10 days ago I posted a blog post called Mad max. The title - referring to a very early maximum sea ice extent - ended with a question mark, because it was far from sure whether the preliminary max reached on February 15th would remain standing. This is because of the oscillatory nature of the final phase of the freezing season, where weather conditions can cause the ice pack to expand very rapidly in one or more of the fringe regions.
Since posting that blog post, JAXA SIE dropped up to 318 thousand square kilometres below the preliminary maximum, but has since crept upwards again. The current difference is 186 thousand square kilometres, which still is quite significant. In fact, a new max becomes less and less probable as time wears on, with the Sun creeping higher in the sky, shining on larger parts of the ice pack every day.
At the same time, with extent relatively low, there's plenty of freezing potential on the fringes. And we're talking about the Arctic here. It has a reputation of crazy swings to uphold. Here's a map with the names of the regions that have a final say in where the maximum ends up, with the orange line showing the average ice pack edge for the 2000's:
And here are the graphs for each of these regions, produced by the prolific Wipneus, that show what has been happening regionally in the past weeks, with the purple line showing the JAXA SIE data for 2015.
First the regions with freezing potential:
Sea ice extent in the Barentsz Sea had been dropping precipitously, but this has come to a halt a couple of days ago. The Bering Sea has been the primary reason for SIE going up again in the past week. Regional SIE in the Okhotsk Sea is as low as it has ever been since records began, for this time of year. It's been going up a bit as well, but potential for re-freeze will probably not build up that much as the melting season is about to start in this region.
The same goes for these two regions on the Atlantic side of the Arctic where SIE levels have been very high this year, due to all the cold that spilled out from the Arctic this winter:
Even if there's a big expansion of wafer thin sea ice in the Bering and Barentsz Seas in the coming week (which gets counted as extent despite it being so thin), ice melting in these two regions may offset the gains enough to prevent a new maximum.
The question of whether we get a record early maximum or record late maximum will be settled in the coming week, and so we turn to the weather forecast. It's temperature and wind speed/direction that interest us, because only a combination of anomalous cold and northerly winds pushing the ice southwards in the Bering and Barentsz Seas can enable an even more spectacular end of the freezing season.
Again, I use the visually appealing forecast maps from the ClimateReanalyzer website (from the Climate Change Institute at the University of Maine), based on the GFS weather forecast model. This animation is slightly larger than usual (I always try to keep them below 1 MB, this one's 1.3 MB), so I apologize if it loads slowly. Keep your eye on the Bering and Barentsz Seas in the green circles:
Only a combination of anomalous cold and northerly winds pushing the ice southwards in the Bering and Barentsz Seas can enable an even more spectacular end of the freezing season.
Well, that's exactly what the forecast is showing right now, up to six days of it. At the same time it's showing anomalously warm temps and winds blowing east in the Baffin, Newfoundland and St. Lawrence regions. Again, the difference right now between today's sea ice extent number and the preliminary maximum is 186 thousand km2.
It's still too early to tell for sure how this is going to end up, but it's not too early to draw a couple of conclusions: If the preliminary max remains standing, it will be the earliest and lowest on record. If it doesn't, we might very well get to see the latest maximum on record, but it will still break the previous record low maximum reached in 2011, and possibly stay below 14 million km2, which would also be a first.
And so a record low maximum it is, regardless of whether it's very early or very late.