气候变化领域集成服务门户(CCPortal): What drives the intensification of mesoscale convective systems over the West African Sahel under climate change?

CCPortal

DOI	10.1175/JCLI-D-19-0380.1
	What drives the intensification of mesoscale convective systems over the West African Sahel under climate change?
	Fitzpatrick R.G.J.; Parker D.J.; Marsham J.H.; Rowell D.P.; Guichard F.M.; Taylor C.M.; Cook K.H.; Vizy E.K.; Jackson L.S.; Finney D.; Crook J.; Stratton R.; Tucker S.
发表日期	2020
ISSN	0894-8755
起始页码	3151
结束页码	3172
卷号	33 期号:8
英文摘要	Extreme rainfall is expected to increase under climate change, carrying potential socioeconomic risks. However, the magnitude of increase is uncertain. Over recent decades, extreme storms over the West African Sahel have increased in frequency, with increased vertical wind shear shown to be a cause. Drier midlevels, stronger cold pools, and increased storm organization have also been observed. Global models do not capture the potential effects of lower- to midtropospheric wind shear or cold pools on storm organization since they parameterize convection. Here we use the first convection-permitting simulations of African climate change to understand how changes in thermodynamics and storm dynamics affect future extreme Sahelian rainfall. The model, which simulates warming associated with representative concentration pathway 8.5 (RCP8.5) until the end of the twenty-first century, projects a 28% increase of the extreme rain rate of MCSs. The Sahel moisture change on average follows Clausius–Clapeyron scaling, but has regional heterogeneity. Rain rates scale with the product of time-of-storm total column water (TCW) and in-storm vertical velocity. Additionally, prestorm wind shear and convective available potential energy both modulate in-storm vertical velocity. Although wind shear affects cloud-top temperatures within our model, it has no direct correlation with precipitation rates. In our model, projected future increase in TCW is the primary explanation for increased rain rates. Finally, although colder cold pools are modeled in the future climate, we see no significant change in near-surface winds, highlighting avenues for future research on convection-permitting modeling of storm dynamics. © 2020 American Meteorological Society.
英文关键词	Lakes; Potential energy; Rain; Shear flow; Storms; Thermodynamics; Velocity; Cloud-top temperatures; Convective available potential energies; Mesoscale Convective System; Near-surface winds; Potential effects; Precipitation rates; Vertical velocity; Vertical wind shear; Climate change; climate change; convective system; extreme event; mesoscale meteorology; potential energy; rainfall; wind shear; Sahel [Sub-Saharan Africa]
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/171361
作者单位	Institute for Climate and Atmospheric Sciences, University of Leeds, Leeds, United Kingdom; Met Office, Exeter, United Kingdom; Centre National de Recherches Météorologiques, Toulouse, France; Centre for Ecology and Hydrology, Wallingford, United Kingdom; Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States
推荐引用方式 GB/T 7714	Fitzpatrick R.G.J.,Parker D.J.,Marsham J.H.,et al. What drives the intensification of mesoscale convective systems over the West African Sahel under climate change?[J],2020,33(8).
APA	Fitzpatrick R.G.J..,Parker D.J..,Marsham J.H..,Rowell D.P..,Guichard F.M..,...&Tucker S..(2020).What drives the intensification of mesoscale convective systems over the West African Sahel under climate change?.Journal of Climate,33(8).
MLA	Fitzpatrick R.G.J.,et al."What drives the intensification of mesoscale convective systems over the West African Sahel under climate change?".Journal of Climate 33.8(2020).