Still trying to understand how the *warmest* August on record, according to awesome +70N 925hPa temps chart produced by Zack Labe, led to such a poor loss of ice extent. No convincing explanation so far....
I am convinced that we had normal melting conditions in 2019.
WTF? Normal melting conditions? With warmest August, 2nd warmes June and 3rd warmest July (and it was quite sunny for a good part of the summer as well)? How can you call that normal? Based on temps, ice should have crashed to nil, but it held up very well, so I have the same question as the original poster: i wonder why we did not lose more ice?
My answers are:
- the GAC of 2012 was truly a powerful and rare phenomenon and simple warm weather is not enough to repeat it
- the Central Pack is really hard to crack
- the Arctic is a mystery 
Your answers are good, especially the third.
When the melting momentum hit a wall in early August I commented then that we were missing something key in our understanding of what drives the melt. They key things that stand out in my mind now are:
- Lack of comprehensive understanding of salinity, heat and movement of water under the ice
- Underestimating the effect of high latitude and other conditions affecting refraction that reduce heat uptake.
- Strong support for ice retention around the emerging "cold poles" - though that pretty much failed completely by July on the Siberian side.
There's far more, no doubt, but that's what jumps out at me now.
I will be watching a number of things now on the refreeze. As others noticed, we are seeing regular cyclical massive intrusions of heat and moisture all the way into the central basin, which themselves show no sign of diminishing.
I think the refreeze of the peripheral central seas (ESS, Chukchi and Laptev in particular) will be strongly retarded. I think the Beaufort and CAA will actually refreeze fairly fast, in keeping with the development of the "cold pole" over northern Canada and Greenland. I think they will catch up rapidly once we reach mid to late November, and I think continued intrusions of heat will offset what would normally be heat lost from those seas. That heat retention will play a key role in how much thickening we see late in the refreeze season.
I will be watching the CAB with considerable interest and am overjoyed by the over-winter expedition being carried out. My prediction of what's ahead is that we will see much higher than typical snowfall, which we know is a very two edged sword. Next spring it will protect the ice. However, if it stacks up too high and too fast, it will seriously impede the very necessary lost of heat out of the arctic basin we need to preserve the ice.
I'm tentatively thinking were going to see conditions much like 2016-2017, with serious drops in FDD's and anemic volume growth, much of which won't happen until after northern hemisphere snowfall locks in colder temperature over the continents.
It will be an interesting season.
(Post script - various models have the remnants of typhoon HAGABIS blowing back up into a *very* powerful storm in the Bering in a few days. That could seriously disturb weather on the Pacific side of the basin. Worth keeping track of, I think.)
