Artic sea ice down to record low volume
2 Oct 2008
Arctic sea ice extent during the 2008 melt season dropped to the second-lowest level since satellite measurements began in 1979, reaching the lowest point in its annual cycle of melt and growth on September 14, 2008. Average sea ice extent over the month of September, a standard measure in the scientific study of Arctic sea ice, was 4.67 million square kilometers (1.80 million square miles) (Figure 1). The record monthly low, set in 2007, was 4.28 million square kilometers (1.65 million square miles); the now-third-lowest monthly value, set in 2005, was 5.57 million square kilometers (2.15 million square miles).
The 2008 season strongly reinforces the thirty-year downward trend in Arctic ice extent. The 2008 September low was 34% below the long-term average from 1979 to 2000 and only 9% greater than the 2007 record (Figure 2). Because the 2008 low was so far below the September average, the negative trend in September extent has been pulled downward, from -10.7 % per decade to -11.7 % per decade (Figure 3).
NSIDC Senior Scientist Mark Serreze said, "When you look at the sharp decline that we've seen over the past thirty years, a 'recovery' from lowest to second lowest is no recovery at all. Both within and beyond the Arctic, the implications of the decline are enormous."
NSIDC Research Scientist Walt Meier said, "Warm ocean waters helped contribute to ice losses this year, pushing the already thin ice pack over the edge. In fact, preliminary data indicates that 2008 probably represents the lowest volume of Arctic sea ice on record, partly because less multiyear ice is surviving now, and the remaining ice is so thin."