DOI: 10.1175/JCLI-D-11-00145.1
Scopus记录号: 2-s2.0-84863283157
论文题名: Thermally driven and eddy-driven jet variability in reanalysis
作者: Li C. ; Wettstein J.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 5 起始页码: 1587
结束页码: 1596
语种: 英语
Scopus关键词: Atmospheric circulation
; Atmospheric waves
; Baroclinic eddy
; Baroclinicity
; Composite analysis
; Diabatic heating
; Dynamical process
; European centre for medium-range weather forecasts
; Extratropical
; Hadley circulation
; Interannual variability
; Meridional fluxes
; Momentum flux
; Momentum transports
; North Atlantic oscillations
; Pacific sector
; Pacific-north america
; Reanalysis
; Teleconnections
; Thermally driven
; Zonal wind
; Atmospheric pressure
; Climatology
; Jets
; Troposphere
; Weather forecasting
; Momentum
; annual variation
; atmospheric circulation
; baroclinic motion
; eddy
; Hadley cell
; jet flow
; teleconnection
; troposphere
; weather forecasting
; wind field
; zonal wind
英文摘要: Two important dynamical processes influence the extratropical zonal wind field: angular momentum transport by the thermally direct Hadley circulation (thermal-driving T) and momentum flux convergence by atmospheric waves (eddies) that develop in regions of enhanced baroclinicity (eddy-driving E). The relationship between extratropical zonal wind variability and these driving processes is investigated using 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) data. Indices representing the processes (iT and iE) are defined based on vertically integrated diabatic heating and meridional convergence of the meridional flux of zonal momentumby eddies, respectively. Zonal wind signatures associated with these indices are identified via composite analysis. In the Atlantic sector, zonal wind variability is mainly associated with momentum flux convergence by baroclinic eddies, supporting the established view that the Atlantic jet is primarily eddy driven. In the Pacific sector, zonal wind variability is associated with both driving processes, evidence that the Pacific jet is both thermally driven and eddy driven. The thermally driven Pacific signature reflects changes in jet strength (intensity and longitudinal extent) with some resemblance to the zonal wind anomalies of the Pacific-North America (PNA) pattern. The eddy-driven signature reflects a latitudinal shift of the jet exit region in both sectors that resembles the zonal wind anomalies of the North Atlantic Oscillation (NAO) or West Pacific (WP) patterns. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52520
Appears in Collections: 气候变化事实与影响
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作者单位: Bjerknes Centre for Climate Research, and Uni Bjerknes Centre, Uni Research, and Department of Earth Science, University of Bergen, Bergen, Norway; Bjerknes Centre for Climate Research, Bergen, Norway; Climate Analysis Section, Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO, United States
Recommended Citation:
Li C.,Wettstein J.J.. Thermally driven and eddy-driven jet variability in reanalysis[J]. Journal of Climate,2012-01-01,25(5)