气候变化领域集成服务门户(CCPortal): Interannual variability of East African rainfall: role of seasonal transitions of the low-level cross-equatorial flow

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DOI	10.1007/s00382-020-05244-z
	Interannual variability of East African rainfall: role of seasonal transitions of the low-level cross-equatorial flow
	Vizy E.K.; Cook K.H.
发表日期	2020
ISSN	0930-7575
起始页码	4563
结束页码	4587
卷号	54
英文摘要	During boreal spring and fall, the low-level cross-equatorial flow along the East African coast weakens and reverses. These transition periods are embedded within the East African rainy seasons—the spring long rains and the fall short rains. ERAI, ERA5, JRA-55, and MERRA2 atmospheric reanalyses and CHIRPS2 and ARC2 rainfall observations are examined to improve our understanding of how the transition periods vary on interannual timescales, and how these variations are related to regional rainfall. Transition period length is positively correlated with spring and fall East African rainfall regionally. Variations in transition period length are associated with the seasonal development and variability of three low-level circulation features, namely, the South Indian Convergence Zone, the Mascarene High over the South Indian Ocean, and the Arabian High over the Arabian Sea. In addition to affecting the low-level moisture transport and convergence over East Africa, these circulation features interact to influence the start and end dates that define the transition period. Composites are constructed and analyzed for different transition period types based on length, start date, and end date to distinguish differences among event types as well as seasonal differences. Air–sea coupling over the western Indian Ocean is stronger for the spring transition than for the fall, modifying precipitation through variations in specific humidity. In the fall transition period, rainfall variations are primarily controlled by circulation variations. These results have implications for climate change prediction over East Africa, for example, as the Indian Ocean warms. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	East African rainfall; Ethiopia; Indian Ocean; Kenya; Long rains; Low-level jet; Mascarene high; Rainfall variability; Short rains; Somali jet; Tanzania
语种	英语
scopus关键词	annual variation; atmospheric circulation; climate change; extreme event; precipitation intensity; prediction; seasonal variation; East Africa; Indian Ocean
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/145462
作者单位	Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78712, United States
推荐引用方式 GB/T 7714	Vizy E.K.,Cook K.H.. Interannual variability of East African rainfall: role of seasonal transitions of the low-level cross-equatorial flow[J],2020,54.
APA	Vizy E.K.,&Cook K.H..(2020).Interannual variability of East African rainfall: role of seasonal transitions of the low-level cross-equatorial flow.Climate Dynamics,54.
MLA	Vizy E.K.,et al."Interannual variability of East African rainfall: role of seasonal transitions of the low-level cross-equatorial flow".Climate Dynamics 54(2020).