Collaborative Research: Eddy fluxes across the Southern Antarctic Circumpolar Current Front near Southeast Indian Ridge

海洋环流通过全球海洋输送热量和碳，并将热量和碳储存在深海中，从而调节地球气候。在南大洋，地球上最强的洋流，南极绕极流（ACC），在海洋盆地之间分配热量、盐和淡水。该项目试图使用系缆仪器来量化南极环极流（ACC）最南端进入南极洲周围水域的热量和盐的交换，该区域靠近ACC锋，中尺度涡旋活动特别高。该项目协调美国和韩国的观测和建模组件。仪器和建模将扩大和加强已经获得资助的韩国项目。部署和回收仪器所需的船舶时间将由韩国提供。每年将通过弹出式数据穿梭器通过遥测技术收集系泊仪器的数据，使仪器在海底不受干扰。这些观测结果将用于改进和验证热通量的全球代理估计。了解热收支的全球背景将以高分辨率数值模型为指导。本项目的目的是测量和诊断印度洋东南脊背风区海洋涡旋热通量。这个位置是主要的ACC涡旋通量热点之一，也是三个ACC锋面在遇到脊复合体时紧密汇聚在一起的区域。在这个热点，平均通量和涡旋通量很可能合谋穿过ACC的宽度。研究的重点是南极寒带锋面的最南端，那里现有的原位测量数据很少，而南极寒带源的热量影响着南大洋的罗斯环流和威德尔环流，最终影响着南极边缘。高分辨率数值模式将为拟议的观测提供更大的背景，并将寻求使用现有全球观测系统的替代估计。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Ocean circulation regulates the Earth’s climate by transporting heat and carbon through the global ocean and storing heat and carbon in the deep ocean. In the Southern Ocean, the strongest current on earth, the Antarctic Circumpolar Current (ACC), distributes heat, salt, and freshwater between ocean basins. This project seeks to use moored instrumentation to quantify the exchange of heat and salt across the southernmost portion of the Antarctic Circumpolar Current (ACC) into the waters around Antarctica in a sector where the ACC fronts are in close proximity and mesoscale eddy activity is particularly high. The project coordinates US and Korean observational and modeling components. The instrumentation and modeling will expand and augment an already funded Korean program. Ship time needed to deploy and recover the instruments will be provided South Korea. Data from the moored instruments will be collected annually by telemetry via pop-up data shuttles, leaving the instruments undisturbed on the seafloor. The observations will be used to refine and verify global proxy estimates of heat fluxes. Global context for understanding the heat budget will be guided by a high-resolution numerical model.The goal of this project is to measure and diagnose ocean eddy heat fluxes in the lee of Southeast Indian Ridge in the ACC. This location stands out as one of the major ACC eddy flux hot spots and as a region where the three ACC fronts converge closely together as they encounter the ridge complex. At this hot spot, mean and eddy fluxes likely conspire to cross the breadth the ACC. The focus is upon the southernmost ACC front where existing in situ measurements are sparse and where ACC-sourced heat influences the Southern Ocean Ross and Weddell gyres and ultimately the Antarctic margin. A high-resolution numerical model will provide the larger context for proposed observations, and proxy estimates will be sought that use the existing global observing system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.