DOI: 10.1007/s00382-013-1797-6
Scopus记录号: 2-s2.0-84897527428
论文题名: Sub-seasonal interannual variability associated with the excess and deficit Indian winter monsoon over the Western Himalayas
作者: Dimri A.P.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 42, 期: 2017-07-08 起始页码: 1793
结束页码: 1805
语种: 英语
英文关键词: Indian winter monsoon
; Sub-seasonal interannual variability
; Western Himalayas
英文摘要: During the winter season (Dec., Jan., and Feb.; DJF) the western Himalaya (WH) receives one-third of its annual precipitation due to Indian winter monsoon (IWM). The IWM is characterized by eastward-moving synoptic weather systems called western disturbances. Seasonal interannual precipitation variability is positively correlated with monthly interannual variabilities. However, it was found that the monthly interannual variabilities differ. The interannual variability for Jan. is negatively correlated with that for Dec. and Feb. Because the entire seasonal interannual variability is in phase with the El Niño Southern Oscillation, it is interesting to investigate such contrasting behavior. Composite analysis based on extreme wet and dry seasons indicates that Dec. and Feb. precipitation variabilities have a high positive (low negative) correlation with eastern (western) equatorial Pacific warming (cooling), whereas Jan. precipitation variability exhibits negligible correlations. Seasonal mid/upper tropospheric cooling over the Himalayas enhances anomalous cyclonic circulation, which along with suppressed convection over the western equatorial Pacific, shifts the 200-hPa subtropical westerly jet southward over the Himalayas. Due to the upper tropospheric anomalous cyclonic circulation, mass transfer favors anticyclone formation at the mid/lower troposphere, which is enhanced in Jan. due to a warmer mid troposphere and hence decreases precipitation compared with Dec. and Feb. Additionally, a weakening of meridional moisture flux transport from the equatorial Indian Ocean to WH is observed in Jan. Further analysis reveals that mid-tropospheric and surface temperatures over WH also play dominant roles, acting as local forcing where the preceding month's surface temperature controls the succeeding month's precipitation. © 2013 Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54632
Appears in Collections: 过去全球变化的重建
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作者单位: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
Recommended Citation:
Dimri A.P.. Sub-seasonal interannual variability associated with the excess and deficit Indian winter monsoon over the Western Himalayas[J]. Climate Dynamics,2014-01-01,42(2017-07-08)