By Steve Goddard
Over the last three years, Arctic Ice has gained significantly in thickness. The graph above was generated by image processing and analysis of PIPS maps, and shows the thickness histogram for June 1 of each year since 2007.
The blue line represents 2008, and the most abundant ice that year was less than 1.5 metres thick. That thin ice was famously described by NSIDC as “rotten ice.” In 2009 (red) the most common ice had increased to more than 2.0 metres, and by 2010 (orange) the most common ice had increased to in excess of 2.75 metres thick.
We have seen a steady year over year thickening of the ice since the 2007 melt season. Thinner ice is more likely to melt during the summer, so the prognosis for a big melt looks much less likely than either of the previous two summers. More than 70% of the ice this year is thicker than 2.25 metres thick. By contrast, more than half of the ice was thinner than 2.0 metres in 2008.
So why did 2008 start out with so little thick ice? Because during the summer of 2007 much of the ice melted or was compressed by the wind. During the winter of 2007-2008, much of the remaining thick ice blew out into the North Atlantic and melted. So by the time that summer 2008 arrived, there was very little ice left besides rotten, thin ice. Which led to Mark Serreze’ famous “ice free North Pole bet.“
Can we find another year with similar ice distribution as 2010? I can see Russian ice in my Windows. Note in the graph below that 2010 is very similar to 2006.
2006 had the highest minimum (and smallest maximum) in the DMI record. Like 2010, the ice was compressed and thick in 2006.
Conclusion : Should we expect a nice recovery this summer due to the thicker ice? You bet ya. Even if all the ice less than 2.5 metres thick melted this summer, we would still see a record high minimum in the DMI charts.
Mark Serreze has a different take for 2010:
“Could we break another record this year? I think it’s quite possible,” said Mark Serreze of the National Snow and Ice Data Center in Boulder, Colo.
Bookmark this post for reference in September.
“The report of my death was an exaggeration“
– Mark Twain
Addendum By Steve Goddard 6/3/10:
Anyone betting on the minimum extent needs to recognize that summer weather can dramatically effect the behaviour of the ice. The fact that the ice is thicker now is no guarantee that it won’t shrink substantially if the summer turns out to be very warm, windy or sunny. Joe Bastardi believes that it will be a warm summer in the Arctic. I’m not a weather forecaster and won’t make any weather predictions.