Presented at the 2014 Ocean Sciences MeetingEvidence from Aquarius and SMOS suggests that the spatial distribution of sea surface salinity (SSS) in low-salinity basins has different characteristics. For instance, in the Bering Sea of the subpolar North Pacific Ocean, a SSS front is visible along the shelf break and slope that confines much of the fresh waters to the shallow shelf region. In the Bay of Bengal of the eastern tropical Indian Ocean, the fresh surface layer extends beyond the shelf break all the way into the interior basin. The far eastern tropical Pacific freshwater pool is dictated not only by precipitation but also by oceanic processes. Questions arise as to why the low-salinity distribution can be steered by seafloor topography in one basin but not in the others, and what are relative contributions of freshwater forcing versus ocean dynamic processes to observed SSS variability. An improved understanding of these questions is prerequisite for understanding where and how ocean salinity can be used as a rain gauge for the global water cycle. This study will provide some answers to these questions.