~Winter heat transfer between ENSO and the North Pole was usually in tandem with sea ice volume and extent. La-Nina more sea ice, El-Nino less sea ice.
~Current 2019 Arctic sea ice extent is often very similar or worser than 2016, which had a January with a very powerful El-Nino, a fascinating fact.
In Arctic pure darkness of the long night, only clouds prevents a massive cooling, stopping very thick accretions of sea ice:
January 2016 equatorial Pacific spawned more clouds all over the world. In the Arctic this meant
less sea ice, it was so. January 2018 had a small La-Nina, it meant less Arctic clouds, more sea ice, it was so, but not by much. Same story January 2019, a neutral ENSO or very light El-Nino, less clouds, implies more sea ice than same period 2016, not so, current 2019 sea ice extent is competitive or often smaller than 2016. Less sea ice with a cooler than 2016 planet, a contradiction, translation: heat was transferred to the North mainly in Arctic sea water, over time it has given a net increase in Arctic Ocean warmth. Despite favorable conditions for ice accretion, sea ice volume goes down. Creating a feedback loop, spring and summer sun has more dark water to warm.
The Arctic atmosphere merely reflects this current heat scenario:
NOAA daily composites 600 mb temperatures, a very close representation of average temperature of the entire troposphere. Spanning 4 to 11 May, with respect to Polar Vortex strength, 2016 closely resembles 2019. Yet 2019 has had nowhere the same heat input from the Equator. 2018 had a very strong Canadian Arctic Archipelago vortice within the Polar Vortex, this was caused by a reduction of clouds and heat over the Northern American continent, 2018 sea ice extent was still reduced, prevented the Polar Vortex from being much fiercer. However, the story here is the dwindling sea ice despite favorable conditions which should prompt a recovery. The heat, it seems, is well dispersed throughout all the oceans of the planet, in turn, extra heat within the Arctic system is reshaping the climate of the entire Northern Hemisphere. WD May 14, 2019