Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:
Yes, I'm still focused on how 2015 is doing compared to the 2013 and 2014 rebound years, and as the volume increase over the past month was lower than that of the previous two Octobers, 2015 has now just dipped below 2013 (30 km3 less volume), while the difference with 2014 is still 1138 km3 less volume.
At the same time the volume increase of the past month was much larger than that of October 2007, and so according to the PIOMAS model 2015 now has 388 km3 more ice than 2007. And the already large difference with 2011 and 2012 has increased some more to 2296 and 2450 km3 respectively. But these months saw quite a steep increase during November and December, so I expect the difference to become smaller again.
As soon as Wipneus posts his detailed PIOMAS volume graph, I'll put it up here.
Edit: And here it is:
We see that the trend line on the PIOMAS sea ice volume anomaly graph has crossed the linear trend again:
Because CT sea ice area has been going up slightly faster than most other years, while sea ice volume has not, the ice pack as a whole hasn't started thickening yet and 2015 is still right between the cluster of very low post-2010 years and the 'old normal'. This is, of course, according to my crude PICT calculation, whereby I divide PIOMAS volume numbers with Cryosphere Today sea ice area numbers:
The same can be seen on the Polar Science Center's thickness graph:
There's not all that much to say with regards to sea ice volume right now, so let's await the coming update(s) to see what this winter cooks up for next year's melting season.
The AO is peaking quite a bit right now:
Similar to 2013 on almost the same date:
Are you watching this, John Christensen (you being the AO guy ;-) )?
Posted by: Arctic Nev | November 11, 2015 at 00:58
Two years ago this resulted in a serious lull in ice growth (not that this means anything at this stage of the freezing season). Will be interesting to see if that happens again this year. The peaks are more sudden, whereas they were more gradual in 2013.
Posted by: Arctic Nev | November 11, 2015 at 01:03
Well, in accordance with the attached graph, the AO has been high for the last two weeks and in spite of that the ice extension increase has been just spectacular.
According to IJIS, today ice extension has reached y 2014 and is the second highest in the last decade.
A high AO means (among other things) the polar vortex is compact and very little heat exchange is happening between arctic and lower latitudes. In other terms, cold air is confined to the Arctic and temperatures are decreasing as a consequence - http://ocean.dmi.dk/arctic/meant80n.uk.php -
In the next few days a massive increase of ice extension is to be expected in Chukchi-Bering area based on the synoptic charts currently available. What is more, SST are lower than average in Okhotsk and in Hudson.
The only area which will be suffering is Barents, in accordance with tradition.
It's an interesting refreezing season up to now, definitely.
Posted by: Cato Uticensis | November 11, 2015 at 18:20
First; thank you Neven for another great PIOMAS update, even if nothing specular could be reported for October.
And yes, Arctic Nev, I certainly have noticed.
If you have been watching DMI's 60N surface pressure charts the past few days, you would notice the simultaneous LPs originating out of the North Pacific - a very intense and compact storm - as well as the North Atlantic, where the entire area between Greenland, Norway and Scotland was under a broad LP.
As Cato points out the strongly positive AO indicates a compact polar vortex, allowing ice to expand well within the boundaries of the vortex.
2013 and 2014 saw little ice expansion right at this time in comparison.
My main point in earlier posts was that a negative AO in wintertime allows the broader area defined in the AO index to be a more effective heat sink, while the broader cloudiness of a positive AO limits the heat sink effect.
The impact of AO on the sea ice depends on the extent of the ice versus the extent of the vortex, as well as certainly the specific distribution of LP and HP areas, which drives the movement of air masses.
Posted by: John Christensen | November 11, 2015 at 21:39