© NASA scientist Joey Comiso, PD
The oldest Arctic ice is disappearing fast
due to global warming. Sea ice coverage in 1980 (bottom) and 2012 (top), as observed by passive microwave sensors on NASA's Nimbus-7 satellite and by the Special Sensor Microwave Imager/Sounder SSMIS. Multi-year ice is shown in bright white, while average sea ice cover is shown in light blue to milky white. The data shows the ice cover for the period of 1 November through 31 January in their respective years.