Impact of Satellite-Derived Precipitation on Simulated Sea-Surface Salinity in the Tropical Indian Ocean

The impact of satellite-derived precipitation on variability of sea-surface salinity (SSS) in the tropical Indian Ocean has been studied using an ocean general-circulation model. Two different experiments have been conducted. In one of the experiments, the model has been forced by precipitation derived from National Center for Environmental Prediction (NCEP) reanalysis, while in the other one, the model has been forced by satellite-derived precipitation. The time span of the experiments is 2003-2005. The simulations have been compared with data from buoy located at 90°E and 1.5°. The comparison suggests that the simulation forced by satellite precipitation captures the high-frequency variability much better than that forced by NCEP precipitation. The reason for this lies in the fact that the regions of high-frequency variability in SSS coincide with the regions of high-frequency variability in the satellite precipitation. As far as the low-frequency part of the SSS variability is concerned, it was found that this was governed by advective process. Hence, satellite precipitation does not have significant impact on this scale of variability.