Interrelationships between Tropical North Pacific Atmospheric Circulation, Explosive Volcanism, Sea Surface Temperature and Western North Pacific Tropical Storms and Typhoons.

Time series of surface atmospheric pressure and sea surface temperature are presented for three areas spanning the tropical North Pacific Equator to 15N from the Central American coast to the coast of Asia. Surface pressure time series are shown for the period between 1946 and 1974, while sea surface temperature data and presented for the period between 1962 and 1974. The relation between the Northern Hemisphere manifestation of Walkers Southern Oscillation and the occurrence of warm and cold sea surface temperatures in the eastern tropical Pacific is shown to support estimates of transport by the Equatorial Countercurrent. Large stratospheric injections of dust and gas by volcanic eruption are shown to generally preceed marked increases in the estimated transport by the Equatorial Countercurrent. Minima of tropical storm and typhoon frequency in the tropical northwest Pacific especially since 1957 are shown to be associated with low east-west pressure across the equatorial Pacific while frequency maxima are associated with high east-west pressure differences.