EXPERIMENTS ON ASSIMILATION OF INITIAL VALUES IN NUMERICAL PREDICTION OF A WARM-SECTOR PRECIPITATION IN SOUTH CHINA

In order to understand the impact of initial conditions upon prediction accuracy of short-term forecast and nowcast of precipitation in South China,four experiments i.e. a control,an assimilation of conventional sounding and surthce data,testing with nudging rainwater data and the assimilation of radar-derived radial wind,are respectively conducted to simulate a case of warm-sector heavy rainfall that occurred over South China,by using the GRAPES MESO model. The results show that (I) assimilating conventional surface and sounding observations helps improve the 24-h rainfall forecast in both the area and order of magnitude; (2) nudging rainwater contributes to a significant improvement of nowcast,and (3)the assimilation of radar-derived radial winds distinctly improves the 24-h rainfall forecast in both the area and order of magnitude. These results serve as signiticant technical reference for the study on short-term forecast and nowcast of precipitation over South China in the thture.

作 者： ZHANG Cheng-zhong WAN Qi-lin HUANG Yan-yan CHEN Zi-tong DING Wei-yu   作者單位： Guangzhou Institute of Tropical and Marine Meteorology,CMA,Guangzhou 510080 China  刊 名： 熱帶氣象學報(英文版)  英文刊名： JOURNAL OF TROPICAL METEOROLOGY  年，卷(期)： 2009 15(1)  分類號： P435  關鍵詞： South China   initial conditions   warm-sector precipitation   numerical simulation experiment