气候变化领域集成服务门户(CCPortal): Variations in the frequency of stratospheric sudden warmings in CMIP5 and CMIP6 and possible causes

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DOI	10.1175/JCLI-D-20-0104.1
	Variations in the frequency of stratospheric sudden warmings in CMIP5 and CMIP6 and possible causes
	Wu Z.; Reichler T.
发表日期	2020
ISSN	0894-8755
起始页码	10305
结束页码	10320
卷号	33 期号:23
英文摘要	The climatological frequency of stratospheric sudden warming events (SSWs) is an important dynamical characteristic of the extratropical stratosphere. However, modern climate models have difficulties in simulating this frequency, with many models either considerably under- or overestimating the observational estimates. Past research has found that models with a higher upper lid tend to simulate a higher and more realistic number of SSWs. The present study revisits this issue and investigates causes for biases in the simulated SSW frequency from the CMIP5 and CMIP6 models. It is found that variations in the frequency are closely related to 1) the strength of the polar vortex and 2) the upward-propagating wave activity in the stratosphere. While it is difficult to explain the variations in the polar vortex strength from the available model output, the stratospheric wave activity is influenced by different aspects of the climatological mean state of the atmosphere in the lower stratosphere. We further find that models with a finer vertical resolution in the stratosphere are overall more realistic: vertical resolution is associated with a smaller cold bias above the extratropical tropopause, more upward-propagating wave activity in the lower stratosphere, and a higher frequency of SSWs. We conclude that not only a high model lid but also a fine vertical resolution in the stratosphere is important for simulating the dynamical variability of the stratosphere. © 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	Vortex flow; Wave propagation; Wave transmission; Dynamical characteristics; Extratropical tropopause; Higher frequencies; Lower stratosphere; Polar vortex strength; Propagating waves; Stratospheric sudden warmings; Vertical resolution; Climate models; atmospheric circulation; atmospheric modeling; climate modeling; CMIP; statistical analysis; stratosphere-troposphere interaction; sudden stratospheric warming
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/171023
作者单位	Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT, United States; Institute of Atmospheric and Climate Science IAC ETH, Swiss Federal Institute of Technology (ETHZ), Zurich, Switzerland
推荐引用方式 GB/T 7714	Wu Z.,Reichler T.. Variations in the frequency of stratospheric sudden warmings in CMIP5 and CMIP6 and possible causes[J],2020,33(23).
APA	Wu Z.,&Reichler T..(2020).Variations in the frequency of stratospheric sudden warmings in CMIP5 and CMIP6 and possible causes.Journal of Climate,33(23).
MLA	Wu Z.,et al."Variations in the frequency of stratospheric sudden warmings in CMIP5 and CMIP6 and possible causes".Journal of Climate 33.23(2020).