气候变化领域集成服务门户(CCPortal): Dry soils can intensify mesoscale convective systems

CCPortal

DOI	10.1073/pnas.2007998117
	Dry soils can intensify mesoscale convective systems
	Klein C.; Taylor C.M.
发表日期	2020
ISSN	0027-8424
起始页码	21132
结束页码	21137
卷号	117 期号:35
英文摘要	Soil moisture can feed back on rainfall through the impact of surface fluxes on the environment in which convection develops. The vast majority of previous research has focused on the initiation of convection, but in many regions of the world, the majority of rain comes from remotely triggered mesoscale convective systems (MCSs). Here we conduct a systematic observational analysis of soil moisture feedbacks on propagating MCSs anywhere in the world and show a strong positive impact of drier soils on convection within mature MCSs. From thousands of storms captured in satellite imagery over the Sahel, we find that convective cores within MCSs are favored on the downstream side of dry patches ≥200 km across. The effect is particularly strong during the afternoon–evening transition when convection reaches its diurnal peak in intensity and frequency, with dry soils accounting for an additional one in five convective cores. Dry soil patterns intensify MCSs through a combination of convergence, increased instability, and wind shear, all factors that strengthen organized convection. These favorable conditions tend to occur in the vicinity of a surface-induced anomalous displacement of the Sahelian dry line/intertropical discontinuity, suggesting a strong link between dry line dynamics and soil moisture state. Our results have important implications for nowcasting of severe weather in the Sahel and potentially in other MCS hotspot regions of the world. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Mesoscale convective systems \| propagating convection \| soil moisture \| dry line
语种	英语
scopus关键词	article; drought; human; human experiment; Sahel; satellite imagery; severe weather; soil moisture; thermodynamics
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160823
作者单位	Klein, C., UK Centre for Ecology and Hydrology, Wallingford, OX10 8BB, United Kingdom, Department of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, 6020, Austria; Taylor, C.M., UK Centre for Ecology and Hydrology, Wallingford, OX10 8BB, United Kingdom, National Centre for Earth Observation, Wallingford, OX10 8BB, United Kingdom
推荐引用方式 GB/T 7714	Klein C.,Taylor C.M.. Dry soils can intensify mesoscale convective systems[J],2020,117(35).
APA	Klein C.,&Taylor C.M..(2020).Dry soils can intensify mesoscale convective systems.Proceedings of the National Academy of Sciences of the United States of America,117(35).
MLA	Klein C.,et al."Dry soils can intensify mesoscale convective systems".Proceedings of the National Academy of Sciences of the United States of America 117.35(2020).