~Siberia CTNP dominates winter 2020-21 in Northern Hemisphere
~New Refraction method helps identify the likeliest protogenesis system causing cold air buildups. Massive cooling areas can stem by very complex geophysical factors, luckily rendered simple by interface observations.
~ In one feedback loop, more snow comes from more clouds, in another loop the deep snow insulated ground cover saves the permafrost from rapidly rising reaching air in Arctic darkness, slowing the ground cooling process. In other words, darkness combined with lack of snow cover favors thermal radiation escaping to space, especially in areas far away from cyclones bringing warm air advection.
Unfortunately, we lack specific snow density data, but Canadian Cryosphere Watch snow cover thickness gives us some clues. Lake Baikal area, the current super cold spot (grey and red) has a deficit in snow as opposed to near the East Siberian sea. But look at Ellesmere