DOI: 10.1007/s00382-015-2534-0
Scopus记录号: 2-s2.0-84947488126
论文题名: A process-based analysis of ocean heat uptake in an AOGCM with an eddy-permitting ocean component
作者: Kuhlbrodt T. ; Gregory J.M. ; Shaffrey L.C.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 45, 期: 2017-11-12 起始页码: 3205
结束页码: 3226
语种: 英语
英文关键词: Advection–diffusion balance
; Antarctic Circumpolar Current
; Eddy-permitting ocean model
; Isopycnal diffusion
; Ocean heat uptake
; Process-based analysis
; Southern Ocean
英文摘要: 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. © 2015, Springer-Verlag Berlin Heidelberg. 资助项目: ERC, National Centre for Atmospheric Science
; NCAS, National Centre for Atmospheric Science
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53915
Appears in Collections: 过去全球变化的重建
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作者单位: NCAS, Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading, United Kingdom; Met Office Hadley Centre, Exeter, United Kingdom
Recommended Citation:
Kuhlbrodt T.,Gregory J.M.,Shaffrey L.C.. A process-based analysis of ocean heat uptake in an AOGCM with an eddy-permitting ocean component[J]. Climate Dynamics,2015-01-01,45(2017-11-12)