To make out the meaning of the latest results we must study the over all circulation picture courtesy NCEP/NCAR , the following are model maps of 600 mb temperatures, at about this altitude we can determine the temperature of the entire troposphere which varies from one geographic point to another. I find these maps helpful, but we must keep in mind that there are no upper stations over the Arctic Ocean.
Last season 2015-2016 had lower pressure average North of Ellesmere. North Atlantic Cyclones died there, now they are attracted or steered by the greatest of the Polar vortex vortices, the Siberian one. But the Arctic Ocean laced with water, much thinner ice, "attracts" Low pressure systems just as much as last winter. Some linger and die over the Pole, while they do, the clouds outright warm everything to huge anomalous temperature gains. From greater open water/thinner sea ice heat flux the Lows die slower, while they do, they "invite" other Northward Lows to replace them, because the shaping of the jet stream is to the North mainly over the Gulf Stream, a huge steady source of moisture. The smaller vortex of the the Polar Vortex vortices, was mainly centered over Baffin Bay, although migrated North or South from that location. This heavily shaped the North Atlantic Jet Stream to bend Northwards.
Warming of the entire Arctic recorded by optical method:
The continuous onslaught of Cyclones Northwards along with the much more open sea water and thinner sea ice had a huge unprecedented effect on the atmosphere, land and frozen or open seas:
January 19 2017, it has been seasonably colder -33 C for about 4 days with a peak dip nearing -40 C, a departure from much warmer winter. The sea horizon from November 2 past, rose 3.5' of arc, a significant drop in height during total darkness compared to last year. A lowered horizon is always characterized by a lesser temperature contrast at the surface to air interface, this latest observation is a strong indication of more heat on the surface which warmed cold clear air more than last year. The best way to explain this is 2 blocks of equal volume of identical matter, one at higher temperature, the other at air temperature, the immediate impact of the warmer block would be to raise the temperature of the air next to it. Likewise, after months of mostly cloudier High Arctic weather, effectively reducing thermal radiation escaping to space, along with greater heat injected by open water and thinner sea ice, the land and sea ice has a net warmer presence, this translates in a lesser temperature contrast reducing horizon heights.
Just at the clearing of clouds, a few days prior, the data was even more compelling: