PIOMAS October 2018
I was ready to write about this 10 days ago, but the data wasn’t out yet. And then life got in the way, as it always does. On the bright side, Wipneus has just updated his PIOMAS graphs to mid-October. More on that below, but first I’ll discuss the minimum.
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:
As always, the minimum was reached in September. This year, the lowest amount of sea ice volume, according to PIOMAS, was reached on September 15th, and ended up 6th lowest on record, after 2010, 2011, 2012, 2016 and 2017. And thus, because the maximum was second lowest on record, total melt was 9th lowest on record:
If we look at the data for the end of September, 2018 has already crept to 5th lowest on record, almost on a par with 2017. Where most years gain a bit of volume during September, 2018 actually lost 119 km3, thus reducing the gap with all years that were lower at the end of August (dipping below 2010), as can be seen on this table showing how the differences with previous years have evolved from last month:
If we then look at Wipneus‘ most recent graph with data up to mid-October, we see that 2018 has gone down even further in the ranking and is now in 3rd place:
So, basically, what we’re seeing, is the recent slow re-freeze reflected in PIOMAS volume data as well. Further confirmation is provided by SMOS, the satellite that measures sea ice thickness up to 1 metre (hat-tip to seaice.de):
This means that the anomaly trend line on the PIOMAS volume anomaly graph is still hovering above the linear trend line (and will continue to do so until next summer, the only question is by how much):
Both average thickness graphs, my crude calculation (by dividing PIOMAS volume numbers with JAXA extent) and the Polar Science Centre version, aren’t showing anything spectacular:
An end has now come to the slow re-freeze, although things still aren’t progressing ultra-fast and 2018 is (among the) lowest on some extent graphs. Temperatures are still relatively high in the Arctic, as can be seen on Zack Labe‘s version of the DMI 80N graph, probably caused this time around by Arctic waters releasing their heat rather than heat getting imported from lower latitudes:
This following on the 3rd warmest September on record, after 2012 and 2016:
And so, this freezing season has the lowest amount of Freezing Degree Days so far, as shown on commenter Tealight‘s graph:
Whether the 2018/2019 freezing season can follow in the footsteps of 2016/2017, or whether it will move towards 2017/2018, is difficult to tell right now. But I wouldn’t be surprised if this winter follows the recent trend of warm winters resulting in low maximums.