The AMSR-E instrument on the Aqua satellite acquires high resolution measurements of the 89 GHz brightness temperature near the poles. Because this is a passive microwave sensor which is not so sensitive to atmospheric effects, this sensor is able to observe the entire polar region every day, even through clouds and snowfall. The false color of the sea ice, derived from the AMSR-E 6.25 km 89 GHz brightness temperature, highlights the fissures or divergence areas in the sea ice cover by warm brightness temperatures (in blue) while cold brightness temperatures, shown in brighter white, represent consolidated sea ice. The sea ice edge is defined by the 15% ice concentration contour in the three-day moving average of the AMSR-E 12.5 km sea ice concentration data.

This animation shows the continuos motion of the Arctic sea ice from January 1 through September 12, 2008 when the sea ice reached the annual minimum extent of 4.52 million square kilometers (1.74 million square miles). This minimum is the second lowest extent recorded since 1979 and is below the 1979 to 2000 average minimum by 2.24 million square kilometers (0.86 million square miles).