气候变化领域集成服务门户(CCPortal): A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations

CCPortal

DOI	10.1007/s00382-017-3787-6
	A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations
	Dai A.; Rasmussen R.M.; Liu C.; Ikeda K.; Prein A.F.
发表日期	2020
ISSN	0930-7575
起始页码	343
结束页码	368
卷号	55
英文摘要	Climate models project increasing precipitation intensity but decreasing frequency as greenhouse gases increase. However, the exact mechanism for the frequency decrease remains unclear. Here we investigate this by analyzing hourly data from regional climate change simulations with 4 km grid spacing covering most of North America using the Weather Research and Forecasting model. The model was forced with present and future boundary conditions, with the latter being derived by adding the CMIP5 19-model ensemble mean changes to the ERA-interim reanalysis. The model reproduces well the observed seasonal and spatial variations in precipitation frequency and histograms, and the dry interval between rain events over the contiguous US. Results show that overall precipitation frequency indeed decreases during the warm season mainly due to fewer light-moderate precipitation (0.1 < P ≤ 2.0 mm/h) events, while heavy (2 < P ≤ 10 mm/h) to very heavy precipitation (P > 10 mm/h) events increase. Dry spells become longer and more frequent, together with a reduction in time-mean relative humidity (RH) in the lower troposphere during the warm season. The increased dry hours and decreased RH lead to a reduction in overall precipitation frequency and also for light-moderate precipitation events, while water vapor-induced increases in precipitation intensity and the positive latent heating feedback in intense storms may be responsible for the large increase in intense precipitation. The size of intense storms increases while their number decreases in the future climate, which helps explain the increase in local frequency of heavy precipitation. The results generally support a new hypothesis for future warm-season precipitation: each rainstorm removes ≥7% more moisture from the air per 1 K local warming, and surface evaporation and moisture advection take slightly longer than currently to replenish the depleted moisture before the next storm forms, leading to longer dry spells and a reduction in precipitation frequency, as well as decreases in time-mean RH and vertical motion. © 2017, Springer-Verlag GmbH Germany.
英文关键词	Climate change; Climate downscaling; Convection-permitting; North America; Precipitation; Precipitation frequency; WRF
语种	英语
scopus关键词	atmospheric convection; boundary condition; climate modeling; CMIP; computer simulation; global warming; precipitation (climatology); precipitation intensity; rainstorm; regional climate; relative humidity; troposphere; water vapor; weather forecasting
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/145429
作者单位	Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, NY 12222, United States; National Center for Atmospheric Research (NCAR), Boulder, CO, United States
推荐引用方式 GB/T 7714	Dai A.,Rasmussen R.M.,Liu C.,et al. A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations[J],2020,55.
APA	Dai A.,Rasmussen R.M.,Liu C.,Ikeda K.,&Prein A.F..(2020).A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations.Climate Dynamics,55.
MLA	Dai A.,et al."A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations".Climate Dynamics 55(2020).