Arctic ice is an important indicator of how fast the global climate is changing. It also impacts that change. Melting sea ice does not raise ocean levels but it reduces the amount of ice and snow cover available to reflect sunlight. Less sea ice means that more of the sun's heat is absorbed by the Arctic ocean, which in turn heats the water, leading, all else being equal, to greater melting of ice on the coasts. Thus, melting sea ice is part of a positive feedback mechanism that is accelerating warming in the Arctic as a result of human induced global warming.
The Arctic "sea ice maximum" occurs when ice in the Arctic sea reaches its largest extent in a given year. For 2013, Arctic sea ice reached its maximum extent on March 15, at 15.13 million square kilometers (5.84 million square miles). That is the sixth lowest maximum level in our satellite records. Details can be found via the National Snow and Ice Data Center and recent news articles.
The record for the lowest Arctic sea minimum, the least amount of Arctic sea ice after the summer melt, was in 2012. The 2012 record beat the previous record low set in 2007 by as much as 27,000 square miles, which is larger than the area of West Virginia. The 2012 melting occurred faster than scientists had predicted. Details of this record low, including charts, can be found in the Washington Post, and New York Times, among other sources. The image, from the Washington Post, shows the amount of Arctic Sea ice when it past the previous record for the minimum.
