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:
March 2018 turned out to be quite cold, relatively speaking (more on that below). And thus, as expected, volume increased by a lot, especially given that it was relatively low at the end of last month. In fact, with 2278 km3, sea ice volume growth during March was the largest in the 2007-2018 period, well above the average of 1832 km3. This means that the gap with 2017 has widened again, whereas the difference with all other years has become smaller. 2011 is now hot on this year's tail, being just 217 km3 behind. I expect this year to end up having the second lowest maximum on record, but you never know.
Here's how the differences with previous years have evolved from last month:
The 2018 trend line can clearly be seen moving back towards the pack on Wipneus' version of the PIOMAS graph:
Naturally, the trend line on the PIOMAS sea ice volume anomaly graph has shot up, moving away from the linear trend line again, meaning volume loss is slightly less than expected, if one were to extrapolate the data average into the future:
If volume is going up, but extent is among the lowest on record, and you divide the one by the other to get average thickness, the number will go up, of course. Hence the PIJAMAS trend line going up slightly faster than the rest, but differences are marginal at this stage anyway:
As often is the case, the same can be said of the Polar Science Centre thickness graph:
So, how cold was March? It was bloody cold, as the British would say. But unlike the British, the Arctic was actually in need of some serious cold, after a bloody mild winter so far. This can clearly be seen on Zack Labe's excellent ranking graph, showing monthly temperatures north of 70° latitude. After being in the top 3 for five months in a row, the last month of winter came in 26th:
My own temperature graphs, for the Arctic as a whole and for the Arctic divided into four quadrants, show the same, with especially the Siberian side of the Arctic taking a plunge compared to previous years, rivaled only by 2013 (click for a larger version):
And here's a visual representation of that, with the temperature anomaly distribution map of the Arctic, as provided by the ESRL PSD daily mean composites website:
With such low temperatures on the Siberian side of the Arctic, it's no wonder that PIOMAS indicates that the sea ice is thicker there, when compared to the 2011-2017 average (image courtesy of the Polar Science Centre):
It will be interesting to see whether that can put a break on sea ice loss this summer, especially as it will be aided by a large amount of land snow, in Siberia as well as the Northern Hemisphere in general. Here's the latest from Rutgers Global Snow Lab, showing the March average, up quite a bit, compared to the previous four Marches:
On the other hand, volume is still second lowest on record, and extent is now lowest, after a large drop was reported yesterday by JAXA. Winter was mild overall, and the situation on the Pacific side of the Arctic is nothing short of spectacular. Things are slowly warming up, the Sun is slowly climbing higher in the Arctic sky, volume is going to hit its maximum this month, and then the circus starts again in May. It could go either way. Nothing in the Arctic is a dead certainty.