The orange line shows the 1981 to 2010 median extent for March 7. (fm.kuac.org)
This is compared to the 13 statistical contributions that show a larger median extent of 4.69 million square kilometers and range from 3.95 to 5.4 million square kilometers (quartiles of 4.23 and 4.81 million square kilometers). (arcus.org)
The orange line shows the 1981 to 2010 median extent for Sept. 10; the black cross indicates the geographic North Pole. (fm.kuac.org)