Two weeks ago, I said Antarctic sea ice extent was very close to setting a record high. Well, it did it on September 26- reaching an extent of 7.51 million square miles, about 20,000 square miles above the previous record set in 2006. (Records have been kept since 1979, in both the Antarctic and Arctic)
I also pointed out the stunning contrast between the Antarctic record high ice levels and the Arctic record low levels set about 10 days apart. But I explained why “it’s incredibly misleading to equate the two records.” In short, the Arctic sea ice difference from the long-term average is much more dramatic than the Antarctic’s.
New NASA imagery reinforces this point.
Look at the Antarctic record maximum sea ice extent and how it compares to the 1979-2000 median extent (yellow line).
Now look at the the Arctic record minimum sea ice extent and how it compares with the 1979-2000 median (yellow line):
Animations further illustrate how much more dramatic the changes are in the Arctic.
Videos courtesy the National Snow and Ice Data Center
As I discussed before, the rapid ice loss in the Arctic is strongly related to warming in the region, although storms and winds contribute as well. In the Antarctic, processes which govern ice changes are more complex and not as well-understood, but it is thought changes in atmospheric circulation (in part, perhaps, resulting from ozone depletion) and precipitation may be behind the slow increase in ice.