I've previously posted about the current state of the ice in January 2013. As I've just reminded myself of the ASCAT system that has replaced QuikScat, I thought I'd reproduce images from PIOMAS gridded data and the drift age model (DAM) together with ASCAT satellite images.
All images are for December. ASCAT from here, select 'ice' then 'arctic'. DAM from here. And PIOMAS produced by myself from PIOMAS gridded data available from here.
ASCAT is the Advanced Scatterometer satellite system, a radar that operates in a frequency band (C-band ~5.3GHz) where multi-year ice shows up as white (high signal return), first year ice shows up as grey (less of a signal return). Compare the ASCAT multi-year ice with thicker December PIOMAS ice and DAM regions of older ice.
The agreement looks good. The ice state at the end of 2012 looks bad - and that's confirmed by satellite, not just models.
PS - knew I had the link somewhere - here's an ftp directory of ASCAT images, various regions and NH.