Collaborative Research: GLOBEC: Mapping the Evolution of Mesoscale Jets and Eddies in the Upwelling Ecosystem off Cape Blanco, OR Using Long Range, High Frequency Radar

合作研究：GLOBEC：使用远程高频雷达绘制布兰科角上升流生态系统中中尺度喷流和涡流的演化图

• 批准号: 0000898
• 负责人: Jeffrey Paduan
• 金额: $ 32.69万
• 依托单位: Naval Postgraduate School
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2006-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0000898&HistoricalAwards=false
• 关键词: Collaborative; Research; GLOBEC; Mapping; Evolution

GLOBEC Mapping the Evolution of Mesoscale Jets and Eddies in the UpwellingEcosystem off Cape Blanco, Oregon, using Long-Range High-Frequency RadarThe PIs will exploit a new capability in ocean observing systems that will enable the space and time mapping of surface currents over an entire coastal upwelling system, including associated jets and eddies. The capability involves the use of High Frequency (BY) radar instruments deployed along the shoreline. The new aspect of these measurements is that it will use systems tuned to the low-frequency end of the B17 band, around 5 MHz, rather than the now commonly used systems that operate between 12 MHz and 25 MHz. The difference in range capability is dramatic. The standard systems typically measure 30 Ian to 50 km from shore with range resolution on the order of 2 km. New data presented here shows that these same instruments operating at 5 MHz are capable of measuring 200 km from shore with range resolution on the order of 6 Ian. This range has been proven by combining the very efficient transmitter technology contained in the commercially available CODAR/SeaSonde with a tuned transmit antenna produced for the University of Michigan!s Multifrequency Coastal Radar (MCR).We propose to use a three-site array of these radars to obtain a three-year time-series of daily maps of mesoscale surface currents over an area approximately 350 km x 180 km in extent, centered on Cape Blanco, Oregon. This region is the planned focus of intense in-situ biophysical sampling over a range of space and time scales during the GLOBEC Northeast Pacific (NEP) program. Recent studies show that Cape Blanco is often a separation point in physical regimes during the upwelling season, where a shelf-trapped alongshore current jet to the north separates from the coast and flows offshore, leaving an eddy-rich regime further south (Smith, 1995; Barth and Smith, 1998). A core hypothesis of GLOBEC NEP is that spatial and temporal variability in mesoscale circulation dominates the physical forcing on zooplankton production, distribution, retention and loss in coastal regions. The radar-derived maps will be used to study the properties of the eddies and jets, and the pathways of particles in the surface layer. The PIs will examine the instances of eddy generation, to determine their frequency of formation, whether they occur preferentially at particular locations, in response to particular wind-forcing events, in winter as well as summer. The propagation characteristics and time-space variations in intensity and scale will be examined. Eddy-jet and eddy-eddy interactions are expected to be well captured by the radar, which can make observations through periods of cloudy skies. Statistics of jet core location and speed will be determined through the seasons, and the relationship between separation events and wind forcing will be examined. Time-series maps of mesoscale currents will provide test cases for modelers. They will also complement satellite remote sensing of surface temperature, ocean color, and surface height.

GLOBEC 使用远程高频雷达绘制俄勒冈州布兰科角上升流生态系统中中尺度喷流和涡流的演化图 PI 将利用海洋观测系统的一项新功能，对整个沿海上升流系统（包括相关喷流和涡流）的表面流进行空间和时间测绘。 该功能涉及使用沿海岸线部署的高频（BY）雷达仪器。 这些测量的新特点是，它将使用调谐到 B17 频段低频端（5 MHz 左右）的系统，而不是现在常用的在 12 MHz 到 25 MHz 之间运行的系统。 范围能力的差异是巨大的。标准系统通常测量距离海岸 30 Ian 至 50 公里的距离，距离分辨率约为 2 公里。这里提供的新数据表明，这些以 5 MHz 运行的相同仪器能够测量距离海岸 200 公里的距离，距离分辨率约为 6 Ian。通过将市售 CODAR/SeaSonde 中包含的非常高效的发射机技术与为密歇根大学的多频海岸雷达 (MCR) 生产的调谐发射天线相结合，该范围已得到证明。我们建议使用这些雷达的三站点阵列来获取大约 350 km x 180 km 区域内中尺度表面电流的三年时间序列每日地图。 范围，以俄勒冈州布兰科角为中心。该区域是 GLOBEC 东北太平洋 (NEP) 计划期间在一系列空间和时间尺度上进行密集原位生物物理采样的计划重点。最近的研究表明，布兰科角通常是上升流季节物理状况中的一个分离点，北边的陆架捕获的近岸急流与海岸分离并流向近海，在更南的地方留下一个富含涡流的状况（Smith，1995；Barth和Smith，1998）。 GLOBEC NEP 的核心假设是，中尺度环流的时空变化主导着沿海地区浮游动物生产、分布、保留和损失的物理强迫。 雷达生成的地图将用于研究涡流和射流的特性以及表层颗粒的路径。 PI将检查涡流产生的情况，以确定它们形成的频率，它们是否优先发生在特定位置，以响应冬季和夏季的特定风力事件。 将检查传播特性以及强度和规模的时空变化。预计雷达能够很好地捕获涡流-喷射和涡流-涡流相互作用，从而可以在多云的天空期间进行观测。喷气核心位置和速度的统计数据将通过季节确定，并且分离事件和风力之间的关系将被检查。 中尺度电流的时间序列图将为建模者提供测试用例。 它们还将补充地表温度、海洋颜色和地表高度的卫星遥感。