气候变化领域集成服务门户(CCPortal): Causes of the long-term variability of southwestern South America precipitation in the IPSL-CM6A-LR model

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DOI	10.1007/s00382-021-05811-y
	Causes of the long-term variability of southwestern South America precipitation in the IPSL-CM6A-LR model
	Villamayor J.; Khodri M.; Villalba R.; Daux V.
发表日期	2021
ISSN	0930-7575
起始页码	537
结束页码	557
英文摘要	Southwestern South America (SWSA) has undergone frequent and persistent droughts in recent decades with severe impacts on water resources, and consequently, on socio-economic activities at a sub-continental scale. The local drying trend in this region has been associated with the expansion of the subtropical drylands over the last decades. It has been shown that SWSA precipitation is linked to large-scale dynamics modulated by internal climate variability and external forcing. This work aims at unravelling the causes of this long-term trend toward dryness in the context of the emerging climate change relying on a large set simulations of the state-of-the-art IPSL-CM6A-LR climate model from the 6th phase of the Coupled Model Intercomparison Project. Our results identify the leading role of dynamical changes induced by external forcings, over the local thermodynamical effects and teleconnections with internal global modes of sea surface temperature. Our findings show that the simulated long-term changes of SWSA precipitation are dominated by externally forced anomalous expansion of the Southern Hemisphere Hadley Cell (HC) and a persistent positive Southern Annular Mode (SAM) trend since the late 1970s. Long-term changes in the HC extent and the SAM show strong co-linearity. They are attributable to stratospheric ozone depletion in austral spring-summer and increased atmospheric greenhouse gases all year round. Future ssp585 and ssp126 scenarios project a dominant role of anthropogenic forcings on the HC expansion and the subsequent SWSA drying, exceeding the threshold of extreme drought due to internal variability as soon as the 2040s, and suggest that these effects will persist until the end of the twenty-first century. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	CMIP6; Decadal variability; Detection and attribution; External forcing; Future scenarios; Hadley Cell expansion; Subtropical Andes drying trend
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183449
作者单位	LOCEAN-IPSL, Sorbonne Université/CNRS/IRD/MNHN, 4 place Jussieu, Paris, 75005, France; Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (CCT-Mendoza/CONICET), Mendoza, Argentina; Laboratoire des Sciences du Climat et de l’Environnement (LSCE, CEA/CNRS/UVSQ), Gif-sur-Yvette, France
推荐引用方式 GB/T 7714	Villamayor J.,Khodri M.,Villalba R.,et al. Causes of the long-term variability of southwestern South America precipitation in the IPSL-CM6A-LR model[J],2021.
APA	Villamayor J.,Khodri M.,Villalba R.,&Daux V..(2021).Causes of the long-term variability of southwestern South America precipitation in the IPSL-CM6A-LR model.Climate Dynamics.
MLA	Villamayor J.,et al."Causes of the long-term variability of southwestern South America precipitation in the IPSL-CM6A-LR model".Climate Dynamics (2021).