Sea ice is decreasing in the Arctic but year-to-year variability in sea ice extent is large. Ice extent is influenced by atmospheric circulation, with temperatures dictating ice melt, and winds shifting the ice, reports the Nature.
According to National Snow and Ice Data Center, through the first half of July, Arctic sea ice extent continued tracking close to levels in 2012, the summer that ended with the lowest September extent in the satellite record.
The stormy weather pattern that characterized June has persisted into July. Nevertheless, sea ice melt began earlier than average over most of the Arctic Ocean.
As of July 18, Arctic sea ice extent was 7.82 million square kilometers (3.02 million square miles). This is just below the two standard deviation value for the date, and just above the level observed on the same date in 2012, the year that ended up having the lowest September extent in the satellite record.
Throughout the month, extent has closely tracked both the two standard deviation and 2012 levels.
Ice extent in the first half of July was well below average in the Kara and Barents sea
s, as it has been throughout the winter and spring. Extent is also below average in the Beaufort and Chukchi seas, between the East Siberian and Laptev seas by the New Siberian Islands, and along the southeast coast of Greenland.
In the last several days, polynyas have formed in the northern Beaufort Sea. Compared to 2012 at this time of year, there is more ice in the southern Beaufort Sea, Baffin Bay
, the Laptev Sea, and north of the New Siberian islands in the East Siberian Sea.
There is less ice this year in the East Greenland
Sea, extending through the Barents and Kara seas, and in the western Beaufort and Chukchi seas.