DOI: 10.1175/JCLI-D-14-00682.1
Scopus记录号: 2-s2.0-84945914287
论文题名: Characteristics and mechanisms of the subseasonal eastward extension of the South Asian high
作者: Ren X. ; Yang D. ; Yang X.-Q.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 17 起始页码: 6799
结束页码: 6822
语种: 英语
Scopus关键词: Climate change
; Rain
; Storms
; Vorticity
; Atmospheric circulation
; Characteristics and mechanisms
; Eastward propagation
; Geo-potential heights
; Monsoons
; Oscillations
; Potential vorticity
; Rainfall condition
; Heating
; air-sea interaction
; atmospheric circulation
; heating
; monsoon
; oscillation
; potential vorticity
; rainfall
; timescale
; China
; Pacific Ocean
; Pacific Ocean (West)
; Qinghai-Xizang Plateau
; South China Sea
英文摘要: This study investigates the features of eastward extension of the South Asian high (SAH) and its connection with diabatic heating and rainfall over eastern Asia on subseasonal time scales. The causes of SAH's eastward extension are examined by potential vorticity (PV) diagnosis with emphasis on the joint role of diabatic heating feedback and midlatitude wave train. The SAH's eastward extension features eastward propagation of a wave train across Eurasia. Among the wave train, the migration of weak high from the western flank of the Tibetan Plateau (TP) to the east of TP contributes to the SAH's eastward extension at the early stage. When the SAH approaches its easternmost position, a strong negative PV (positive geopotential height) center prevails to the east of the TP at 200 hPa. The associated anomalies in diabatic heating and rainfall include the anomalous heating and above-normal rainfall over the South China Sea (SCS) and subtropical western Pacific occurring 12 days before the SAH's easternmost stretch, and then anomalous cooling and below-normal rainfall over the southern foot of the TP and southern China and heating and above-normal rainfall over the northern TP and northern China a week later. The anomalous heating and ascending motion over the northern TP and northern China act to increase negative PV locally at 200 hPa. The cooling and descending induce positive PV over southern China. The north-south dipolar structure of PV anomaly with the climatological northerly flow is favorable to southward advection of a negative PV anomaly at 200 hPa. The anomalous heating over the SCS-western Pacific helps to develop a below-normal rainfall condition over southern China via inducing a lower-level anomalous cyclone over coastal region. These processes are conducive to the SAH's eastward extension at its later stage. © 2015 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50666
Appears in Collections: 气候变化事实与影响
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作者单位: Institute for Climate and Global Change Research, Jiangsu Collaborative Innovation Center for Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing, China
Recommended Citation:
Ren X.,Yang D.,Yang X.-Q.. Characteristics and mechanisms of the subseasonal eastward extension of the South Asian high[J]. Journal of Climate,2015-01-01,28(17)