Two days have passed since the previous update, and in those two days the storm re-intensified, bottomed out at 971 hPa (slightly higher than the first lowest central pressure of 968 hPa), as can be seen on the image on the left, provided by Environment Canada. It quickly weakened after that, but lo and behold, the image on the right shows it has re-intensified again and is currently at 971 hPa as well!
Just like that, as if it's nothing. Which brings us to the first of three questions (there were two in the previous updates, but now there's a third one at the end of this blog post):
1. Is this a Great Arctic Cyclone?
I'm still not entirely sure how this storm will rank, compared to previous storms. Remember the quote from Simmonds and Rudeva paper I mentioned in update 1:
The plot shows that AS12 was at the tail of the distribution and, at 966.38 hPa, was the lowest in our record, beating the previous deepest (966.94 hPa) (for a storm at 06UTC 7 August 1995) by 0.56 hPa. The next lowest central pressure, 969.23 hPa, was associated with a cyclone at 06UTC 22 August 1991, followed by the fourth lowest storm central pressure in the earlier part of that month 00UTC 7 August 1991 (970.47 hPa).
But it's definitely a very powerful storm, and even if it doesn't boast the lowest central pressure, all these re-intensifications will probably have it score high in other requirements for GAC nomenclature. And that reminds me of something I wrote back in 2012, following a quote that is highly relevant today:
“This past week’s storm was exceptional, and the occurrence of Arctic storms of extreme intensity is a topic deserving closer investigation,” noted Walsh. “With reduced ice cover and warmer sea surfaces, the occurrence of more intense storms is certainly a plausible scenario. The limitation at present is the small sample size of exceptional events, but that may change in the future.”
That last bit is the reason I'm hesitant calling this the Great Arctic Cyclone of 2012, or Arcticane, or some such. What if we see a similar cyclone in 2013 or 2014? We'll run out of names.
Mind you, I don't want to downplay the importance and magnitude of this storm, it's by far the biggest thing I have seen in the Arctic since I started the blog, but to me this whole event isn't about the storm itself, but about a possible new regime - a new aspect of the new abnormal - with big summer storms in the middle of the Arctic.
I called it the new abnormal at the time, but if this becomes 'normal' (compare coverage of this storm to 2012, for instance), then what cachet does the name 'Great Arctic Cyclone' still have?
2. What is this storm doing to the ice?
It seems the impact is a lot less spectacular than it was in 2012, even though the ice pack is looking like mess. This may be partly because this storm is hitting later in August, but I think the main difference is the lack of preconditioning that I have mentioned over and again this melting season. This is the main reason the record won't be broken this year, regardless of the cyclone.
As can be seen on the JAXA SIE and CT SIA graphs below, 2016 had every opportunity to overtake 2007 and go second lowest, but the past few days showed relatively small drops, not enough to make an impression:
This animation of Uni Bremen sea ice concentration maps for the past 7 days shows how the ice has been following the winds, but any flashing has been compensated by unflashing (ice disappearing from the satellite sensor's view, and then reappearing again), the bite towards the pole has stopped growing and a sliver of ice is still blocking the Northern Sea Route (although boats manage to get through it all right):
Will the cyclone re-intensify again and move the ice around some more? Here's what the ECMWF model is forecasting for the coming 6 days (click for a larger version, and go to the ASIG Forecasts page for daily forecasts):
Wow, as if things weren't interesting enough already. The cyclone is going to weaken considerably in the coming days, but not fizzle out completely. It's a quite large and intense high pressure area over the Beaufort Sea that is going to add some more flavour to the mix. If that 1030-1035 hPa comes about, aided by the cyclone over the Siberian side of the Arctic, this Dipole configuration could cause quite a bit of compaction, if it persists.
And you bet there is a lot of compaction potential right now, as all those cyclones this summer have stirred the ice pack, pushing floes apart, away from the centre. The CAJAX compactness graph shows that 2016 is currently among the lowest on record:
Wipneus' compactness graphs where SIE and SIA come from the same source (CAJAX is a combination of the JAXA SIE and CT SIA graphs above), show that compactness is lowest on record for the highest-resolution Uni Hamburg data, and lowest for the date when it comes to the low-resolution NSIDC NASA Team data.
So there's compaction, but that massive Dipole set-up will push out even more ice towards the hot North Atlantic waters that will simply devour it. And given the highly fractured and dispersed ice pack south of the Pole in the Atlantic sector, we come to our last question for this update:
How close will open water get to the Pole?
It's difficult to assess because the cyclone's clouds hide what goes on below, but over on the ASIF Jim Hunt posted this latest Sentinel 1A image of the area in question:
Will we see a North Hole like we did in 2010, or will the bite on the Siberian side, between the East Siberian and Laptev Seas, extend even further, past the 85N mark that was reached by open water in 2014?
Either way, as one commenter on the ASIF put it: Mankind breaks North Pole's heart.
While another commenter has tried to depict what the Great Arctic Cyclone of 2016 has been doing to the Arctic in the past week: