The summer of 2016 saw the joint second lowest Arctic sea ice extent. But in the middle of October unusual Arctic weather has led to it becoming the lowest extent. At the same time, Antarctic sea ice extent has also reached record lows. Tamino has a simple and clear post about what a surprising thing this is.
Why is it so low?
The plot below shows the mean November Arctic sea ice extent, the sea ice extent on 16 November 2016, and the difference between the extents from 1993 to 2016. Regions shaded at the top end of the scale (the red colours) mean there is less ice now compared with in 1993.
The stand out region (to me!) is North Russia where the Kara Sea is almost entirely clear, followed by Hudson Bay, Baffin Bay, East Greenland and the edge of the Chukchi Sea. I was interested in what was going on in the Kara Sea so I made a movie of the sea ice extent from 1 November 2016 to 16 November 2016.
The striking thing in the clip for November 2016 is that the sea ice extent has actually reduced in the Kara Sea!
The sea ice extent in Chukchi Sea is increasing, but very slowly - and you can see from my previous image that it is very low compared with 1993.
Clearly the Arctic is experiencing strange conditions at the moment. On the climatereanalyzer.org website you can see the 5-day forecast from 17 November 2016 (tomorrow).
The temperature departure from average is off the scale over the Arctic Ocean. It's much colder over Russia.
These are astonishing observations. When the winds change and the cold air currently over Russia ends up over the ocean I would expect it to freeze up rapidly (once the surface layers have cooled). But starting so late in the year the sea ice could end up thin enough for something impressive in the near future.
I made a gif of the full current Arctic growing season up to 16 November 2016.
I have already written a little about the this years Antarctic sea ice extent in the Antarctic Peninsula sea ice late winter 2016, in The Western Weddell Sea ice factory, in The development of the Amundsen Sea Polynya, in Dotson Getz Polynya ice growth, and in The Prince Gustav Channel is opening.
For interest, I chose November 1993 for comparison for two reasons, first it’s just before the big Arctic sea decline, and secondly I was in the Arctic for 4 months that year doing my PhD research.
Tamino is noting that the global sea ice is "About 6.9 standard deviations below the 1981-2010 mean." . Amazing times.