stay on-topic
If only we had a forum called Best Forum Posts (which under no foreseeable circumstances would include more than 4-5 per 1000, two weeks at current rates). Here #1330 and #1336 might very well make the cut.
The Chukchi is about the same this morning -- a 896 km swim due north from Big Diomede to the first ice solid enough for a walrus, seal or polar bear to haul out on for a rest.
The GFS forecast had extremely cold Siberian air passing north of Wrangel but on the subject of warm surface air being entrained over the Bering/Chukchi, seems to be in conflict with ECMWF. That would be unremarkable except that ECMWF is more skilled whereas forecast products like nullschool and possibly Hycom use GFS. [fixed by JimH in #1347: uses NavGem; nullschool ECMWF available at windytv]
Consequently I've issued a standing W&S
emergency advisory hindcast (wait-and-see what happened yesterday). In terms of re-analysis, the lee side polynya around Wrangel island is quite informative. While that is not exactly open water, it shows when there was enough oomph in the mean wind field to move the needle. Similarly for small islands of Franz Josef and Severnaya Zemlya.
The top animations run from 01 Nov to 11 Dec. The Modis image and context are from the 7th; the best fit to our favorite ice products seems to be 'none of the above'. Nice bit on ice types and formation here:
http://www.pmel.noaa.gov/arctic-zone/essay_wadhams.htmlBelow is a sketchy scenario for this chain of events hypothesized as the 'new normal' weather pattern (not freak weather), feel free to revise, toss, or enhance:
-1- Emissions cause greenhouse effect, raising air and water temperatures.
-2- Arctic is most affected in autumn via amplification mechanism.
-3- The heat gradient between equator and Arctic is diminished.
-4- Jet stream slows and wobbles according to franciscan theory.
-5- Polar air streams down to mid-latitudes in eastern US on down-wobble.
-6- Mid-Pacific and Siberian air stream north on up-wobble to replace missing Arctic air.
-7- Warm air and water flow north through Bering Strait to the Chukchi, stalling lateral refreeze.
-8- Return to -4- and repeat as appropriate.
-9- Expect two strong winter storms like the 27 Dec 15 to bring moisture and insulating clouds.
-10- Less winter freeze onto bottom ice results in thinner ice at beginning of melt season.
-11- The open water season better matches peak insolation season.
-12- More water vapor in air means more energetic summer cyclones early and late.
-13- Reduced albedo in summer and thin ice/dry snow cover in winter add to planetary heat.
-14- Return to -1- and repeat until permafrost and methane kick in.