DOI: 10.1007/s00382-016-3190-8
Scopus记录号: 2-s2.0-84973109232
论文题名: The impact of multidecadal Atlantic meridional overturning circulation variations on the Southern Ocean
作者: Zhang L. ; Delworth T.L. ; Zeng F.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 48, 期: 2017-05-06 起始页码: 2065
结束页码: 2085
语种: 英语
英文关键词: Antarctic sea ice
; Atlantic meridional overturning circulation
; Southern Ocean
英文摘要: The impact of multidecadal variations of the Atlantic meridional overturning circulation (AMOC) on the Southern Ocean (SO) is investigated in the current paper using a coupled ocean–atmosphere model. We find that the AMOC can influence the SO via fast atmosphere teleconnections and subsequent ocean adjustments. A stronger than normal AMOC induces an anomalous warm SST over the North Atlantic, which leads to a warming of the Northern Hemisphere troposphere extending into the tropics. This induces an increased equator-to-pole temperature gradient in the Southern Hemisphere (SH) upper troposphere and lower stratosphere due to an amplified tropical upper tropospheric warming as a result of increased latent heat release. This altered gradients leads to a poleward displacement of the SH westerly jet. The wind change over the SO then cools the SST at high latitudes by anomalous northward Ekman transports. The wind change also weakens the Antarctic bottom water (AABW) cell through changes in surface heat flux forcing. The poleward shifted westerly wind decreases the long term mean easterly winds over the Weddell Sea, thereby reducing the turbulent heat flux loss, decreasing surface density and therefore leading to a weakening of the AABW cell. The weakened AABW cell produces a temperature dipole in the SO, with a warm anomaly in the subsurface and a cold anomaly in the surface that corresponds to an increase of Antarctic sea ice. Opposite conditions occur for a weaker than normal AMOC. Our study here suggests that efforts to attribute the recent observed SO variability to various factors should take into consideration not only local process but also remote forcing from the North Atlantic. © 2016, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53311
Appears in Collections: 过去全球变化的重建
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作者单位: Atmospheric and Oceanic Science, Princeton University, Princeton, NJ, United States; NOAA/Geophysical Fluid Dynamics Laboratory, 201 Forrestal Rd, Princeton, NJ, United States
Recommended Citation:
Zhang L.,Delworth T.L.,Zeng F.. The impact of multidecadal Atlantic meridional overturning circulation variations on the Southern Ocean[J]. Climate Dynamics,2017-01-01,48(2017-05-06)