The PIOMAS project attempts to measure the “volume” of the arctic sea-ice. This is difficult and has been an elusive piece of data to obtain, and the PIOIMAS project is critisized for various reasons, but likely is our best attempt so far. I find the above graph interesting for it suggests the sea-ice has been thickening the past few years. (The current year is the red line.)
Of course, “average thickness” is a bit of a ridiculous concept, as the thickness of the ice varies greatly. The Laptev Sea, which exports a lot of ice due to winds howling off shore from Siberia, can have open water when it is -40°, and often has only a skim of ice less than a foot thick which will melt easily in the summer sunshine, but all that exported sea-ice tends to be carried by cross-polar flow and crunch up against the north coast of Canada, where the ice can be twenty feet thick.
The PIOMAS “volume” is determined by gathering data involving thickness and data involving area, and doing the simple equation that gives you volume, and it too shows the recent years have seen an increase, and the the Pole is failing to become ice free.
None of this really addresses the issue of whether the ice will last, for thick ice doesn’t mean much if it is in Fram Strait. Such ice will be blown down the east coast of Greenland and be melted in the Atlantic in mere months. Meanwhile thick ice north of Canada is caught in the Polar Gyre which will rotate it around the Pole, and can keep it around for more than five years.
However it is important to note that volume has increased despite the fact the extent of ice at the minimum was at its lowest levels ever, in recent times.
Now, if the area is less but the volume is more, it suggests that the ice that remains is thicker and more solid and more able to resist melting. This may explain why the “peak” of the arctic ice extent graph was so flat, and took so long to begin falling.
In fact the NOAA prediction of ice extent is even suggesting that the ice will reach above normal levels by mid July.
All in all, it looks bad for people who bet the Pole would be ice-free by the summer of 2015. It is especially hard on people who gambled to a degree where they started farms on Greenland. Such people do exist, and it sours them when there is no sign of the “Death Spiral.”
NOTE FURTHER INFORMATION, PLUS SOME SCATHING CRITICISM, CAN BE FOUND WITHIN A EXCELLENT, CONCISE OVERVIEW AT