气候变化领域集成服务门户(CCPortal): The impacts of climate change on the winter water cycle of the western Himalaya

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DOI	10.1007/s00382-020-05383-3
	The impacts of climate change on the winter water cycle of the western Himalaya
	Hunt K.M.R.; Turner A.G.; Shaffrey L.C.
发表日期	2020
ISSN	0930-7575
起始页码	2287
结束页码	2307
卷号	55
英文摘要	Some 180 million people depend on the Indus River as a key water resource, fed largely by precipitation falling over the western Himalaya. However, the projected response of western Himalayan precipitation to climate change is currently not well constrained: CMIP5 GCMs project a reduced frequency and vorticity of synoptic-scale systems impacting the area, but such systems would exist in a considerably moister atmosphere. In this study, a convection-permitting (4 km horizontal resolution) setup of the Weather Research and Forecasting (WRF) model is used to examine 40 cases of these synoptic-scale systems, known as western disturbances (WDs), as they interact with the western Himalaya. In addition to a present-day control run, three experiments are performed by perturbing the boundary and initial conditions to reflect pre-industrial, RCP4.5 and RCP8.5 background climates respectively. It is found that in spite of the weakening intensity of WDs, net precipitation associated with them in future climate scenarios increases significantly; conversely there is no net change in precipitation between the pre-industrial and control experiments despite a significant conversion of snowfall in the pre-industrial experiment to rainfall in the control experiment, consistent with the changes seen in historical observations. This shift from snowfall to rainfall has profound consequences on water resource management in the Indus Valley, where irrigation is dependent on spring meltwater. Flux decomposition shows that the increase in future precipitation follows directly from the projected moistening of the tropical atmosphere (which increases the moisture flux incident on the western Himalaya by 28%) overpowering the weakened dynamics (which decreases it by 20%). Changes to extreme rainfall events are also examined: it is found that such events may increase significantly in frequency in both future scenarios examined. Two-hour maxima rainfall events that currently occur in 1-in-8 WDs are projected to increase tenfold in frequency in the RCP8.5 scenario; more prolonged (1-week maxima) events are projected to increase fiftyfold. © 2020, The Author(s).
英文关键词	Climate change; Himalaya; Modelling; Pseudo global warming; Western disturbances
语种	英语
scopus关键词	boundary condition; climate change; climate effect; CMIP; precipitation (climatology); synoptic meteorology; vorticity; winter; Himalayas; Indus River
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/145317
作者单位	Department of Meteorology, University of Reading, Reading, United Kingdom; National Centre for Atmospheric Sciences, University of Reading, Reading, United Kingdom
推荐引用方式 GB/T 7714	Hunt K.M.R.,Turner A.G.,Shaffrey L.C.. The impacts of climate change on the winter water cycle of the western Himalaya[J],2020,55.
APA	Hunt K.M.R.,Turner A.G.,&Shaffrey L.C..(2020).The impacts of climate change on the winter water cycle of the western Himalaya.Climate Dynamics,55.
MLA	Hunt K.M.R.,et al."The impacts of climate change on the winter water cycle of the western Himalaya".Climate Dynamics 55(2020).