OCEAN · SEA SURFACE SALINITY

Sea Surface Salinity

How salty the sea surface is — a live global map of the ocean’s dissolved-salt content, the partner of temperature in setting how dense seawater is and what drives the deep currents. Fresh purples mark the great river plumes (Amazon, Congo, Ganges) and the rainy equator; salty yellows mark the evaporating subtropical gyres and the Mediterranean and Red Sea. Salinity is a rain-gauge for the whole planet, tracing Earth’s evaporation and rainfall belts and feeding the global overturning. Updated daily as an 8-day running mean from NASA’s SMAP mission.