Apologies for taking so long to reply... I'll spare you my usual excuses, though I don't doubt they would impress you with their earnest sincerity and momentous import of the ways I manage to waste time ...
Here is the reasoning why I proposed that the last 1 meter of ASI from 1m average thickness would melt to 0m faster than from 2m to 1m average thickness:
-- As we lose the older thicker MYI, the remaining ice has higher percentage of younger, and thus saltier and easier to melt FYI. Everybody seems to agree on that.
e.g. As interstitial noted at
https://forum.arctic-sea-ice.net/index.php/topic,2709.msg201895.html#msg201895 Thinner ice, presumably with higher portion of First year Ice...
"has pockets with high salt concentrations in it. Some of the pockets even most may not of frozen solid.
...When the temperature climbs above -21C the pockets of high salt concentration melt first. The temperature is still too low to melt the pure ice.
... This is how multiyear ice is formed each freeze and thaw cycle of salty water can more and more salts out until it is pure ice with no salts. That makes the multiyear ice fresher and more melt resistant."
--
But here is the main reason - the Thorndike (1975?) chart showing the differential rate at which ice of different thicknesses increases thickness, that Chris Reynolds posted to explain the Slow Transition hypothesis. To me it says that unless there is some hysteresis effect, then that curve in reverse shows that thin ice also melts MUCH faster for the same amount of heat input. For a given amount of heating energy, e.g. melting degree days in summer, more ice is lost per unit of energy in summer by thin vs. thick ice, just as more ice is gained by thinner ice for the same amount of freezing degree days during the winter.
Here is the Thorndike chart
(And you know its good because it is Neven's account icon!)
Here is my reversed version, with zoom into the last 2 meters.
Seems to me that the Thorndike chart, when reversed, shows the amount of ice lost for the same amount of heat added to ice of different thicknesses. Just as the original chart shows the amount of ice gained for the same amount of heat lost from ice of different thicknesses.
Thus, I am using Chris Reynolds' Slow Transition evidence to reach an opposite conclusion.
This is a simple case of Teslacle's Deviant ("What comes in, must go out") to Fudd's First Law of Opposition ("If you push something hard enough, it will fall over") -- for you Firesign Theatre fans. Seriously though, as a thermodynamic equation, what works in one direction should work in the reverse unless there is some hysteric effect at work. (e.g. Teslacle was right! This could be Vulvaire's Correlate to Teslacle - "What went out, comes back in.")
Another chart adapted from an ASIF post by Jim Hunt
https://forum.arctic-sea-ice.net/index.php/topic,2709.msg201631.html#msg201631 shows the same phenomenon. I didn't reverse this one, but you can do that in your head.
The only argument against a quicker final meter melt notion is that the because the CAB is at higher latitude, the melting process will stall as the Arctic ice melt reaches the high latitude end game. And I might buy that idea if humanity was intelligent enough to stop pumping greenhouse gases into the atmosphere at an increasing rate, but not seeing evidence that we will, one can only suppose that warming will continue, and in fact that the rate of warming is increasing.
I admit that gerontocrat's open water chart (up thread at
https://forum.arctic-sea-ice.net/index.php/topic,2348.msg235525.html#msg235525) requires a huge rate increase in CAB September open water to have a BOE anytime soon.
But the cumulative evidence argues that that is indeed what will happen. While gerontocrat's CAB volume trend chart shows it reaches zero a few years later (ca. 2040?) than the whole-Arctic Wipneus volume chart (2032), it is not that much later. That suggests that the CAB does not have enough extra resistance against melt to combat the inexorable warming and Arctic amplification underway.
As Tor Bejnar noted at
https://forum.arctic-sea-ice.net/index.php/topic,933.msg113144.html#msg113144"I have also long considered the 'quick' loss of summer ice in the non-CAB regions over the past 30 years (e.g., the Beaufort going, in August, from 2/5th coverage to none between 2013 and 2016) not to be predictive of how fast CAB ice will be lost. I think this discussion of bathymetry adds some geophysical creds to Chris's theses. This doesn't mean, however, that I'm 'now' convinced Chris is right. I think other issues like CO2-equivalent,
mobility and storminess (emphasis added GK) may well 'over' compensate for the bathymetry-related suppression of warm water currents remaining near the ocean surface."
As Bruce noted at
https://forum.arctic-sea-ice.net/index.php/topic,778.msg32178.html#msg32178"Chris, I don't see any reason for the rate of summer melt increase to flatline, slow down, or even be linear. As the ice thins, the surface/volume ratio increases, which should increase the rate of melt. The thick MYI held off major assaults in 2017 and 2012, but that ice is nearly gone. What we have now is this "mesh ice" that spreads out as the edges melt (which, though it is a negative feedback (because it keeps more of the ocean covered with ice), is a short-lived one). That spreading increases the surface (both top and bottom) that can melt."
In a second instance of using Chris Reynolds' evidence to reach an opposite conclusion, I will reinterpret a chart he posted at at
https://forum.arctic-sea-ice.net/index.php/topic,933.0.html Read his post to see how he uses that to argue for the slow transition. To me it shows that September ASI volume hits zero ca. 2027, even earlier than the Wipneus chart.
As for the hiatus, I think we've beat that to death. I'll just repeat that 10 yearly data points is simply not long enough to make statistically valid conclusions for data with high interannual variability. I will go out on a limb and bet that the 2012 minimum volume record has a 50% chance of being replaced in 2020, likely won't last beyond September 2021, and almost certainly won't last beyond Sept. 2022.
That said by the guy who expected the October slow refreeze to continue based on GFS forecast showing continued high Arctic temperature anomalies over the last 10 days, when just the opposite happened. I guess I was confusing the tail and the dog - my new guess is that the air temp. anomalies were high because the water transitioning to ice was giving off heat to warm the air above it.