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DOI	10.1002/joc.7489
	Intraseasonal descriptors and extremes in South African rainfall. Part I: Summer climatology and statistical characteristics
	Ullah, Asmat; Pohl, Benjamin; Pergaud, Julien; Dieppois, Bastien; Rouault, Mathieu
通讯作者	Ullah, A (corresponding author)，Univ Bourgogne, Ctr Rech Climatol, UMR 6282 Biogeosci, 6 Blvd Gabriel, F-21000 Dijon, France.
来源期刊	INTERNATIONAL JOURNAL OF CLIMATOLOGY
ISSN	0899-8418
EISSN	1097-0088
出版年	2021-12
英文摘要	Rainfall extremes are of major and increasing importance in semi-arid countries and their variability has strong implications for water resource and climate impacts on the local societies and environment. Here, we examine intraseasonal descriptors (ISDs) and wet extremes in austral summer rainfall (November-February) over South Africa (SA). Using daily observations from 225 rain gauges and ERA5 reanalysis between 1979 and 2015, we propose a novel typology of wet extreme events based on their spatial fraction, thus differentiating large- and small-scale extremes. Long-term variability of both types of extreme rainfall events is then extensively discussed in the context of ISDs. The results demonstrate that using 7% of spatial fraction simultaneously exceeding the local threshold of the 90th percentile produces remarkable results in characterizing rainfall extremes into large- and small-scale extremes. Austral summer total rainfall is found to be primarily shaped by large-scale extremes which constitute more than half of the rainfall amount under observation, and nearly half in ERA5. Observation (ERA5) shows an average of 8 +/- 5 (20 +/- 7) days per season associated with large-scale extremes, which are comprised in 5 +/- 3 (10 +/- 3) spells with an average persistence of at least 2 days. Overall, we find a strong dependence of total rainfall on the number of wet days and wet spells that are associated with large-scale extremes. We also find that large- and small-scale extremes are well-organized and spatially coherent in nature yet extreme conditions during small-scale events are found sporadic over the region, contrasting with large-scale events for which extreme conditions are found over a larger and coherent region.
英文关键词	climate variability intraseasonal descriptors rainfall extremes South Africa spatial coherence
类型	Article ; Early Access
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000735752600001
WOS关键词	TROPICAL-TEMPERATE TROUGHS ; INDIAN CONVERGENCE ZONE ; EQUATORIAL EAST-AFRICA ; INTERANNUAL VARIABILITY ; DRY SPELLS ; INTERDECADAL VARIABILITY ; PRECIPITATION EXTREMES ; PROJECTED CHANGES ; RAINY SEASONS ; EL-NINO
WOS类目	Meteorology & Atmospheric Sciences
WOS研究方向	Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/377042
作者单位	[Ullah, Asmat; Pohl, Benjamin; Pergaud, Julien] Univ Bourgogne Franche Comte, Ctr Rech Climatol, UMR 6282 Biogeosci, CNRS, Dijon, France; [Dieppois, Bastien] Coventry Univ, Ctr Agroecol Water & Resilience, Coventry, W Midlands, England; [Rouault, Mathieu] Univ Cape Town, Nansen Tutu Ctr Marine Environm Res, Dept Oceanog, Cape Town, South Africa
推荐引用方式 GB/T 7714	Ullah, Asmat,Pohl, Benjamin,Pergaud, Julien,et al. Intraseasonal descriptors and extremes in South African rainfall. Part I: Summer climatology and statistical characteristics[J],2021.
APA	Ullah, Asmat,Pohl, Benjamin,Pergaud, Julien,Dieppois, Bastien,&Rouault, Mathieu.(2021).Intraseasonal descriptors and extremes in South African rainfall. Part I: Summer climatology and statistical characteristics.INTERNATIONAL JOURNAL OF CLIMATOLOGY.
MLA	Ullah, Asmat,et al."Intraseasonal descriptors and extremes in South African rainfall. Part I: Summer climatology and statistical characteristics".INTERNATIONAL JOURNAL OF CLIMATOLOGY (2021).