北西太平洋における海面水温と台風の発達の間の関係

Abstract

The monthly mean data of sea surface temperature (SST) of COADS (Comprehensive Ocean-At-mospheric Data Set) was analyzed in relation with tropical cyclone activity in the Northwest Pacific in the period from 1951 to 1985.The original data of SST for mesh of two degree latitude and longitude interval is smoothed over five meshes to incooperate the scale of a tropical cyclone.The probability of tropical storm genesis shows the maximum value over the sea area with SST of 28.0-30.0℃.In the region with SST lower than 28.0℃, the probability decreases sharply with decreasing of SST. And in the region higher than 30.0℃ the probability also decreases.The interannual variation of the sea area with SST in 29.0-30.0℃ is distinct. The annual total area with SST of 29.0-30.0℃ decrease in 1965, 72, 75, 76, and 82 distinctively.In these years except for 1975, El Nino Event occurred in the Eastern Equatorial Pacific, and it is considered that the event caused to reduce the area with SST in 29.0-30.0℃.In these years, the area with SST in 28.0-29.0℃ increases conversely.Therefore, the total area of 28.O-29.0ｰC does not change significantly, and tropical storm genesis does not change largely even El Nino year.The annual number of tropical strom genesis in the area under study changes with the area with SST in 28.0-30.0℃, with the correlation coefficient of 0.57.The deepening rate of central pressure increases with SST in the latitudal belts except for 6-8ﾟN.The deepening of central pressure is distinct between 130ﾟE and 160ﾟE, where SST is higher than the other longitudal zones.