DOI: 10.1007/s00382-014-2178-5
Scopus记录号: 2-s2.0-84939898001
论文题名: Modeling winter rainfall in Northwest India using a hidden Markov model: understanding occurrence of different states and their dynamical connections
作者: Pal I. ; Robertson A.W. ; Lall U. ; Cane M.A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 44, 期: 2017-03-04 起始页码: 1003
结束页码: 1015
语种: 英语
英文关键词: Diagnostics
; Northwest India
; Western disturbances
; Winter precipitation
英文摘要: A multiscale-modeling framework for daily rainfall is considered and diagnostic results are presented for an application to the winter season in Northwest India. The daily rainfall process is considered to follow a hidden Markov model (HMM), with the hidden states assumed to be an unknown random function of slowly varying climatic modulation of the winter jet stream and moisture transport dynamics. The data used are from 14 stations over Satluj River basin in winter (December–January–February–March). The period considered is 1977/78–2005/06. The HMM identifies four discrete weather states, which are used to describe daily rainfall variability over study region. Each state was found to be associated with a distinct atmospheric circulation pattern, with the driest and drier states, State 1 and 2 respectively, characterized by a lack of synoptic wave activity. In contrast, the wetter and wettest states, States 3 and 4 respectively, are characterized by a zonally oriented wave train extending across Eurasia between 20N and 40N, identified with ‘western disturbances’ (WD). The occurrence of State 4 is strongly conditioned by the El Nino and Indian Ocean Dipole (IOD) phenomena in winter, which is demonstrated using large-scale correlation maps based on mean sea level pressure and sea surface temperature. This suggests that there is a tendency of higher frequency of the wet days and intense WD activities in winter during El Nino and positive IOD years. These findings, derived from daily rainfall station records, help clarify the sequence of Northern Hemisphere mid-latitude storms bringing winter rainfall over Northwest India, and their association with potentially predictable low frequency modes on seasonal time scales and longer. © 2014, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54537
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Civil Engineering, College of Engineering and Applied Science, University of Colorado Denver, 1200 Larimer Street, Campus Box 116, Denver, CO, United States; International Research Institute for Climate and Society (IRI), The Earth Institute at Columbia University, Palisades, NY, United States; Department of Earth and Environmental Engineering, Columbia University, New York, NY, United States; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
Recommended Citation:
Pal I.,Robertson A.W.,Lall U.,et al. Modeling winter rainfall in Northwest India using a hidden Markov model: understanding occurrence of different states and their dynamical connections[J]. Climate Dynamics,2014-01-01,44(2017-03-04)