气候变化领域集成服务门户(CCPortal): Crucial Roles of Eastward Propagating Environments in the Summer MCS Initiation Over the U.S. Great Plains

CCPortal

DOI	10.1029/2021JD034991
	Crucial Roles of Eastward Propagating Environments in the Summer MCS Initiation Over the U.S. Great Plains
	Song F.; Feng Z.; Leung L.R.; Pokharel B.; Wang S.Y.S.; Chen X.; Sakaguchi K.; Wang C.-C.
发表日期	2021
ISSN	2169-897X
卷号	126 期号:16
英文摘要	This study aims to further understand the environments supporting summer mesoscale convective system (MCS) initiation in the U.S. Great Plains. A self-organizing map analysis is conducted to identify four types of summer MCS initiation environments during 2004–2017: Type-1 and Type-2 feature favorable large-scale environments, Type-3 has favorable lower-level and surface conditions but unfavorable upper-level circulation, while Type-4 features the most unfavorable large-scale environments. Despite the unfavorable large-scale environment, convection-centered composites reveal the presence of favorable sub-synoptic scale environments for MCS initiation in Type-3 and Type-4. All four types of MCS initiation environments delineate clear eastward propagating features in many meteorological fields, such as potential vorticity, surface pressure, and equivalent potential temperature, upstream up to 25° west of and ∼36 h before MCS initiation. While the propagating environments and local, non-propagating low-level moisture are important to MCS initiation at the foothill of the Rocky Mountains, MCS initiation in the Great Plains is supported by the coupled dynamical and moisture anomalies, both associated with eastward propagating waves. Hence, MCSs initiated in the plains can produce more rainfall than those initiated at the foothill due to a more abundant moisture supply. By tracking MCSs and mid-tropospheric perturbations (MPs), a unique type of sub-synoptic disturbances with Rocky Mountains origin, it is shown that ∼30% of MPs are associated with MCS initiation, mostly in Type-4. Although MPs are related to a small fraction of MCS initiation, MCSs that are associated with MPs tend to produce more rainfall in a larger area with a stronger convective intensity. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	convection initiation; eastward propagating environments; large-scale environments; local moisture; mesoscale convective systems; mid-tropospheric perturbations
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/237069
作者单位	Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, United States; Department of Plants, Soils, and Climate/Utah Climate Center, Utah State University, Logan, UT, United States; Department of Meteorology and Atmospheric Science, and Center for Advanced Data Assimilation and Predictability Techniques, The Pennsylvania State University, University Park, PA, United States; Central Weather Bureau, Taipei, Taiwan
推荐引用方式 GB/T 7714	Song F.,Feng Z.,Leung L.R.,et al. Crucial Roles of Eastward Propagating Environments in the Summer MCS Initiation Over the U.S. Great Plains[J],2021,126(16).
APA	Song F..,Feng Z..,Leung L.R..,Pokharel B..,Wang S.Y.S..,...&Wang C.-C..(2021).Crucial Roles of Eastward Propagating Environments in the Summer MCS Initiation Over the U.S. Great Plains.Journal of Geophysical Research: Atmospheres,126(16).
MLA	Song F.,et al."Crucial Roles of Eastward Propagating Environments in the Summer MCS Initiation Over the U.S. Great Plains".Journal of Geophysical Research: Atmospheres 126.16(2021).