A NUMERICAL SIMULATION STUDY OF TYPHOON RANANIM

Using the high resolutions non-hydrostatic model ARPS, the typhoon Rananim (0414) was simulated by using the Cinrad Doppler radar data, the results before and after typhoon landfall show that ARPS performs well to simulate the track, the variation of center pressure as well as the severe heavy rain of Rananim. Meanwhile, the simulated composite radar reflectivity was compared with radar observed composite reflectivity. The numerical results reveal that the asymmetrical structure of Rananim plays an important role in it's westward deflecting after landfall. The sensitivity simulation experiments of terrain effect on Rananim were also investigated, the terrain of the Southeast China forces Ranarim turning right slightly on its motion and increased its intensity obviously when typhoon is far away from the coastline, while the terrain only impacts slightly on storm intensity when it landfall. The results show that topographic lifting contributes greatly to precipitation enhancement, and makes its distribution of precipitation more uneven.