The instrument forms part of the Aquarius/SAC-D (Satélite de Aplicaciones Científicas) observatory, a collaboration between NASA and Argentina’s space agency, Comisión Nacional de Actividades Espaciales. The observatory was launched on 10 June, and Aquarius itself became operational on 25 August. The new map represents a composite
of the data it has collected since then.

‘Aquarius’ salinity data are showing much higher quality than we expected to see this early in the mission,’ said the project’s principal investigator, Gary Lagerloef of Earth & Space Research in Seattle. ‘Aquarius will soon allow scientists to explore the connections between global rainfall, ocean currents and climate variations.’

The new map demonstrates Aquarius’ ability to detect large-scale salinity distribution features clearly and with sharp contrast. It includes a number of well-known ocean-salinity features, such as the 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 future, scientists will be able to use Aquarius to monitor how these features change over time and study how they are linked to climate and variations in the weather.

‘This is a great moment in the history of oceanography,’ said Aquarius science team member Arnold Gordon, of Columbia University in New York. ‘The first image raises many questions that oceanographers will be challenged to explain.’