气候变化领域集成服务门户(CCPortal): Atmospheric tropical modes are important drivers of Sahelian springtime heatwaves

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DOI	10.1007/s00382-020-05569-9
	Atmospheric tropical modes are important drivers of Sahelian springtime heatwaves
	Guigma K.H.; Guichard F.; Todd M.; Peyrille P.; Wang Y.
发表日期	2021
ISSN	0930-7575
卷号	56 期号:2021-05-06
英文摘要	Heatwaves pose a serious threat to human health worldwide but remain poorly documented over Africa. This study uses mainly the ERA5 dataset to investigate their large-scale drivers over the Sahel region during boreal spring, with a focus on the role of tropical modes of variability including the Madden–Julian Oscillation (MJO) and the equatorial Rossby and Kelvin waves. Heatwaves were defined from daily minimum and maximum temperatures using a methodology that retains only intraseasonal scale events of large spatial extent. The results show that tropical modes have a large influence on the occurrence of Sahelian heatwaves, and, to a lesser extent, on their intensity. Depending on their convective phase, they can either increase or inhibit heatwave occurrence, with the MJO being the most important of the investigated drivers. A certain sensitivity to the geographic location and the diurnal cycle is observed, with nighttime heatwaves more impacted by the modes over the eastern Sahel and daytime heatwaves more affected over the western Sahel. The examination of the physical mechanisms shows that the modulation is made possible through the perturbation of regional circulation. Tropical modes thus exert a control on moisture and the subsequent longwave radiation, as well as on the advection of hot air. A detailed case study of a major event, which took place in April 2003, further supports these findings. Given the potential predictability offered by tropical modes at the intraseasonal scale, this study has key implications for heatwave risk management in the Sahel. © 2020, The Author(s).
英文关键词	Drivers; Heatwaves; Intraseasonal; Sahel; Tropical modes
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/183385
作者单位	University of Sussex, Brighton, United Kingdom; Centre National de Recherches Météorologiques (CNRS) / Météo-France UMR 3589 Toulouse, Haute Garonne, France
推荐引用方式 GB/T 7714	Guigma K.H.,Guichard F.,Todd M.,et al. Atmospheric tropical modes are important drivers of Sahelian springtime heatwaves[J],2021,56(2021-05-06).
APA	Guigma K.H.,Guichard F.,Todd M.,Peyrille P.,&Wang Y..(2021).Atmospheric tropical modes are important drivers of Sahelian springtime heatwaves.Climate Dynamics,56(2021-05-06).
MLA	Guigma K.H.,et al."Atmospheric tropical modes are important drivers of Sahelian springtime heatwaves".Climate Dynamics 56.2021-05-06(2021).