THE COUPLING RELATIONSHIP BETWEEN TROPICAL UPPER SEA TEMPERATURE FIELD AND EAST ASIAN SUMMER MONSOON

In order to study the variability of the upper sea temperature in the tropical Pacific and Indian Oceans and reveal their coupling relationship with East Asian summer monsoon circulation, the singular value decomposition is employed to reveal the variation of 120 m sea temperature in the tropical Pacific and Indian Oceans, the main modalities of anomalous activities of the East Asian summer monsoon, and their mutual relation.The results show that during the summer of years with strong summer monsoon, the western Pacific subtropical high is weak and its location is northerly.In years with strong summer monsoon, the sinking movement of vertical velocity anomalies in East Asia weakens the Meiyu front and vice versa.When the 850 hPa east trade winds in the equatorial central and eastern Pacific Ocean are enhanced, the middle Indian Ocean and the western Pacific Ocean show westerly anomalies.Meanwhile, if the meridional wind anomalies on both sides of the equator in the central Indian Ocean/ eastern Pacific and East Asia show a clear convergent and divergent pattern, respectively, the corresponding 120 m sea temperature shows a La Niña state and is easy to trigger the strong East Asian summer monsoon.