I'll be regularly writing updates on the current sea ice extent (SIE) as reported by IJIS (a joint effort of the International Arctic Research Center and the Japan Aerospace Exploration Agency) and compare it to the sea ice extents in the period 2006-2009. The JAXA graph is favoured by almost everyone, probably because it looks so nice compared to other graphs (like the one by Arctic ROOS, the University of Bremen and the Danish Meteorological Institute). All the years have a nice colour of their own which makes it easy to eyeball the differences between trends. Most of the betting on minimum SIE is based on the IJIS data. NSIDC has a nice explanation of what sea ice extent is in their FAQ.
June 9th 2010
With a reported melt of 99,844 square km for yesterday 2010 had the highest melt for three days in a row. This number will be revised later today (16:00 CET), but will probably remain the highest melt for this date. Of course, we're still in the zone of the 'erroneous blip' where until this year you'd see all the years on the graph make a funny jump due to parametrization issues. Or as it's put on the IJIS website: "because the surface of the Arctic sea-ice becomes wet in summer due to the melting of ice which changes satellite-observed signatures of sea-ice drastically". But still, highest melt is highest melt and 2010 is breaking away from other years at the moment, especially from 2007 which had a reported melt of only 5,625 square km on yesterday's date:
2006: -297K
2007: -411K
2008: -477K
- 2009: -483K
The breaking away of 2010 is also getting clearer on the IARC-JAXA graph (click to enlarge):
The 2010 trend line will probably creep back to the other trend lines before the melt season starts off in earnest (around summer solstice, June 21st), but it has quite a head start at the moment.
UPDATE: there was quite a big revision of 30K square km this afternoon (every day at 16:00 CET), so yesterday wasn't the highest reported melt for that date after all, 2008 was 781 square kilometres lower.
They actually smooth out the 'erroneous blip' between May 20 to June 11, so we no longer see the spike around the first few days of June. I would have prefered that they just left things as they were, rather than smooth things to look pretty.
If they are using a standard smoothing algorithm, this is causing the actual ice lost to be under reported in late may, and overreported in early June, with the greatest smoothing occuring June 1, tapering to none before May 20 and after June 11.
Since we are at the tail edge of the smoothing, I suspect that the value between what it would be if they didnt smooth the data, compared to the smooth data would be within 5000 Km by now. Regardless, we are see a nice breakaway, and it will get harder everyday, for the 2007 numbers to converge.
Posted by: Lord Soth | June 09, 2010 at 16:03
Exactly, Lord Soth. I didn't formulate that as well as you just did.
And I didn't see that +30K revision coming (3rd time that's happened to me this year :-) ), so yesterday wasn't the highest melt for that date after all, 2008 was 781 square kilometres lower. What a difference a revision makes!
Posted by: Neven | June 09, 2010 at 16:28
2010 is now running 9 days ahead of 2007. I'd expect that to tighten a bit as we reach the point where 2007 went in to freefall, but for the moment it certainly is "breaking away".
Posted by: GFW | June 09, 2010 at 17:43
As implicit in the previous comments, sea ice extent is tricky--just when you think you know what's coming, in situ conditions change and the curve heads off in a new direction, leaving you with only the bread crumbs required for a facial deep-fry. (Egg, bread crumbs. . . never mind, silly quip.)
That said, though, it sure doesn't look like anything close to "recovery" is in the cards anytime soon. (Except of course to "Steve Goddard," who seemed to put a lot of weight on "cold Arctic weather for the last couple of weeks"--IIRC.) SSTs look mostly pretty elevated around the ice margins, there are widespread polynyas throughout the ice (see Cryosphere Today images), and tropospheric temps continuing to be highly elevated despite the subsidence of El Nino conditions (though I'd like to see what the spatial distributions look like.)
Lastly, it's at least interesting that the extent is diverging as widely as it seems to be doing: this is the point of the year which exhibits the lowest variability in total extent, historically speaking. It's tempting to see it as yet another factor suggesting that there's a novel "sea ice regime" emerging.
Posted by: Kevin McKinney | June 10, 2010 at 14:36
If you are looking for a prediction for ice movement, I use a service from the Russia that gives the predicted mean sea ice drift for a week.
http://www.aari.nw.ru/clgmi/forecast/show_drift.asp?fign=0&lang=0
When I see large vectors heading south, or towards warmer waters, its bad news for the ice.
Posted by: Lord Soth | June 10, 2010 at 17:54
That's an interesting map, LS. It reminds me a bit of that animation JeffID made at The Air Vent last year. But that's just because of the arrow, I don't know if these things have any relation. :-)
The Russian site looks interesting. I'll mention it when I do a blog post on all the interesting sites to watch out for when monitoring the Arctic.
Do you also check this site from the International Arctic Buoy Programme?
Posted by: Neven | June 10, 2010 at 18:09