DOI: 10.1175/JCLI-D-15-0704.1
Scopus记录号: 2-s2.0-84977505671
论文题名: A genesis index for monsoon disturbances
作者: Ditcheka S.D. ; Boos W.R. ; Camargo S.J. ; Tippett M.K.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2016
卷: 29, 期: 14 起始页码: 5189
结束页码: 5203
语种: 英语
Scopus关键词: Atmospheric humidity
; Estimation
; Hurricanes
; Meteorology
; Potential energy
; Regression analysis
; Vorticity
; Absolute vorticity
; Convective available potential energies
; Cyclogenesis/cyclolysis
; Environmental variables
; Low pressure systems
; Monsoons
; Statistical techniques
; Vertical wind shear
; Atmospheric thermodynamics
; climatology
; cyclogenesis
; humidity
; meteorology
; monsoon
; regression analysis
; synoptic meteorology
; vorticity
; Australia
; South Asia
英文摘要: Synoptic-scale monsoon disturbances produce the majority of continental rainfall in the monsoon regions of South Asia and Australia, yet there is little understanding of the conditions that foster development of these low pressure systems. Here a genesis index is used to associate monsoon disturbance genesis in a global domain with monthly mean, climatological environmental variables. This monsoon disturbance genesis index (MDGI) is based on four objectively selected variables: Total column water vapor, low-level absolute vorticity, an approximate measure of convective available potential energy, and midtropospheric relative humidity. A Poisson regression is used to estimate the index coefficients. Unlike existing tropical cyclone genesis indices, the MDGI is defined over both land and ocean, consistent with the fact that monsoon disturbance genesis can occur over land. The index coefficients change little from their global values when estimated separately for the Asian-Australian monsoon region or the Indian monsoon region, suggesting that the conditions favorable for monsoon disturbance genesis, and perhaps the dynamics of genesis itself, are common across multiple monsoon regions. Vertical wind shear is found to be a useful predictor in some regional subdomains; although previous studies suggested that baroclinicity may foster monsoon disturbance genesis, here genesis frequency is shown to be reduced in regions of strong climatological vertical shear. The coefficients of the MDGI suggest that monsoon disturbance genesis is fostered by humid, convectively unstable environments that are rich in vorticity. Similarities with indices used to describe the distribution of tropical cyclone genesis are discussed. © 2016 American Meteorological Society. 资助项目: NSF, Norwegian Nurses Organisation
; ONR, Office of Naval Research
; ONR, Office of Naval Research
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50073
Appears in Collections: 气候变化事实与影响
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作者单位: Yale University, New Haven, CT, United States; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, United States; Center of Excellence for Climate Research, Department of Meteorology, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, NY, United States
Recommended Citation:
Ditcheka S.D.,Boos W.R.,Camargo S.J.,et al. A genesis index for monsoon disturbances[J]. Journal of Climate,2016-01-01,29(14)