This morning NASA launched Aquarius/SAC-D, a satellite designed to measure from space the one characteristic that most distinguishes the ocean from other bodies of water – its salt concentration or salinity. Salinity fundamentally affects the biology, chemistry, and physics of the ocean, yet remains largely unmeasured throughout much of the world’s waters.
Traditional salinity measurements require ship-based deployment of instruments lowered into the water, so historical data exist only where survey vessels have gone. Such ship-based work will still be necessary, but Aquarius will provide large-scale images of sea surface salinity worldwide and much more frequently than can be achieved by ships alone. While optimized for ocean salinity measurements, Aquarius can also measure soil moisture.
Aquarius is the product of an international collaborative effort between NASA and the Argentine space agency, with contributions by Canada, France, Brazil, and Italy. This new capability will enhance and complement the European Space Agency’s Soil Moisture and Ocean Salinity satellite designed primarily to measure soil moisture.
Aquarius will also bolster efforts related to our National Ocean Policy, which was created by Executive Order last July and has nine priority objectives, including ocean observing. The new capability that Aquarius promises will enhance our ability to deliver on many of the Policy’s other objectives such as on climate change, water quality, conditions in the Arctic, and improvement of our understanding of ocean processes. These in turn will support ecosystem management objectives.
The first remotely sensed image of sea surface salinity was produced in 1998 using an airborne instrument, and this helped to pave the way for the decade-long effort that led to today’s launch. As the person who led that airborne effort, and as someone now closely involved in the Administration’s ocean policy activities, I am very pleased to congratulate the Aquarius team on a successful launch and I look forward to seeing the scientific results.
Jerry Miller is Assistant Director for Ocean Sciences at the White House Office of Science and Technology Policy