This map is the result of one very busy month of data collected by NASA's Aquarius instrument, offering the first ever global map of the ocean surface's saltiness. This information has potentially profound implications for our understanding of changing climates.
You can click on the map up top to get a closer look at Aquarius's work. The map is crucial because the way that salinity varies from place to place along the ocean surface plays a key role in the climate cycle. This is because salt levels are linked to the movement of freshwater all around the planet, as well as the circulation of ocean currents in general. Before Aquarius, we've only had a rough idea of how salinity varies in different locations, so this map provides a vital new clue in the effort to understand the deeper mechanisms of Earth's climate.
NASA's Jet Propulsion Laboratory offers this explanation of some of the key features:
The map shows several well-known ocean salinity features such as higher salinity in the subtropics; higher average salinity in the Atlantic Ocean compared to the Pacific and Indian oceans; and lower salinity in rainy belts near the equator, in the northernmost Pacific Ocean and elsewhere. These features are related to large-scale patterns of rainfall and evaporation over the ocean, river outflow and ocean circulation. Aquarius will monitor how these features change and study their link to climate and weather variations.
Other important regional features are evident, including a sharp contrast between the arid, high-salinity Arabian Sea west of the Indian subcontinent, and the low-salinity Bay of Bengal to the east, which is dominated by the Ganges River and south Asia monsoon rains. The data also show important smaller details, such as a larger-than-expected extent of low-salinity water associated with outflow from the Amazon River.