Regional Climate Modeling on the Multi-Timescale Oscillation of Precipitation over China in the Summer of 1998

The comparison study on the ability of regional climate model to describe the multi-timescale oscillation of precipitation over climatic subregions of China was conducted,in terms of the wavelet decomposition technique,based on a seasonal scale regional climate modeling to the summer of 1998 with RegCM3.The results show that the model can reproduce the scenario of monthly precipitation over subregions,as well as the withdraw/extension of precipitation belt over eastern China,but the discrepancy of simulated and observed temporal variation of daily precipitation is significant.Generally,the simulated precipitation at lower-frequency is better than that at higher-frequencies,and the error for the simulation to high-frequency precipitation is bigger basically.There exist the main precipitation oscillations in each climatic subregion.The main precipitation oscillations over Southern China(with lower-frequency and 8-day period) and over the lower and middle reaches of Yangtze River(with 4-day period) are simulated in a precise manner,which is the reason why the precipitation is reproduced well over those subregions in the summer of 1998.