气候变化领域集成服务门户(CCPortal): Observational Evidence of State-Dependent Positive and Negative Land Surface Feedback on Afternoon Deep Convection Over the Southern Great Plains

CCPortal

DOI	10.1029/2019GL086622
	Observational Evidence of State-Dependent Positive and Negative Land Surface Feedback on Afternoon Deep Convection Over the Southern Great Plains
	Qiu S.; Williams I.N.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:5
英文摘要	The detection of soil moisture-precipitation feedback is complicated by the dependence of feedback sign on atmospheric state and cloud types. We evaluated responses of convective clouds to changes in surface evaporative fraction (EF) from satellite and ground-based measurements over the Southern Great Plains in summer months. Strong responses to EF were inferred only after accounting for tropospheric states supporting systematically positive or negative responses. State dependence (inferred from controlled model experiments) explains the weak response found in previous studies. The probability of transitions from shallow to deep cumulus, and subsequent precipitation onset, increases by 58% over drier surfaces in weakly stratified environments having deeper boundary layers. Boundary layer dynamics play a more important role than low-level relative humidity in these environments. Wetter surfaces yield increased deep convection in moist and thermally stratified environments. The distinct pathways of convective initiation over dry and wet land surfaces can play important roles in drought onset and termination. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Atmospheric humidity; Boundary layers; Clouds; Drought; Landforms; Natural convection; Precipitation (chemical); Soil moisture; Surface measurement; Boundary layer dynamics; Convective initiation; Evaporative fraction; Ground based measurement; shallow-to-deep cumulus transition; Southern great plains; Stratified environments; Thermally stratified environment; Feedback; boundary layer; convection; cumulus; drought; feedback mechanism; land surface; land-atmosphere interaction; relative humidity; soil moisture; troposphere; Great Plains
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170618
作者单位	Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
推荐引用方式 GB/T 7714	Qiu S.,Williams I.N.. Observational Evidence of State-Dependent Positive and Negative Land Surface Feedback on Afternoon Deep Convection Over the Southern Great Plains[J],2020,47(5).
APA	Qiu S.,&Williams I.N..(2020).Observational Evidence of State-Dependent Positive and Negative Land Surface Feedback on Afternoon Deep Convection Over the Southern Great Plains.Geophysical Research Letters,47(5).
MLA	Qiu S.,et al."Observational Evidence of State-Dependent Positive and Negative Land Surface Feedback on Afternoon Deep Convection Over the Southern Great Plains".Geophysical Research Letters 47.5(2020).