UPDATE: 8AM PST 9/13/10 JAXA has updated with their final Sept 12th data, up for the second straight day there’s been a gain:
The latest value : The latest value : 5,005,000 km2 (September 12, 2010 final data)
While the vagaries of wind and weather can still produce an about-face, indications are that the 2010 Arctic sea ice melt season may have turned the corner, earlier than last year.
In the JAXA data, there was a gain of 33,593 km2 in a single day on 9/11/10 and another gain of 18, 594 km2 on 09/12/10 (final data):
09,08,2010,4989375 09,09,2010,4972656 09,10,2010,4952813 09,11,2010,4986406 09,12,2010,5005000
Last year, when I correctly called the turn, it was September 14th:
That is a gain of almost 26,719 km2 from the Sept 13th value of 5, 249, 844 km2 which may very well turn out to be the minimum extent for 2009.
And it is not just the JAXA plot that indicates a turn the corner bump for 2010. The DMI 30% extent graph is showing a very sharp uptick.
Here is the relevant area zoomed and annotated:
ADDENDUM: Last year’s DMI graph about this time had similarly abrupt uptick:
Temperatures at 80°N and above are now dropping quickly, after some delay:
The annotations are mine, the current temperature is approximately -5.5° C. I say approximately, as DMI doesn’t make the data available here, only the graphical output, so I’ve had to draw a line and estimate based on the coarse scale they provide. Seawater freezes at a temperature of -1.9° C (source here) but varies with salinity. Call it -2° C, but clearly now air temperatures are cold enough above 80°N to expect some refreezing.
The NSIDC Arctic extent plot shows the beginning of a flattening, but since their smoothing algorithm adds a reporting delay, we won’t see the turn (if it holds) until about two days from now.
If it is indeed the turn, then Arctic Sea Ice minimum for 2010 will end up at 4,952,813 km2
I may make a follow up post and have a look at all the forecast players mid to late week if the turn is confirmed. Of course my forecast has been proven incorrect already, but then, so have others.
Polar weather forecasts suggest colder weather ahead, and historically, the timing is right for a turn.
One such indicator is the Arctic Oscillation, shown below:
Source, NOAA Climate Prediction Center:
The forecast shows a deepening AO in the next few days, which traditionally means colder temperatures and a refreeze.
So, we’ll watch and wait, and I’ll update if the turn is confirmed.