by Neven Acropolis via Arctic Sea Ice blog
I’m starting this blog post off with a conclusion that was reached a while back already: Sea ice on the Atlantic side of the Arctic looks vulnerable, sea ice on the Pacific side should be thicker.
Right, with that out of the way we can now look at various aspects of the 2011/2012 freezing season, and compare them to previous years, to be precise the previous freezing season of 2010/2011, and the freezing seasons leading up to and following that other record year: 2006/2007 and 2007/2008. Simply put: I’ll be comparing 2007, 2008, 2011 and 2012 before their respective start of the melting season.
I’ll try not to use too many words, but I’ll be using a lot of images. Click on them images if you want a bigger version.
I’ll start with the AARI ice age maps. These images are for the end of April, and they look upside down, because it’s from the perspective of the Russians who produced them:
This year, at the end of April, the Arctic seems to hold less of the brown ‘old ice’ than last year and 2007 (older version), and a tad more than 2008, that had relatively little multi-year ice (MYI) after the 2007 melting season/massacre.
Another source that was already mentioned in the A first clue blog post, were these images based on data compiled by NASA senior research scientist Josefino Comiso from NASA’s Nimbus-7 satellite and the U.S. Department of Defense’s Defense Meteorological Satellite Program (credit: NASA/Goddard Scientific Visualization Studio). The images show the amount of MYI at its maximum, I presume:
These images look similar to the ones from AARI, with 2012 showing less old ice/MYI than 2007 and 2011, and a bit more than 2008 (look at the graph in the bottom right image). However, at the time a flag was raised by Spanish blogger Diablobanquiso on his excellent blog, maintaining there was more MYI than AARI and Comiso indicated. He based himself on ASCAT radar images, where slightly brighter white represents older ice. The following image shows March 16th 2011 and March 15th 2012 side by side (unfortunately there are no radar images available from 2007 and 2008), with 2012 merging into an imagemade by Diablobanquisa, showing what part was missing from AARI and Comiso: