Deep oceanic convection: the outsized role of small-scale processes

深海对流：小尺度过程的巨大作用

• 批准号: 2875472
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2875472
• 关键词: Deep; oceanic; convection; outsized; role

Deep-water formation (convection) at high-latitudes, and more specifically in the Labrador Sea in the subpolar North Atlantic, forms a key part of the large-scale ocean circulation. This enables the exchange of gases between the atmosphere and deep ocean, and thus contributes to the global oceanic sequestration of carbon. In a warming climate, added volumes of freshwater into the Labrador Sea, associated with the increased melting of Greenland ice sheet and of Arctic sea-ice, are expected to reduce or shutdown convection, which would reduce the ocean's potential to mitigate climate change. In the western Labrador Sea, freshwater is exchanged between the basin boundary and interior due in part to small-scale (submesoscale <10 km) processes. Recent evidence revealed that eddies, sea-ice, and atmospheric (wind and buoyancy) forcing can all influence these small-scale processes. However, high-resolution observations in the Labrador Sea are scarce due to extreme winter conditions. Thus, the mechanisms responsible for the cessation of convection remain poorly understood and are largely neglected by climate models.This project will use multi-year measurements from autonomous platforms (gliders) to investigate the role of small-scale processes on the cessation of convection. The student will determine the competing effects of eddies, atmospheric forcing, and sea-ice on the lifecycle of convection.

高纬度地区的深水形成（对流），更具体地说，是在北大西洋副极地的拉布拉多海，形成了大规模海洋环流的一个关键部分。这使得大气和深海之间的气体交换成为可能，从而有助于全球海洋固碳。在气候变暖的情况下，随着格陵兰冰盖和北极海冰的融化，流入拉布拉多海的淡水量增加，预计会减少或关闭对流，这将降低海洋减缓气候变化的潜力。在拉布拉多海西部，淡水在盆地边界和内部之间交换，部分原因是小尺度（中尺度以下<10公里）过程。最近的证据表明，涡旋、海冰和大气（风和浮力）作用力都可以影响这些小尺度过程。然而，由于极端的冬季条件，拉布拉多海的高分辨率观测很少。因此，对造成对流停止的机制仍然知之甚少，气候模式基本上忽略了这一点，本项目将利用自主平台（滑翔机）的多年测量数据，调查小尺度过程对对流停止的作用。学生将确定对流生命周期中涡旋、大气强迫和海冰的竞争效应。