Arctic Sea Ice

2011/2012 Winter Analysis

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.

Ice age

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:

NSIDC Arctic sea ice news April 2012

Interesting bits from the NSIDC monthly analysis:

Arctic sea ice enters the spring melt season

Arctic sea ice reached its annual maximum extent on March 18, after reaching an initial peak early in the month and declining briefly. Ice extent for the month as a whole was higher than in recent years, but still below average.

As the melt season begins, researchers look at a variety of factors that may contribute to summer ice melt. While the maximum extent occurred slightly later than average, the new ice growth is very thin and likely to melt quickly. Ice age data indicate that despite the higher extent compared to recent years, the winter sea ice continues to be dominated by younger and thinner sea ice.

Ice Age

No,  this is not a review of one of the Disney sequels. Fredt34 sent me a mail to draw my attention to this ice analysis map from the Arctic and Antarctic Research Institute from St. Petersburg, Russia. This institute had some great weekly sea ice displacement forecast maps last year, but unfortunately the web page went down in the middle of the melting season.

This ice analysis map is nice too, though, as it gives us an idea of the age of different parts of the ice pack, which is why I think this blog post will fit in nicely with the recent string of posts on sea ice thickness.

Here's the current situation according to AARI (click for a larger version):

The light blue shows where the open sea is, and the dark blue is for water covered with Nilas (very thin ice). The pink is for young ice between 0-30 cm thick, and the green is first-year ice with a thickness of 30-200 cm. The brown colour for olde ice that survived at least one melting season, is what interests us most, as all the other colours will probably melt out this season.

To us Europeans and Americans this image might look like it's upside down, but that's because it's from a Russian perspective. They are perfectly entitled to do this. In fact, I'll even flip this Arctic sea ice age figure from the NSIDC March analysis (courtesy of J. Maslanik and C. Fowler from the University of Colorado) so it's easier to compare: