A process-based analysis of ocean heat uptake in an AOGCM with an eddy-permitting ocean component
A process-based analysis of ocean heat uptake in an AOGCM with an eddy-permitting ocean component
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具有允许涡流海洋分量的 AOGCM 中海洋吸热的基于过程的分析
DOI：
10.1007/s00382-015-2534-0
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发表时间：
2015
期刊：
影响因子：
4.6
通讯作者：
L. Shaffrey
中科院分区：
文献类型：
--
作者：
T. Kuhlbrodt;J. Gregory;J. Gregory;L. Shaffrey
气候系统中储存的人为增加的热量约有90%在海洋中。因此，了解海洋热吸收的细节是相关的。在这里，我们提出了一个详细的，基于过程的分析海洋热吸收（OHU）过程中的HiGEM1.2，一个大气-海洋环流模式与涡旋允许的海洋成分的1/3°分辨率。类似于其他各种模式，HiGEM 1.2表明，全球热收支是由向下平流的热量向上等密度扩散补偿为主。只有在热带海洋上层，我们才能发现向下的穿透扩散和向上的热量平流之间的经典平衡。热量的向上等密度线扩散主要位于南大洋，因此南大洋主导着全球热量收支。我们比较的响应4xCO 2强迫和增强的风应力强迫在南大洋。这突出了区域过程对全球海洋热量吸收的重要性。这些主要是高纬度地区的地表通量和对流，以及南大洋中纬度地区的平流。扩散的变化不太重要。与CMIP 5模式一致，HiGEM 1.2在4xCO 2运行中显示了中纬度南大洋的一条强OHU带，主要是平流。相比之下，在高纬度的南大洋地区，对流的抑制导致了OHU。在增强的风应力运行中，对流在南半球高纬度地区得到加强，导致热量损失，而南半球中纬度地区的OHU的大小与4xCO 2结果非常相似。值得注意的是，在增强的风应力运行中，只有非常小的全球OHU。风应力强迫只是导致热量的重新分布。我们将南部高纬度地区的海洋变化与气候变化对南极绕极流（ACC）的影响联系起来。它在4xCO 2运行中减弱，在风应力运行中加强。减弱是由于缩小的ACC，造成的威德尔环流的扩张，和平坦的等密度线，这是由风应力强迫和降水增加的组合解释。
About 90 % of the anthropogenic increase in heat stored in the climate system is found in the oceans. Therefore it is relevant to understand the details of ocean heat uptake. Here we present a detailed, process-based analysis of ocean heat uptake (OHU) processes in HiGEM1.2, an atmosphere–ocean general circulation model with an eddy-permitting ocean component of 1/3° resolution. Similarly to various other models, HiGEM1.2 shows that the global heat budget is dominated by a downward advection of heat compensated by upward isopycnal diffusion. Only in the upper tropical ocean do we find the classical balance between downward diapycnal diffusion and upward advection of heat. The upward isopycnal diffusion of heat is located mostly in the Southern Ocean, which thus dominates the global heat budget. We compare the responses to a 4xCO2 forcing and an enhancement of the windstress forcing in the Southern Ocean. This highlights the importance of regional processes for the global ocean heat uptake. These are mainly surface fluxes and convection in the high latitudes, and advection in the Southern Ocean mid-latitudes. Changes in diffusion are less important. In line with the CMIP5 models, HiGEM1.2 shows a band of strong OHU in the mid-latitude Southern Ocean in the 4xCO2 run, which is mostly advective. By contrast, in the high-latitude Southern Ocean regions it is the suppression of convection that leads to OHU. In the enhanced windstress run, convection is strengthened at high Southern latitudes, leading to heat loss, while the magnitude of the OHU in the Southern mid-latitudes is very similar to the 4xCO2 results. Remarkably, there is only very small global OHU in the enhanced windstress run. The wind stress forcing just leads to a redistribution of heat. We relate the ocean changes at high Southern latitudes to the effect of climate change on the Antarctic Circumpolar Current (ACC). It weakens in the 4xCO2 run and strengthens in the wind stress run. The weakening is due to a narrowing of the ACC, caused by an expansion of the Weddell Gyre, and a flattening of the isopycnals, which are explained by a combination of the wind stress forcing and increased precipitation.
影响因子：
4.6
作者：
P. Good;William Ingram;William Ingram;F. H. Lambert;J. Lowe;J. M. Gregory;J. M. Gregory;M. Webb;M. Ringer;P. Wu
通讯作者：
P. Good;William Ingram;William Ingram;F. H. Lambert;J. Lowe;J. M. Gregory;J. M. Gregory;M. Webb;M. Ringer;P. Wu
影响因子：
3.6
作者：
Meijers, A. J. S.;Shuckburgh, E.;Wang, Z.
通讯作者：
Wang, Z.