The Observed Seasonal Cycle of Submesoscale Processes in the Antarctic Marginal Ice Zone
The Observed Seasonal Cycle of Submesoscale Processes in the Antarctic Marginal Ice Zone
复制标题
南极边缘冰带次中尺度过程的观测季节周期
DOI：
10.1029/2019jc015587
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发表时间：
2020-06-01
影响因子：
3.6
通讯作者：
Swart, S.
中科院分区：
文献类型：
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作者：
Biddle, L. C.;Swart, S.
亚尺度流是上层海洋中发生在几公里尺度的能量过程。这些现象对气候很重要，因为它们可以强烈影响地表和深海之间的热量、碳和生物地球化学特性的垂直运动。由于缺乏观测，人们对南极边缘冰区（MIZ）和海冰下的它们的存在和大小知之甚少。我们提供了 2008 年南半球夏末至春季的威德尔海东部标记的南象海豹水文数据，以评估南极 MIZ 次中尺度过程的强度和季节性。我们考虑海冰覆盖、海洋应力变化和混合层深度之间的联系以及它们如何影响亚中尺度通量。我们发现，亚尺度流（240 Wm(-2)）的等效热通量大小存在很强的季节性周期，活动高峰出现在仲冬。海冰覆盖变化增加的时期（可能与铅有关）也与仲冬亚中尺度通量的重新分层有关。这些发现对于理解上层海洋层化的幅度和变化具有重要意义，因此强调了在全球气候模型中开发南极 MIZ 次中尺度过程参数化的重要性。
Submesoscale flows are energetic processes in the upper ocean that occur at scales of a few kilometers. These phenomena are important to climate because they can strongly impact vertical motions of heat, carbon, and biogeochemical properties between the surface and deep ocean. Their presence and magnitude are poorly understood in the Antarctic marginal ice zone (MIZ) and under sea ice due to a lack of observations. We present tagged southern elephant seal hydrographic data from the eastern Weddell Sea, over the austral late summer to spring in 2008, to assess the magnitude and seasonality of submesoscale processes in the Antarctic MIZ. We consider the linkages between sea ice cover, ocean stress variability, and mixed layer depth and how these influence the submesoscale fluxes. We find that there is a strong seasonal cycle in the magnitude of the equivalent heat flux from submesoscale flows (240 Wm(-2)), with peak activity occurring in midwinter. Periods of increased variability in sea ice cover, likely associated with leads, are also linked to restratification through submesoscale fluxes in midwinter. These findings have implications for understanding the magnitude and variability of upper ocean stratification and therefore highlights the importance of developing parameterizations for submesoscale processes in the Antarctic MIZ within global climate models.