~Optically significant event of very cold stable air mass centered in the West of Canadian Arctic Archipelago was made to move by warm cyclone interaction.
~Most significant coldest upper air measured by vertical sun disk method in 20 years, had remarkably stable properties lasting at least 4 weeks.
A steady area of cold air kept sun disks shrunken for nearly a month, but not near the surface, this particular nature of steadiness is interesting, but the level of cold was not seen since 2002,
which was several years after massive 1998 El-Nino, now likewise several years after massive El-Nino peaking end of 2015, we see the result of steady La-Nina influence of less clouds, particularly away from influx of Northern moisture from frequent North Atlantic warm cyclone injections, the dry air it seems, survived mainly to the West and South of central CAA. The West CTNP (Cold Temperature North Pole) vortex just recently got displaced Westwards towards Alaska: