Collaborative Research: Characteristics and Origins of Eddies beneath Antarctic Sea Ice

合作研究：南极海冰下涡流的特征和起源

• 批准号: 2220969
• 负责人: Georgy Manucharyan
• 金额: $ 17.58万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220969&HistoricalAwards=false
• 关键词: Collaborative; Research; Characteristics; Origins; Eddies

The world ocean is continuously in motion, and a large fraction of this motion takes the form of "eddies", nearly-horizontal swirls of water spanning tens to hundreds of kilometers. These eddies affect the ocean by mediating large-scale currents, redistributing heat, and supplying nutrients to oceanic ecosystems. Consequently, the ocean science community has historically invested substantial effort in characterizing the properties and impact of these eddies. In polar regions, the sea ice cover inhibits observations of eddies, and the relatively small horizontal size of the eddies hampers computer simulations of their behavior. Nonetheless, previous studies have identified an active population of eddies beneath the Arctic sea ice and shown that these eddies play a crucial role in maintaining the large-scale circulation in the Arctic seas. However, there has been no systematic attempt to study such eddies under Antarctic sea ice, leaving a significant gap in our understanding of eddies and their contribution to the large-scale ocean circulation around Antarctica.The proposed research combines multiple approaches to improve our understanding of the eddy dynamics. Statistical characterizations of the sub-sea ice eddy field will be derived using hydrographic observations under Antarctic sea ice from Argo floats and instrumented seals. High-resolution global ocean and sea ice models will be used to track the simulated eddies back to their formation sites to identify the eddy formation mechanisms. Theoretical calculations will be conducted to test the hypothesis that the eddies primarily originate from hydrodynamic instabilities associated with subsurface density gradients. These theoretical, modeling, and data analysis approaches will be combined to estimate the eddies' contribution to lateral tracer transports and their impact on mean circulations of the near-Antarctic ocean. The proposed work will facilitate future scientific endeavors by providing publicly-available databases of detected eddy properties. This project will support the research of several junior scientists: an undergraduate student, two graduate students, and an early-career faculty member.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.

世界海洋一直在运动，这一运动的很大一部分采用了“涡流”的形式，几乎是水的水，跨越数十公里。这些涡流通过介导大规模电流，重新分布热量并为海洋生态系统供应营养来影响海洋。因此，海洋科学界历来投入了大量努力来表征这些涡流的财产和影响。在极地区域，海冰覆盖抑制了涡流的观察结果，并且涡流的水平尺寸相对较小，缩小了其行为的计算机模拟。尽管如此，先前的研究已经确定了北极海冰下方的涡流人群，并表明这些涡流在维持北极海中的大规模循环方面起着至关重要的作用。然而，没有系统地尝试研究南极海冰下的这种涡流，在我们对涡流的理解及其对南极围绕大规模海洋循环的贡献方面留下了很大的差距。拟议的研究结合了多种方法来提高我们对涡流动态的理解。海底冰场的统计表征将使用来自Argo浮子和仪器密封的南极海冰下的水文观测来得出。高分辨率的全球海洋和海冰模型将用于跟踪模拟的涡流回到其地层地点，以识别涡层。将进行理论计算以检验以下假设：涡流主要源于与地下密度梯度相关的流体动力学不稳定性。这些理论，建模和数据分析方法将合并，以估计涡流对侧向示踪剂运输的贡献及其对近十次海洋平均循环的影响。拟议的工作将通过提供可检测到的涡流的公开数据库来促进未来的科学努力。该项目将支持几位初级科学家的研究：一名本科生，两名研究生和一个早期职业教职员工。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子的评估来评估的支持，并具有更广泛的影响。