气候变化领域集成服务门户(CCPortal): The effect of explicit convection on couplings between rainfall, humidity, and ascent over Africa under climate change

CCPortal

DOI	10.1175/JCLI-D-19-0322.1
	The effect of explicit convection on couplings between rainfall, humidity, and ascent over Africa under climate change
	Jackson L.S.; Finney D.L.; Kendon E.J.; Marsham J.H.; Parker D.J.; Stratton R.A.; Tomassini L.; Tucker S.
发表日期	2020
ISSN	08948755
起始页码	8315
结束页码	8337
卷号	33 期号:19
英文摘要	The Hadley circulation and tropical rain belt are dominant features of African climate. Moist convection provides ascent within the rain belt, but must be parameterized in climate models, limiting predictions. Here, we use a pan-African convection-permitting model (CPM), alongside a parameterized convection model (PCM), to analyze how explicit convection affects the rain belt under climate change. Regarding changes in mean climate, both models project an increase in total column water (TCW), a widespread increase in rainfall, and slowdown of subtropical descent. Regional climate changes are similar for annual mean rainfall but regional changes of ascent typically strengthen less or weaken more in the CPM. Over a land-only meridional transect of the rain belt, the CPM mean rainfall increases less than in the PCM (5% vs 14%) but mean vertical velocity at 500 hPa weakens more (17% vs 10%). These changes mask more fundamental changes in underlying distributions. The decrease in 3-hourly rain frequency and shift from lighter to heavier rainfall are more pronounced in the CPM and accompanied by a shift from weak to strong updrafts with the enhancement of heavy rainfall largely due to these dynamic changes. The CPM has stronger coupling between intense rainfall and higher TCW. This yields a greater increase in rainfall contribution from events with greater TCW, with more rainfall for a given large-scale ascent, and so favors slowing of that ascent. These findings highlight connections between the convective-scale and larger-scale flows and emphasize that limitations of parameterized convection have major implications for planning adaptation to climate change. © 2020 American Meteorological Society.
语种	英语
scopus关键词	Belts; Climate models; Parameterization; Rain; Tropics; Adaptation to climate changes; Fundamental changes; Hadley circulation; Intense rainfalls; Mean vertical velocity; Rainfall contributions; Regional climate changes; Underlying distribution; Climate change; atmospheric convection; climate change; humidity; rainfall; regional climate; updraft; Africa
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/178722
作者单位	School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Met Office, Exeter, United Kingdom; National Centre for Atmospheric Science, School of Earth and Environment, University of Leeds, Leeds, United Kingdom
推荐引用方式 GB/T 7714	Jackson L.S.,Finney D.L.,Kendon E.J.,et al. The effect of explicit convection on couplings between rainfall, humidity, and ascent over Africa under climate change[J],2020,33(19).
APA	Jackson L.S..,Finney D.L..,Kendon E.J..,Marsham J.H..,Parker D.J..,...&Tucker S..(2020).The effect of explicit convection on couplings between rainfall, humidity, and ascent over Africa under climate change.Journal of Climate,33(19).
MLA	Jackson L.S.,et al."The effect of explicit convection on couplings between rainfall, humidity, and ascent over Africa under climate change".Journal of Climate 33.19(2020).