气候变化领域集成服务门户(CCPortal): Drought in the Eastern Cape region of South Africa and trends in rainfall characteristics

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DOI	10.1007/s00382-020-05413-0
	Drought in the Eastern Cape region of South Africa and trends in rainfall characteristics
	Mahlalela P.T.; Blamey R.C.; Hart N.C.G.; Reason C.J.C.
发表日期	2020
ISSN	0930-7575
起始页码	2743
结束页码	2759
卷号	55
英文摘要	Much of the Eastern Cape province in South Africa has been experiencing a severe drought since 2015. This drought has had major socio-economic effects particularly on the large impoverished rural population as well as on some urban areas where supplied water services have broken down in several cases. The region is influenced by both midlatitude and tropical systems leading to a complex regional meteorology that hitherto has not been much studied compared to other parts of South Africa. Here, the ongoing drought is examined in the context of long-term trends and the interannual rainfall variability of the region. Although the region has experienced drought in all seasons since 2015, focus here is placed on the spring (September–November) which shows the most consistent and robust signal. On average, this season contributes between about 25–35% of the annual rainfall total. Based on CHIRPS data, it is found that this season shows a significant decreasing trend in both rainfall totals as well as the number of rainfall days (but not heavy rainfall days) for spring over most of the province since 1981. On interannual time scales, the results indicate that dry (wet) springs over the Eastern Cape are associated with a cyclonic (anticyclonic) anomaly southeast of South Africa as part of a shift in the zonal wavenumber 3 pattern in the midlatitudes. Over the landmass, a stronger (weaker) Botswana High is also apparent with increased (decreased) subsidence over and near the Eastern Cape which is less (more) favourable for cloud band development and hence reduced (enhanced) rainfall during dry (wet) springs. Analysis of mid-century (2040–2060) CMIP5 rainfall projections suggests that there may be a flattening of the annual cycle over the Eastern Cape with the winter becoming wetter and the summer drier. For the spring season of interest here, the multi-model projections also indicate drying but less pronounced than that projected for the summer. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Drought/floods; Rainfall variability; South Africa; Trends
语种	英语
scopus关键词	annual variation; cloud microphysics; drought; flood; rainfall; regional climate; spring (season); trend analysis; Eastern Cape; South Africa
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/145284
作者单位	Department of Oceanography, University of Cape Town, Rondebosch, South Africa; OUCE, Oxford University, Oxford, United Kingdom
推荐引用方式 GB/T 7714	Mahlalela P.T.,Blamey R.C.,Hart N.C.G.,et al. Drought in the Eastern Cape region of South Africa and trends in rainfall characteristics[J],2020,55.
APA	Mahlalela P.T.,Blamey R.C.,Hart N.C.G.,&Reason C.J.C..(2020).Drought in the Eastern Cape region of South Africa and trends in rainfall characteristics.Climate Dynamics,55.
MLA	Mahlalela P.T.,et al."Drought in the Eastern Cape region of South Africa and trends in rainfall characteristics".Climate Dynamics 55(2020).