气候变化领域集成服务门户(CCPortal): Role of ocean mesoscale structures in shaping the Angola-Low pressure system and the southern Africa rainfall

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DOI	10.1007/s00382-020-05199-1
	Role of ocean mesoscale structures in shaping the Angola-Low pressure system and the southern Africa rainfall
	Desbiolles F.; Howard E.; Blamey R.C.; Barimalala R.; Hart N.C.G.; Reason C.J.C.
发表日期	2020
ISSN	0930-7575
起始页码	3685
结束页码	3704
卷号	54
英文摘要	Southern African climate is under the influence of both tropical and subtropical systems which result in a complex region where important interactions co-exist over a large spectrum of spatiotemporal scales. The Angola Low (AL), situated on boundary between tropical and subtropical southern Africa, has been diagnosed as a key driver of moisture distribution in the region on daily to seasonal time scales. It has been demonstrated that the AL pressure system is sensitive to the dynamics of the neighbouring oceans, but to date no study has considered the model resolution of air–sea interactions required to simulate this sensitivity. Using sensitivity experiments with a regional atmospheric model, which differ only in the mesoscale sea surface temperature (SST) forcing characteristics (either the full spectrum of SST variability or only its large-scale components are included), we first quantify the importance of SST gradients on the AL strength and variability. The results suggest that the mesoscale SST variability of the Angola–Benguela Frontal Zone (ABFZ) plays a key role in AL activity, particularly during the late summer. Synoptic-scale tropical lows, which form the AL, are automatically detected, and the results suggest more extreme events occur when the model is forced by mesoscale SSTs (everywhere and in the ABFZ area only). The rainfall resulting from those events suggests that tropical-low episodes are associated with nearly 15% of the total rain in Angola and Namibia. The link between AL dynamics and wet spells is also discussed, with the former showing a different spatial pattern as well as frequency when the ocean is fully resolved. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Angola Low pressure system; Atmospheric dynamics; Mesoscale air–sea interactions; Regional climate simulations; Southern Africa climate
语种	英语
scopus关键词	air-sea interaction; atmospheric modeling; atmospheric moisture; low pressure system; mesoscale meteorology; rainfall; sea surface temperature; spatiotemporal analysis; Angola; Namibia
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/145510
作者单位	Department of Oceanography, University of Cape Town, Cape Town, South Africa; School of Geography and the Environment, University of Oxford, Oxford, United Kingdom; Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan, Italy
推荐引用方式 GB/T 7714	Desbiolles F.,Howard E.,Blamey R.C.,et al. Role of ocean mesoscale structures in shaping the Angola-Low pressure system and the southern Africa rainfall[J],2020,54.
APA	Desbiolles F.,Howard E.,Blamey R.C.,Barimalala R.,Hart N.C.G.,&Reason C.J.C..(2020).Role of ocean mesoscale structures in shaping the Angola-Low pressure system and the southern Africa rainfall.Climate Dynamics,54.
MLA	Desbiolles F.,et al."Role of ocean mesoscale structures in shaping the Angola-Low pressure system and the southern Africa rainfall".Climate Dynamics 54(2020).