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

合作研究：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

• 批准号: 0000734
• 负责人: P. Michael Kosro
• 金额: $ 89.09万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0000734&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利用远程高频雷达绘制俄勒冈州布兰科角外上升生态系统中尺度喷流和涡流的演变情况PI将利用海洋观测系统中的一种新能力，能够对整个沿海上升流系统的表面流，包括相关的喷流和涡流，进行空间和时间绘图。 这种能力包括使用沿海岸线沿着部署的高频（BY）雷达仪器。 这些测量的新方面是，它将使用调谐到B17频段低频端（约5 MHz）的系统，而不是现在常用的在12 MHz至25 MHz之间运行的系统。 射程能力的差异是戏剧性的。标准系统通常测量距离海岸30伊恩至50公里，距离分辨率约为2公里。这里提供的新数据表明，这些相同的仪器在5 MHz下工作，能够测量距离海岸200公里，距离分辨率约为6伊恩。这一范围已被证明是通过结合非常有效的发射机技术包含在商业上可获得的CODAR/SeaSonde与调谐发射天线生产的密歇根大学！的多频海岸雷达（MCR）。我们建议使用一个三站阵列的这些雷达，以获得一个为期三年的时间序列的每日地图的中尺度表面流的面积约350公里× 180公里的范围内，中心的布兰科，俄勒冈州。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现场生物物理采样的计划重点。最近的研究表明，在上升流季节，布兰科角往往是物理状态的分离点，在那里，北部被陆架困住的沿岸急流与海岸分离，流向近海，在更南部留下一个涡流丰富的状态（Smith，1995年; Barth和Smith，1998年）。 GLOBEC NEP的一个核心假设是，中尺度环流的空间和时间变化主导着对沿海地区浮游动物生产、分布、保留和损失的物理强迫。 雷达导出的地图将用于研究涡旋和喷流的特性，以及粒子在表面层中的路径。 PI将检查涡流生成的实例，以确定它们的形成频率，它们是否优先发生在特定位置，以响应特定的风强迫事件，在冬季和夏季。 将检查强度和尺度的传播特性和时空变化。预计雷达将很好地捕捉到涡喷流和涡涡相互作用，雷达可以在多云的天空中进行观测。将通过季节确定喷流核心位置和速度的统计数据，并将检查分离事件和风强迫之间的关系。 中尺度海流的时间序列图将为建模者提供测试案例。 它们还将补充卫星对表面温度、海洋颜色和表面高度的遥感。