气候变化领域集成服务门户(CCPortal): Eastward-propagating planetary waves in the polar middle atmosphere

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DOI	10.5194/acp-21-17495-2021
	Eastward-propagating planetary waves in the polar middle atmosphere
	Tang L.; Gu S.-Y.; Dou X.-K.
发表日期	2021
ISSN	1680-7316
起始页码	17495
结束页码	17512
卷号	21 期号:23
英文摘要	According to Modern-Era Retrospective Research Analysis for Research and Applications (MERRA-2) temperature and wind datasets in 2019, this study presents the global variations in the eastward-propagating wavenumber 1 (E1), 2 (E2), 3 (E3) and 4 (E4) planetary waves (PWs) and their diagnostic results in the polar middle atmosphere. We clearly demonstrate the eastward wave modes exist during winter periods with westward background wind in both hemispheres. The maximum wave amplitudes in the Southern Hemisphere (SH) are slightly larger and lie lower than those in the Northern Hemisphere (NH). Moreover, the wave perturbations peak at lower latitudes with smaller amplitudes as the wavenumber increases. The period of the E1 mode varies between 3-5d in both hemispheres, while the period of the E2 mode is slightly longer in the NH (∼48h) than in the SH (∼40h). The periods of the E3 are ∼30h in both the SH and the NH, and the period of E4 is ∼24h. Despite the shortening of wave periods with the increase in wavenumber, their mean phase speeds are relatively stable, ∼53, ∼58, ∼55 and ∼52m/s at 70° latitudes for E1, E2, E3 and E4, respectively. The eastward PWs occur earlier with increasing zonal wavenumber, which agrees well with the seasonal variations in the critical layers generated by the background wind. Our diagnostic analysis also indicates that the mean flow instability in the upper stratosphere and upper mesosphere might contribute to the amplification of the eastward PWs. © 2021 Liang Tang et al.
语种	英语
scopus关键词	atmospheric dynamics; data set; mesosphere; middle atmosphere; Northern Hemisphere; planetary atmosphere; polar meteorology; satellite data; Southern Hemisphere; stratosphere; wave propagation; wind field; wind velocity; zonal wind
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246405
作者单位	Electronic Information School, Wuhan University, Wuhan, China
推荐引用方式 GB/T 7714	Tang L.,Gu S.-Y.,Dou X.-K.. Eastward-propagating planetary waves in the polar middle atmosphere[J],2021,21(23).
APA	Tang L.,Gu S.-Y.,&Dou X.-K..(2021).Eastward-propagating planetary waves in the polar middle atmosphere.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(23).
MLA	Tang L.,et al."Eastward-propagating planetary waves in the polar middle atmosphere".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.23(2021).