The Impact of Ocean Margin Processes in the Labrador Sea on the Atlantic Meridional Overturning Circulation

拉布拉多海是世界海洋中少数几个深水形成的地方之一。这些水从拉布拉多海输出，成为经向翻转环流向南分支的一部分。以前的观测工作主要集中在拉布拉多海内部深层对流的作用上。来自观测和数值海洋模式的最新证据明确表明，海洋边界附近的过程可能与拉布拉多海水域的欧拉式下降和新转化水域的快速输出最为相关。我们建议将拉布拉多海西缘的系泊观测与高分辨率数值模式模拟相结合，以了解这两个过程对北大西洋次极经向翻转环流的作用。具体来说，我们想要测试(i)沿拉布拉多海边缘是否（以及在哪里）发生了下行，（ii）下行如何与对流和涡旋活动的季节性演变相关，（iii）拉布拉多海西部边缘附近新转化的快速水如何输出，以及（iv）这两个过程（下行，快速输出）如何影响大西洋经向翻转环流的时间变异性。

The Labrador Sea is one of the few places in the world ocean, where deep water formation takes place. This water is exported from the Labrador Sea to become part of the southward branch of the meridional overturning circulation. Previous observational work has largely focused on the role of deep convection in the interior of the Labrador Sea. Recent evidence from observations and numerical ocean models specifically indicate that processes near the ocean boundaries might be most relevant for both Eulerian downwelling of waters in the Labrador Sea and the fast export of newly transformed waters. We propose to analyze mooring based observations at the western margin of the Labrador Sea together with high resolution numerical model simulations to understand the role both processes play for the meridional overturning circulation in the subpolar North Atlantic. Specifically, we want to test (i) if (and where) downwelling occurs along the margins of the Labrador Sea, (ii) how downwelling relates to the seasonal evolution of convection and eddy activity, (iii) how fast waters newly transformed near the western margin of the Labrador Sea are exported, and (iv) how the two processes (downwelling, fast export) affect the temporal variability of the Atlantic meridional overturning circulation.