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

阿古尔哈斯洋流将温暖而咸的亚热带印度洋水沿着东非海岸向南输送。经过好望角，阿古拉哈斯洋流越过非洲大陆的尖端，转向印度洋，向南大西洋抛出大量涡流，穿过位于南非海岸西南部的开普敦盆地。这些漩涡是相互作用的大型旋转涡环，有时合并，有时分裂成更小的结构。总而言之，这个充满能量的流场向西北方向移动，穿过开普敦盆地，将热量和盐分带入更新鲜的南大西洋。事实证明，这种从印度洋涌入的热量和盐分对我们海洋的大规模颠覆循环非常重要，这种循环将热量和盐分从一个盆地重新分配到另一个盆地，并跨越纬度，帮助控制我们的气候。然而，由于流场的混沌性质，测量从印度洋到大西洋的热通量和盐通量并不是微不足道的。我们提出了一套新的测量方法，使我们能够测量热量和盐通量，不仅是在从太空中可以看到的非常大的涡流(又称阿古拉斯环)中，而且还包括对大洋间通量的贡献仍未得到解释的较小的涡流特征。这些测量包括系泊、海洋湍流、高分辨率水文测量、海滑器和两种不同类型的拉格朗日漂流物，这些漂浮物将在海面和2000米深进行测量。此外，我们将在与即将到来的SWOT卫星的科学校准阶段重合的时间进行这些测量，以便为该任务提供地面真实数据。

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.