SMAP Maps: Sea Surface Salinity (Northern Hemisphere)

NASA's Soil Moisture Active Passive (SMAP) mission began collecting sea surface salinity data in April 2015, overlapping with Aquarius observations for approximately three months. Using the same frequency as Aquarius (L-band; 1.41 GHz), SMAP's global salinity measurements continue the time series that began with Aquarius in August 2011.

The maps in this slideshow are generated from Version 4.0 (V4) of the SMAP sea surface salinity Level-3 (mapped) data. These monthly averaged data are gridded at 25 x 25 km (15.5 X 15.5 mi) resolution, with an approximate spatial resolution of 70km. They show a range of salinities from 33 to 38 using the Practical Salinity Scale (PSS; Lewis, 1980), which is roughly equivalent to parts per thousand. PSS and PSU (Practical Salinity Units, which is also used), are different names for the same thing.

Dark blues and purples represent lower salinities while reds show areas of higher sea surface salinity.

Click here to view a slideshow of sea surface salinity in the southern hemisphere.