气候变化领域集成服务门户(CCPortal): Protected convection as a metric of dry air influence on precipitation

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DOI	10.1175/JCLI-D-20-0384.1
	Protected convection as a metric of dry air influence on precipitation
	Ahmed F.; Neelin J.D.
发表日期	2021
ISSN	08948755
起始页码	3821
结束页码	3838
卷号	34 期号:10
英文摘要	Entrainment of dry tropospheric air can dilute cloud buoyancies and strongly affect the occurrence and intensity of convection. To measure this dry air influence on tropical precipitation, rainfall values that would occur when convection is ‘‘protected’’ from dry air dilution are estimated. An empirical relationship between tropical oceanic precipitation and entraining buoyancy in the lower troposphere (from the surface to 600 hPa) is leveraged. Protected buoyancies are computed by allowing a plume model to entrain saturated air at environmental temperature. These buoyancies are then used to estimate precipitation from protected convection. In most regions, the protected precipitation greatly exceeds the observed precipitation. Warm waters adjoining continents display striking disparities between observed and protected rainfall pointing to rainfall climatologies severely limited by dry air. The most prominent of these regions include the Red Sea and the Persian Gulf, followed by the Caribbean Sea, the Gulf of Mexico, and the seas surrounding the Maritime Continent. We test if similar large precipitation values are realizable in the Community Atmospheric Model (CAM5), wherein the parameterized convection in small (;28 3 28) pockets is allowed to only entrain saturated air. The precipitation within these pockets shows strong enhancement that is maintained over time, and is compensated by slight reductions in neighboring regions. In the model, protecting convection yields larger precipitation values over ocean than over land; protected precipitation also intensifies in a uniform SST warming experiment. The model experiments suggest that protected pockets in numerical simulations could be used to mimic the consequences of meteorological protection—from closed circulation or moisture shielding effects—that generate extreme precipitation. Ó 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy
英文关键词	Atmosphere; Buoyancy; Entrainment; Precipitation; Tropics
语种	英语
scopus关键词	Buoyancy; Oceanography; Rain; Tropics; Troposphere; American meteorological societies; Community atmospheric model; Copyright informations; Empirical relationships; Environmental temperature; Extreme precipitation; Rainfall climatologies; Tropical precipitation; Air entrainment
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/178580
作者单位	Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA, United States
推荐引用方式 GB/T 7714	Ahmed F.,Neelin J.D.. Protected convection as a metric of dry air influence on precipitation[J],2021,34(10).
APA	Ahmed F.,&Neelin J.D..(2021).Protected convection as a metric of dry air influence on precipitation.Journal of Climate,34(10).
MLA	Ahmed F.,et al."Protected convection as a metric of dry air influence on precipitation".Journal of Climate 34.10(2021).