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 13th 2010
I distinctly remember this happening last year and the year before: IJIS is not updating their graph and data. A difficult time for the neurotics (like me) who have become used to this daily ritual. I don't know what the reason is, but the graph hasn't been updated since June 10th. Perhaps it has to do with the smoothing of the erroneous blip (that period has just ended June 11th), or data didn't come in (there are a few gaps in the trend lines, marked on the IJIS csv-sheet with -9999) because the AMSR-E sensor on the Aqua satellite is being updated or whatever is they do with sensors and satellites. We'll just have to wait and see.
Since the last update there were two more or less average melting days with a reported decrease of 65K and 60K (the average since the start of May is 68K), both were the second highest melt on this date compared to 2006-2009.
The current difference with those other years is as follows:
2006: -269K
2007: -463K
2008: -409K
- 2009: -558K
I'll be updating these numbers as soon as IJIS starts reporting again.
TIPS - Other interesting blog posts concerning Arctic ice:
An article by Patrick Lockerby explaining what 'finger rafting' is, with a cool video from Yosemite National Park.
Gareth Renowden from Hot Topic just has an interesting piece out with some links leading to the International Polar Year’s Oslo Science Conference.
RealClimate also has a post discussing the 4th International Polar Year Conference.
In the meantime Steven Goddard is still preferring to discuss volume and thickness rather than extent.
I see the same thing happens occasionally with Cryosphere Today. I suspect that the computer updates the results automatically, and if the update program crashes on the weekend, it does not get fixed until Monday.
This can also happen during solar events, but nothing major is happening.
http://www.spaceweather.com/
Posted by: Lord Soth | June 13, 2010 at 14:52
That sounds very plausible, LS. I remember when the same thing happened last year over at CA Phil. informed us that there were no updates because of maintenance being conducted on the Aqua satellite, but I can't seem to find any mention of that now.
Nothing happened today around the revision time (16:00 hrs CET), so hopefully whatever it is gets fixed tomorrow.
Posted by: Neven | June 13, 2010 at 16:24
This has happened to both the NSIDC site (a couple of times) and the IJIS site in the last few months - and it always seems to happen on the weekend, so it's quite likely that it's as simple a reason as LS suggests.
Posted by: GFW | June 13, 2010 at 22:24
In (weak) defense of Goddard, he isn't the first person to push volume: Joe Romm has been doing that for a while. And to a certain extent, much like in theory Pielke Sr. is right that ocean heat content is a better measure of global warming than surface temperature, in theory ice volume likely is a better measure of Arctic ice health than ice extent.
The problem is that in practice ice volume, much like ocean heat content, is hard to measure - much harder than the more standard ice extent. Goddard's specific problem is that he is using his own wacky pixel counting methodology to claim that ice volume isn't dropping precipitously, in contrast to the more standard scientifically approved sources. that, in addition to his hypocrisy (I don't want to spend the time and brain cells on it, but I'd love to see a collection of Goddard quotes from when ice extent was surprisingly high for much of April, compared to similar quotes from the last couple weeks when he had his Road to Damascus moment and converted to a volume-only prophet)
Posted by: M | June 14, 2010 at 15:57
Oh. You already made such a collection - thanks!
http://neven1.typepad.com/blog/2010/06/2010-sie-predictions-goddard-and-watts.html
Posted by: M | June 14, 2010 at 16:02
Welcome, M!
Sure. But what bothers me a bit is that over at WUWT fun was being made of 'alarmists' (I'm one, not everybody who believes in AGW is) discussing sea ice volume, and now that the tables are finally reversing, the pseudo-skeptic talk has been about nothing but thickness and volume. There's only one word for that: hypocritical.
Posted by: Neven | June 14, 2010 at 16:20
IJARC JAXA still with delay? Bremen has a nice alternative: http://www.iup.uni-bremen.de:8084/amsr/ice_ext_n.png
Posted by: Kiesewetter | June 14, 2010 at 21:24
JAXA has just updated.
Posted by: David Gould | June 15, 2010 at 11:14
Thanks, David Gould! I'll be writing a new update today to compare the numbers.
Posted by: Neven | June 15, 2010 at 13:07
I am also tracking Arctic Sea Ice, here's my version of recent trends.
http://processtrends.com/images/RClimate_JAXA_Arctic_SIE_latest.png
2010 is melting much faster than 2006, year with lowest June and 2007, year with lowest Sept.
Posted by: D Kelly O'Day | June 15, 2010 at 15:31