Arctic sea ice extent breaks 2007 record low

Figure 1. Arctic sea ice extent for August 26, 2012 (right) was 4.10 million square kilometers (1.58 million square miles), which was 70,000 square kilometers (27,000 square miles) below the September 18, 2007 daily extent of 4.17 million square kilometers (1.61 million square miles, left). The orange line shows the 1979 to 2000 median extent for that day. The black cross indicates the geographic North Pole.

This visualization shows the extent of Arctic sea ice on Aug. 26, 2012, the day the sea ice dipped to its smallest extent ever recorded in more than three decades of satellite measurements, according to scientists from NASA and the National Snow and Ice Data Center. The data is from the U.S. Defense Meteorological Satellite Program’s Special Sensor Microwave/Imager. The line on the image shows the average minimum extent from the period covering 1979-2010, as measured by satellites. Every summer the Arctic ice cap melts down to what scientists call its “minimum” before colder weather builds the ice cover back up. The size of this minimum remains in a long-term decline. The extent on Aug. 26. 2012 broke the previous record set on Sept. 18, 2007. But the 2012 melt season could still continue for several weeks. Image credit: Scientific Visualization Studio, NASA Goddard Space Flight Center

Figure 2. The graph above shows Arctic sea ice extent as of August 26, 2012, along with daily ice extent data for 2007, the previous record low year, and 1980, the record high year. 2012 is shown in blue, 2007 in green, and 1980 in orange. The 1979 to 2000 average is in dark gray. The gray area around this average line shows the two standard deviation range of the data. The 1981 to 2010 average is in sky blue.