气候变化领域集成服务门户(CCPortal): The modulation of daily southern Africa precipitation by el Niño-Southern oscillation across the summertime wet season

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DOI	10.1175/JCLI-D-20-0379.1
	The modulation of daily southern Africa precipitation by el Niño-Southern oscillation across the summertime wet season
	Hoell A.; Gaughan A.E.; Magadzire T.; Harrison L.
发表日期	2021
ISSN	0894-8755
起始页码	1115
结束页码	1134
卷号	34 期号:3
英文摘要	The spatiotemporal evolution of daily southern Africa precipitation characteristics, and associated atmospheric circulation, related to El Niño and La Niña is examined across the region's November-April wet season. Precipitation characteristics are examined in terms of monthly changes in daily average precipitation, the number of precipitation days, and the number of heavy precipitation days in three independently constructed estimates of observed precipitation during 1983-2018. Mechanisms related to precipitation changes, including contributions from mass divergence, water vapor transports, and transient eddies, are diagnosed using the atmospheric moisture budget based on the ERA5 reanalysis. El Niño is related to precipitation anomalies that build during December-March, the core of the rainy season, culminating in significantly below average values stretching across a semiarid region from central Mozambique to southeastern Angola. A broad anticyclone centered over Botswana drives these precipitation anomalies primarily through anomalous mass divergence, with moisture advection and transient eddies playing secondary roles. La Niña is related to significantly above average daily precipitation characteristics over all Africa south of 208S in February and much less so during the other five months. February precipitation anomalies are primarily driven through mass divergence due to a strong anomalous cyclonic circulation, whereas a similar circulation is more diffuse during the other months. The spatiotemporal evolutions of anomalies in daily precipitation characteristics across southern Africa related to El Niño and La Niña are not equal and opposite. The robustness of an asymmetric evolution, which could have implications for subseasonal forecasts, needs to be confirmed with analysis of additional empirical data and established with climate model experimentation. © 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Arid regions; Atmospheric pressure; Budget control; Climate models; Digital storage; Moisture; Atmospheric circulation; Atmospheric moisture; Daily precipitations; Model experimentations; Precipitation anomalies; Precipitation characteristics; Spatiotemporal evolution; Water vapor transport; Precipitation (meteorology)
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170938
作者单位	NOAA Physical Sciences Laboratory, Boulder, CO, United States; University of Louisville, Department of Geography and Geosciences, Louisville, KY, United States; Famine Early Warning Systems Network, Gaborone, Botswana; Department of Geography, University of California Santa Barbara, Santa Barbara, CA, United States
推荐引用方式 GB/T 7714	Hoell A.,Gaughan A.E.,Magadzire T.,et al. The modulation of daily southern Africa precipitation by el Niño-Southern oscillation across the summertime wet season[J],2021,34(3).
APA	Hoell A.,Gaughan A.E.,Magadzire T.,&Harrison L..(2021).The modulation of daily southern Africa precipitation by el Niño-Southern oscillation across the summertime wet season.Journal of Climate,34(3).
MLA	Hoell A.,et al."The modulation of daily southern Africa precipitation by el Niño-Southern oscillation across the summertime wet season".Journal of Climate 34.3(2021).