Modeling of the 1998 East Asian Summer Monsoon by a limited area model with P-sigma incorporated coordinate

The 1998 East Asian Summer Monsoon is simulated by use of an improved nine- level p-sigma model the boundary forcing is the South China Sea Monsoon Exp eriment (SCSMEX) reanalysis data from May 1 to August 31, 1998. It is found that basic features of the atmospheric circulation (such as the South Asia high and the West Pacific subtropical high) can be simulated fairly. Howev er the South Asia high is a little stronger than the observed, while the We st Pacific subtropical high a little weaker. Seen from variations of the ti me correlation coefficient, this model is good for the short-time climate s imulation (less than two months), while for the long-time simulation, its c limate drift is a little obvious. It can be also seen from the spatial dist ribution of correlation coefficient that the worse simulation areas of the model are located in the Tibetan Plateau and the adjacent northwest Indo-Ch ina Peninsula. For the simulation of precipitation, the movement of rain be lt from May to June can be simulated, but the simulation of July and August precipitation shifts obviously to north of the observed. It is also found from the analysis of sensitive experiment that the improvement of the neste d boundary condition has a great impact on the simulation results, especial ly on the precipitation, so the model and the nesting technique need furthe r improvements.