气候变化领域集成服务门户(CCPortal): The influence of southeastern African river valley jets on regional rainfall

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DOI	10.1007/s00382-021-05846-1
	The influence of southeastern African river valley jets on regional rainfall
	Barimalala R.; Blamey R.C.; Desbiolles F.; Reason C.J.C.
发表日期	2021
ISSN	0930-7575
英文摘要	The impacts of the low level jets that form through the gaps in the topography in the Limpopo and Zambezi River Valleys (LRV and ZRV) on southern African climate are investigated. ERA-5 reanalysis data and numerical experiments using regional climate models reveal that the two valleys act as main gateways for southwest Indian Ocean-sourced moisture inflows into southern Africa. The effects of the LRV jet are stationary and mostly confined to south of Limpopo. By blocking the LRV, the moisture convergence in the interior of the subcontinent reduces and leads to a weakening in both the Angola Low and the ridging high over southeastern Africa. These are unfavorable conditions for the southward transport of moisture, causing a decrease of up to 50% of the subtropical southern African total summer rainfall. In contrast, the influence of the Zambezi jet varies with the season. During early austral summer, a blocked ZRV results in an overall deficit in rainfall in the subcontinent. It then leads to a weaker Mozambique Channel Trough, intensified Angola Low, hence increase in rainfall during January and February. Toward the end of the austral summer season, the absence of the Zambezi jet allows more moisture from the tropical Atlantic to penetrate into the mainland which then converges with moisture transported from the Indian Ocean and triggers excess rainfall over the tropical areas. These results have important implications for understanding the intraseasonal and interannual rainfall variability over the subcontinent during the summer half of the year. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Limpopo jet; Low level moisture fluxes; Southern African rainfall; Zambezi jet
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/183415
作者单位	Department of Oceanography, University of Cape Town, Private Bag X3, Rondebosch, Cape Town, 7701, South Africa; Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan, Italy
推荐引用方式 GB/T 7714	Barimalala R.,Blamey R.C.,Desbiolles F.,et al. The influence of southeastern African river valley jets on regional rainfall[J],2021.
APA	Barimalala R.,Blamey R.C.,Desbiolles F.,&Reason C.J.C..(2021).The influence of southeastern African river valley jets on regional rainfall.Climate Dynamics.
MLA	Barimalala R.,et al."The influence of southeastern African river valley jets on regional rainfall".Climate Dynamics (2021).