Local and Remote Influences on the Heat Content of the Labrador Sea: An Adjoint Sensitivity Study
Local and Remote Influences on the Heat Content of the Labrador Sea: An Adjoint Sensitivity Study
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DOI：
10.1002/2018jc013774
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发表时间：
2018-04
影响因子：
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通讯作者：
Daniel C. Jones;G. Forget;B. Sinha;S. Josey;E. Boland;A. Meijers;E. Shuckburgh
中科院分区：
文献类型：
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作者：
Daniel C. Jones;G. Forget;B. Sinha;S. Josey;E. Boland;A. Meijers;E. Shuckburgh
拉布拉多海是地球上少数几个内部海洋可以通过强烈的局部冬季对流直接与大气交换热量的地区之一，这可能会影响北大西洋气候和全球表面变暖的状况。利用观测约束的海洋伴随模式，我们发现拉布拉多海年平均热含量对温度/盐度变化敏感(1)潜在水源路径（如亚极环流、北大西洋洋流、墨西哥湾流）和(2)西非和欧洲大陆架，这些都不是拉布拉多海的重要水源区域。西非沿海/大陆架调整机制可能由沿大陆架风应力的变化激发，包括沿海岸波导向格陵兰岛传播的压力异常，改变北大西洋大陆架间压力梯度和改变拉布拉多海的热辐合。我们还发现，非局部（在空间和时间上）热通量（例如在Irminger海，冰岛以南的海域）可以对拉布拉多海的热含量产生强烈影响。了解和预测拉布拉多海的状况及其对北大西洋气候和全球表面变暖的潜在影响，将需要监测伊尔明格海、亚极地环流、西非和欧洲大陆架/海岸系统等偏远地区的海洋和大气特性。
The Labrador Sea is one of the few regions on the planet where the interior ocean can exchange heat directly with the atmosphere via strong, localized, wintertime convection, with possible implications for the state of North Atlantic climate and global surface warming. Using an observationally-constrained ocean adjoint model, we find that annual mean Labrador Sea heat content is sensitive to temperature/salinity changes (1) along potential source water pathways (e.g. the subpolar gyre, the North Atlantic Current, the Gulf Stream) and (2) along the West African and European shelves, which are not significant source water regions for the Labrador Sea. The West African coastal/shelf adjustment mechanism, which may be excited by changes in along-shelf wind stress, involves pressure anomalies that propagate along a coastal waveguide towards Greenland, changing the across-shelf pressure gradient in the North Atlantic and altering heat convergence in the Labrador Sea. We also find that non-local (in space and time) heat fluxes (e.g. in the Irminger Sea, the seas south of Iceland) can have a strong impact on Labrador Sea heat content. Understanding and predicting the state of the Labrador Sea and its potential impacts on North Atlantic climate and global surface warming will require monitoring of oceanic and atmospheric properties at remote sites in the Irminger Sea, the subpolar gyre, and along the West African and European shelf/coast system, among others.