Possible Arctic Ocean Gyre pressure switchover date modeled, but questions remain

~ECMWF  projects a Low over the Arctic Ocean gyre area

~  Latest sun data contradicts some of its forecast

  We start with Greenland Melt extent being very quiet:

If there is a great cold atmosphere area to the West of Greenland,  it would certainly affect its melt rate.  It is so.

   The latest sun data seems to indicate a stubborn cold zone at least 140 km wide in diameter,  this because of limitations of a high sun , 20 degrees in elevation,  which refraction method helps measure,  covering a smaller atmospheric transect.  Not long ago it was 400 km wide.... 

At any rate,  the CAA upper atmosphere is very cold,  perhaps more so than reported to ECMWF:

   The sudden ECMWF drop in pressure height over the Canadian Arctic Archipelago by June 9 is the only question over this forecast,  come so would result in a  surprise large displacement of the coldest  zone in the Northern Hemisphere.    Note the projected Cyclone over the Arctic Ocean gyre area,  this would be the first time in more than a month of such an image.  

   A switchover from steady High to Low was much forecasted in late April:   http://eh2r.blogspot.com/2018/04/2018-annual-spring-summer-projection-by.html

  Not quite like this ECMWF effort,  we await June 9 and report back.....  

WD May 30, 2018

Deep refraction observing vs super computers outlooks

~Long term weather projections have been consistently bad,  no better than flipping a coin as
  some suggest.

~EH2r refraction methods likely will surpass supercomputers,  with only data from mainly one station at a very strategic location  vs hundreds of the world wide grid  for the machines.

   May 9   Accuweather summer projection  has little resemblance to EH2r circulation projections.

http://eh2r.blogspot.ca/2018/04/2018-annual-spring-summer-projection-by.html

    According to 24 days ago EH2r projection,  which has been to date  quite accurate, t he only time the West with  above normal summer temperatures would be end of summer,
Central Canada should be equal  slightly below to normal, at beginning and very end of summer,   Eastern Canada above normal till summer end.   Baffin Island is way off,  must be colder to seasonal throughout.

Weather Channel does something smart ,  it splits the summer into 3 months.  However,  there does not seem to be any coherence with EH2r outlook:

May 18 projection seems to be made from the same super computer run,  West of a vortex should have influx from the North,  unless the North warms incredibly,  it should be cooler there from beginning of summer till end of July. 

NOAA  looks pretty good at equal to average temperatures in the Midwest despite not projecting for each month,  the deep Southwest US above normal seems reasonable given the lack of circulation from the greater distance to the Cold Temperature North Pole.  Eastern North America would be an "A" would it be not for end of summer cloudiness cooling. 

ECMWF  based May 1,  June-July-August-September 2018...  June is the one with the most probability below normal temperatures at 60 to 70 % in deep blue.  The particular fixation with Western North America being probably warmer is illogical,  the flow suggested by ECMWF  West of the CAA (Canadian Arctic Archipelago) infers a flow from the North
throughout all 4 months.  Advection from the South should boost a warming (Eastern North America).  The UK becoming progressively warmer than normal as summer progresses looks good.  Barents sea area warmer mid summer onwards seems correct,  equally Alaska above average temperatures throughout makes sense.  Although seems that ECMWF model is calling for El-Nino to reappear as well.

ECMWF looks good in many regions despite the same common flaw,  all models except NOAA seem to rely heavily on the same  western North America warming.  We shall see if this holds true.  WD May 20, 2018

The cold air mirror: snow

~Snow can be as complex as it can be simple
~Where are the thicker layers on sea ice?
~  The Equation of winter T***<=Ts  helps,  only if remote sensing provides true skin temperatures

 

    NOAA map room temperatures May 13 2018, closely outline the shrinking snow carpet,  alas snow water equivalent map seems to have a trace snow layer North of Alaska, when not visually seen,  nevertheless with continued particular attention to the Behring sea area, we see 0 to -5 C outline (green) coinciding with spring sea ice break from shore almost at a normal date given the lasting great CTNP of the CAA. Wherever sea ice exists, it is possible for surface air temperature to exceed 0 C, but the ice field must be broken:

     When sea ice breaks the ice field surface air warms by open water absorbing sun light, T*** top of sea ice mainly covered by snow, becomes T* * partially covered, only then surface temperatures may be much warmer. So far so good,  the surface temperature map above does not contradict the equations,  except for the missing snow . But while using the same rules, we can find where the most snow lies, for this we need “surface skin temperatures”, which are no longer easily found on the web, but can be taken on IR satellite pictures only when there are no clouds masking the ground.

The imprint of snow basically mirrors where cold spring air mass is,  from here we can see the coming June -July weather circulation configuration,  forming as expected if the maps are accurate. We need watch for surface air temperatures on whatever ice buoy station there is.  Not many and few,  we must rely on surface model calculations, presumably based from these "skin temperatures" .   Given that these are correct,  sometimes they are not,  but allowing us the indulgence that they are, we can make out where most of deep snow exists:

NOAA map room, 7  day mean temperature for May 7 to may 13 2018.  The snow dominates the blue regions,  exactly where 2 Cold Temperature North Poles exist,  not to mention Greenland,  which is one giant snow pack.  The blue green zone, 0 to -5 C,  is more exposed sea ice,  more apt to have earlier melt ponds,  snow may lie on top of water over sea ice as well.   I would consider a +.5 C surface air reading ideal to guaranty water on ground or ice. WD May 14,2018

   

   

Invisible INVINCIBLE

~Some circulation models may not have a correct prognosis of the current location and extent of the great CTNP 'vortice' of 2018

  ~  Proof checking the GFS,  not quite getting High Arctic circulation  right;

Central CAA ice crystals in May?  Very good ice crystal display including Parry Arc,  in the bottom foreground ice fog,  with a form of organic smog,  not common within the last 10 years or so.  Sure signals usually associated with a  deeply cold Upper Atmosphere. 

GFS 850 mb Geopotential height and vorticity April 30 onwards.  brings a Cyclone right over the Arctic Ocean Gyre area,  not possible if there is a  major cold temperature "vortice"  hovering over the Canadian Arctic Archipelago (CAA),  the  Low pressures should head Southwards instead. 

    And so they did:

CMC actual surface maps following the projection above, As we can see the GFS fizzled in precision,  highly likely because closest thing to AI or the supercomputer creating its circulation models,  does not consider the "vortice" hovering about the CAA as  a significant cold area.  Notice the Lows following the outline of the coldest one rather than going towards the Pacific Ocean.   Which did not make any sense.  Confirming so we look at latest GFS:

   The GFS seems to be more precise within about 3 days in the CAA region of Arctic,  I am sure it is more potent elsewhere with more numerous upper air stations,  but no Lows hovering towards the Arctic Ocean Gyre yet...    Note to mr AI ,  there will be a switchover from High pressure over the Gyre area to Low pressure,  but Highs are still colder than Lows,  wait a bit or review at :  http://eh2r.blogspot.ca/2018/04/2018-annual-spring-summer-projection-by.html

    In case some weather expert will note that 850 mb GFS is not quite at surface, we look at latest 850 mb analysis which reflects CMC's surface prognosis quite well:

                                          CMC may 6 2018 850 mb chart.   wd May 6 2018

2018 annual spring summer projection by mainly unorthodox underutilized optical methods PART 3

~2017 projection (in purple)  morphed with 2018 forecast discussion

   The pathway to perfection is laced with accurate evaluations

~ A surprise cooling temperature shift caused by too much snow on the ground, changed winter from all time cloudiest and warmest, to seasonal. 

Quite similar to current 2018 prognosis,  winter 17-2018 gradually accumulated snow precipitation instead of coming on early like during previous year winter.  Just past Arctic winter was not uniform at all everywhere,  Bering sea region being warmest throughout  winter , just South of CAA being coldest,  with a wide region receiving a lot of snow  in particular the North Pole to Greenland sector,  most of the CAA and likely Barents and Greenland sea zones.   

~ It doesn't spare nor slow sea ice ultimate demise

  2017 melt season minima was 8th place out of 36  in a crowded field,  the next higher 4 rankings were slightly higher in extent.  

~ 2015-16 world all time warming trend may be slightly stalled at a very warm level

NASA 2017 Gisstemp  3rd place for Northern Hemisphere,  2018 will be between 4th and 6th place.  

Northern Hemisphere projection 2017:


Hurricanes and Tornados


There is no reason to believe that Tornados will be more frequent than average, there is a colder atmosphere than 2016 , but it is largely confined to the High Arctic Troposphere, its effect largely nullified in the warmer stratosphere without any greater high speed laminal wind formations as what made 2011 prediction successful. The Stratosphere is unusually normal, the very Cold at center -80 C Polar Stratospheric Vortex lasted a very short time, barely made a high speed spin around the Pole compared to other more prominent years. However heat contrasts will exist at the higher latitudes, perhaps displacing tornado alley Northwards. Hurricanes should be less frequent because the Sahara will be especially hot this year, its sand dust greatly affects Hurricane formations . Typhoons should be normal in numbers as with a Neutral ENSO season, since I have not seen nor detected any significant ENSO trend.

2018 conditions and circulation are dissimilar,  the Polar jet stream should be largely confined at much higher latitudes with mainly one dominant CTNP driving it:

600 mb air temperature closely represents the Density Weighted Temperature of the entire atmosphere,  it is of way better usage than often overused 500mb,  because 600 mb height is more at the center of the troposhere.    NOAA daily composites are often adequate,  sometimes way off,     such is the case for 600 mb to the West of Canadian Arctic Archipelago for 2018.  2002 March 25 to April 25 600 mb temperature map is more like what is going on during the same period in 2018.   However 2002 over all circulation is from another era,  when there was much thicker sea ice spanning a wider area of the Arctic year round,  2002 started just getting away from one of the coldest long lasting  La-Nina  in history,  almost 3 years.   2018 La-Nina from El-Nino 2016 rebound has been struggling , sputtering,  has been unstable ,  weak and predictable as irregular.  I have observed definite La-Nina tendencies similar to spring 2008 "Big Blue" eternal cloudy free spring, roughly 47 days long in late winter early spring 2018,  with an El-Nino like warm cloud boost over  all in 3 months just past.  So this summer will sputter at irregular occasions warm and cool,  dry and wet likewise world wide.  2002 was much more stable.  But this I agree with NOAA daily composites,  2018 has a smaller area of very cold air in the Arctic.  Smaller means the jet stream will be closer to the Arctic than tornado alley,  but I wont be surprised if tornados will strike and vanish in likewise ENSO mentioned cycles.

2011 was the marquee year for tornados,  it was foreseen as such ,   there are no real very close similarities with 2011,  300 mb Geopotential height has the lower tropopause oh the other side of the world,  while the amount of raw kinetic energy has been tame:

   End of winter stratospheric Polar vortex varies in strength from year to year,  2018 had a smaller less expansive and shorter in duration one than 2011,  the latter had upper winds much in excess of 200 knots.  Laminal velocities as such don't disappear but dissipate throughout the Upper air,  the stronger the upper winds the more there should be tornados.

Typhoons  never seemed to have stopped in intensity during the last few years,  ENSO being Neutral again will continue the trend.  Hurricanes will of course occur again,  but I like the 2002 historical tracks as a good approximation model already experienced on Earth, 

    We must keep in mind the distant CTNP cell influencing circulation,  the grasp of this circulation extends beyond its sight.  But again 2002 circulation is not quite like 2018,  because of mainly one cold vortex left (maintained by Greenland)  minus the much warmer Atlantic sea water temperatures,  which would mean  more numerous fierce hurricanes (than 2002) arcing towards the NE,  but for those venturing  at Mexicos latitude,  further away from the CTNP center of gravity,   no real sense of direction, aimless meanderings.    The last CTNP, or what is left of it, will attract cyclones,  watch for a one two punch,  first a cyclone heading towards Greenland,  creating a path or rather an enclosure with a Greenland High stretching South, the following cyclone,  if hurricane,  will fall into the trap forcing its pathway almost straight North.  

Northern Hemisphere temperature prediction


In all years since 2004, this was the easiest thing to do, since I simply transposed or calibrated Arctic Sun disk vertical disk gains statistics as a defacto Northern Hemisphere temperature average. It worked marvelously well. But now , excess snow on Arctic lands makes it more difficult.
The colder spring time Arctic Atmosphere should stall NH warming gains or temperatures trending upwards as within the last few years, making 2017 # 3 warmest in history.

  And so it exactly was.


Sea Ice should be #1 lowest volume and likely lowest extent in history

   Not so,  but very close to it,  the failure here was the missing concept of cold air "feeding",  which occurs to the West of a cold temperature vortex,  simply because the circulation around a cold temperature vortex is Southwards to its West and Northwards to its East.  During summer, temperature roles are reversed,  a Low is usually colder than a High.  2018 expectation will be reminiscent to the past recent summers,  but for a shorter time period,
the strong summer cyclonic cloud dominance abridged will mean more sun hitting sea ice, I would expect 2nd place in sea ice extent with a very close to a clear navigation lane across Atlantic to Pacific, an open sea passage near or at the Pole.

Difficult as it may be, the lowest volume of sea ice at 2017 Maxima, combined with consistent rapid sea ice displacement velocities and the huge amount of snowfall stemming from the warmest Arctic winter in history, literally makes it easy for a change, #1 least volume of sea ice come September, with a bit of a problem with extent predictability, because sea ice is spread out from continuous daily displacements. The East Siberian sea to North Pole "arm" or ice bridge will figure prominent again, but will be eventually wiped out given the Gyre circulation, made strong last year, was recently reinforced. 

      This arm will appear and disappear fast in 2018,  because of the dominance of Gyre anticyclone
with a brief  cyclonic interlude.  

 The stable presence of an Anticyclone North of Alaska is normal when the Canadian Archipelago atmosphere is coldest, the clouds presence encompassing this anticyclone span is also very normal in spring. Eventually the temperature dew point spread will widen due to solar warming and the effect of a huge area High over the Arctic Ocean will hit like in 2007. I would expect record number of melt Ponds -late- from all that thick snow cover. 

     I expect earliest melt ponds since 2008, they should appear where a lot of snow has fallen, since we only have an educated guess as to where this is, melt ponds should appear in all North Pole quadrants except the Greenland sector.

 This will accelerate the melt rapidly, numerous melt ponds will signal the start of very rapid melting, after seemingly sluggish melt daily rates interspersed with at times great variations caused by the lack of sea ice consolidation. The North Pole will be partially ice free because pack ice will be moving all over the place. A good Yacht Captain should be able to make to the Pole though.

2018 melting rate will slow mid melting season,  it will give the impression of sea ice spared a great disaster again. But the return of the Gyre High in August  will compact thinner sea ice pans to the detriment of extent and to the gain of ridging against the Canadian Arctic Archipelago.

Other parts of the world predictions
The Okanagan valley BC will be hot and dry at first then turn quite wet, Midwest North America will be mostly dry and very hot with clean air from the North except from forest fires, NE coast of Canada and US cooler wet turning same as Midwest come July. Finally Western Europe record high temperatures, not as much as North African records.

Hindsight being 20/20:

2007 projection had pretty good predictions,  the Okanagan Canada  besieged by record rains,  was about to seriously flood at the time 2017 projection was written,  until the weather changed hot and dry, floods were averted.    NW Europe was very warm as summer NASA map shows,  difficult to say about North Africa,  but it was equally quite hot.  Eastern North America was cool and wet at least till mid summer,  2018 will see a reversal,  cool in the West warmer in the East.  Then summer end vice versa.

The summer will linger well into fall, the fall well into winter again. With Arctic record snow
fall mixing sea ice data with floating snow.

We should find out about how much snow has corrupted the sea ice extent data this September after strong Arctic Ocean anticyclone gyre compactions.

DISCOVERIES 2017-18

There were 3 important discoveries in 2017-18 observation season, 1) A major one, T***<Ts Temperature of top of snow field is always colder or equal to air surface temperature, the equation of winter, first thought to be a sea horizon effect discovered many years before. 2) Sea ice horizon elevation is inversely proportional to precipitable water in the upper air column, implying the importance of solar shortwave radiation. A drier upper air provides a greater radiation conduit during the melt season. This brings 2007 melt to mind, when massive multi year thick sea ice melted very rapidly under an Arctic dipole, which was a very steady presence of anticyclone in July( unusual since ) , over the Arctic Ocean gyre area. Much drier air during any period with the presence of the sun highly increases shortwave radiation transfers:

 With nearly same temperature during most of the period preceding and almost identical wind speeds, one day later from April 2 to 3, with time on these pictures from left to right 1 minute apart (April 3 to the right) . We have here a rare combination of required factors to determine if precipitable water (pw) column affects the energy balance at the sea ice horizon. The only difference was pw wetter by 2 mm the evening before, 5.32 vs 3.62 mm. The air was gradually drying up  towards a normal Arctic 2 mm,  more shortwave was hitting the surface on April 3, the horizon was always lower than preceding day throughout the 3rd as well. Local apparent noon warming was not as strong on the 2nd,  therefore rebound of horizon height goes quicker in the evening.
More such comparisons will determine the extent of pw effects...

Discovery #3 awaits testing through repetition.  WD April 29-30, 2018

2018 annual spring summer projection by mainly unorthodox underutilized optical methods PART 2

~  Past winter prognosis ,  remarkable contradictions.


The great Cold Temperature North Pole  vortex of Western Canadian Arctic Archipelago.  

  We start at winter end,  when contrary to present time most of the dark season Arctic was warmer and cloudy.  Somehow the heat influence grasp of North Atlantic cyclones nearly constantly circumnavigating North Greenland from the East fell short of South of the 70th parallel,   somehow the upper air got colder in an important sector of the Arctic,  this cold air aggregate sprung out in force in March,  it had multiple density layers causing amazing sunsets :

I have filmed a few Wegener blank strips over the years,  this one was entirely complicated.    This kiss of the mirror sun type,  had amazing gravity waves in the lower frame, shown here ascending with the inverse lower sun disk limb.  Up to 4 gravity waves mystically appeared bright adjoining the deep dark,  blank zone, implying ducted light which got scattered out to extinction by the very long distance travelled, up to or in excess of 2000 kilometers. 

   Stacked Green flashes vanish as fast as they were created.  Sunsets were for the most part shifted Northwards in March compared to previous 10 years,  with one setting at -2.3 degrees below the horizon,  a very rare recent 8 year occasion, much more common in 2002-2005 period,  the last time this happened was once in 2014 and once in 2010 .   April sunsets disappeared slightly Southwards than average.   The near surface air in April was prominently adiabatic.

  An apparent contradiction,  this March 31 2018 sun disk vertical diameter is large, 24.90 arc minutes,  at an altitude close to the horizon,  2018 horizon sun disks tended to be vertically thicker near the horizon,  much diminished than average well above.  This described the structure of the atmosphere,  warmer very near the ground, much much colder in the upper atmosphere,  in fact sun disk data was astounding:

   What is the score?  

                                                     Levels @ #1  Year   Ranking   

                                          19   2016 First Place

14 2015 2

11 2006 3

9 2005 4

9 2009 4

9 2010 4

9 2011 4

9 2013 4

8 2012 5

5 2017 6

4 2004 7

4 2007 8

4 2008 9

4 2014 10

2 2002 11

1 2003 12

                    0 2018 ? 13 dead last

            With more than 500 vertical sun disk  measurements within 120 decimal levels,  taken by high resolution telescope photos from -0.9 to 10.9 degrees astronomical elevations.   Mostly with March and April data,  February was cloudy.  This 2018 '0' result is amazing,  it implies a very cold Upper Atmosphere,  in fact the coldest since the start of vertical sun disk measurements, mainly to the West of central Canadian Arctic Archipelago ,  a location not measured by soundings.  Not one of 120 possible decimal elevation levels average sun disk diameters was all time highest.   This forced me to look at the bottom of rankings vertical dimensions results for the first time ever,  there is something peculiar about them,  many occurred during La-Nina trending periods but mostly with neutral or neutral trending  end of winters:  

2002 -0.1 0.0 0.1 0.2 0.4 0.7 0.8 0.9 1.0 1.2 1.3 1.1 2003 0.9 0.6 0.4 0.0 -0.3 -0.2 0.1 0.2 0.3 0.3 0.4 0.4 2004 0.4 0.3 0.2 0.2 0.2 0.3 0.5 0.6 0.7 0.7 0.7 0.7 2005 0.6 0.6 0.4 0.4 0.3 0.1 -0.1 -0.1 -0.1 -0.3 -0.6 -0.8 2006 -0.8 -0.7 -0.5 -0.3 0.0 0.0 0.1 0.3 0.5 0.7 0.9 0.9 2007 0.7 0.3 0.0 -0.2 -0.3 -0.4 -0.5 -0.8 -1.1 -1.4 -1.5 -1.6 2008 -1.6 -1.4 -1.2 -0.9 -0.8 -0.5 -0.4 -0.3 -0.3 -0.4 -0.6 -0.7 2009 -0.8 -0.7 -0.5 -0.2 0.1 0.4 0.5 0.5 0.7 1.0 1.3 1.6 Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ 2010 1.5 1.3 0.9 0.4 -0.1 -0.6 -1.0 -1.4 -1.6 -1.7 -1.7 -1.6 2011 -1.4 -1.1 -0.8 -0.6 -0.5 -0.4 -0.5 -0.7 -0.9 -1.1 -1.1 -1.0 2012 -0.8 -0.6 -0.5 -0.4 -0.2 0.1 0.3 0.3 0.3 0.2 0.0 -0.2 2013 -0.4 -0.3 -0.2 -0.2 -0.3 -0.3 -0.4 -0.4 -0.3 -0.2 -0.2 -0.3 2014 -0.4 -0.4 -0.2 0.1 0.3 0.2 0.1 0.0 0.2 0.4 0.6 0.7 2015 0.6 0.6 0.6 0.8 1.0 1.2 1.5 1.8 2.1 2.4 2.5 2.6 2016 2.5 2.2 1.7 1.0 0.5 0.0 -0.3 -0.6 -0.7 -0.7 -0.7 -0.6 2017 -0.3 -0.1 0.1 0.3 0.4 0.4 0.2 -0.1 -0.4 -0.7 -0.9 -1.0 2018 -0.9 -0.8

NOAA/ National Weather Service National Centers for Environmental Prediction Climate Prediction Center 5830 University Research Court College Park, Maryland 20740 Page Author: Climate Prediction Center Internet Team Page last modified: Disclaimer

     El-Nino  or El-Nino trending periods tend to expand vertical sun disks ,  this leads me to conclude that there is a strong causality between vertical sun disk dimensions and ENSO variations.    Brings attention to 2018 ENSO direction?  It seems that it will be a neutral ENSO summer.   The larger question would be whether Arctic sun disks can infer the temperature of a large part of Pacific equator,  it appears so.   

   First Melt 2018 

           As reported before, First Melt 2018 was earliest in history,  but with the most frequent resumption of sea ice horizons to astronomical 0 degrees elevation afterwards.  This directly implies all time lowest sea ice thickness,  actually close to it with actual auger measurements,  this was largely achieved by extra snow precipitation as mentioned above,  it snowed during most of the dark season due in large part to Southern cyclones directly hitting the Archipelago from the continent (mainly Pacific Ocean in origin,  with one long lasting quasi-stationary Hudson Bay event) , or by  North Atlantic Lows circumnavigating Northern Greenland  .     When Astronomical Horizon is attained the sea ice bottom may melt due to the thermally neutral balance at sea ice to air interface,  in other words no loss of heat towards space due to top of sea ice temperature being equal to surface air.  The more frequent and longer  Astronomical Horizon occurs above the sea ice horizon the less likely a great sea ice accretion will occur.  

  Near Refraction Observations

     Amazing results again with the near refraction areas,  almost all winter with very weak refraction heights, hardly having significant variations,  in darkness just as much as during sunlight periods,   this has been a continuing increasing trend going back to 2010,  implying a change in temperature structure of the lower atmosphere towards a more unstable one.

  Structure of a very cold stable Upper Arctic Atmosphere

     Data gathered by the usual means added to optical refraction techniques revealed a peculiar structure of a very cold Upper Atmosphere late winter 2018.  It has mainly an adiabatic surface to air interface spanning up to 100 meters or so,  then has a stable sometimes strong inversion,   increasing the temperature profile to a warm maxima usually below 850 mb,  or 1000 meters in altitude, after maxima peak adiabatic profile resumes till the tropopause.  Refraction sun disk observations suggest a deep cooling above the profile maxima,  not often measured by traditional means due to scarcity of Arctic stations.  End of winter 2018 vertical sun disk diameters  above 2 degrees elevation have been exceptionally consistently smaller than 2002-2017 average.   Especially at higher than 10 degrees elevation,  a very rare event,  not seen since 2002,  following a prolonged very cold La-Nina which ensued after 1998 then strongest in history El-Nino.    1998 -2001 La-Nina was so cold 2003  disk observations did not recover in expanded sun diameters even during 2002-2003 mild El-Nino.   Near surface deep inversions reduce vertical sun disk diameters below especially 2 degrees elevation having at least 19.4  atmospheric thickness and more,  this means that at the number of density layers bending sun rays upwards increase 19 fold,  a prominent near surface inversion would give the impression of a very cold atmosphere,  but that is not necessarily so at higher elevations.  Above 10 degrees elevation the number of increased density layers are only 6 fold more,   above that altitude surface inversions don't affect sun disk diameters very much.  Shorter vertical diameters above 10 degrees gives a very significant cold atmosphere signal.  Reverse wise,  closer to near the horizon,  expanded sun disks imply a warmer adiabatic or isothermal temperature profile.   The often observed adiabatic surface interface may only be from thinner sea ice radiating more heat towards space.  WD April 28 2018