DOI: 10.1007/s00382-015-2784-x
Scopus记录号: 2-s2.0-84939188528
论文题名: Monsoon-extratropical circulation interactions in Himalayan extreme rainfall
作者: Vellore R.K. ; Kaplan M.L. ; Krishnan R. ; Lewis J.M. ; Sabade S. ; Deshpande N. ; Singh B.B. ; Madhura R.K. ; Rama Rao M.V.S.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 46, 期: 2017-11-12 起始页码: 3517
结束页码: 3546
语种: 英语
英文关键词: Ageostrophic transverse circulations
; Extreme precipitation events
; Indian summer monsoon
; Midlatitude interactions
英文摘要: Extreme precipitation and flood episodes in the Himalayas are oftentimes traced to synoptic situations involving connections between equatorward advancing upper level extratropical circulations and moisture-laden tropical monsoon circulation. While previous studies have documented precipitation characteristics in the Himalayan region during severe storm cases, a comprehensive understanding of circulation dynamics of extreme precipitation mechanisms is still warranted. In this study, a detailed analysis is performed using rainfall observations and reanalysis circulation products to understand the evolution of monsoon-extratropical circulation features and their interactions based on 34 extreme precipitation events which occurred in the Western Himalayas (WEH) during the period 1979–2013. Our results provide evidence for a common large-scale circulation pattern connecting the extratropics and the South Asian monsoon region, which is favorable for extreme precipitation occurrences in the WEH region. This background upper level large-scale circulation pattern consists of a deep southward penetrating midlatitude westerly trough, a blocking high over western Eurasia and an intensifying Tibetan anticyclone. It is further seen from our analysis that the key elements of monsoon-midlatitude interactions, responsible for extreme precipitation events over the WEH region, are: (1) midlatitude Rossby wave breaking, (2) west-northwest propagation of monsoon low-pressure system from the Bay of Bengal across the Indian subcontinent, (3) eddy shedding of the Tibetan anticyclone, (4) ageostrophic motions and transverse circulation across the Himalayas, and (5) strong moist convection over the Himalayan foothills. Furthermore, high-resolution numerical simulations indicate that diabatic heating and mesoscale ageostrophic effects can additionally amplify the convective motions and precipitation in the WEH region. © 2015, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53691
Appears in Collections: 过去全球变化的重建
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作者单位: Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India; Desert Research Institute, Reno, NV, United States; National Severe Storms Laboratory, Norman, OK, United States
Recommended Citation:
Vellore R.K.,Kaplan M.L.,Krishnan R.,et al. Monsoon-extratropical circulation interactions in Himalayan extreme rainfall[J]. Climate Dynamics,2016-01-01,46(2017-11-12)