Clear air moisture species; some let through Long Wave Radiation, some bounce it back

 ~A recent steady continuous influx of Cyclonic moist air originating from the  North Atlantic steered counterclockwise around Northern Greenland often did not show up as clouds
~Upper Air remnants of moist air mixed with smaller deep cold CAA vortice usually hanging about 67 North 85 West for weeks.
~This vortice was like a "black hole" steering all atmospheric matter around it.
~Many were observed as having clear air exotic moisture events ,  which despite apparently no clouds,  transformed the horizon as if there were clouds.
~This meant Long Wave Radiation did not freely escape towards space and gave very low sea ice horizons.

   South Cornwallis Island,  it was -34 C on January 21 2018,  with apparent clear skies,  further to the South it was much colder.  This very low sea ice horizon is counterintuitive,  does not respect the concept of clear air Long Wave radiation escaping to space.   Unless the upper Air profile has Long Wave reflecting moisture rich layers.  Precipitable water was a mere 2.7 mm.  At this horizon altitude,  there is much less sea ice accretion than when top of sea ice/snow is super cold,  when top is extremely cold the horizon can rise up to 3 times higher, in fact measured sea ice thickness stalled for weeks along with sighting such low horizons.
The horizon elevations in all quadrants were consistently lower for most of the long night of 2017-18.

  Jan 22 00 UTC 2018 71924 Upper Air relative Humidity profile vs Altitude,  it wasn't a dry profile despite 2.7 mm total precipitable.  Some of the moisture layers had exotic Long Wave properties
which reflected back Long wave radiation as if there were clouds.

    University of Wyoming map Jan 22 2018 00 UTC,   total precipitable looking throughout the Arctic ,  there was not much water in the atmosphere basically everywhere,  but water can take many forms,  either from super cooled to many different species of ice crystals.   In the Canadian Arctic Archipelago, some had "cloud like" properties,  despite not being seen.  WD February 27,2018

Big Lead Spring Break event 3 months early

~The legendary  "Big Lead" exists,  it shows up in various ways depending of date of year
~This February 26 2018 showing comes with lateral and perpendicular fractures with micro-fractures
~ This usually was an early June event....

Look very carefully North of Central Canadian Arctic Archipelago.  To the left there will be a small cyclone moving East,  it will bring out the Big Lead.  A deeper look reveals a chaotic well battered sea ice prior to these lead creations.  Right after or during the big coastal movement was like a tremor causing many lead fractures to bring out heat signatures,  open water everywhere:  

This kind of break up action was a late May or early June event.  This February 26 2018 badly broken up sea ice is a qualifier of current state of Arctic Ocean ice,  looser, more fluid,  a special feature of a not so long ago beginning of summer.   However, Big Leads showed in February's not so distant past,  but had a very typical look of a single lead parallel to the Canadian Arctic Archipelago Coast without the fractures,   it opened and appeared to shut quickly,  because air temperatures were very cold (-45 to -50C) ,  open water froze rapidly,  drifting snow swiftly covered the fresh ice,  tides also closed the gaps.  It typically visually disappeared in 2 days.  WD February 26, 2018

A different Arctic in 30 years, very cold atmospheric region moved South where land dominates

~Very thick sea ice had one major  impact,  it centered the Cold Temperature North Pole (CTNP) more towards the North Pole.

~We look back and remember a different long night climate.  

     Moving North towards the North Pole at longitude 90 degrees West ,  this February 10 1988 infra red satellite picture demonstrates great white,  meaning really deep cold weather spanning huge distances: 

The coldest area was Northern Greenland and Ellesmere,  where very thick sea ice was abundant.  

Extreme North Pole trekkers  starting from Northern Ellesmere experienced the frequent -45 to -50 C welcoming temperatures.

30 years later:

The great white area is much smaller with this CMC animation sequence,  very well to the South of Ellesmere Island strangely not only warmer for this day February 20 2018,  but for weeks!

The consequence of this much smaller cold zone shifts weather patterns for a great region of the world.  Especially repeatedly directing warm Cyclones hugging Greenland's East Coast towards the North Pole then back towards the Canadian Arctic Archipelago.  Making said Ellesmere way warmer than Nunavut and NWT Canada mainlands.   These are different weather days.  When coldest air is from the South of the High Arctic:

 Looking back 30 years ago,  february 8 1988,  the coldest air was over the Arctic Ocean, when  freezing -45 C's were common until mid March. Today the Arctic Ocean surface air is radically warmer,  driven by smaller cold air vortices on both North American and Eurasian continents which move continuous ocean warmed cyclones towards the North Pole. The consequences of this results in what is called Arctic warming Amplification. 

   NOAA Map room 30 day surface anomaly January 20 to February 18 2018 clearly depicts a great warming of the Arctic Ocean surface air, going in tandem with thinner sea ice.  
1988 NOAA daily composites with 30 day same period as above was much more colder on the anomaly side of temperatures over the Arctic Ocean in particular.  WD Feb 21, 2018