Running time: 1 min
Sea ice age from 1987 through end of October 2013. Age class 1 means “first-year ice,” which is ice that formed in the most recent winter. The oldest ice (9+) is ice that is more than 9 years old. Animation by NOAA climate.gov, based on research data provided by Mark Tschudi, CCAR, University of Colorado, with funding from NASA.