In my most recent blog post I set out to compare Quikscat multi-year ice and PIOMAS ice thicker than 2m, both in January, the post digressed so I am presenting the comparison here.
PIOMAS doesn't explicitly provide ice age, but using ice thickness as a proxy for ice age it is possible to compare modelled and observed MYI distribution.
Ice thickens from open water or thin ice at the end of the summer towards 2m thick by April, MYI by January can already be in excess of 2m thick. I use this assumption and compare the white region of Quikscat to the blue region (>2m thick) in PIOMAS. Quikscat was the satellite 'radar' system that preceded ASCAT. In it young ice (<2 years approx) shows up as grey, old ice (>3 years approx) shows up as white.
The coloured images that follow are PIOMAS, black and white are Quikscat. And we're comparing the blue region in PIOMAS and the white sea ice region in Quikscat.
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
This series of images shows what a good job PIOMAS is doing in terms of the spatial positioning of the thicker older ice, indeed I am still staggered at how good PIOMAS is. The images also show the decline of older thicker multi-year ice in the first part of this century, and this is shown not just by a model, but by satellite data from a system originally designed to monitor winds.
There's also a similar comparison using ASCAT here.
http://dosbat.blogspot.co.uk/2013/02/ascat-piomas-and-dam.html