A variety of climatological factors converged this year in a perfect storm that dramatically melted the Arctic Ocean's ice cover to a record low. The abrupt downturn could be a harbinger of ice-poor summers for decades to come.
In late summer, scientists reported that Arctic sea ice had shrunk to cover only about 4.2 million square kilometers (SN: 10/13/07, p. 238). That area is about 38 percent below the long-term average for late-summer ice coverage. Moreover, it's a striking 23 percent below the previous record low, set just 2 years ago. An adverse combination of factors contributed to this year's steep decline, researchers noted last week at a meetin