2012 Sea Ice Prediction Evaluations

Before launching in to my estimates for this year, I have to evaluate last year's estimates.  Not much point in making estimates if you don't re-examine how well the previous ones were.

Last year's observed (NSIDC) September monthly average sea ice extent was 3.6 million km^2.  That blew away the old record set in 2007.

Our June 2012 Estimates were:
4.9 Wang, Grumbine, Wu -- statistical correction of CFS
4.8 Wu, Grumbine, Wang -- semi-physical correction of CFS
4.4 Grumbine, Wu, Wang -- Purely statistical from prior Septembers

July:
4.9 Wang, Grumbine, Wu -- statistical correction of CFS
4.7 Wu, Grumbine, Wang -- semi-physical correction of CFS

August:
3.9 Wang, Grumbine, Wu -- statistical correction of CFS

No updates in August for the semi-physical CFS correction as it hadn't looked like it was coming out any different than the prior months.

The Wang et al. was the best of all August estimates, and was still too conservative by 300,000 km^2 (the approximate land area of Poland, the Philippines, Norway, or Ecuador).  The observed mean extent, of 3.6 million km^2 was about 20% larger than India.  The 1979-2000 average was 7.0 million km^2 -- almost double what we just saw, and about the 10% smaller than Australia.