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 18th 2010
Yesterday I was expecting to write that 2010 was slowly returning to the pack and join the other years before the unofficial start of the season (on the 21st of June, the day of the year with the longest hours of daylight in the northern hemisphere), as it had come in 4th the day before yesterday, and 2nd the day after that. But 2010 seems to have decided it wants to remain an Einzelgänger a little while longer and had the highest reported melt of today's date: 77,812 square km.
With just 23K to go it looks like the 10 million square km threshold will be officially crossed tomorrow, 4 days ahead of 2006 and a whole week ahead of 2007.
The current difference between 2010 and the other years is as follows:
2006: -262K (59,609)
2007: -500K (63,328)
2008: -590K (56,474)
- 2009: -649K (55,938)
Between brackets is the average daily melt for June. These averages get a bit higher towards the end of the month in anticipation of the heavy melting of July and August. With a current average daily melt of 62,555 square km 2010 has a good chance of beating the other years, but it will need 1 or 2 century breaks to do so.
On NOAA's daily AO index we can see that the Arctic Oscillation is still in a positive phase:
TIPS - Other interesting blog posts concerning Arctic ice:
Patrick Lockerby has published the second instalment of his MODIS satellite image tutorial called 'Rapidfire for Citizen Scientists'.
Wayne Davidson has a short update out. Quote:
Big Blue is expanding everywhere in the high Arctic, leads along the Arctic Archipelago coast are clearly seen for the first time since early spring. This will accelerate the melting tremendously, since its occurring at the solstice, very high sun, and will further demolish previous ice extent records. Everything is coming about as expected.... Unfortunately....