The extraordinary situation in the Arctic has to be mentioned before too many more days have passed. I've no time to write a detailed article at the moment, so what I'll do instead is post some information that's been around the traps lately. First some tweets from Zach Labe (@ZLabe), who has been keeping us all informed on Twitter.
Okay, maybe time to let the #Arctic know what season it is -> another drop in #seaice extent from the last 24-hours (3rd day in a row, JAXA) pic.twitter.com/2Fl1pQUsD4— Zack Labe (@ZLabe) November 20, 2016
Then there's this - 2016 didn't register as the lowest ice extent on record when ice is the lowest, but it has been the lowest ice extent for much of the year:
Mark Brandon (@icey_mark) has a couple of articles about this unusual situation. One of them goes into some detail, with lots of images. The other is a gif of the growing season in the Arctic this year from 1 September 2016 to 16 November 2016.Current record low #Arctic sea ice is not uncommon for 2016, in fact 160 days this year (~49.5% YTD) have broken new record lows (JAXA) pic.twitter.com/wc9VI3wAoy— Zack Labe (@ZLabe) November 20, 2016
|Figure 1 | Map showing mean surface temperature, anomalies for October, from the 1951-1980 mean. Source: GISS NASA|
Update - from Tony Banton
Tony Banton (a UK meteorologist) has explained what has led to the unusual warming in the Arctic (from his comment below). I've added some links in square brackets, and added para breaks.
Tony Banton November 23, 2016 at 3:19 AM
There appear to be a few reasons to the warm arctic currently.
Firstly the Stratospheric PV did not develop as usual this year [see here]. It is weak and currently headed for Siberia instead of strong and sat over the pole.
This has allowed a -AO (High pressure) to dominate the Arctic [see here and here] - which means diverging air and along with the greater open waters evaporating more cloud, has stopped temperatures from falling away.
Of course at the start of the freeze, waters were well above normal and a period of +NAO [see here] may well have kept them from falling that quickly in the Barents, Kara and Laptev Seas. The weak Strat PV is thought to be tied up with low Solar at the mo (means less warming via UV destruction of low latitude stratospheric O3 and so a weaker DeltaT there) and the extra moisture available from the E-Siberian Seas aided the early/faster/greater than usual westward advance of Eurasian snow-cover, leading to a large pole of cold to form and build a strong Siberian High. This in itself favours a winter predominance of -AO. Also a La Nina favours early winter -AO.
Long range forecasts indicate it's persistence to at least the end of the year.
References and further reading
What the Heck Is Going on at the North Pole? - article by Phil Plait at Slate, 21 November 2016
Global sea ice shrinking at unprecedented speeds, warns scientist - article by Lucy Pasha-Robinson at The Independent, 20 November 2016
How Much Arctic Sea Ice Are You Melting? Scientists Have an Answer - article by Amina Khan at Sci-Tech Today, 4 November 2016