Ocean Heat Storage in Response to Changing Ocean Circulation Processes
Ocean Heat Storage in Response to Changing Ocean Circulation Processes
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DOI：
10.1175/jcli-d-19-1016.1
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发表时间：
2020-11-01
影响因子：
4.9
通讯作者：
Savita, A.
中科院分区：
文献类型：
--
作者：
Dias, Fabio Boeira;Fiedler, R.;Savita, A.
由于局部增加的热量（“增加”）和由于热传输的变化（“再分布”），海洋热储存在海洋中进行了量化2xCO 2模拟。虽然增加的热量储存在全球占主导地位，但再分配也做出了重要的区域贡献，特别是在热带地区。热量再分布主要由环流变化决定，概括为超余流输送，垂直混合变化的影响很小。虽然以前的研究强调了高纬度地区的再分配反馈的贡献，但这项研究表明，热量的再分配也占低纬度地区热量储存的65%和中纬度（35度-50度）南大洋的25%。热带变暖是由于层结增加和副热带环流向赤道输送热量之间的相互作用，副热带环流将热量从副热带重新分配到低纬度地区。大西洋的格局是显着不同于其他盆地，导致较大的盆地平均热储存。增加的热储存在整个中纬度南大洋均匀分布，并占总储存量的主导地位。然而，再分配储存在南极绕极流以北的大西洋和印度部分的热量，对45度S的热量储存峰值有重要贡献。南大洋的再分布是由于副热带锋的热辐合增强和响应于表面热量、淡水和动量通量扰动的层结减少造成的。这些结果突出表明，海洋热储存的分布既反映了被动的热量吸收，也反映了海洋环流过程变化引起的主动的热量再分配。因此，必须更好地了解重新分布的热输运，以准确预测海洋热吸收效率，海洋热储存和热空间海平面的变化。
Ocean heat storage due to local addition of heat ("added'') and due to changes in heat transport ("redistributed'') were quantified in ocean-only 2xCO2 simulations. While added heat storage dominates globally, redistributionmakes important regional contributions, especially in the tropics. Heat redistribution is dominated by circulation changes, summarized by the super-residual transport, with only minor effects from changes in vertical mixing. While previous studies emphasized the contribution of redistribution feedback at high latitudes, this study shows that redistribution of heat also accounts for 65% of heat storage at low latitudes and 25% in the midlatitude (35 degrees-50 degrees S) Southern Ocean. Tropical warming results from the interplay between increased stratification and equatorward heat transport by the subtropical gyres, which redistributes heat from the subtropics to lower latitudes. The Atlantic pattern is remarkably distinct from other basins, resulting in larger basin-average heat storage. Added heat storage is evenly distributed throughout midlatitude Southern Ocean and dominates the total storage. However, redistribution stores heat north of the Antarctic Circumpolar Current in the Atlantic and Indian sectors, having an important contribution to the peak of heat storage at 45 degrees S. Southern Ocean redistribution results from intensified heat convergence in the subtropical front and reduced stratification in response to surface heat, freshwater, and momentum flux perturbations. These results highlight that the distribution of ocean heat storage reflects both passive uptake of heat and active redistribution of heat by changes in ocean circulation processes. The redistributed heat transportmust therefore be better understood for accurate projection of changes in ocean heat uptake efficiency, ocean heat storage, and thermosteric sea level.