~The reign of Ellesmere and North Greenland Cold temperature North Pole has been seriously challenged
~Rather changed, the CTNP of winter 20-21 was often found in Central to Eastern Siberia.
~Is rather an indication of a moderate La-Nina, and something as simple as the nature of surface snow.
2020 will be likely #1 shared with 2016 Global warmest year in history, as predicted in April here, from the same EH2r projection page a small El-Nino, or trending El-Nino happened April-May (the sun disk refraction method expected so) then a modest La-Nina gradually came about (very difficult to predict because of this blob, ENSO trends were strongly masked by the North Pacific warm temperature blob. One of the greatest factors of 2020 making the warmest Global temperature as was in 2016 (the year of super strong El-Nino) , was the worldwide diminution of pollution activities due to Covid-19. Summer came to be hot because of this, with dire consequences including USA West coast very damaging Armageddon wild fires, along with Siberia temperatures at +30 C.
Arctic sea ice extent at September minima came very close to beat 2012, just off prediction by 1 step , #2 least expansive sea ice at minima, this still has serious consequences though, which brings us to the topic at hand. Since onset of winter the prime CTNP, was mostly centered in Siberia, a strange turn of events, the hottest Siberian summer heat wave in history, preceded the coldest spot in current winter at about the same region. It may be a matter of snow, largely how compact it is, in the Canadian Arctic, with snow covering the permafrost was/is strangely less compacted (due to extensive cloud cover and record warm temperatures), having greater insulation properties, this should have reinforced cooling especially in total Darkness:
SAR image 10-01-21 , Ellesmere Island, likely warmed by thinner sea ice (black) everywhere surrounding, except its Northern most point. A strong CTNP often hovers over this Island year round. The dark Fjords are all with fast ice (new and thin), except for a few multi year floes. There is apparently a great deal of snow over Ellesmere, not having any effect on pronounced cooling, as one would expect.
While Siberia seems to have less cement snow cover:
The other reason was explained in April 2020 as linked on the URL above, 2020 summer CTNP was largely at the North Pole,
continuing all the way to autumn, the Eurasian flow of air was from Ural's Eastwards, a drier atmosphere, making the sudden onset of radiative cooling with lowering sun more impactful in Russia. There is another plausible explanation, La-Nina and the said Pacific warm temperature blob. La-Nina effects were largely nullified over much of North America, because of this Temp. blob. However, the very warm North Pacific made it warmer for North America, certainly not giving perfect weather, because of expansive prolonged periods of cloudiness. La-Nina however modest, is still about, this reduced cloud cover all over the world except East of the North Pacific. In the Arctic, the upper atmosphere was indeed largely dry except for the very lowest altitudes, all that open water from 2nd lowest historical Arctic sea ice extent has certainly made the Arctic warmer and snowier, but the Polar upper atmosphere was consistently devoid of moisture above about 1000 meters or so. The Canadian vortice, usually one of two vortices forming the Polar Vortex, got less dominant and shrunken, while Siberia with a dryer sky cover, with lesser clouds. acquiring snow faster and earlier, was sufficient to shift the location of the coldest vortice of the Polar Vortex, to reside East of Northern Russia. WD January 10, 2021