The Dynamics behind Subinertial Variability along the Southeast Greenland Coast

格陵兰东南沿岸的海洋环流对全球气候影响具有重要意义。密度高的水越过丹麦海峡基床流入主要的北大西洋盆地，促成了全球环流，将热量分布到全球各地。此外，来自大西洋深层盆地的温水侵入格陵兰海岸的寒冷峡湾，在那里冰川融化，从而导致全球海平面上升，并可能导致区域海洋环流的变化。这些流动的强度随几天的频率而变化，这种变化的原因尚不清楚。该项目的主要目标是确定导致这种变化的根本动力，特别是被称为海岸困住波的海浪所起的作用。这项工作揭示了是什么导致了这种主导的变化模式，这项工作将有助于改进气候预测，并帮助设计该地区的观测监测计划。这项工作的结果将使物理海洋学家和气候科学家受益，因为它将从根本上了解格陵兰运行的关键气候过程的可变性。该项目将支持一名女性早期职业科学家，对一名研究生进行数值海洋模型培训，并通过开发个人研究项目来支持本科生教育。格陵兰东南沿海的中、深层交换流在全球气候系统中起着关键作用。最近对两个这样的交换流动(丹麦海峡深处的溢流和中深度范围的峡湾-陆架交换)的观测证据表明，它们都受亚惯性变化(几天的时间尺度)的支配。此外，我们的初步结果表明，丹麦海峡溢流和格陵兰东南海岸峡湾-陆架交换的变化是相互关联的，这导致我们建议对它们进行整体研究。尽管亚惯性变化在格陵兰东南海岸无处不在，但这些变化的潜在动力尚不清楚。我们假设它们是被困在海岸的海浪的印记，并将结合现有的观测，结合现实的高分辨率数值模式模拟和理想化的过程研究，研究它们的性质、强迫机制和对交换流的影响。这一奖项反映了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。

Oceanic circulation along the southeast Greenland coast has climate impacts of global significance. The spillage of dense water over the Denmark Strait sill into the main North Atlantic basin, contributes to a global circulation that distributes heat over the globe. In addition, warm water from the deep Atlantic basin intrudes into the cold fjords along the Greenland coast, where it melts glaciers and thus contributes to global sea level rise and potentially to changes in the regional ocean circulation. The intensity of these flows varies with a frequency of several days and the cause of this variability is not known. The main goal of this project is to determine the underlying dynamics causing this variability, and specifically the role played by waves known as coastal-trapped waves. Shedding light on what causes this dominant mode of variability, this work will aid to improve climate predictions and help design observational monitoring programs in the region. The results from this work will benefit physical oceanographers and climate scientists, as it will provide a fundamental understanding of variability in key climatic processes operating in Greenland. The project will support a female early career scientist, the training of a graduate student in numerical ocean modeling, and undergraduate student education through the development of individual research projects. Mid-depth and deep exchange flows along the southeast Greenland coast play a key role in the global climate system. Recent observational evidence of two such exchange flows (the deep Denmark Strait Overflow and fjord-shelf exchange in the mid-depth range) suggests that they are both governed by sub-inertial variability (time scale of several days). Furthermore, our preliminary results suggest that variability in the Denmark Strait Overflow and fjord-shelf exchange along the southeast Greenland coast are connected, which leads us to propose that they should be studied holistically. Despite sub-inertial variations being ubiquitous along the southeast Greenland coast, the underlying dynamics of these variations are not clear. We hypothesize that they are the imprint of coastal-trapped waves, and will study their properties, forcing mechanisms and impact on exchange flows using a combination of realistic high-resolution numerical model simulations and idealized process studies, synthesized with existing observations.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.