By Sid Perkins
From San Francisco, at a meeting of the American Geophysical Union
Satellite observations of the Arctic Ocean show that the amount of sea ice there this year was the lowest it’s been in more than 20 years.
In September, the extent of the sea ice–defined as the area in which ice covers at least 15 percent of the ocean’s surface–was 5.27 million square kilometers, says Julienne C. Stroeve, a climatologist at the National Snow and Ice Data Center in Boulder, Colo. Of that area, sea ice actually covered about 3.6 million square kilometers, a figure 17 percent lower than normal for that time of year and 9 percent below the previous minimum for a September. The earlier record low was set in 1998, during the late stages of the strongest El Nio ever seen and when the global average temperature had been much higher than normal for several months.