This animation compares the difference in the area, volume and depth of the average September Arctic sea ice between 1979, shown in blue, and 2013, shown in orange. The data from these two years has been projected onto a circle to provide for easy visual comparison without altering its area or volume.
The depth of the sea ice is measured in meters. This data comes from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS). This system combines real observations of the Arctic sea ice from 1979 through the present with data of the ocean and atmosphere to produce a complete picture of the changes in Arctic Sea ice area, thickness, and volume. The sharp spike at the center of the visualization represents the very real phenomenon of thick ice ridges form by ice dynamics.