Maps, Graphs, and Data

Energy and Matter: Aquarius Sea Surface Salinity (2011-2014)

Aquarius Sea Surface Salinity

Salinity is key to studying the water cycle and ocean circulation, both of which are related to climate. Over decades, the amount of salt in ocean basins has been fairly stable. The water cycle operates on much faster time scales, however, causing changes in salinity patterns.

Changes in sea surface salinity (concentration of dissolved salt), provide a fingerprint of Earth's freshwater cycle. Salinity decreases when freshwater enters the ocean from rivers, melting ice, rain and snow. Processes that cause freshwater to exit the ocean such as evaporation and formation of sea ice raise salinity. Differences in dissolved salt content also play a major role in moving seawater, and the heat it carries, around the globe.

This visualization shows sea surface salinity observations (September 2011-September 2014) from the Aquarius/SAC-D mission, a collaboration between NASA and the Space Agency of Argentina. The data is shown on a spinning globe.

Higher salinity areas are shown in red. These regions of high evaporation are sometimes called "ocean deserts." Blue colors represent lower salinities, resulting from freshwater inputs into the ocean. These include Amazon River outflow that appears as a ribbon-like feature in the tropical Atlantic, a zone of persistent rainfall that spans the tropical Pacific, and melting ice near Earth's poles.

View the Video Interview (2015) with visualizer Kel Elkins for a guided walk through of this visualization, starting at 1:25.

Credit: NASA Scientific Visualization Studio