I prefer to look at the refreeze on november 5 to see how last melting season really did, how much heat was left in water [and/or came in with Atlantic Waters] ... the Atlantic side is colder but it should struggle to refreeze cause the freezing momentum is weak
Right. While insolation provides negligible heat to the Arctic Ocean ice towards the end of August, sea water has far greater heat capacity and thermal conductivity than air -- and never mind local clouds, Atlantic Waters come up from the Gulf of Mexico.
North of the Barents and east to the Laptev, breakdown of stratification is not so much wind-dependent on mixing as on roughness induced tidal turbulence, especially over the Yermak Plateau (per many studies, eg N-ICE2015).
There's been confusion up-forum citing studies from the late 1990's, here's the 2017's to look at, both free full text:
https://tinyurl.com/yctkrnlbhttps://tinyurl.com/y758r27n I Polyakov et al April 2017 write: Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline and shoaling of the intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin [~Svalbard].
The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching atlantification of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows.
The open water minimum in the Arctic Ocean proper was reached on 07 Sep 2016 using pixel count areas in UH AMSR2, which at 3 km resolution is a great improvement over 25 km resolution. (Open water is far easier to determine by satellite than accurate mid-range concentrations. Pixels in the PS projection deviate only by a few percent from equal-area north of 70º, so negligibly in subtractive comparisons.)
It's important not to throw in Greenland Sea ice, as NSIDC does for their
10 Sep 16 minimum. It should be subtracted, not added -- never in the satellite record has this ice made its way back into the Arctic Ocean. (Summer 2017 has seen little Fram export so it is somewhat moot this year.)
For inter-year comparison and current year prediction, it also makes sense not to include 'Barents Boundary' ice that lies south of the continental shelf bathymetric break, ice which is probably going to melt regardless of clouds, cool air or low wind. Atlantification hasn't gone away, it's just been smothered (temporarily masked) by ever-incoming ice.
The animation below determines this boundary using a 7 day AMSR2 average centered on the 2016 minimum; the resulting mask can then be applied as a future-driven correction to current data.
The noteworthy development this summer has been a steady push of ice up against and through this line of islands. While no one has a clue to the winds or weather beyond D5 (Aug 24th), ice models that use forecasts see this cyclonic push continuing.
Indeed, the a worse-case scenario for ice loss on the Atlantic side (3rd frame, 2nd animation) could see quite a bit of ice move into the thinning/melting zone over the next month, even as elsewhere the refreeze season had begun (as in in fall 2016). This suggests a more nuanced (regionally hybrid) definition of 'minimum' would more accurately characterize the situation.
2016 IB+CAA Bering Green Open Water
09 01 263333 6136 9173 278642 09 02 270160 6136 9173 285469 09 03 269975 6136 9173 285284 09 04 269383 6136 9173 284692 09 05 268931 6136 9173 284240 09 06 272316 6136 9173 287625 09 07 273760 6136 9173 289069 * 09 08 270858 6136 9173 286167 09 09 270580 6136 9173 285889 09 10 267496 6136 9173 282805 09 11 265534 6136 9173 280843 09 12 260439 6136 9173 275748 09 13 257114 6136 9173 272423 09 14 257850 6136 9173 273159 09 15 257601 6136 9173 272910 09 16 255402 6136 9173 270711 09 17 254694 6136 9173 270003
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