Cryosat delivered their first map – showing Jan-Feb 2011 ice thickness in metres.
For the past two years I have been getting constant flak from alarmists for using Navy PIPS2 maps. Turns out PIPS2 is very accurate. However, they seem to have been taken offline as of May 23.
Walt Meier wrote this on WUWT
PIPS vs. PIOMAS revisited
There was a lot of discussion earlier this year on the PIPS model sea ice fields vs. the PIOMAS model fields (e.g., here). At the beginning of the melt season, PIPS showed quite a bit of thick (3-4 m) ice throughout much of the Arctic Ocean, which wouldn’t be expected to melt completely. This portended less loss of ice during the summer. However, the PIPS fields did not agree well with the ice age fields, which showed less thick ice and a more dispersed multiyear ice cover. As it turned out, I think the PIPS were indeed to too thick, resulting in a forecast that was too high.
On the other hand, the PIOMAS total volume anomaly estimates were quite low going into the summer, indicating thinner ice and suggesting a low extent was likely. As I said previously, the volume seemed to me to be too low. Indeed, the PIOMAS forecast was lower than the actual minimum, though in the end it didn’t do a half-bad job in its prediction (4.7 predicted vs. 4.9 actual, in millions of sq km). To be sure, some of this could be attributed to luck, because there is always the wildcard of what the weather will do over the summer. Regardless, it is clear from the ice age, other ice thickness observations, and the overall state of the ice cover that volume is at or near record lows compared to at least the past 30 years. So while PIOMAS may be biased too low on ice volume, it captures the overall thinning trend and seems to better represent the actual state of the ice cover than PIPS.
h/t to Marc Morano