气候变化领域集成服务门户(CCPortal): Downstream suppression of baroclinic waves

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DOI	10.1175/JCLI-D-20-0483.1
	Downstream suppression of baroclinic waves
	Boljka L.; Thompson D.W.J.; Li Y.
发表日期	2021
ISSN	0894-8755
起始页码	919
结束页码	930
卷号	34 期号:3
英文摘要	Baroclinic waves drive both regional variations in weather and large-scale variability in the extratropical general circulation. They generally do not exist in isolation, but rather often form into coherent wave packets that propagate to the east via a mechanism called downstream development. Downstream development has been widely documented and explored. Here we document a novel but also key aspect of baroclinic waves: the downstream suppression of baroclinic activity that occurs in the wake of eastward propagating disturbances. Downstream suppression is apparent not only in the Southern Hemisphere storm track as shown in previous work, but also in the North Pacific and North Atlantic storm tracks. It plays an essential role in driving subseasonal periodicity in extratropical eddy activity in both hemispheres, and gives rise to the observed quiescence of the North Atlantic storm track 1-2 weeks following pronounced eddy activity in the North Pacific sector. It is argued that downstream suppression results from the anomalously low baroclinicity that arises as eastward propagating wave packets convert potential to kinetic energy. In contrast to baroclinic wave packets, which propagate to the east at roughly the group velocity in the upper troposphere, the suppression of baroclinic activity propagates eastward at a slower rate that is comparable to that of the lower to midtropospheric flow. The results have implications for understanding subseasonal variability in the extratropical troposphere of both hemispheres. © 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Kinetic energy; Kinetics; Troposphere; Wave packets; General circulation; Group velocities; Propagating disturbances; Propagating waves; Regional variation; Southern hemisphere storm tracks; Subseasonal variability; Upper troposphere; Storms
语种	英语
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/170940
作者单位	Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States
推荐引用方式 GB/T 7714	Boljka L.,Thompson D.W.J.,Li Y.. Downstream suppression of baroclinic waves[J],2021,34(3).
APA	Boljka L.,Thompson D.W.J.,&Li Y..(2021).Downstream suppression of baroclinic waves.Journal of Climate,34(3).
MLA	Boljka L.,et al."Downstream suppression of baroclinic waves".Journal of Climate 34.3(2021).