气候变化领域集成服务门户(CCPortal): Moisture sources and transport during an extreme rainfall event over the Limpopo River Basin, southern Africa

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DOI	10.1016/j.atmosres.2021.105849
	Moisture sources and transport during an extreme rainfall event over the Limpopo River Basin, southern Africa
	Rapolaki R.S.; Blamey R.C.; Hermes J.C.; Reason C.J.C.
发表日期	2021
ISSN	0169-8095
卷号	264
英文摘要	Intermittent heavy rainfall over an eleven day period (11–21 January 2013) led to devastating floods over parts of South Africa and southern Mozambique, with regions within the Limpopo River Basin (LRB) being the worst affected. Previous observational work, based on an Eulerian analysis and low resolution data, indicated that moisture emanating from anomalously warm waters off the Angolan coast played a very important role in the evolution of this heavy rainfall event. However, there has been some debate about this moisture source and the general synoptic settings of the event that produced the heavy rainfall in the LRB. In this study, an analysis of the event using WRF model (12 km resolution) simulations, reanalyses, SAWS synoptic maps and NASA satellite images indicated that a tropical low was largely responsible for the floods which occurred over the LRB, particularly between 17 and 21 January. Moisture sources and transport are determined using the HYSPLIT model forced with WRF output and reveal a new perspective on the complex evolution of the event. During the early parts of the event, there were two core moisture source regions: i) a continental source with moisture being supplied from the Congo Basin region and, ii) a local oceanic region with moisture originating from the Agulhas Current and the Mozambique Channel. As the event progressed, the dominant moisture input was from parts of the South Indian Ocean including off the coast of Tanzania/Mozambique and to the east of Madagascar. Two days showed a moisture contribution from the tropical South Atlantic Ocean. A WRF sensitivity study with the observed warm SST anomaly off Angola replaced by climatological SST there indicated a reduction of moisture from the tropical South East Atlantic Ocean in the beginning and towards the end of the event, when there was some of the heaviest rainfall over the LRB, thereby reinforcing the suggestion that there was also some moisture being sourced from the tropical South East Atlantic during part of the observed event. When calculated over the entire 11–21 January 2013 event, there were four moisture sources, the largest contribution of which was from the Agulhas Current/Mozambique Channel and the South Indian Ocean, accounting for 53% of the moisture, followed by the continental source (25%). The tropical western Indian Ocean had the third largest contribution, at 17%, and the midlatitude South Atlantic Ocean (5%) contributed the least. © 2021 Elsevier B.V.
英文关键词	HYSPLIT; Limpopo River Basin; Moisture-transport; Rainfall; Southern Africa; WRF
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/236558
作者单位	Department of Oceanography, University of Cape Town, South Africa; SAEON Egagasini Node, Private Bag X2, Roggebaai, Cape Town, 8012, South Africa
推荐引用方式 GB/T 7714	Rapolaki R.S.,Blamey R.C.,Hermes J.C.,et al. Moisture sources and transport during an extreme rainfall event over the Limpopo River Basin, southern Africa[J],2021,264.
APA	Rapolaki R.S.,Blamey R.C.,Hermes J.C.,&Reason C.J.C..(2021).Moisture sources and transport during an extreme rainfall event over the Limpopo River Basin, southern Africa.Atmospheric Research,264.
MLA	Rapolaki R.S.,et al."Moisture sources and transport during an extreme rainfall event over the Limpopo River Basin, southern Africa".Atmospheric Research 264(2021).