Do you see that 2016 trend line simply refusing to go up, ending at the lowest level on record for this time of year? That's because of this:
The Arctic has stubbornly refused to refreeze before, but this is another event we can add to the unprecedented list. After ending second/third lowest on record around minimum time, there was a rapid refreeze that was traditionally touted as the End of Global Warming, but for the past weeks things have been at a figurative standstill. Whatever the respective roles of natural variability and AGW, these wild swings do not inspire confidence in a semi-stable system (and the same goes, unfortunately, for the Antarctic).
The slow refreeze inevitably has an effect on sea ice volume, as modelled by PIOMAS. As of November 1st, sea ice volume is lowest on record, but this post covers the month of October only, and at the end of that month, 2016 was just marginally behind 2012. But with an increase of just 1648 km3 during October (only 2007 managed to have an increase below 2 million in the past decade) 2016 has left all other years in the dust.
Here's how the differences with previous years have evolved from last month:
The 'flatline' can also clearly be seen on Wipneus' version of the PIOMAS volume graph: