Big, big changes this month, and not for the good. Due to extremely high, or maybe I should say non-low temperatures in the Arctic the past month, this new year opens with the smallest monthly volume increase for January in the 2006-2016 record. 2007 saw an increase of 2848 km3, but 2016 goes one better with 2794 km3, in all other years volume went up by more than 3000 km3.
This means that, yet again, current volume has crept closer to the post-2010 years and widened the gap with pre-2010 years. Below the change in difference between January 1st and 31st is shown:
On January 31st 2016 the Arctic has just 104 km3 of sea ice volume than the same date in 2012, the year of the record melting season. The difference with 2013, the year that followed the big melting season, is still 803 km3, but it has gone down by 920 km3 in just the past month. The difference with last year (when two rebound years caused a marked increase in volume) has changed to a whopping 1692 km3. 2016 is still in 4th position, just like last month, but the gap with the top 3 has diminished radically. I could go on. Really big changes.
On Wipneus' version of the volume graph we can clearly see how differently the 2016 trend line moves from other trend lines around it:
This all means that the trend line on the PIOMAS sea ice volume anomaly graph has moved down, away from the linear trend's 2 STD territory:
Last month I wondered how much higher it would get, now I'm wondering whether it will cross the blue linear trend line before the melting season starts.
To my surprise there's also something of an effect on the PICT graph (my crude average sea ice thickness calculation, derived by dividing PIOMAS volume numbers with Cryosphere Today sea ice area numbers), although not large:
Cryosphere Today sea ice area growth stalled quite a bit during January, going lowest a couple of times, but it seems volume growth was relatively lower still.
The same can more or less be seen on the PSC's thickness graph:
Not that average thickness tells us all that much. There could be 1 km2 of ice left in the Arctic Ocean, but if it were 3 metres thick, it would be off this chart. It's more interesting to look at the thickness distribution. Luckily we have Wipneus who produces all kinds of wonderful maps for us. This one compares current sea ice thickness distribution (as modelled by PIOMAS) to previous years, red means more ice now, blue means less ice now:
I'm kicking myself for not posting an analysis of the first half of the 2015/2016 freezing season as I promised I would do, if only to be able to more or less predict this slow volume growth. I'll do that later this week, as we absolutely need to know what the winter has meant for the Arctic's sea ice so that we can assess initial conditions as accurately as possible.
But winter is far from over. The past week or so weather conditions in the Arctic have been more conducive to ice growth, and there are plenty of weeks left to come to thicken that ice pack before the Sun comes out again.