DOI: 10.1002/2017JD028007
Scopus记录号: 2-s2.0-85044972844
论文题名: Changes in Stratospheric Transport and Mixing During Sudden Stratospheric Warmings
作者: delaCámara A. ; Abalos M. ; Hitchcock P.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 7 起始页码: 3356
结束页码: 3373
语种: 英语
英文关键词: Brewer-Dobson circulation
; effective diffusivity
; potential vorticity
; stratospheric dynamics
; sudden stratospheric warming
; transport and mixing
Scopus关键词: atmospheric circulation
; atmospheric transport
; climate modeling
; downwelling
; mixing ratio
; potential vorticity
; simulation
; stratosphere
; tracer
; upwelling
英文摘要: The extreme disruptions of the wintertime stratospheric circulation during sudden stratospheric warmings (SSW) have large effects on tracer concentrations through alterations in transport. This study analyzes the changes in residual circulation and isentropic mixing associated with SSWs, by performing composites using reanalysis (European Centre for Medium-Range Weather Forecasts Re-Analysis Interim) and simulations of the Whole Atmosphere Community Climate Model. The advective Brewer-Dobson circulation accelerates around 15 days prior to the wind reversal at 60°N, 10 hPa during the onset of SSWs. Soon afterward, it decelerates, leading to reduced advective transport into the vortex and descent over the pole, which persist for more than 2 months below 30 hPa. The isentropic mixing has a distinct signature in altitude: It is enhanced at the central date of the SSW in the midstratosphere (about 10 hPa or 800 K), and this signal is delayed and more persistent at lower altitudes. It is shown that sufficiently deep SSWs (particularly those related to Polar-night Jet Oscillation events) have a stronger response in the Brewer-Dobson circulation and mixing. In particular, both the polar downwelling and the tropical upwelling are anomalously weak in the lower stratosphere for 90 days after the onset of Polar-night Jet Oscillation events. The redistribution of potential vorticity during the life cycle of SSWs is discussed due to its relevance for the stratospheric circulation. It is shown that the diffusive flux of potential vorticity, calculated in equivalent latitude coordinates, remains anomalously high in the lower stratosphere, a feature that is not seen in more conventional advective eddy fluxes across latitude circles. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114092
Appears in Collections: 气候减缓与适应
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作者单位: National Center for Atmospheric Research, Boulder, CO, United States; Departamento Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Madrid, Spain; Instituto de Geociencias (CSIC-UCM), Madrid, Spain; Laboratoire de Météorologie Dynamique/IPSL, École Polytechnique, Université Paris-Saclay, Palaiseau, France
Recommended Citation:
delaCámara A.,Abalos M.,Hitchcock P.. Changes in Stratospheric Transport and Mixing During Sudden Stratospheric Warmings[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(7)