The area of Arctic sea ice passed a numerical milestone this week: into the 21st Century. In the first week of August, with a month or more to go in the melt season, area has dropped below not just the year-to-date values of previous years, but the annual low points of any satellite-era year before 2007 (Cryosphere Today data). The current area is slightly below even the previous record holder, 2007, for this date, and is heading for a minimum down with the “modern” group of post-2006 values. Figure 1visualizes the comparison between area on August 4 and the lowest days of previous years — which ranged from August 31 to September 30. The median date for minimum area is September 8 or 9.
There is no trend toward earlier or later minimum dates, so we can’t yet predict when that will fall this year. While the melt season continues, I will be updating this graphic regularly for our Daily Graphs page.
UPDATE SEPTEMBER 2011
In the weeks after the post above was written (August 4 2011), Arctic sea ice area continued to decline. By the second week of September, it edged past the previous record low set in 2007. While Figure 1 above remains in its original form, I will be updating Figure 2 below to reflect the final minimum record for 2011.