THE EFFECT OF THE THERMAL STATE OF EQUATORIAL EASTERN PACIFIC ON THE FREQUENCY OF TYPHOONS OVER WESTERN PACIFIC

Based on the monthly data of thirty years in 1949-1979,we revealed that there are time lag correlations between the freguency of typhoons of the west Pacific and east equatorial Pacific sea surface temperature. It is indicated when the east equatorial Pacific sea surface temperature is colder(warmer) than normal, the latitudinal circulations are stronger(weaker) than normal. These circulations are situated on the both sides of the west Pacific convergence zone formed principally by the east and west wind in the lower atmosphere. As a result, the inter-tropical convergence zone related with the formation of typhoons is more active(less active).