Pub Date : 2006-05-23DOI: 10.1109/BALTIC.2006.7266194
M. J. Howarth, R. Proctor, M. Smithson, R. Player, P. Knight
The pilot coastal observatory in the eastern Irish Sea integrates (near) real-time measurements with coupled models in a pre-operational coastal prediction system. The aim is to develop the underpinning science for marine management, focusing on the impacts of storms, eutrophication and the relative importance of events viz-a-viz the mean. Real time current measurements are obtained from a seabed mounted acoustic Doppler current profiler; deployment started in August 2002, via acoustic modems and the Orbcomm satellite e-mail system, and from a shore based HF radar via telephone landlines. There are also real time measurements from a surface buoy and a directional wave buoy and from an instrumented ferry, all via Orbcomm. The measurements are integrated with a suite of nested 3-dimensional hydrodynamic and ecological models run daily, focusing on the Observatory area by covering the ocean/shelf of northwest Europe (at 12 km resolution), the Irish Sea (at 1.8 km) and Liverpool Bay (at 200-300m resolution). All measurements and model outputs are displayed on the Web-site (http://coastobs.pol.ac.uk).
{"title":"The Liverpool Bay coastal observatory","authors":"M. J. Howarth, R. Proctor, M. Smithson, R. Player, P. Knight","doi":"10.1109/BALTIC.2006.7266194","DOIUrl":"https://doi.org/10.1109/BALTIC.2006.7266194","url":null,"abstract":"The pilot coastal observatory in the eastern Irish Sea integrates (near) real-time measurements with coupled models in a pre-operational coastal prediction system. The aim is to develop the underpinning science for marine management, focusing on the impacts of storms, eutrophication and the relative importance of events viz-a-viz the mean. Real time current measurements are obtained from a seabed mounted acoustic Doppler current profiler; deployment started in August 2002, via acoustic modems and the Orbcomm satellite e-mail system, and from a shore based HF radar via telephone landlines. There are also real time measurements from a surface buoy and a directional wave buoy and from an instrumented ferry, all via Orbcomm. The measurements are integrated with a suite of nested 3-dimensional hydrodynamic and ecological models run daily, focusing on the Observatory area by covering the ocean/shelf of northwest Europe (at 12 km resolution), the Irish Sea (at 1.8 km) and Liverpool Bay (at 200-300m resolution). All measurements and model outputs are displayed on the Web-site (http://coastobs.pol.ac.uk).","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127173552","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506330
D. Hayes, A. Jenkins, S. McPhail
The March 2003 deployment of Autosub in the Antarctic was the first field study under the Autosub Under Ice program of the UK Natural Environment Research Council. Several missions were run under sea ice in the western Bellingshausen Sea at depths ranging from 90 to 200 m. Data from the upward-looking ADCP on the autonomous underwater vehicle (AUV) indicate a strongly oscillating horizontal velocity of the ice underside due to ocean swell. Swell period, height, direction, and directional spread are computed every 800 m from the ice edge to 10 km inward. To our knowledge, these are the first scalar and directional wave data collected by an AUV under sea ice. We observe exponential, period-dependent attenuation of waves propagating through sea ice. Mean period increases with distance from the ice edge. Directional spectra show gradual changes in swell properties during propagation through the ice pack. The wave field appears to refract during propagation. The spread does not seem to relate to distance from the ice edge. More under-ice runs and modeling are needed to confirm these observations. If suitably deployed, an ordinary ADCP may be used with this technique to study waves in open or ice-covered water, both scalar and directional properties.
2003年3月Autosub在南极的部署是英国自然环境研究委员会Autosub under Ice项目下的第一次实地研究。在别令斯豪森海西部90至200米深度的海冰下进行了几次任务。来自自主水下航行器(AUV)上的向上ADCP的数据表明，由于海洋膨胀，冰层底部的水平速度振荡强烈。从冰缘向内10公里每800米计算一次膨胀周期、高度、方向和方向扩散。据我们所知，这是AUV首次在海冰下收集标量波和定向波数据。我们观察到波浪在海冰中传播的指数周期衰减。平均周期随距离冰缘的增加而增加。方向谱显示，在通过浮冰的传播过程中，膨胀特性逐渐发生变化。波场在传播过程中出现折射。这种扩散似乎与离冰缘的距离无关。需要更多的冰下运行和建模来证实这些观察结果。如果部署得当，普通ADCP可以与该技术一起用于研究开放或冰覆盖水中的波，包括标量和方向性质。
{"title":"Surface wave decay and directional spectra in the marginal sea ice zone measured by an autonomous underwater vehicle","authors":"D. Hayes, A. Jenkins, S. McPhail","doi":"10.1109/CCM.2005.1506330","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506330","url":null,"abstract":"The March 2003 deployment of Autosub in the Antarctic was the first field study under the Autosub Under Ice program of the UK Natural Environment Research Council. Several missions were run under sea ice in the western Bellingshausen Sea at depths ranging from 90 to 200 m. Data from the upward-looking ADCP on the autonomous underwater vehicle (AUV) indicate a strongly oscillating horizontal velocity of the ice underside due to ocean swell. Swell period, height, direction, and directional spread are computed every 800 m from the ice edge to 10 km inward. To our knowledge, these are the first scalar and directional wave data collected by an AUV under sea ice. We observe exponential, period-dependent attenuation of waves propagating through sea ice. Mean period increases with distance from the ice edge. Directional spectra show gradual changes in swell properties during propagation through the ice pack. The wave field appears to refract during propagation. The spread does not seem to relate to distance from the ice edge. More under-ice runs and modeling are needed to confirm these observations. If suitably deployed, an ordinary ADCP may be used with this technique to study waves in open or ice-covered water, both scalar and directional properties.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123691753","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506351
P. Spain, R. Marsden, D. Barrick, C. Teague, C. Ruhl
The RiverSonde radar makes non-contact measurement of a horizontal swath of surface velocity across a river section. This radar, which has worked successfully at several rivers in the western USA, has shown encouraging correlation with simultaneous measurements of average currents at one level recorded by an acoustic travel-time system. This work reports a field study intercomparing data sets from a 600 kHz Channel Master ADCP with the RiverSonde radar. The primary goal was to begin to explore the robustness of the radar data as a reliable index of discharge. This site is at Three Mile Slough in northern California, USA. The larger intent of the work is to examine variability in space and time of the radar's surface currents compared with subsurface flows across the river section. Here we examine data from a couple of periods with strong winds.
{"title":"Field intercomparison of Channel Master ADCP with RiverSonde radar for measuring river discharge","authors":"P. Spain, R. Marsden, D. Barrick, C. Teague, C. Ruhl","doi":"10.1109/CCM.2005.1506351","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506351","url":null,"abstract":"The RiverSonde radar makes non-contact measurement of a horizontal swath of surface velocity across a river section. This radar, which has worked successfully at several rivers in the western USA, has shown encouraging correlation with simultaneous measurements of average currents at one level recorded by an acoustic travel-time system. This work reports a field study intercomparing data sets from a 600 kHz Channel Master ADCP with the RiverSonde radar. The primary goal was to begin to explore the robustness of the radar data as a reliable index of discharge. This site is at Three Mile Slough in northern California, USA. The larger intent of the work is to examine variability in space and time of the radar's surface currents compared with subsurface flows across the river section. Here we examine data from a couple of periods with strong winds.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130392934","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506360
M. Martini, F. L. Lightsom, C. Sherwood, Jingping Xu, J. Lacy, A. Ramsey, R. Horwitz
The U.S. Geological Survey (USGS) has developed a set of MATLAB tools to process and convert data collected by Sontek Hydra instruments to netCDF, which is a format used by the USGS to process and archive oceanographic time-series data. The USGS makes high-resolution current measurements within 1.5 meters of the bottom. These data are used in combination with other instrument data from sediment transport studies to develop sediment transport models. Instrument manufacturers provide software which outputs unique binary data formats. Multiple data formats are cumbersome. The USGS solution is to translate data streams into a common data format: netCDF. The Hydratools toolbox is written to create netCDF format files following EPIC conventions, complete with embedded metadata. Data are accepted from both the ADV and the PCADP. The toolbox will detect and remove bad data, substitute other sources of heading and tilt measurements if necessary, apply ambiguity corrections, calculate statistics, return information about data quality, and organize metadata. Standardized processing and archiving makes these data more easily and routinely accessible locally and over the Internet. In addition, documentation of the techniques used in the toolbox provides a baseline reference for others utilizing the data.
{"title":"Hydratools, a MATLAB/spl reg/ based data processing package for Sontek Hydra data","authors":"M. Martini, F. L. Lightsom, C. Sherwood, Jingping Xu, J. Lacy, A. Ramsey, R. Horwitz","doi":"10.1109/CCM.2005.1506360","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506360","url":null,"abstract":"The U.S. Geological Survey (USGS) has developed a set of MATLAB tools to process and convert data collected by Sontek Hydra instruments to netCDF, which is a format used by the USGS to process and archive oceanographic time-series data. The USGS makes high-resolution current measurements within 1.5 meters of the bottom. These data are used in combination with other instrument data from sediment transport studies to develop sediment transport models. Instrument manufacturers provide software which outputs unique binary data formats. Multiple data formats are cumbersome. The USGS solution is to translate data streams into a common data format: netCDF. The Hydratools toolbox is written to create netCDF format files following EPIC conventions, complete with embedded metadata. Data are accepted from both the ADV and the PCADP. The toolbox will detect and remove bad data, substitute other sources of heading and tilt measurements if necessary, apply ambiguity corrections, calculate statistics, return information about data quality, and organize metadata. Standardized processing and archiving makes these data more easily and routinely accessible locally and over the Internet. In addition, documentation of the techniques used in the toolbox provides a baseline reference for others utilizing the data.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129407319","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506327
D. Driver, G. Jeans, C. Harragin, A. Moore
Current measurements were conducted close to major deepwater development locations in the Gulf of Mexico during summer 2004 due to the proximity of a loop current eddy. Shortly after the passage of Hurricane Ivan, some ADCP data sets showed evidence for apparently very strong subsurface jet currents. The very high error and vertical velocities in parts of the water column affected by these jets would often be a reason to invalidate these data. However the very high apparent current speeds and similarities with features recently reported in the region prompted a more detailed investigation. So far evaluation of the apparent jet data itself remains inconclusive, but the lack of similar features in simultaneous data collected from a nearby platform, using a different type of ADCP, suggests that the apparent jets may not be real.
{"title":"The validity of apparent subsurface jet currents in the Gulf of Mexico","authors":"D. Driver, G. Jeans, C. Harragin, A. Moore","doi":"10.1109/CCM.2005.1506327","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506327","url":null,"abstract":"Current measurements were conducted close to major deepwater development locations in the Gulf of Mexico during summer 2004 due to the proximity of a loop current eddy. Shortly after the passage of Hurricane Ivan, some ADCP data sets showed evidence for apparently very strong subsurface jet currents. The very high error and vertical velocities in parts of the water column affected by these jets would often be a reason to invalidate these data. However the very high apparent current speeds and similarities with features recently reported in the region prompted a more detailed investigation. So far evaluation of the apparent jet data itself remains inconclusive, but the lack of similar features in simultaneous data collected from a nearby platform, using a different type of ADCP, suggests that the apparent jets may not be real.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127873067","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506349
T. Mudge, J. Sloat, J. Chen
In 2004 SonTek developed, in conjunction with Environment Canada, a new methodology for measuring current flow under ice cover. Mini-Acoustic Doppler Profilers (ADP) were deployed from above the ice cover and water velocity data were collected with SonTek's new Stationary Measurement Software. These initial field tests were made on the Mackenzie River at Fort Simpson, North West Territories, Canada. The original field site was chosen for its demanding environment conditions. At Fort Simpson, the Mackenzie River was over 1 km wide, with approximately thick 1 m of fast ice, areas with up to 80 cm of frazzle ice and currents of about 1 m/s. Temperatures dropped to below -20/spl deg/C during part of the February field tests. A full set of Mini-ADPs (3.0 MHz, 1.5 MHz and PC-ADP) were utilized at various locations to generate velocity profiles from the water-ice boundary layer to the bottom boundary layer. SonTek's Stationary Software was used to stitch various velocity profiles into a single discharge summary. Further refinements to the methodology and software have been ongoing in Canada and Asia. In March 2005 data was collected from a new field location at Heihe, Heilongjiang province in Northern China. The Heilongjiang River borders northern China and Siberia. It was about 700 m wide, with a maximum velocity of about 0.7 m/s and a total flow in winter of approximately 600 m/sup 3//s. In spring, the flow rates increase and the maximum velocities can get to 2 m/s.
{"title":"Discharge and current profiles under the ice","authors":"T. Mudge, J. Sloat, J. Chen","doi":"10.1109/CCM.2005.1506349","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506349","url":null,"abstract":"In 2004 SonTek developed, in conjunction with Environment Canada, a new methodology for measuring current flow under ice cover. Mini-Acoustic Doppler Profilers (ADP) were deployed from above the ice cover and water velocity data were collected with SonTek's new Stationary Measurement Software. These initial field tests were made on the Mackenzie River at Fort Simpson, North West Territories, Canada. The original field site was chosen for its demanding environment conditions. At Fort Simpson, the Mackenzie River was over 1 km wide, with approximately thick 1 m of fast ice, areas with up to 80 cm of frazzle ice and currents of about 1 m/s. Temperatures dropped to below -20/spl deg/C during part of the February field tests. A full set of Mini-ADPs (3.0 MHz, 1.5 MHz and PC-ADP) were utilized at various locations to generate velocity profiles from the water-ice boundary layer to the bottom boundary layer. SonTek's Stationary Software was used to stitch various velocity profiles into a single discharge summary. Further refinements to the methodology and software have been ongoing in Canada and Asia. In March 2005 data was collected from a new field location at Heihe, Heilongjiang province in Northern China. The Heilongjiang River borders northern China and Siberia. It was about 700 m wide, with a maximum velocity of about 0.7 m/s and a total flow in winter of approximately 600 m/sup 3//s. In spring, the flow rates increase and the maximum velocities can get to 2 m/s.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132436966","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506332
S. Anderson, P. Matthews
This paper describes the development of a towed acoustic Doppler current profiler (ADCP) system that is used to support operational monitoring of deepwater currents. The towed body configuration provides a quiet and stable sensor platform that can be readily relocated and deployed from different vessels. High-frequency ADCPs are used in towed bodies for several shallow water applications. This towfish system is unique because it employs a 75 kHz RDI Long Ranger ADCP packaged in a large Endeco/YSI type 850 V-Fin. The towfish is 1.3 /spl times/ 1.4 /spl times/ 0.7 meters and weighs 185 kg in air. The towfish, winch and electronics are housed in a customized container that allows for a single point lift for loading and a 2.5 by 3.5 meter footprint on deck. In 2004, the towfish was used operationally in the Gulf of Mexico to survey upper ocean currents. The surveys were successful with only minor setbacks. The system calibrations were found to be very robust and stable. The towfish was deployed at nominally 20 meters depth with tow speeds of 1 to 3 m/s. The ADCP provided continuous along-track profiles with good data down to the instrument's maximum range of 500 meters. Raw data were telemetered to shore for processing and integration with satellite imagery and other in situ observations to provide a real-time synoptic analysis.
本文介绍了拖曳式声学多普勒电流剖面仪(ADCP)系统的开发，该系统用于支持深水洋流的操作监测。拖曳体配置提供了一个安静而稳定的传感器平台，可以很容易地从不同的船只上重新定位和部署。高频adcp用于拖曳体的几种浅水应用。这个拖鱼系统是独一无二的，因为它采用了75 kHz RDI Long Ranger ADCP封装在一个大型Endeco/YSI型850 V-Fin中。拖鱼身长1.3倍/ 1.4倍/ 0.7米，在空中重185公斤。拖鱼、绞车和电子设备被安置在一个定制的集装箱中，允许单点升降装载，甲板占地2.5米乘3.5米。2004年，拖鱼在墨西哥湾被用于调查上层洋流。调查很成功，只有一些小挫折。结果表明，该系统的标定具有良好的鲁棒性和稳定性。拖鱼被部署在20米的深度，拖速为1到3米/秒。ADCP在仪器最大探测距离500米的范围内提供了连续的沿轨迹剖面数据。原始数据被遥测到岸上进行处理，并与卫星图像和其他现场观测相结合，以提供实时天气分析。
{"title":"A towed 75 kHz ADCP for operational deepwater current surveys","authors":"S. Anderson, P. Matthews","doi":"10.1109/CCM.2005.1506332","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506332","url":null,"abstract":"This paper describes the development of a towed acoustic Doppler current profiler (ADCP) system that is used to support operational monitoring of deepwater currents. The towed body configuration provides a quiet and stable sensor platform that can be readily relocated and deployed from different vessels. High-frequency ADCPs are used in towed bodies for several shallow water applications. This towfish system is unique because it employs a 75 kHz RDI Long Ranger ADCP packaged in a large Endeco/YSI type 850 V-Fin. The towfish is 1.3 /spl times/ 1.4 /spl times/ 0.7 meters and weighs 185 kg in air. The towfish, winch and electronics are housed in a customized container that allows for a single point lift for loading and a 2.5 by 3.5 meter footprint on deck. In 2004, the towfish was used operationally in the Gulf of Mexico to survey upper ocean currents. The surveys were successful with only minor setbacks. The system calibrations were found to be very robust and stable. The towfish was deployed at nominally 20 meters depth with tow speeds of 1 to 3 m/s. The ADCP provided continuous along-track profiles with good data down to the instrument's maximum range of 500 meters. Raw data were telemetered to shore for processing and integration with satellite imagery and other in situ observations to provide a real-time synoptic analysis.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133205216","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506329
R. Pinkel
Summary form only given. Multibeam Doppler acoustic sounders have been used for the past 30 years to estimate the three components of fluid velocity as a function of range. Efforts to use the separate beams as a spatial array, exploiting the velocity variability that occurs across the array have been less common. Estimates of Reynolds stresses have proven significant in under-ice and sea floor boundary layers. However, since the pioneering work of Plueddemann (1983), significant stresses have not been observed in the mid-water column. In September-October 2002, an eight-beam 140-160 kHz sonar was deployed at 400 m depth above the Kaena Ridge, west of the Hawaiian island of Oahu. The site is a known generating area for internal tides. One objective of the study was to determine the location of momentum and energy fluxes associated with baroclinic tidal rays. In contrast to the open ocean case, strong quasi-deterministic momentum fluxes are observed over the Kona Ridge, with magnitudes approaching 10/sup -4/ m/sup 2//s/sup 2/. The spatial pattern of the flux suggests that numerous source locations are contributing to the tidal motion in the lower half of the 1100 m-deep water column. In the upper ocean the dominant motion was generated at the northern edge of the ridge crest. Significant stresses are also found in high-frequency lee waves that are found near the sea floor.
{"title":"Acoustic measurements of baroclinic energy and momentum fluxes on the Hawaiian ridge","authors":"R. Pinkel","doi":"10.1109/CCM.2005.1506329","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506329","url":null,"abstract":"Summary form only given. Multibeam Doppler acoustic sounders have been used for the past 30 years to estimate the three components of fluid velocity as a function of range. Efforts to use the separate beams as a spatial array, exploiting the velocity variability that occurs across the array have been less common. Estimates of Reynolds stresses have proven significant in under-ice and sea floor boundary layers. However, since the pioneering work of Plueddemann (1983), significant stresses have not been observed in the mid-water column. In September-October 2002, an eight-beam 140-160 kHz sonar was deployed at 400 m depth above the Kaena Ridge, west of the Hawaiian island of Oahu. The site is a known generating area for internal tides. One objective of the study was to determine the location of momentum and energy fluxes associated with baroclinic tidal rays. In contrast to the open ocean case, strong quasi-deterministic momentum fluxes are observed over the Kona Ridge, with magnitudes approaching 10/sup -4/ m/sup 2//s/sup 2/. The spatial pattern of the flux suggests that numerous source locations are contributing to the tidal motion in the lower half of the 1100 m-deep water column. In the upper ocean the dominant motion was generated at the northern edge of the ridge crest. Significant stresses are also found in high-frequency lee waves that are found near the sea floor.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129930115","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506337
D. Barrick, R. Long, C. Whelan, C. Cooper, J. Abadín
A single SeaSonde HF radar operates on Chevron's Genesis deep-water floating platform in the Gulf of Mexico. The radar's purpose is to provide advance warning of strong loops or eddies that approach the rig. A single radar like this, however, only produces a map of the surface current component toward or away from the radar, called a radial map. A pair of radars with overlapping coverage is required for a 2D total vector map. Despite this limitation, and overcoming the strong antenna pattern distortions caused by the all-steel rig, useful information was obtained to a distance of 90 km. To verify the accuracy and utility, comparisons were done with an ADCP 72 km away. Low-pass filtering was used to remove short-term inertial oscillations, revealing close agreement with the 40-m deep ADCP measurement of the persistent geostrophic loops. Both saw the strong loop features.
{"title":"Advance warning of loop current from single-site SeaSonde on Genesis oil platform in the Gulf of Mexico","authors":"D. Barrick, R. Long, C. Whelan, C. Cooper, J. Abadín","doi":"10.1109/CCM.2005.1506337","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506337","url":null,"abstract":"A single SeaSonde HF radar operates on Chevron's Genesis deep-water floating platform in the Gulf of Mexico. The radar's purpose is to provide advance warning of strong loops or eddies that approach the rig. A single radar like this, however, only produces a map of the surface current component toward or away from the radar, called a radial map. A pair of radars with overlapping coverage is required for a 2D total vector map. Despite this limitation, and overcoming the strong antenna pattern distortions caused by the all-steel rig, useful information was obtained to a distance of 90 km. To verify the accuracy and utility, comparisons were done with an ADCP 72 km away. Low-pass filtering was used to remove short-term inertial oscillations, revealing close agreement with the 40-m deep ADCP measurement of the persistent geostrophic loops. Both saw the strong loop features.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121488300","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506348
J. Parra, A. Alonso-Martirena Tornos, F. B. López, A.P. Castillo
In the year 2004 a system was designed, installed and tested in the River Guadiana coastal plain estuary to provide with real-time net flow data to the Automatic Hydrological Information System, which is the control and monitoring tool of the River Guadiana Water Authority.
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