Climatology of Explosive Cyclones off the East Asian Coast

The climatology of explosive cyclogenesis off the east Asian coast was studied, based on 30 years (1958–87) of surface analyses. There were two favorable areas for explosive deepening, one over the eastern Sea of Japan, and the other over the northwestern Pacific, east and southeast of Japan. The latter was located close to the warm Kuroshio Current. The frequency of explosive cyclogenesis reached a local minimum over Japan. The geographic distribution of explosive-cyclone frequency suggests that the explosive cyclogenesis is influenced by the Japanese islands. In addition, a positive correlation is found between explosive-cyclogenesis frequency and the El Niño episodes during 1958–87. The physical relationship between these two phenomena, however, is not well understood.