DOI: 10.1175/JCLI-D-16-0824.1
Scopus记录号: 2-s2.0-85021129057
论文题名: Bjerknes compensation in meridional heat transport under freshwater forcing and the role of climate feedback
作者: Yang H. ; Wen Q. ; Yao J. ; Wang Y.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 14 起始页码: 5167
结束页码: 5185
语种: 英语
Scopus关键词: Atmospheric thermodynamics
; Climate change
; Climate models
; Clouds
; Earth (planet)
; Earth atmosphere
; Energy balance
; Heat flux
; Heat storage
; Heat transfer
; Tropics
; Water
; Atlantic meridional overturning circulations
; Atmosphere-ocean interactions
; Energy transport
; Large-scale circulation
; Meridional heat transports
; Ocean dynamics
; Ocean heat transport
; Surface temperature changes
; Oceanography
英文摘要: Using a coupled Earth climate model, freshwater forcing experiments are performed to study the Bjerknes compensation (BJC) between meridional atmosphere heat transport (AHT) and meridional ocean heat transport (OHT). Freshwater hosing in the North Atlantic weakens the Atlantic meridional overturning circulation (AMOC) and thus reduces the northward OHT in the Atlantic significantly, leading to a cooling (warming) in the surface layer in the Northern (Southern) Hemisphere. This results in an enhanced Hadley cell and northward AHT. Meanwhile, the OHT in the Indo-Pacific is increased in response to the Hadley cell change, partially offsetting the reduced OHT in the Atlantic. Two compensations occur here: compensation between theAHTand the Atlantic OHT, and that between the Indo-PacificOHTand the Atlantic OHT. The AHT change undercompensates the OHT change by about 60% in the extratropics, while the former overcompensates the latter by about 30% in the tropics due to the Indo-Pacific change. The BJC can be understood from the viewpoint of large-scale circulation change. However, the intrinsic mechanism of BJC is related to the climate feedback of the Earth system. The authors' coupled model experiments confirm that the occurrence of BJC is an intrinsic requirement of local energy balance, and local climate feedback determines the extent of BJC, consistent with previous theoretical results. Even during the transient period of climate change, the BJC is well established when the ocean heat storage is slowly varying and its change is much weaker than the net local heat flux change at the ocean surface. The BJC can be deduced from the local climate feedback. Under the freshwater forcing, the overcompensation in the tropics is mainly caused by the positive longwave feedback related to clouds, and the undercompensation in the extratropics is due to the negative longwave feedback related to surface temperature change. Different dominant feedbacks determine different BJC scenarios in different regions, which are in essence constrained by local energy balance. © 2017 American Meteorological Society. 资助项目: NSF, National Science Foundation
; NSF, National Science Foundation
; NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48849
Appears in Collections: 气候变化与战略
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作者单位: Laboratory for Climate and Ocean-Atmosphere Studies, School of Physics, Peking University, Beijing, China; Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China; National Marine Environmental Forecasting Center, State Oceanology Administration, Beijing, China
Recommended Citation:
Yang H.,Wen Q.,Yao J.,et al. Bjerknes compensation in meridional heat transport under freshwater forcing and the role of climate feedback[J]. Journal of Climate,2017-01-01,30(14)