WindSat and RAMA Buoy: a comparison of ocean-atmosphere data

Ocean-atmosphere data deployed along the equatorial Indian Ocean were used for validating the ocean-atmosphere data recorded by the WindSat satellite. Three RAMA Buoys mounted at 67 °E, 80.5°E and 90 °E along the equator were used to evaluate the sea surface temperature (SST), wind speeds and precipitation obtained by the WindSat satellite, except for precipitation in the eastern equatorial Indian Ocean. The SST from WindSat shows significant correlation with that from RAMA Buoy, with coefficient correlations of 0.95, 0.88 and 0.83, respectively. The root mean square errors (RMSEs) of the WindSat SST relative to RAMA Buoy data were 0.28, 0.29 and 0.32 °C, respectively. In this study, the quality performances of the WindSat wind speed were also satisfactory, with coefficient correlation of 0.64, 0.7 and 0.58 in each RAMA buoy. The corresponding RMSEs of the wind speeds were 1.46, 1.37 and 1.63 ms−1. Meanwhile, the WindSat precipitations reveal weak correlation with RAMA Buoy data, in particular in the eastern equatorial Indian Ocean. Overall, the WindSat satellite data for each measurement parameters can be used to replace in-situ observation data after taking into account the measurement errors