气候变化领域集成服务门户(CCPortal): Common Mechanism for Interannual and Decadal Variability in the East African Long Rains

CCPortal

DOI	10.1029/2020GL089182
	Common Mechanism for Interannual and Decadal Variability in the East African Long Rains
	Walker D.P.; Marsham J.H.; Birch C.E.; Scaife A.A.; Finney D.L.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:22
英文摘要	The East African long rains constitute the main crop-growing season in the region. Interannual predictability of this season is low in comparison to the short rains, and recent decadal drying contrasts with climate projections of a wetter future (the “East African climate paradox”). Here, we show that long rains rainfall totals are strongly correlated with 700 hPa zonal winds across the Congo basin and Gulf of Guinea ((Formula presented.)). Westerly anomalies align with more rainfall, with the same mechanism controlling covariability on interannual and decadal time scales. On both time scales wind anomalies are linked to geopotential anomalies over the Sahel and Sahara, and warming there. Rainfall and wind are significantly correlated with the Madden-Julian Oscillation (MJO) amplitude, and around 18% of the decadal drying can be explained by MJO amplitude variability. This work shows that predictions of East African rainfall across time scales require robust prediction of both zonal winds and MJO activity. ©2020. The Authors.
英文关键词	Climatology; Cultivation; Time measurement; Amplitude variability; Climate projection; Decadal timescale; Decadal variability; East african climates; Growing season; Madden-Julian oscillation; Robust predictions; Rain; amplitude; annual variation; decadal variation; geopotential; Madden-Julian oscillation; rainfall; zonal wind; Atlantic Ocean; Gulf of Guinea; Sahara; Sahel
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169474
作者单位	School of Earth and Environment, University of Leeds, Leeds, United Kingdom; National Centre for Atmospheric Science, Leeds, United Kingdom; Met Office Hadley Centre, Exeter, United Kingdom; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
推荐引用方式 GB/T 7714	Walker D.P.,Marsham J.H.,Birch C.E.,et al. Common Mechanism for Interannual and Decadal Variability in the East African Long Rains[J],2020,47(22).
APA	Walker D.P.,Marsham J.H.,Birch C.E.,Scaife A.A.,&Finney D.L..(2020).Common Mechanism for Interannual and Decadal Variability in the East African Long Rains.Geophysical Research Letters,47(22).
MLA	Walker D.P.,et al."Common Mechanism for Interannual and Decadal Variability in the East African Long Rains".Geophysical Research Letters 47.22(2020).