In the comment section of the last SIE Update Werther came up with a very interesting image. In his own words:
I did some CAD work based on CT 23 sep 2007 and 18 sep 2010, scaling the lot on Google Earth (Bering St – Svalbard ca 3725 km). I drew high concentration (+90%, the reds and purples) and low concentration (15-90% the blues, greens and yellows). The pixel-counters may be more exact, but 2010 has almost 200k less extent in the high concentration compared to 2007. Note that 2007 had very small low concentration extent (some 10 % of total SIE).
It didn't take me long to realize that this deserves some more attention, especially as TypePad cuts off images that don't fit the width of the comment section. So here's the image in full:
It really does look like 2010 had less high concentration extent than 2007 did.
Werther says: "I take it that 2007 cannot be seen as an exception, the situation now is even worse." I tend to agree. Thanks for this great image, Werther!