Abstract:Based on the high resolution ocean-atmosphere data from 1982 to 2015, this study reveals the ocean-atmosphere relationship in the equatorial Indian Ocean on the inter-annual timescale in terms of the correlation between the Sea Surface Temperature (SST) and sea surface wind speed. The results show that the ocean-atmosphere relationship in Indian Ocean manifests significant regional and seasonal characteristics. The correlation between the SST and surface wind speed anomalies appearred positive only in the western equatorial Indian Ocean and southeast equatorial Indian Ocean during summer (July-September), which was manifested as ocean-to-atmosphere forcing, while the correlations in other regions and months were all negative, which was manifested as atmosphere-to-ocean forcing. The regression analysis shows that the SST anomalies in the western equatorial Indian Ocean during the summer might influence the sea surface wind field via the sea level pressure adjustment mechanism, that is, the sea temperature increase made the boundary layer air warmer, leading to the increase of convergence of sea surface wind field, and vice versa. In addition, the AM2.1 model was used for the simulation test. The test results successfully reproduced the positive correlation between the surface temperature of the western equatorial Indian Ocean and the sea surface wind speed in summer.