摘要
Based on the analysis of tropical cyclone （TC） database in the Northwest Pacific （NWP） from 1945 to 2008, we not only extract the temporal variation of TC intensity and frequency, but also give their spatial distribution both in the NWP and in the South China Sea （SCS）. The results show that there is an observational increase of TC activities, which manifests as the enhancement of the power dissipation index （PDI） and the growth of TC frequency, especially for typhoons and strong typhoons. The inbomogeneous spatial distributions of TC frequency and intensity are also provided both in the NWP and in the SCS. For example, the region of Zhongsha Islands and Dongsha Islands in the SCS （15°-22°N, 115° - 120°E）, west to the Philippine Islands is the place with frequent occurrence of strong typhoons, among which the wind speed of 7 TCs in 64 years exceeds 60 m/s.
Based on the analysis of tropical cyclone （TC） database in the Northwest Pacific （NWP） from 1945 to 2008, we not only extract the temporal variation of TC intensity and frequency, but also give their spatial distribution both in the NWP and in the South China Sea （SCS）. The results show that there is an observational increase of TC activities, which manifests as the enhancement of the power dissipation index （PDI） and the growth of TC frequency, especially for typhoons and strong typhoons. The inbomogeneous spatial distributions of TC frequency and intensity are also provided both in the NWP and in the SCS. For example, the region of Zhongsha Islands and Dongsha Islands in the SCS （15°-22°N, 115° - 120°E）, west to the Philippine Islands is the place with frequent occurrence of strong typhoons, among which the wind speed of 7 TCs in 64 years exceeds 60 m/s.
基金
supported by the National High Technology Research and Development Program of China(863 Program,Grant No.2006AA09A103-4)
the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KJCX-YW-L02)
