Evolutions of flow field and heat exchange on equatorial Pacific surface in El Nino-La Nina cycle

Abstract-In this paper, the monthly averages and deviations of temperature, pressure, tonal wind, specific humidity, cloud rover and the components of heat budget have been remputed on the equatorial (5°S-3°N) Pacific surface (EPS) based on the 2^*×2^* grid data of CORDS from 1950 to 1987 and the evolutions of tt0ese elements have been provided. Two feedback mechanisms of El Nino-La Nina cycle which include the dynamic, thermal and hydrological processes in the coupled air-sea system are verified. During El Nino, the pressure gradient and trade wind decreased on the EPS, the sensible and latent heat exchanges enlarged on the central-eastern EPS, the water vapor and cloud cover rose in the atmo sphere, the net longwave radiation and incident solar radiation decreased and the net gain (loss) of the heat reduced (increased) on the central and eastern EPS:During La Nina the circumstances were opposite