A Heavy Rainfall Event in Autumn over Beijing--Atmospheric Circulation Background and Hindcast Simulation Using WRF  

作　　者：Xiangrui LI Ke FAN Entao YU 

机构地区：[1]Nansen-Zhu International Research Centre,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029 [2]University of Chinese Academy of Sciences,Beijing 100049 [3]Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing 210044 [4]Joint Laboratory for Climate and Environmental Change at Chengdu University of Information Technology,Chengdu 610225

出　　处：《Journal of Meteorological Research》2018年第3期503-515,共13页气象学报（英文版）

基　　金：Supported by the National Nature Science Foundation of China(41325018 and 41421004);State Administration of Foreign Experts Affairs of P.R.China

摘　　要：Heavy rainfall events often occur in Beijing during summer but rarely in autumn. However,during 3-5 September2015, an exceptionally heavy rainfall event occurred in Beijing. Based on the reanalysis data and the Weather Research and Forecasting(WRF) model simulations, the main contributing factors and the predictability of this heavy rainfall event were examined through comprehensive analyses of vorticity advection and water vapor transport/budget. The results indicate that a "high-in-the-east-low-in-the-west" pattern of 500-hPa geopotential height over the Beijing area played an important role. The 850-hPa low-level jet(LLJ) provided a mechanism for rising motion and transported abundant water vapor into the Beijing area. Two-way nested hindcast experiments using WRF well reproduced the atmospheric circulation and LLJ. Quantitative analysis indicates that the WRF model with the rapid update cycle(RUC) land surface scheme and the single-moment 6-class(WSM6) microphysics scheme exhibited the best skill, and the model performance improved with a higher resolution. Further analysis indicates that the bias in the precipitation forecast was caused by the bias in water vapor transport.Heavy rainfall events often occur in Beijing during summer but rarely in autumn. However,during 3-5 September2015, an exceptionally heavy rainfall event occurred in Beijing. Based on the reanalysis data and the Weather Research and Forecasting(WRF) model simulations, the main contributing factors and the predictability of this heavy rainfall event were examined through comprehensive analyses of vorticity advection and water vapor transport/budget. The results indicate that a "high-in-the-east-low-in-the-west" pattern of 500-hPa geopotential height over the Beijing area played an important role. The 850-hPa low-level jet(LLJ) provided a mechanism for rising motion and transported abundant water vapor into the Beijing area. Two-way nested hindcast experiments using WRF well reproduced the atmospheric circulation and LLJ. Quantitative analysis indicates that the WRF model with the rapid update cycle(RUC) land surface scheme and the single-moment 6-class(WSM6) microphysics scheme exhibited the best skill, and the model performance improved with a higher resolution. Further analysis indicates that the bias in the precipitation forecast was caused by the bias in water vapor transport.

关 键 词：heavy rainfall WRF model water vapor supply AUTUMN Beijing area 

分 类 号：P426.62[天文地球—大气科学及气象学] P434