DOI: 10.1007/s00382-016-2990-1
Scopus记录号: 2-s2.0-84988650152
论文题名: A statistical downscaling model for summer rainfall over Pakistan
作者: Kazmi D.H. ; Li J. ; Ruan C. ; Zhao S. ; Li Y.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 47, 期: 2017-07-08 起始页码: 2653
结束页码: 2666
语种: 英语
英文关键词: CGT
; CVSR
; ENSO
; Interannual model
; Summer monsoon
英文摘要: A statistical approach is utilized to construct an interannual model for summer (July–August) rainfall over the western parts of South Asian Monsoon. Observed monthly rainfall data for selected stations of Pakistan for the last 55 years (1960–2014) is taken as predictand. Recommended climate indices along with the oceanic and atmospheric data on global scales, for the period April–June are employed as predictors. First 40 years data has been taken as training period and the rest as validation period. Cross-validation stepwise regression approach adopted to select the robust predictors. Upper tropospheric zonal wind at 200 hPa over the northeastern Atlantic is finally selected as the best predictor for interannual model. Besides, the next possible candidate ‘geopotential height at upper troposphere’ is taken as the indirect predictor for being a source of energy transportation from core region (northeast Atlantic/western Europe) to the study area. The model performed well for both the training as well as validation period with correlation coefficient of 0.71 and tolerable root mean square errors. Cross-validation of the model has been processed by incorporating JRA-55 data for potential predictors in addition to NCEP and fragmentation of study period to five non-overlapping test samples. Subsequently, to verify the outcome of the model on physical grounds, observational analyses as well as the model simulations are incorporated. It is revealed that originating from the jet exit region through large vorticity gradients, zonally dominating waves may transport energy and momentum to the downstream areas of west-central Asia, that ultimately affect interannual variability of the specific rainfall. It has been detected that both the circumglobal teleconnection and Rossby wave propagation play vital roles in modulating the proposed mechanism. © 2016, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53502
Appears in Collections: 过去全球变化的重建
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作者单位: State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; College of Global Change and Earth System Sciences (GCESS), Beijing Normal University, Beijing, China; Joint Center for Global Change Studies, Beijing, China; North China Sea Marine Forecasting Center of State Oceanic Administration, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
Recommended Citation:
Kazmi D.H.,Li J.,Ruan C.,et al. A statistical downscaling model for summer rainfall over Pakistan[J]. Climate Dynamics,2016-01-01,47(2017-07-08)