To make up for this somewhat belated PIOMAS update (below), I have for you Andy Lee Robinson's latest update of his Volume ice cube 3D video:
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:
Indeed, the lowest amount of sea ice volume, or minimum, was reached a few weeks ago. With 4539 km3 it was the 4th lowest minimum on record. But, of course, after having broken the number for lowest maximum on record back in April, this means total volume decrease for the 2017 melting season was lower than it was at the end of the last 10 melting seasons, coming in slightly higher than 2006 (16,217 km3 vs 16,198 km3):
After the mild winter there was a risk of records being broken all over the place, PIOMAS volume being one of the most conspicuous ones. Just an average of what we've seen in the past 10 years, would have sufficed easily, but it didn't happen, as I explained last month. This graph by Zack Labe, showing monthly temperatures in the Arctic, tells a large part of the story. Lots of red during the winter, but then a reversal in May and June (the melting momentum months), followed by a staggering 29th warmest July and 21st warmest August:
In the latest monthly summary posted on the NSIDC website, we see the atmospheric visualization of the same phenomenon:
Figure 2b. This image shows the departure from average sea level pressure in millibars over the Arctic for June, July, and August in 2017. Yellows and reds indicate higher than average pressures; blues and purples indicate lower than average pressures.
That's the Arctic for you. Nothing is a dead certainty. I hope the expression is ambivalent enough to make you feel more secure. ;-)
As for the past month, 2017 had the slowest decrease for the second month in a row. In fact it was a slight increase of 318 km3 (September is the month of slight increases/decreases), and so the difference with previous years have yet again become smaller or larger, depending on ranking, although 2017 is still fourth overall.
Here's how the differences with previous years have evolved from last month:
And here's Wipneus' version of the PIOMAS graph:
Nothing much changed on the PIOMAS sea ice volume anomaly graph. If there's a rapid re-freeze the trend line could break through the linear trend (straight blue line) again:
Nothing much has changed on the thickness plots:
So, that was it, officially, for the 2017 melting season. We'll now wait and see whether we get a third freak winter in a row, or whether this turnaround will be consolidated.