CryoSat-2 Data Used to Make First Complete Map of Ocean Dynamic Topography in Arctic
22.12.2010 - Atmosphere & Space, Water & Oceans, Ice & Snow, Bi-polar
ESA’s CryoSat-2 satellite, which was launched in April 2010, has produced the first complete picture of ocean dynamic topography in the Arctic Ocean – its first major scientific accomplishment – according to presentation at the American Geophysical Union (AGU) Fall Meeting. While the primary mission of the satellite is to measure sea-ice thickness, its ability to map the shape of the sea surface allows scientists to determine whether Arctic currents are changing as a result of winds blowing more freely on ice-free waters.
CryoSat-2 features one of the highest resolution synthetic aperture radars (SAR) ever put into orbit. This instrument sends pulses of microwave energy which bounce off the surface of the sea-ice and water in the leads between sections of sea ice. Measuring the difference in height between these two surfaces, scientists can calculate the overall volume of the marine ice cover in the Arctic. However CryoSat-2 is a powerful tool in the study of ocean behaviour. The map of the shape of the sea surface the satellite data was able to devise features the Beaufort Gyre, the great clockwise rotation of water that shifts sea-ice around the Arctic, as well as other topographic features related to the Transpolar Drift and the East Greenland Current, which is responsible for exporting much sea ice into the Atlantic.
As the Arctic has recently experienced sea-ice retreat far beyond the projections of most climate computer models, the currents could start moving faster, driven by winds. The process might eventually have an impact on circulation patterns beyond the Arctic basin in Norway and Greenland.
