Last year I wrote a series of five posts called End Zone, comparing different aspects of the final phase of the Arctic melting season in different years, to be able to predict a bit what those last weeks of the 2010 melting season could be holding in store. A lot of that ground work still stands, so I don't have to repeat it this year. In this post I'll be looking at sea ice concentration and sea surface temperatures mainly, as these are most interesting right now. I basically said everything there is to say about atmospheric pressure, air temperature and ice displacement (no more PIPS, sniff) last year.
Sea ice concentration
I'm trying out something new here, which I hope you'll like. I'm comparing the years of the new Arctic era with 2011 on August 29th by fading the images:
2011 looks quite a bit like 2007, except that the large protuberance is sticking out in the East Siberian Sea instead of the Laptev Sea. That protuberance blocked the Northern Sea Route right till the end of the 2007 melting season. This year it's been wide open since very early on.
The same goes for 2009. The NWP was still blocked back then. In fact, there was more ice almost everywhere, compared to this year. I guess it wasn't dubbed the 'year of recovery' for nothing.
This year looks quite similar to last year in shape, but there was less ice along the Greenland coast in 2010. The edge of the ice pack almost reaches Svalbard and Franz Josef Land though. Of course, last year was the year that showed large holes in the interior of the ice pack. This year the warm waters of the Laptev Sea seem to be eating their way into the ice pack. My guess is that the Arm of multiyear ice that held out until the end of the 2010 melting season, won't do so this year, for the simple fact that it contains less MYI.
The big difference I see between this year and other years is the total amount of ice in the channels of the Queen Elizabeth Islands. All years have ice there, but this year the eastern part of that region in the Canadian Archipelago is almost completely empty of ice.
Compared to other years, 2007 is showing smaller areas of low concentration ice, because there was a lot of compaction going on back then. In last year's End Zone instalment on sea ice concentration there's an animation that shows how the shape and concentration of the ice pack developed in the last weeks of 2007, 2008 and 2009.
Sea surface temperatures
These images come from the EORC-JAXA webpage and here's what the SST anomalies have looked like so far in August:
And here's another animation of the SSTs in the four previous years fading from August to September:
You see the warmth getting sucked out of the ocean during September, except for that huge red blob on the Pacific side in 2007 (which caused a slow freeze-up). Other than that blob 2011 resembles 2007 (and 2008) pretty much. It's not all over the Pacific side like it was then, but it's warmer in the Laptev Sea.
We'll have to wait and see how long the SSTs can continue nibbling at the ice pack, especially on the weak looking Pacific edge...