Arctic summer sea-ice age 1981–2000 compared with 2007, 2008, and 2009

These images compare ice age, a proxy for ice thickness, in 2007, 2008, 2009, and the 1981–2000 average. 2009 saw an increase in second-year ice over 2008. At the end of summer 2009, 32% of the ice cover was second-year ice and three-year and older ice were 19% of the total ice cover, the lowest in the satellite record.