This pair of maps shows the median age of February sea ice from 1981-2009 (left) compared to February 2009 (right). Ice more than two years old is dark blue, ice that is one to two years old is medium blue, and ice that is less than one year old is light blue. Compared to the median conditions at the end of winter (the median is the number halfway between the lowest and highest numbers in a range), the ice pack of February 2009 contains much less old ice (dark blue).