DOI: 10.1007/s00382-014-2433-9
Scopus记录号: 2-s2.0-84943815198
论文题名: Global radiative adjustment after a collapse of the Atlantic meridional overturning circulation
作者: Drijfhout S.S.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 45, 期: 2017-07-08 起始页码: 1789
结束页码: 1799
语种: 英语
英文关键词: Abrupt climate change
; Atmospheric feedbacks
; Bipolar seesaw
; Meridional overturning circulation
; Thermohaline circulation
英文摘要: The transient climate response to a collapse of the Atlantic meridional overturning circulation (AMOC) is analysed from the difference between two ensembles of climate model simulations with ECHAM5/MPI-OM, one with hosing and the other without hosing. The primary effect of the collapse is to redistribute heat over the two hemispheres. However, Northern Hemisphere sea ice increase in response to the AMOC collapse induces a hemisphere-wide cooling, amplified by atmospheric feedbacks, in particular water vapour. The Southern Hemisphere warming is governed by slower processes. After 25 years the global cooling peaks. Thereafter, the response is characterised by a gradual readjustment of global mean temperature. During the AMOC collapse a downward radiation anomaly arises at the top of the atmosphere (TOA), heating the earth’s surface. The net downward radiation anomaly at TOA arises from reduced longwave emission by the atmosphere, overcompensating the increased net upward anomalies in shortwave and longwave radiation at the surface. This radiation anomaly is associated with net ocean heat uptake: cooling of the overlying atmosphere results from reduced ocean heat release through the increase of sea-ice cover in the North Atlantic. The change in energy flow arises from the reduction in latent and sensible heat flux, which dominate the surface radiation budget. Similar experiments with a climate model of intermediate complexity reveal a stronger shortwave response that acts to reduce the net downward radiation anomaly at TOA. The net shortwave and longwave radiation anomalies at TOA always decrease during the first 100 years after the AMOC collapse, but in the intermediate complexity model this is associated with a sign change after 90 years when the net radiation anomaly at TOA becomes upward, accompanied by net ocean heat loss. After several hundred years the longwave and shortwave anomalies increase again, while the net residual at TOA remains small. This radiative adjustment is associated with the transition to a colder climate. © 2014, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53991
Appears in Collections: 过去全球变化的重建
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作者单位: Royal Netherlands Meteorological Institute (KNMI), PO Box 210, De Bilt, Netherlands; National Oceanography Centre, University of Southampton, Southampton, United Kingdom
Recommended Citation:
Drijfhout S.S.. Global radiative adjustment after a collapse of the Atlantic meridional overturning circulation[J]. Climate Dynamics,2015-01-01,45(2017-07-08)