SIMULATION OF ACTIVITY OF THE ASIAN SUMMER MONSOON AND HEAVY RAINFALLS IN CHINA IN 1998 WITH REGIONAL CLIMATE MODEL
LIU Yiming DING Yihui National Climate Center,Beijing 100081
The activity of the Asian summer monsoon and heavy rainfalls in China in 1998 has been simulated by the RegCM-NCC (Regional Climate Model in NCC).The RegCM-NCC can simulate the position of the West Pacific subtropic high very well,especially its maintenance,the first and second northward jumps and retreat.It was successful for RegCM-NCC to capture the whole process of the monsoon onset,active-break cycle and large scale northward advance.The monsoon outbroke in the northern part of the South China Sea on May 17 and then the rainstorm in South China entered a concentrating period.The monsoon completely outbroke over the whole South China Sea (SCS) during May 22 to 25,with the rain season in South China entering peak period. With the onset of Indian monsoon,the monsoon flow over the SCS advanced to the region to the south of the Yangtze River and the Yangtze River Basin and the early summer rainy season in South China came to end.It was successful for RegCM-NCC to reproduce the position and movement of the seasonal rain belt and the moisture transport in 1998 summer in China.The rainy season in China in 1998 summer can be divided into 7 episodes,including the pre-summer rainy season in South China and two episodes of the Meiyu season (the normal and the second Meiyu). The shortcoming of the RegCM-NCC is overestimation of precipitation amounts and moisture transport.