气候变化领域集成服务门户(CCPortal): The April 2010 North African heatwave: when the water vapor greenhouse effect drives nighttime temperatures

CCPortal

DOI	10.1007/s00382-020-05204-7
	The April 2010 North African heatwave: when the water vapor greenhouse effect drives nighttime temperatures
	Largeron Y.; Guichard F.; Roehrig R.; Couvreux F.; Barbier J.
发表日期	2020
ISSN	0930-7575
起始页码	3879
结束页码	3905
卷号	54
英文摘要	North Africa experienced a severe heatwave in April 2010 with daily maximum temperatures (Tmax) frequently exceeding 40∘C and daily minimum temperatures (Tmin) over 27∘C for more than five consecutive days in extended Saharan and Sahelian areas. Observations show that areas and periods affected by the heatwave correspond to strong positive anomalies of surface incoming longwave fluxes (LWin) and negative anomalies of incoming shortwave fluxes (SWin). The latter are explained by clouds in the Sahara, and by both clouds and dust loadings in the Sahel. However, the strong positive anomalies of LWin are hardly related to cloud or aerosol radiative effects. An analysis based on climate-model simulations (CNRM-AM) complemented by a specially-designed conceptual soil-atmospheric surface layer model (SARAWI) shows that this positive anomaly of LWin is mainly due to a water vapor greenhouse effect. SARAWI, which represents the two processes driving temperatures, namely turbulence and longwave radiative transfer between the soil and the atmospheric surface layer, points to the crucial impact of synoptic low-level advection of water vapor on Tmin. By increasing the atmospheric infrared emissivity, the advected water vapor dramatically increases the nocturnal radiative warming of the soil surface, then in turn reducing the nocturnal cooling of the atmospheric surface layer, which remains warm throughout the night. Over Western Sahel, this advection is related to an early northward incursion of the monsoon flow. Over Sahara, the anomalously high precipitable water is due to a tropical plume event. Both observations and simulations support this major influence of the low-level water vapor radiative effect on Tmin during this spring heatwave. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Greenhouse effect; Heatwave; North Africa; Radiative physics
语种	英语
scopus关键词	advection; air temperature; climate modeling; cloud cover; computer simulation; dust; greenhouse effect; heat wave; monsoon; radiative transfer; soil surface; water vapor; Sahara
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/145467
作者单位	CNRM, Université de Toulouse, Météo-France, CNRS, Toulouse, France
推荐引用方式 GB/T 7714	Largeron Y.,Guichard F.,Roehrig R.,et al. The April 2010 North African heatwave: when the water vapor greenhouse effect drives nighttime temperatures[J],2020,54.
APA	Largeron Y.,Guichard F.,Roehrig R.,Couvreux F.,&Barbier J..(2020).The April 2010 North African heatwave: when the water vapor greenhouse effect drives nighttime temperatures.Climate Dynamics,54.
MLA	Largeron Y.,et al."The April 2010 North African heatwave: when the water vapor greenhouse effect drives nighttime temperatures".Climate Dynamics 54(2020).