using the model of Corcos. The results are shown to accurately represent the convective ridge portion of the wavenumber-frequency spectra where the dominant energy exists.
{"title":"Wavenumber-frequency analysis of turbulent wall pressure fluctuations over a wide Reynolds number range of Turbulent Pipe Flows","authors":"W. Keith, A. Foley, K. Cipolla","doi":"10.23919/OCEANS.2011.6106964","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6106964","url":null,"abstract":"Measurements of the autospectra and coherence of turbulent wall pressure fluctuations were made in the circular test section of the Quiet Water Tunnel Facility at the Naval Undersea Warfare Center in Newport, Rhode Island. The pipe diameter Reynolds numbers varied from 2.09 × 105 to 1.85 × 106. The coherence measurements are shown to collapse well with the similarity scaling over the entire range of Reynolds numbers. Wavenumber-frequency spectra are estimated by computing the spatial Fourier transform of the measured coherence, using the model of Corcos. The results are shown to accurately represent the convective ridge portion of the wavenumber-frequency spectra where the dominant energy exists.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"46 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77271847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6106933
M. Rivera, Brian E. Lawton, Chryssostomos Chyrssostomidis
Inquiry-driven and place-based education can be a powerful way to improve science literacy in students, simultaneously changing their perceptions about the environments in which they live, their individual roles in conservation, and by extension, their views of higher education and possible careers in science. However, authentic scientific inquiry opportunities that are outdoors and/or associated with the marine environment have limitations related to risk liability, funding availability, complicated logistics to get students to study sites, and time away from other classes for all-day field trips. Emerging technologies utilizing the internet and the concept of ‘telepresence’ can provide a means to overcome many of these obstacles by ‘bringing the place to the classroom’. In a pilot program executed by the Hawai'i Institute of Marine Biology (HIMB) at the University of Hawai'i at Mānoa and in partnership with the Massachusetts Institute of Technology Sea Grant's Autonomous Underwater Vehicle (AUV) Laboratory, we demonstrate the application of using cutting edge ocean engineering technology, in the form of a mini autonomous submarine vehicle, to expose students to ‘outdoor’ marine science experiences they otherwise might be unlikely to get. The AUV is controlled interactively through the internet, transmitting data and images in real time directly to students in the classroom. HIMB scientists developed marine science lessons that harness the capabilities of the AUV, emphasizing the process of scientific inquiry and investigation. The lessons were also designed to relate science topics to broader environmental issues affecting Hawai'i's ecosystems. In this paper, we provide a brief overview of the pilot project and present preliminary student evaluation results that provide evidence for the potential of this approach in science education in Hawai'i and beyond.
{"title":"Reef Missions: Engaging students in science and the marine environment using an autonomous underwater vehicle","authors":"M. Rivera, Brian E. Lawton, Chryssostomos Chyrssostomidis","doi":"10.23919/OCEANS.2011.6106933","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6106933","url":null,"abstract":"Inquiry-driven and place-based education can be a powerful way to improve science literacy in students, simultaneously changing their perceptions about the environments in which they live, their individual roles in conservation, and by extension, their views of higher education and possible careers in science. However, authentic scientific inquiry opportunities that are outdoors and/or associated with the marine environment have limitations related to risk liability, funding availability, complicated logistics to get students to study sites, and time away from other classes for all-day field trips. Emerging technologies utilizing the internet and the concept of ‘telepresence’ can provide a means to overcome many of these obstacles by ‘bringing the place to the classroom’. In a pilot program executed by the Hawai'i Institute of Marine Biology (HIMB) at the University of Hawai'i at Mānoa and in partnership with the Massachusetts Institute of Technology Sea Grant's Autonomous Underwater Vehicle (AUV) Laboratory, we demonstrate the application of using cutting edge ocean engineering technology, in the form of a mini autonomous submarine vehicle, to expose students to ‘outdoor’ marine science experiences they otherwise might be unlikely to get. The AUV is controlled interactively through the internet, transmitting data and images in real time directly to students in the classroom. HIMB scientists developed marine science lessons that harness the capabilities of the AUV, emphasizing the process of scientific inquiry and investigation. The lessons were also designed to relate science topics to broader environmental issues affecting Hawai'i's ecosystems. In this paper, we provide a brief overview of the pilot project and present preliminary student evaluation results that provide evidence for the potential of this approach in science education in Hawai'i and beyond.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"25 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77601542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6106918
S. James, S. Lefantzi, Janet Barco, Erick Johnson, Jesse D. Roberts
Increasing interest in marine hydrokinetic (MHK) energy has led to significant research regarding optimal placement of emerging technologies to maximize energy capture and minimize effects on the marine environment. Understanding the changes to the near- and far-field hydrodynamics is necessary to assess optimal placement. MHK projects will convert energy (momentum) from the system, altering water velocities and potentially water quality and sediment transport as well. Maximum site efficiency for MHK power projects must balance with the requirement of avoiding environmental harm. This study is based on previous modification to an existing flow, sediment dynamics, and water-quality code (SNL-EFDC) where a simulation of an experimental flume is used to qualify, quantify, and visualize the influence of MHK energy generation. Turbulence and device parameters are calibrated against wake data from a flume experiment out of the University of Southampton (L. Myers and A. S. Bahaj, “Near wake properties of horizontal axis marine current turbines,” in Proceedings of the 8th European Wave and Tidal Energy Conference, 2009, pp. 558–565) to produce verified simulations of MHK-device energy removal. To achieve a realistic velocity deficit within the wake of the device, parametric studies using the nonlinear, model-independent, parameter estimators PEST and DAKOTA were compared to determine parameter sensitivities and optimal values for various constants in the flow and turbulence closure equations. The sensitivity analyses revealed that the Smagorinski subgrid-scale horizontal momentum diffusion constant and the k-ε kinetic energy dissipation rate constant (Cε4) were the two most important parameters influencing wake profile and dissipation at 10 or more device diameters downstream as they strongly influence how the wake mixes with the bulk flow. These results verify the model, which can now be used to perform MHK-array distribution and optimization studies.
人们对海洋水动力(MHK)能源的兴趣日益浓厚，这导致了对新兴技术的最佳配置进行了大量研究，以最大限度地获取能源并最大限度地减少对海洋环境的影响。了解近场和远场流体力学的变化对于评估最佳安置是必要的。MHK项目将从系统中转换能量(动量)，改变水流速度，并可能改变水质和沉积物的输送。水电项目的最大场地效率必须与避免环境危害的要求相平衡。本研究基于先前对现有水流、泥沙动力学和水质规范(SNL-EFDC)的修改，其中使用了一个实验水槽的模拟来确定、量化和可视化MHK能量产生的影响。湍流和设备参数是根据南安普顿大学水槽实验的尾流数据进行校准的(L. Myers和a . S. Bahaj，“水平轴海流涡轮机的近尾流特性”，发表于第八届欧洲波浪和潮汐能源会议论文集，2009年，第558-565页)，以产生mhk设备能量去除的验证模拟。为了在设备尾迹内实现真实的速度赤字，使用非线性、模型无关的参数估计器PEST和DAKOTA进行参数研究，以确定流动和湍流闭合方程中各种常数的参数灵敏度和最佳值。灵敏度分析表明，Smagorinski亚网格尺度水平动量扩散常数和k-ε动能耗散率常数(Cε4)是影响尾迹分布和下游10个及以上装置直径处耗散的两个最重要参数，它们强烈影响尾迹与体流的混合情况。这些结果验证了该模型，该模型现在可以用于进行mhk阵列分布和优化研究。
{"title":"Verifying marine-hydro-kinetic energy generation simulations using SNL-EFDC","authors":"S. James, S. Lefantzi, Janet Barco, Erick Johnson, Jesse D. Roberts","doi":"10.23919/OCEANS.2011.6106918","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6106918","url":null,"abstract":"Increasing interest in marine hydrokinetic (MHK) energy has led to significant research regarding optimal placement of emerging technologies to maximize energy capture and minimize effects on the marine environment. Understanding the changes to the near- and far-field hydrodynamics is necessary to assess optimal placement. MHK projects will convert energy (momentum) from the system, altering water velocities and potentially water quality and sediment transport as well. Maximum site efficiency for MHK power projects must balance with the requirement of avoiding environmental harm. This study is based on previous modification to an existing flow, sediment dynamics, and water-quality code (SNL-EFDC) where a simulation of an experimental flume is used to qualify, quantify, and visualize the influence of MHK energy generation. Turbulence and device parameters are calibrated against wake data from a flume experiment out of the University of Southampton (L. Myers and A. S. Bahaj, “Near wake properties of horizontal axis marine current turbines,” in Proceedings of the 8th European Wave and Tidal Energy Conference, 2009, pp. 558–565) to produce verified simulations of MHK-device energy removal. To achieve a realistic velocity deficit within the wake of the device, parametric studies using the nonlinear, model-independent, parameter estimators PEST and DAKOTA were compared to determine parameter sensitivities and optimal values for various constants in the flow and turbulence closure equations. The sensitivity analyses revealed that the Smagorinski subgrid-scale horizontal momentum diffusion constant and the k-ε kinetic energy dissipation rate constant (Cε4) were the two most important parameters influencing wake profile and dissipation at 10 or more device diameters downstream as they strongly influence how the wake mixes with the bulk flow. These results verify the model, which can now be used to perform MHK-array distribution and optimization studies.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"50 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91390388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6106903
Ehsan Sadighrad, F. Ahmadi-Givi, A. Bidokhti
The ocean thermohaline circulation is caused by water density contrasts. This circulation has large capacity of carrying heat around the globe and it thus affects the energy budget and further affects the climate. Henry Stommel's (1958) abyssal circulation article contained the first theoretical analysis of the deep thermohaline circulation (THC). Due to Stommel's reasoning the incoming heat flux via the sun's radiation is stirred downward by wind and the thermal convection, and heats up the waters down to the thermocline and that this subsurface source of heat must be offset by a source of cold if the ocean is not to become continuously warmer. The resulting flow pattern is still used as the zero-order circulation of the deep oceans of the world. Since Caspian Sea is the world's largest inland body of salty water, therefore the study of circulation pattern in this sea for determination of pollution propagation and sediment transport is important. This study is based on a numerical model for prediction of a 2-D behavior of the Caspian Sea circulation due to the effect of uniform surface wind force and density gradients. The model is based on the equations of Navier-Stokes, salinity, and heat applying finite element method. It is assumed that the dominant surface wind is in the north-west direction. Simulation results include flow pattern of the circulation, relative vorticity, and density changes. The subdomain is partitioned into tetrahedral mesh elements and hence, the boundaries are partitioned into tetrahedral boundary elements. The specifications of medium such as fluid velocity under wind stress, inward heat flux, heat capacity of fluid, thermal conductivity, heat, and salinity diffusion coefficients are mentioned. The results of simulation and water circulation show that there are counterclockwise circulations in the South and North Caspian and clockwise circulations in the Middle Caspian. Relative vorticity, circulation and density pattern are presented and at the end some suggestions are made to obtain the results similar to reality.
{"title":"Finite element modeling of surface layer circulation in the Caspian Sea","authors":"Ehsan Sadighrad, F. Ahmadi-Givi, A. Bidokhti","doi":"10.23919/OCEANS.2011.6106903","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6106903","url":null,"abstract":"The ocean thermohaline circulation is caused by water density contrasts. This circulation has large capacity of carrying heat around the globe and it thus affects the energy budget and further affects the climate. Henry Stommel's (1958) abyssal circulation article contained the first theoretical analysis of the deep thermohaline circulation (THC). Due to Stommel's reasoning the incoming heat flux via the sun's radiation is stirred downward by wind and the thermal convection, and heats up the waters down to the thermocline and that this subsurface source of heat must be offset by a source of cold if the ocean is not to become continuously warmer. The resulting flow pattern is still used as the zero-order circulation of the deep oceans of the world. Since Caspian Sea is the world's largest inland body of salty water, therefore the study of circulation pattern in this sea for determination of pollution propagation and sediment transport is important. This study is based on a numerical model for prediction of a 2-D behavior of the Caspian Sea circulation due to the effect of uniform surface wind force and density gradients. The model is based on the equations of Navier-Stokes, salinity, and heat applying finite element method. It is assumed that the dominant surface wind is in the north-west direction. Simulation results include flow pattern of the circulation, relative vorticity, and density changes. The subdomain is partitioned into tetrahedral mesh elements and hence, the boundaries are partitioned into tetrahedral boundary elements. The specifications of medium such as fluid velocity under wind stress, inward heat flux, heat capacity of fluid, thermal conductivity, heat, and salinity diffusion coefficients are mentioned. The results of simulation and water circulation show that there are counterclockwise circulations in the South and North Caspian and clockwise circulations in the Middle Caspian. Relative vorticity, circulation and density pattern are presented and at the end some suggestions are made to obtain the results similar to reality.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"82 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89665769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6107083
M. Woolsey, V. Asper, A. Diercks, R. Jarnagin, P. Lowe, A. Gossett, R. Highsmith
The seafloor mapping AUVs Eagle Ray and Mola Mola have vastly different capabilities and operational requirements, yet they perform complementary tasks. These AUVs are operated by the National Institute for Undersea Science and Technology (NIUST), which is a NOAA sponsored partnership between the University of Mississippi and the University of Southern Mississippi. Eagle Ray collects Multibeam sonar bathymetry and CTD data, as well as data from guest payloads. Mola Mola collects color images of the seafloor along with multibeam bathymetry. In back-to-back dives, Mola Mola can conduct focused studies over targets determined from broad surveys carried out by Eagle Ray, but the two vehicles have also had successful cruises independently.
{"title":"Expanding the capabilities of the NIUST AUVs","authors":"M. Woolsey, V. Asper, A. Diercks, R. Jarnagin, P. Lowe, A. Gossett, R. Highsmith","doi":"10.23919/OCEANS.2011.6107083","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6107083","url":null,"abstract":"The seafloor mapping AUVs Eagle Ray and Mola Mola have vastly different capabilities and operational requirements, yet they perform complementary tasks. These AUVs are operated by the National Institute for Undersea Science and Technology (NIUST), which is a NOAA sponsored partnership between the University of Mississippi and the University of Southern Mississippi. Eagle Ray collects Multibeam sonar bathymetry and CTD data, as well as data from guest payloads. Mola Mola collects color images of the seafloor along with multibeam bathymetry. In back-to-back dives, Mola Mola can conduct focused studies over targets determined from broad surveys carried out by Eagle Ray, but the two vehicles have also had successful cruises independently.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"89 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84281106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6107139
H. Cheyne, C. Clark, J. Walrod, N. Gholson, M. Ornee
Current methods for acoustically monitoring marine mammal habitats to mitigate against potential disruptions are compromised in their effectiveness due to non-real-time analysis, such as with archival recorders, or high system noise, such as with towed hydrophone arrays used with seismic surveys. To realize the advantages of both archival and real-time analysis systems, we are developing a portable and autonomous system for acquiring and analyzing towed hydrophone array data in real-time, by combining archival recording hardware, signal detection firmware, and high-bandwidth satellite communication onto a solar- and wave-powered glider platform. Such a system would be capable of persistent, autonomous, real-time monitoring of marine mammals in areas that would otherwise not be surveyed, as it will not require a local ship for its deployment, its retrieval, or reception of data for human review. This paper describes the ongoing development work to demonstrate the feasibility of integrating a WaveGlider with the archival recording electronics and a towed four-element hydrophone array to capture and output acoustic data to an on-ship data collection system.
{"title":"Developing a portable and persistent autonomous real-time marine mammal acoustic monitor","authors":"H. Cheyne, C. Clark, J. Walrod, N. Gholson, M. Ornee","doi":"10.23919/OCEANS.2011.6107139","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6107139","url":null,"abstract":"Current methods for acoustically monitoring marine mammal habitats to mitigate against potential disruptions are compromised in their effectiveness due to non-real-time analysis, such as with archival recorders, or high system noise, such as with towed hydrophone arrays used with seismic surveys. To realize the advantages of both archival and real-time analysis systems, we are developing a portable and autonomous system for acquiring and analyzing towed hydrophone array data in real-time, by combining archival recording hardware, signal detection firmware, and high-bandwidth satellite communication onto a solar- and wave-powered glider platform. Such a system would be capable of persistent, autonomous, real-time monitoring of marine mammals in areas that would otherwise not be surveyed, as it will not require a local ship for its deployment, its retrieval, or reception of data for human review. This paper describes the ongoing development work to demonstrate the feasibility of integrating a WaveGlider with the archival recording electronics and a towed four-element hydrophone array to capture and output acoustic data to an on-ship data collection system.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"1 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84308016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-19DOI: 10.23919/OCEANS.2011.6107018
M. Wayne Turner, J. Cleland, J. Baker
A Seawater Activated Power System (SWAPS) has most recently been tested for providing all electrical power for a US Navy Deep Water Detection System (DWADS). DWADS requires 40 kW bursts of power to produce acoustic pulses that are detected by submerged receivers whose signals are transmitted to and analyzed by ship or shore based operators.
{"title":"Seawater Activated Power System (SWAPS): Energy for Deep Water Detection, ocean platforms, buoys, surface craft and submersibles","authors":"M. Wayne Turner, J. Cleland, J. Baker","doi":"10.23919/OCEANS.2011.6107018","DOIUrl":"https://doi.org/10.23919/OCEANS.2011.6107018","url":null,"abstract":"A Seawater Activated Power System (SWAPS) has most recently been tested for providing all electrical power for a US Navy Deep Water Detection System (DWADS). DWADS requires 40 kW bursts of power to produce acoustic pulses that are detected by submerged receivers whose signals are transmitted to and analyzed by ship or shore based operators.","PeriodicalId":19442,"journal":{"name":"OCEANS'11 MTS/IEEE KONA","volume":"123 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85652300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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