DOI: 10.1175/JCLI-D-13-00550.1
Scopus记录号: 2-s2.0-84899049342
论文题名: Seasonal variations of subtropical precipitation associated with the southern annular mode
作者: Hendon H.H. ; Lim E.-P. ; Nguyen H.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 9 起始页码: 3446
结束页码: 3460
语种: 英语
Scopus关键词: Climate change
; Eddy momentum flux
; Meridional circulation
; Mid-latitude storms
; Precipitation anomalies
; Seasonal variation
; Southern Annular Mode
; Subtropical climates
; Subtropical jet
; Tropics
; climate change
; eddy
; jet stream
; meridional circulation
; precipitation (climatology)
; rainfall
; seasonal variation
; storm track
; subtropical region
; westerly
英文摘要: Seasonal variations of subtropical precipitation anomalies associated with the southern annular mode (SAM) are explored for the period 1979-2011. In all seasons, high-polarity SAM, which refers to a polewardshifted eddy-driven westerly jet, results in increased precipitation in high latitudes and decreased precipitation in midlatitudes as a result of the concomitant poleward shift of the midlatitude storm track. In addition, during spring-autumn, highSAMalso results in increased rainfall in the subtropics. This subtropical precipitation anomaly is absent during winter. This seasonal variation of the response of subtropical precipitation to the SAM is shown to be consistent with the seasonal variation of the eddy-induced divergent meridional circulation in the subtropics (strong in summer and weak in winter). The lack of an induced divergent meridional circulation in the subtropics during winter is attributed to the presence of the wintertime subtropical jet, which causes a broad latitudinal span of eddy momentum flux divergence due primarily to higher phase speed eddies breaking poleward of the subtropical jet and lower speed eddies not breaking until they reach the equatorward flank of the subtropical jet. During the other seasons, when the subtropical jet is less distinctive, the critical line for both high and low speed eddies is on the equatorward flank of the single jet and so breaking in the subtropics occurs over a narrow range of latitudes. The implications of these findings for the seasonality of future subtropical climate change, in which a shift to high SAMin all seasons is expected to be promoted, are discussed. © 2014 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51105
Appears in Collections: 气候变化事实与影响
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作者单位: Centre for Australian Weather and Climate Research, Bureau of Meteorology, Melbourne, Australia
Recommended Citation:
Hendon H.H.,Lim E.-P.,Nguyen H.. Seasonal variations of subtropical precipitation associated with the southern annular mode[J]. Journal of Climate,2014-01-01,27(9)