Cryosat: Europe’s ice explorer
Most scientists agree that our planet is getting warmer. The first 10 years of this century were the warmest decade on record. This is likely to cause important changes to the climate of Europe. But what about the polar ice caps? Is the ice melting? If so, what effect will this have on global climate and sea level?
A European satellite is now providing some of the answers. Launched on 8 April 2010, Cryosat flies over the poles at an altitude of 720 km.
Using a state-of-the-art radar instrument, Cryosat measures tiny changes in ice thickness by bouncing radio signals off the surface and picking up the echoes. If the echoes come back more quickly, the ice surface must be higher.
Cryosat is able to detect changes of less than 2 cm per year in the height of ice floating on the Arctic Ocean. Over the huge ice sheets on the continent of Antarctica, it can measure annual changes of less than 2 mm.
These results help scientists to find out whether the Arctic sea ice is breaking up and melting. They also show whether the ice sheets that cover the land mass of Antarctica and the surrounding sea are shrinking or growing. This is important because sea level may rise many metres if the ice sheets melt. Many low-lying cities and countries could then be flooded.
CryoSat is the third Earth Explorer mission to be launched within ESA’s Living Planet programme (after GOCE, ESA’s gravity mission and SMOS, ESA’s water mission).