For ice extent in the Arctic, the bar is set at 15M km2. The average in the last 11 years occurs on day 73 at 15.07M before descending. Most years are able to clear 15M, except for 2006, 2007 and 2015 who topped out below that height.
Yesterday, March 2, 2016 cleared 15M, but will not reach that level again. 2016 will now drop down to 14.6M, rise to day 84 average of 14.9M, then start the descent into spring and summer. Typically, Arctic ice extent loses 67 to 70% of the March maximum by mid September, before recovering the ice in building toward the next March.
As reported previously, 2017 rose to the average in February, then lost extent for two days and is now increasing again. The next two weeks will be interesting. The average year in the last eleven gained about 20k km2 from now to mid March. But the variability ranged from 2015 losing 350K while 2010 gained 300k km2. What will the ice do this year? Where will 2017 rank in the annual Arctic Ice High Jump competition?
As reported previously, Arctic ice extents are solid in most seas, but continue to fluctuate at the margins. In the latter part of February 2017 there was a great leap upward for nine days, nearly reaching average and surpassing 2016, before falling back after day 53. The surplus over 2006 is now 500k km2. SII reports about 360k km2 less extent than MASIE.
The Atlantic upward leap and back in Barents and Baffin.
Note both Barents and Baffin pulled back slightly.
The Pacific shifting up and down in Bering and Okhotsk.
While the seesaws are tilting back and forth on the margins, the bulk of the Arctic is frozen solid. And with limited places where more extent can be added, the pace of overall growth has slowed.
The table below shows ice extents in the seas comprising the Arctic, comparing 2017 day 058 with the same day average over the last 11 years and with 2006.
The table shows that 2017 ice extent exceeds 2006 by about 500k km2 at this date. Surpluses are sizeable in Barents, Baffin and Okhotsk, with only the Baltic showing a deficit. Baffin and Okhotsk are now average, and the 300k km2 deficit to average comes from Bering in the Pacific, and Barents and Greenland Seas on the Atlantic side
The big picture compares this day in 2017 with 2006. Not much change overall, but a slight increase of 500k km2.