Quantifying Interocean Fluxes across the Cape Cauldron Hotspot of Eddy Kinetic Energy

量化涡动能大锅角热点的洋间通量

• 批准号: NE/X006468/1
• 负责人: Yueng-Djern Lenn
• 金额: $ 30.97万
• 依托单位: Bangor University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX006468%2F1
• 关键词: Quantifying; Interocean; Fluxes; across; Cape

The Agulhas current carries warm and salty subtropical Indian Ocean water south along the coast of east Africa. Past the Cape of Good Hope, the Agulhas Current overshoots the tip of the African continent and turns back towards the Indian Ocean, throwing lots of eddies into the south Atlantic across the Cape Basin, located southwest of South African coast. These eddies are large rotating vortex rings that interact with each other, sometimes merging, sometimes breaking up into smaller structures. All together this energetic flow field moves northwest across the Cape Basin carrying heat and salt into the fresher south Atlantic. It turns out this influx of heat and salt from the Indian Ocean is really important for the large-scale overturning circulation of our oceans which redistribute heat and salt from basin to basin and across latitudes in a way that helps control our climate. However, measuring the heat and sal flux from the Indian to Atlantic Oceans is not trivial because of the chaotic nature of the flow field. We propose a novel set of measurements that will let us measure the heat and salt fluxes, not just in the really large eddies that can be seen from space (aka Agulhas Rings), but also the smaller eddying features whose contribution to the interocean fluxes is still unaccounted for. These measurements include moorings, ocean turbulence, fine-resolution hydrographic surveys, seagliders and two different types of lagrangian drifters set to measure at the surface and at 2000-m depth. In addition, we will make these measurements at a time that coincides with the science calibration phase of the upcoming SWOT satellite, so as to provide ground-truthed data for that mission.

阿古拉斯洋流带着温暖咸的亚热带印度洋水沿着东非海岸向南流动。经过好望角后，阿古拉斯洋流越过非洲大陆的顶端，转回印度洋，在南非海岸西南方向的开普盆地向南大西洋注入大量漩涡。这些漩涡是相互作用的大型旋转漩涡环，有时合并，有时分裂成更小的结构。这股充满能量的流场一起向西北方向移动，穿过开普盆地，将热量和盐带到更新鲜的南大西洋。事实证明，来自印度洋的热量和盐的涌入对我们海洋的大规模翻转环流非常重要，它将热量和盐从一个盆地重新分配到另一个盆地，跨越纬度，以某种方式帮助控制我们的气候。然而，由于流场的混沌性，测量从印度洋到大西洋的热量和盐通量并非易事。我们提出了一套新的测量方法，使我们不仅可以测量从太空中可以看到的真正大的漩涡（又名阿古拉斯环）的热量和盐的通量，而且还可以测量对海洋间通量贡献尚不清楚的较小的漩涡特征。这些测量包括系泊、海洋湍流、高分辨率水文测量、滑翔机和两种不同类型的拉格朗日漂流仪，分别在海面和2000米深度进行测量。此外，我们将在即将到来的SWOT卫星的科学校准阶段进行这些测量，以便为该任务提供地面真实数据。