Presented at the 2018 Ocean Sciences MeetingThe accuracy of satellite-observed sea surface salinity (SSS) in the northwest Pacific was evaluated by comparing with in situ salinity measurements from Argo floats and buoys. Differences between satellite SSS and in situ measurements indicated their dependence on geolocation, sea surface temperature (SST), and other oceanic and atmospheric conditions. SSS errors tended to be decreased under conditions of relatively high SST, low salinity, low latitudes, and summer. Such conditions suggest the potential for using satellite SSS to examine typhoons in tropical regions. We investigated the responses of the upper ocean by analyzing changes in SSS and SST during typhoon events. Peculiar freshening of SSS detected in the left side of the typhoon correlated more strongly with higher precipitation in the left side than that in the right side. The freshening rate to the precipitation rate was about -0.0401 psu/mm/h with statistical significance. This freshening appeared at an initial stage of the typhoon rather than its latter half. This spatially different pattern was verified by Argo measurements. Changes in the vertical profiles of Argo salinity supported the partial freshening shown in the satellite observations as well as the characteristic surface cooling and deepening of the mixed layer after the typhoon passed.