DOI: 10.1002/2017JD027620
Scopus记录号: 2-s2.0-85040724457
论文题名: MJO-Related Intraseasonal Variation in the Stratosphere: Gravity Waves and Zonal Winds
作者: Alexander M.J. ; Grimsdell A.W. ; Stephan C.C. ; Hoffmann L.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 2 起始页码: 775
结束页码: 788
语种: 英语
英文关键词: gravity waves
; intraseasonal variation
Scopus关键词: altitude
; anomaly
; atmospheric circulation
; drag
; experiment
; gravity wave
; heating
; latent heat flux
; Madden-Julian oscillation
; precipitation (climatology)
; seasonal variation
; stratosphere
; temperature profile
; tropopause
; wave generation
; wave modeling
; wave propagation
; wavelength
; wind profile
; zonal wind
英文摘要: Previous work has shown eastward migrating regions of enhanced temperature variance due to long-vertical wavelength stratospheric gravity waves that are in sync with intraseasonal precipitation and tropopause wind anomalies associated with the Madden-Julian Oscillation (MJO). Here the origin of these intraseasonal gravity wave variations is investigated with a set of idealized gravity wave-resolving model experiments. The experiments specifically test whether tropopause winds act to control gravity wave propagation into the stratosphere by a critical level filtering mechanism or play a role in gravity wave generation through an obstacle source effect. All experiments use identical convective latent heating variability, but the large-scale horizontal wind profile is varied to investigate relationships between stratospheric gravity waves and zonal winds at different levels. Results show that the observed long vertical wavelength gravity waves are primarily sensitive to stratospheric zonal wind variations, while tropopause wind variations have only a very small effect. Thus, neither the critical level filter mechanism nor the obstacle source play much of a role in the observed intraseasonal gravity wave variations. Instead, the results suggest that the stratospheric waves follow the MJO precipitation sources, and tropopause wind anomalies follow the same sources. We further find evidence of intraseasonal wave drag effects on the stratospheric circulation in reanalyzed winds. The results suggest that waves drive intraseasonal stratospheric zonal wind anomalies that descend in altitude with increasing MJO phases 3 through 7. Eastward anomalies descend farther than westward, suggesting that MJO-related stratospheric waves cause larger eastward drag forces. ©2017. 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/114673
Appears in Collections: 气候减缓与适应
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作者单位: NorthWest Research Associates—Boulder Office, Boulder, CO, United States; National Centre for Atmospheric Science-Climate, Department of Meteorology, University of Reading, Reading, United Kingdom; Jülich Supercomputing Centre, Forschungzentrum Jülich, Jülich, Germany
Recommended Citation:
Alexander M.J.,Grimsdell A.W.,Stephan C.C.,et al. MJO-Related Intraseasonal Variation in the Stratosphere: Gravity Waves and Zonal Winds[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(2)