Assessment of Dynamic Downscaling of the Extreme Rainfall over East Asia Using a Regional Climate Model  

作　　者：高艳红 Yongkang XUE 彭雯 Hyun—Suk KANG Duane WALISER 

机构地区：[1]Laboratory for Climate Environment and Disasters of Western ChinaCold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences, Lanzhou 730000 [2]Department of Geography and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA [3]Climate Research Laboratory National Institute of Meteorological Research Korea Meteorological Administration, Korea [4]Jet Propulsion Laboratory/California Institute of Technology, California, USA

出　　处：《Advances in Atmospheric Sciences》2011年第5期1077-1098,共22页大气科学进展（英文版）

基　　金：supported by the funding of the Key Program of the Chinese Academy of Sciences (Grant No.KZCX2-YW-328);the National Key Basic Research Program (2005CB422003);National Science Foundation Center of China (NSFC) (40871001);the US JPL Grant No. 1278492,NOAA Grant Nos NA07OAR4310226 and NA08OAR4310591

摘　　要：This study investigates the capability of the dynamic downscaling method （DDM） in an East Asian climate study for June 1998 using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research non-hydrostatic Mesoscale Model （MM5）.Sensitivity experiments show that MM5 results at upper atmospheric levels cannot match reanalyses data,but the results show consistent improvement in simulating moisture transport at low levels.The downscaling ability for precipitation is regionally dependent.During the monsoon season over the Yangtze River basin and the pre-monsoon season over North China,the DDM cannot match observed precipitation.Over Northwest China and the Tibetan Plateau （TP）,where there is high topography,the DDM shows better performance than reanalyses.Simulated monsoon evolution processes over East Asia,however,are much closer to observational data than reanalyses.The convection scheme has a substantial impact on extreme rainfall over the Yangtze River basin and the pre-monsoon over North China,but only a marginal contribution for Northwest China and the TP.Land surface parameterizations affect the locations and pattern of rainfall bands.The 10-day re-initialization in this study shows some improvement in simulated precipitation over some sub-regions but with no obvious improvement in circulation.The setting of the location of lateral boundaries （LLB） westward improves performance of the DDM.Including the entire TP in the western model domain improves the DDM performance in simulating precipitation in most sub-regions.In addition,a seasonal simulation demonstrates that the DDM can also obtain consistent results,as in the June case,even when another two months consist of no strong climate/weather events.This study investigates the capability of the dynamic downscaling method （DDM） in an East Asian climate study for June 1998 using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research non-hydrostatic Mesoscale Model （MM5）.Sensitivity experiments show that MM5 results at upper atmospheric levels cannot match reanalyses data,but the results show consistent improvement in simulating moisture transport at low levels.The downscaling ability for precipitation is regionally dependent.During the monsoon season over the Yangtze River basin and the pre-monsoon season over North China,the DDM cannot match observed precipitation.Over Northwest China and the Tibetan Plateau （TP）,where there is high topography,the DDM shows better performance than reanalyses.Simulated monsoon evolution processes over East Asia,however,are much closer to observational data than reanalyses.The convection scheme has a substantial impact on extreme rainfall over the Yangtze River basin and the pre-monsoon over North China,but only a marginal contribution for Northwest China and the TP.Land surface parameterizations affect the locations and pattern of rainfall bands.The 10-day re-initialization in this study shows some improvement in simulated precipitation over some sub-regions but with no obvious improvement in circulation.The setting of the location of lateral boundaries （LLB） westward improves performance of the DDM.Including the entire TP in the western model domain improves the DDM performance in simulating precipitation in most sub-regions.In addition,a seasonal simulation demonstrates that the DDM can also obtain consistent results,as in the June case,even when another two months consist of no strong climate/weather events.

关 键 词：DDM MM5 cumulus convection scheme land parameterization RE-INITIALIZATION lateral boundary location 

分 类 号：P458.121[天文地球—大气科学及气象学]