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，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、盐分和淡水。该项目力求使用系泊仪器来量化南极绕极洋流最南端进入南极洲周围水域的热量和盐分交换情况，在该区域，绕极洋流锋面非常接近，中尺度涡旋活动特别强烈。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增强一个已经得到资助的韩国项目。韩国将向韩国提供部署和回收这些设备所需的船只时间。来自系泊仪器的数据将通过弹出式数据穿梭每年通过遥测收集，使仪器在海底不受干扰。这些观测将被用来改进和验证全球对热通量的代理估计。了解热量收支的全球背景将由高分辨率数值模式指导。该项目的目标是测量和诊断ACC东南印度洋脊背风处的海洋涡热通量。这一位置是主要的ACC涡流热点之一，也是ACC三个锋面在遇到脊状复合体时紧密汇聚在一起的区域。在这个热点，平均通量和涡流很可能共同穿过ACC的广度。重点放在最南端的ACC锋面上，那里现有的现场测量很少，ACC来源的热量影响南大洋、罗斯和韦德尔环流，并最终影响南极边缘。高分辨率的数值模型将为建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代理估计。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.