气候变化领域集成服务门户(CCPortal): Seasonal sensitivity of the cross-equatorial Hadley cell response to extratropical thermal forcings

CCPortal

DOI	10.1175/JCLI-D-19-0938.1
	Seasonal sensitivity of the cross-equatorial Hadley cell response to extratropical thermal forcings
	Hwang Y.-T.; Chung P.-C.
发表日期	2021
ISSN	08948755
起始页码	3327
结束页码	3342
卷号	34 期号:9
英文摘要	This study explores the seasonal sensitivity of tropical circulation responses to an idealized extratropical thermal forcing using the Community Atmosphere Model version 5 coupled to a slab ocean. The thermal heating over the Southern Ocean is held constant, and the tropical responses in each month of the year are investigated. An anomalous cross-equatorial cell and a southward tropical rain belt shift occur every month. The anomalous cross-equatorial cell has a strong influence on the strengths of the Hadley cell and the subtropical jet in the winter hemisphere; in contrast, it has nearly no impact on the Hadley cell and the subtropical jet strengths in the summer hemisphere. The seasonal variation of the anomalous cross-equatorial cell is small (&30% of the annual mean change), and could be understood via the energetic and the sea surface temperature gradient perspectives. Both perspectives point to the seasonality of the anomalous ocean heat uptake within the deep tropics as the key factor explaining the weak seasonality of the anomalous cross-equatorial cell. We propose a hypothesis explaining about 75% of this seasonal variation via the climatological position of the ITCZ relative to the anomalous cross-equatorial cell. The results suggest a modest seasonality in tropical precipitation and circulation responses to extratropical forcing. Also, such seasonality may be partly predicted by the climatological seasonal cycle of the tropical circulations. © 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Air-sea interaction; Angular momentum; Climate change; Energy transport; Hadley circulation; Teleconnections
语种	英语
scopus关键词	Clouds; Cytology; Oceanography; Surface waters; Tropics; Community atmosphere model; Ocean heat uptake; Sea Surface Temperature gradients; Seasonal variation; Subtropical jet; Thermal forcing; Tropical precipitation; Tropical response; Cells
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178600
作者单位	Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan
推荐引用方式 GB/T 7714	Hwang Y.-T.,Chung P.-C.. Seasonal sensitivity of the cross-equatorial Hadley cell response to extratropical thermal forcings[J],2021,34(9).
APA	Hwang Y.-T.,&Chung P.-C..(2021).Seasonal sensitivity of the cross-equatorial Hadley cell response to extratropical thermal forcings.Journal of Climate,34(9).
MLA	Hwang Y.-T.,et al."Seasonal sensitivity of the cross-equatorial Hadley cell response to extratropical thermal forcings".Journal of Climate 34.9(2021).