LONG-RANGE CHANGES OF CORRELATION BETWEEN THE TYPHOON FREQUENCIES IN SEVEN REGIONS IN EAST ASIA AND SEA SURFACE TEMPERATURE IN THE NORTH PACIFIC

The correlation coefficients between the typhoon frequencies for the seven regions in East Asia (i.e.Xisha, Guangzhou, Xiamen, Shanghai, Naha, Kagoshima and Nagoya) and the monthly-mean sea surface temperature (SST) from 2 years before to 1 year after are calculated, indicating that the most significant correlation appears in the period from the summer of 2 years before to the summer of 1 year before.During this period negative correlations are located in the northwestern part of the North Pacific while the positive ones located in the southeastern part.It is found that the positive correlations change into the negative ones in Equatorial East Pacific in the same year (simultaneous correlation).The high-level correlation region in 1 year after is found in the area of Alaska Current.It is also suggested that there are interannual variations of about 1, 1.5 and 2 years for the changes of the correlation intensity.