气候变化领域集成服务门户(CCPortal): Interhemispheric Temperature Gradient and Equatorial Pacific SSTs Drive Sahel Monsoon Uncertainties under Global Warming

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DOI	10.1175/JCLI-D-23-0162.1
	Interhemispheric Temperature Gradient and Equatorial Pacific SSTs Drive Sahel Monsoon Uncertainties under Global Warming
	Guilbert, Marcellin; Terray, Pascal; Mignot, Juliette; Ollier, Luther; Gastineau, Guillaume
发表日期	2024
ISSN	0894-8755
EISSN	1520-0442
起始页码	37
结束页码	3
卷号	37 期号:3
英文摘要	The Sahel is one of the most vulnerable regions to climate change. Robust estimation of future changes in the Sahel monsoon is therefore essential for effective climate change adaptation. Unfortunately, state-of-the-art climate models show large uncertainties in their projections of Sahel rainfall. In this study, we use 32 models from CMIP6 to iden-tify the sources of this large intermodel spread of Sahel rainfall. By using maximum covariance analysis, we first highlight two new key drivers of this spread during boreal summer: the interhemispheric temperature gradient and equatorial Pacific sea surface temperature (SST) changes. This contrasts with previous studies, which have focused mainly on the Northern Hemisphere rather than the global scale, and in which the Pacific Ocean has been neglected in favor of the Atlantic. Next, we unravel the physical mechanisms behind these statistical relationships. First, the modulation of the interhemispheric temperature gradient across the models leads to varying latitudinal positions of the intertropical convergence zone and, consequently, varying Sahel rainfall intensity. Second, models that exhibit less warming than the multimodel mean in the equatorial Pacific, thereby projecting a less El Nino-like mean state, simulate enhanced precipitation over the central Sahel in the future through modulations of the Walker circulation, the tropical easterly jet, the meridional tropospheric temperature gradient, and hence regional zonal wind shear. Finally, we show that these two indices collectively explain 62% of Sahel rainfall change uncertainty: 40% due to the interhemispheric temperature gradient and 22% through equato-rial Pacific SST.
英文关键词	Teleconnections; Monsoons; Climate change; Uncertainty
语种	英语
WOS研究方向	Meteorology & Atmospheric Sciences
WOS类目	Meteorology & Atmospheric Sciences
WOS记录号	WOS:001148802900001
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/308504
作者单位	Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); Universite Paris Cite; Museum National d'Histoire Naturelle (MNHN); Institut de Recherche pour le Developpement (IRD); Sorbonne Universite
推荐引用方式 GB/T 7714	Guilbert, Marcellin,Terray, Pascal,Mignot, Juliette,et al. Interhemispheric Temperature Gradient and Equatorial Pacific SSTs Drive Sahel Monsoon Uncertainties under Global Warming[J],2024,37(3).
APA	Guilbert, Marcellin,Terray, Pascal,Mignot, Juliette,Ollier, Luther,&Gastineau, Guillaume.(2024).Interhemispheric Temperature Gradient and Equatorial Pacific SSTs Drive Sahel Monsoon Uncertainties under Global Warming.JOURNAL OF CLIMATE,37(3).
MLA	Guilbert, Marcellin,et al."Interhemispheric Temperature Gradient and Equatorial Pacific SSTs Drive Sahel Monsoon Uncertainties under Global Warming".JOURNAL OF CLIMATE 37.3(2024).