Spontaneous meltdown, a matter of ice temperature.

             North of Alaska new rapid melting area 120,000 Km^2 appears sudden,  but is more something to do with water and sea ice temperature.   Note buoy 2014C likely floating about in the wider open zone to the West , is reporting -1 C water,  likely enough to help further the thawing process.    What appeared more solid a mere 6 days earlier almost disappears overnight.  Despite -2 C weather,  which is permeated by a Low pressure system.  Sea ice appears most fragile when  the ice temperature is equal to surface water,  particularly at this time of the year.  The total accumulated heat by open water won't go rapidly,  only very cold surface air temperatures will stop this process.  WD August28,2014

40% ice? Resolution at Cryosphere Today radically misses wide open water .

           Cryosphere today ,  August 18, 2014 .  Infamous McClintock passage of the NW passage.  The same channel responsible for the death of 126 sailors of HMS Erebus and Terror fame in 1848, during the said "mini ice age".  Notorious for its perineal rough and thick sea ice until about a decade or so ago, it now opens completely every melt season.  So as some say, 2014 melt is similar to a "recovery" or archipelago sea ice looks massively menacing and a return to a clogged NW passage of old.  Well CTpresentation, as above,  may hint that there may be some form of return to the past.  Not so:

NASA Eosdis view of the same area August 17 2014.  The Channel Prince of Wale shore has more than 20 nautical miles of open water, with very little ice,  not at all as presented by CT.  This probably means that CT uses grids in excess of 20 nautical miles.  Of which if there is 15% of ice the data would evaluate a wrong Area number.    So now the Passage is about to open by winds and further melting. But using CT data one would leave his boat moored in Baffin Bay or Cambridge Bay rather than attempt the passage at all,  and eventually return to the South if using the same coloured map.  WD August 20,2014

7 day ice melt, as fast as it goes, but late in the season

Despite clouds NOAA Visible wavelength sat pictures clearly depict rapid melt and clockwise rotation of North Beaufort Sea Ice.   The wider open clear water near Banks Island is August 16 (compared to August 9 1 week earlier),  there is no ice to draw from this Island, therefore the ocean appears really clear,  the rest of the August 16 picture is veiled by clouds.  The big 160,000 Km^2 North of Barrow circular melt  has lost most of its broken internal ice,  may be not enough to register on the CT Area data, clouds don't help showing that it expanded as well. WD August 16,2014

Rapid disintegration rate may not be measured accurately because there is more than 15% of sea ice left.

   There is lateral displacement of sea ice every where as seen here for NOAA visible pictures between August 9, 2014 (mostly clear) and August 11, 2014  (large clouds with shadow top right).  What is seen is a new large area of open water about 160,000 Km^2 (on the 9th) just North of Barrow Alaska,   expanding rapidly wherever there is ice,  but it easily has some remnants in extent more than 15% which will not let this expanse be measured in area until there is > than 76% of open water.  This leaves measurement metrics a bit off, and particularly strange, when we can see great melting but no daily records of it can be noted.  Eventually when there will be less than 14% of ice left in open water zones the drop in extent and area will show rather large on daily data records as seen on JAXA or  Cryosphere Today.  But the area to the South of Expanse has roughly 50% water, all of this is considered as 100% ice. WD August 11,2014


    Rapid ice shoreline melting

August 6 NOAA image (with clouds lower left) compared to August 11 PM NOAA demonstrates rapid melting in progress at every ice edge.  But envelopment must occur first.  The main process of compaction is 2 pronged,  first the main pack is pushed together,  then the ice shore scatters with thicker ice moving inwards faster,  leaving thinner ice behind (by winds).  The thinner ice gets enveloped by warmer sea water when exposed to sunlight.  The ice, known by buoy data, is at the same temperature
as the sea surface,  any warming obliterates it to water.   A second melting process,  quite interesting by its look,  may be a precursor to a complete melting of larger chunks of sea ice.  A melting occurs in the middle of a pack,  likely because there was thinner ice laced with leads there.   Thawing spreads outwards by sunlight warming sea water ever more so taking hold of the region.    Compaction moves the ice as a whole,  warmer water reaches the scattered ice and envelopment is amplified.    Again the rate of melting is extremely fast,  considering the ice appeared to have withstood the onslaught of summer hardly unscathed,  but it is not so, sea ice was transformed, from hard and cold to as warm as sea water and soft,  ripe for elimination.   In 2007 this process occurred earlier with a combination of warmer weather and total insolation which devastated the thickest pack ice very quickly.  But same process,  even with lower cooler sun, it happens just as much.  WdAugust11,2014

Clouds forgiving us a sight, NOAA August 6 to 12 visible picture again brings out a clear break down
of shore ice vanishing as quick as I have ever seen it,  thanks to buoy data, we know why,  again data remote sensing numbers don't suggest,  not even a mere hint of this action.  So the proper interpretation
of ice status is not 2 dimensional but 4, consisting of area,  thickness and  temperature.   A glance of larger ice extent does not tell the whole picture. For instance,  the ability of sea ice to change the weather depends on its temperature,  not acting as a heat sink affects Global Circulations which in turn affect the pack same as any meteorological feedback mechanism.  wd August 12, 2014

15,091 km^2 lost but likely no noticeable record of it

~Must be aware that overall records need a closer look

August 5-6-7 2014 NASA EOSDIS  Lower left cloud is 5,  clear air is 6 and Upper left cloud is 7.  Of the East Siberian Sea area.  The main pack is retreating steadily due to high pressure circulation,  but it leaves readily melting residual sea ice in its wake likely affecting the overall result when using area or extent 15% threshold as done by JAXA or Cryosphere Today. Instead of approximately 15K km^2 retreat,  the numbers from the 15% threshold method apparently would show much smaller result.  The current favourable for compaction  action in the East Siberian sea sector also is part of a larger stronger Arctic Basin Gyre movement which makes the other side of the Pole pack expand Eastwards in the warm North Atlantic,  giving the impression that there is no movement or action in that quadrant.   The over all result makes Sea ice extent and Area numbers look quite small. While there is indeed serious movement and melting going about.  WD August 7, 2014

What is the difference?

  Cryosphere Today very much like 2007 and 2012 so far.  Both preceding years have common sea ice features.  But 2014 has likely over all thinner ice than 2007 and 2012.  WD July 2, 2014

And NOW the Ocean is the HEAT SINK

~Top of sea ice Final stages of a buoy before it floats on sea water.


    June 13 2014,  buoy 2014b sits on top of sea ice with heat taking hold of its surface fuelled by the sun:

   The ice was mostly colder than air and sea water.  Ta>Tw>Ti,  sea ice holding the buoy up is a heat sink,  very bad for its health.   Ice survives between thermistor 5 and 17 ,  about 120 cm thick.

   2 weeks later,  the sea becomes the heat sink:

    Ta>Ti>Tw,  sea ice barely survives between T(9) and T(16),  70 cm thick really soft and rotten.
Was it not for natures glorious ,  no brilliant! - latent heat of fusion point which changes as sea ice becomes saltier,  the ice exists at higher temperatures than sea water!  Now we've seen what happened,  in a mere 2 weeks, sea ice owes its existence to sea water temperature,  which is nearly constant.  While soon there will be no more surface air heat to absorb ,  because top of sea ice is melting fast (40 cm in a week),  while bottom tries to last.     WD June 30, 2014

   Day later evening, inexorable progression towards annihilation, what remains of sea ice becomes warmer and warmer,net solar forcing exceeds the cooling effect of the ocean which itself warms since having become a heat sink.  But the ice survives, nevertheless the onslaught,  this can be seen by rapid diurnal cooling, (extreme left of graph), while sea water exhibits hardly a wave whimper (extreme right).   But time is running out since 0 C progression with thermistors, from left to right, continues.  Wd(july 1,2014)

Anatomy of doomed sea ice

~Optical Effects from atmospheric refraction help reveal thickness of buoy ice

2014b presently has significant temperature variations at top of ice and snow layer now likely water, because thermistors measure above 0 C temperatures:

  Ice Buoy Temperature chart 10 cm apart thermistors,  starting from likely at snow top to 310 centimetres in sea water, Day 25 04:00 12:00 UTC and 26 00:00 UTC. 

    But where is the bottom of ice ?  It is likely where temperatures do not vary at thermistor 18 (180 cm),  since top fresh water starts at thermistor 7 (70 cm depth),  the ice is likely about 110 cm thick.  What I have learned from 

refraction studies serves well,   there is a wide variance of diurnal temperatures caused by solar forcing typical of sea ice (snow as well),  either on very top or at highest ice layers.  On the other hand,  sea water may not vary in temperature as much because it is so insulated by thick layer of ice and snow.  From this reasoning, the bottom melted by 20 cm and top by 40.   Sea ice freezes sea water at -1.6 to -1.8 C,  but the ice column has rejected salt,  so the melting temperature of sea ice becomes higher gradually from bottom to top. 

Healthier sea ice is monitored by nearby 2014C

   2014C is further to the South and East of 2014B by 247 nautical miles.  The said ice thickness may be off by 30 cm,  with about 150 cm thickness given that below thermistor 19, the temperatures are stratified with very little diurnal thermal variances.   

 WD June 26,2014  

20114b interesting cloudy vs sunny thermal variances

  Still of the ice world buoy2004b on day 26 June 2014 appeared to have very little resonance with the temperature diurnal effect from above the ice.  NOAA observations seem to indicate extensive cloudiness. Or partially sunny conditions:

  With more sunshine or higher clouds more or less confirmed by 2013f buoy, with a site camera, we can note where resonating thermal effects cross the air snow/ice barrier. Diurnal temperatures in the ice column are more prominent. WD June28,2014   

The COAST is TOASTING sea ice.

During same time period the Beaufort sea opened extremely fast,  courtesy NASA EOSDIS,

June 21 (the one with less ice) 2nd to June 23, 2014.   

Bottom black bar is NOAA VIS HRPT June 22, 2014 at 20:50 UTC.  The second is 22:34 UTC 1 hour 44 minutes later.  North of Alaska coast separating from its ice at staggering speed. There is a lot of melting combined with winds and current doing this. Last year the same retreat occurred 3 weeks later and was much smaller and slower.

From optical based hypothesis to reality

~Must consider present snow layer as an upward extension of sea ice

~~Hypothesis largely confirmed!!!

   A typical day of a buoy,  taking temperatures 10 cm intervals from top of snow downwards.   The optical refraction method confirms that this buoy is functional!!!

  Please read hypothesis:

http://eh2r.blogspot.ca/2014/05/finding-sea-ice-underside-melting-at.html

   Consider snow layer as ice.   Then read the buoy data (written colour are my comments):
Yellow:  surface temperature,  blue background:  peak minima temperature in snow or ice layer.  Grey background is ice thickness in meters……:

April 7,2014:

~Buoy 2014b  72.54N 149.52W

Date,Latitude (degrees),Longitude (degrees),Quality (+/- km),Air Temp (C),Air Pressure (mb),Snow Surface Position (m),Ice Thickness(m),Ice Surface Position (m),Ice Bottom Position(m),T1 (C),T2 (C),T3 (C),T4 (C),T5 (C),T6 (C),T7 (C),T8 (C),T9 (C),T10 (C),T11 (C),T12 (C),T13 (C),T14 (C),T15 (C),T16 (C),T17 (C),T18 (C),T19 (C),T20 (C),T21 (C),T22 (C),T23 (C),T24 (C),T25 (C),T26 (C),T27 (C),T28 

(C),T29 (C),T30 (C),T31 ©

Overnight lower atmospheric INVERSION,  horizon appears high:

"04/07/2014 12:00","     72.5376","   -149.5226","GPS","    -28.61","   1012.55","      0.03","      1.54","      0.00","     -1.54","    -29.14","    -29.07","    -28.84","    -26.98","    -19.70","    -15.81","    -14.15","    -13.06","    -11.88","    -10.75","     -9.74","     -8.71","     -7.85","     -6.93","     -5.84","     -4.96","     -4.02","     -2.88","     -1.69","     -1.63","     -1.57","     -1.67","     -1.69","     -1.57","     -1.57","     -1.59","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

Gradual diurnal warming … It was likely sunny.  

"04/07/2014 13:00","","","","    -29.03","   1012.68","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/07/2014 14:00","","","","    -28.61","   1012.68","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/07/2014 15:00","","","","    -27.96","   1012.41","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

Horizon near true astronomical Horizon:

"04/07/2014 16:00","     72.5374","   -149.5243","GPS","    -26.19","   1012.41","      0.03","      1.54","      0.00","     -1.54","    -25.97","    -26.16","    -26.05","    -24.57","    -19.26","    -16.06","    -14.40","    -13.25","    -11.94","    -10.81","     -9.80","     -8.77","     -7.79","     -6.93","     -5.84","     -4.96","     -4.08","     -2.88","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.65","     -1.57","     -1.50","     -1.57","     -1.63"

Further gradual warming:

"04/07/2014 17:00","","","","    -24.40","   1012.21","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/07/2014 18:00","","","","    -23.01","   1012.07","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/07/2014 19:00","","","","    -23.06","   1011.94","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

Close to LAN,  snow/ice temperature minima lowers downwards towards ice bottom,  horizon dropped significantly as well:

"04/07/2014 20:00","     72.5372","   -149.5284","GPS","    -22.86","   1011.94","      0.03","      1.54","      0.00","     -1.54","    -15.09","    -15.98","    -17.01","    -18.69","    -17.49","    -15.81","    -14.46","    -13.31","    -12.07","    -10.87","     -9.80","     -8.71","     -7.85","     -6.86","     -5.84","     -4.96","     -4.02","     -2.82","     -1.69","     -1.63","     -1.63","     -1.61","     -1.69","     -1.57","     -1.50","     -1.59","     -1.59","     -1.57","     -1.57","     -1.57","     -1.63"

Surface temperature stall:

"04/07/2014 21:00","","","","    -22.02"," 

 1012.14","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/07/2014 22:00","","","","    -21.42","   1012.07","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/07/2014 23:00","","","","    -21.47","   1012.01","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

Post-local apparent noon horizon at lowest point, there was a significant lower atmosphere adiabatic lapse rate:

"04/08/2014 00:00","     72.5367","   -149.5333","GPS","    -21.06","   1011.73","      0.02","      1.54","      0.00","     -1.54","     -5.96","     -4.02","     -5.29","    -13.33","    -16.17","    -15.37","    -14.21","    -13.31","    -12.07","    -10.87","     -9.86","     -8.77","     -7.79","     -6.86","     -5.84","     -4.90","     -4.08","     -2.82","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.50","     -1.59","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

"04/08/2014 01:00","","","","    -20.47","   1011.60","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/08/2014 02:00","","","","    -21.28","   1011.53","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/08/2014 03:00","","","","    -22.29","   1011.33","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

Horizon still low despite slight cooling, suspect latent heat of fusion event

(perhaps at 01:00) where bottom ice froze by 1 cm but released heat:

"04/08/2014 04:00","     72.5363","   -149.5390","GPS","    -22.95","   1011.33","      0.03","      1.55","      0.00","     -1.55","    -13.33","    -13.71","    -15.75","    -18.12","    -16.48","    -15.12","    -14.02","    -13.25","    -12.13","    -10.93","     -9.93","     -8.83","     -7.85","     -6.93","     -5.84","     -4.96","     -4.08","     -2.88","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.50","     -1.53","     -1.59","     -1.57","     -1.50","     -1.57","     -1.63"

Diurnal evening cooling:

"04/08/2014 05:00","","","","    -24.79","   1011.19","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/08/2014 06:00","","","","    -26.44","   1011.06","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/08/2014 07:00","","","","    -26.92","   1011.06","","","","","","","","",""

 Inversion started a few hours prior,  horizon rose and was rising further; Snow/ice layer cooled more than surface air:

"04/08/2014 08:00","     72.5366","   -149.5449","GPS","    -26.74","   1011.06","      0.03","      1.55","      0.00","     -1.55","    -27.36","    -27.49","    -27.00","    -24.45","    -18.25","    -15.37","    -14.08","    -13.18","    -12.13","    -11.00","     -9.99","     -8.90","     -7.91","     -6.99","     -5.90","     -5.02","     -4.08","     -2.88","     -1.76","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.59","     -1.59","     -1.57","     -1.50","     -1.57","     -1.63"

"04/08/2014 09:00","","","","    -25.90","  

-----------------------------------------------------------------------------

 On April 7, the measurement times were not in line with specific thermal events on that day, but on April 4  it was a different story:

April 4,  2014:

Pre-LAN horizon was already at low true astronomical horizon (a favourably warm or cloudy day combination),  at this point bottom ice melts earlier:

04/04/2014 12:00","     72.5080","   -149.2189","GPS","    -22.76","   1014.31","      0.03","      1.53","      0.00","     -1.53","    -22.74","    -22.04","    -21.56","    -20.65","    -17.30","    -15.18","    -13.90","    -13.06","    -11.94","    -10.87","     -9.80","     -8.65","     -7.66","     -6.68","     -5.59","     -4.64","     -3.70","     -2.70","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.59","     -1.59","     -1.57","     -1.57","     -1.57","     -1.63"

Surface temperature stall:
"04/04/2014 13:00","","","","    -23.22","   1014.24","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/04/2014 14:00","","","","    -23.17","   1014.18","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/04/2014 15:00","","","","    -23.60","   1013.77","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

Horizon was low, surface of snow/ice warms, bottom ice lost 1 cm (needs sonar confirmation):

"04/04/2014 16:00","     72.5125","   -149.2523","GPS","    -23.47","   1013.23","      0.04","      1.52","      0.00","     -1.52","    -23.05","    -22.17","    -21.81","    -21.28","    -17.81","    -15.43","    -14.08","    -13.12","    -11.94","    -10.81","     -9.80","     -8.71","     -7.72","     -6.74","     -5.59","     -4.64","     -3.77","     -2.70","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.59","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

Very Slow or stalled diurnal warming:

"04/04/2014 17:00","","","","    -23.05","   1013.23","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/04/2014 18:00","","","","    -22.86","   1012.89","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/04/2014 19:00","","","","    -22.50","   1012.68","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

1 hour prior local apparent noon , lowest horizon:

"04/04/2014 20:00","     72.5179","   -149.2950","GPS","    -21.87","   1012.28","      0.03","      1.53","      0.00","     -1.53","    -19.58","    -19.58","    -19.28","    -19.32","    -17.30","    -15.37","    -14.08","    -13.12","    -11.88","    -10.81","     -9.74","     -8.65","     -7.66","     -6.74","     -5.59","     -4.71","     -3.77","     -2.57","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

Slow surface temperature stall:

"04/04/2014 21:00","","","","    -20.94","   1011.94","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/04/2014 22:00","","","","    -20.39"," 

 "04/04/2014 23:00","","","","    -19.75","   1011.60","","","","","","","","","","","","","","","","","","","","","","","","",

"","","","","","","","","","",""

After LAN peak warming period consists of surface to air interface Adiabatic profile, horizon was low, ice minima at lowest point nearer middle of ice column.

"04/05/2014 00:00","     72.5258","   -149.3425","GPS","    -18.82","   1010.92","      0.03","      1.53","      0.00","     -1.53","    -13.77","    -14.53","    -13.66","    -15.47","    -16.04","    -14.99","    -13.90","    -13.06","    -11.88","    -10.75","     -9.74","     -8.65","     -7.66","     -6.68","     -5.59","     -4.64","     -3.77","     -2.63","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.59","     -1.57","     -1.57","     -1.57","     -1.63"

Surface Temperature stall:

"04/05/2014 01:00","","","","    -18.68","   1010.72","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/05/2014 02:00","","","","    -18.61","   1010.58","","","","","","","","","","","","","","","","","","","","","","","","",

 Snow/ice coldest layer rose towards surface: 

"","","","","","","","","","",""

"04/05/2014 03:00","","","","    -19.10","   1010.24","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/05/2014 04:00","     72.5327","   -149.3823","GPS","    -19.16","   1009.97","      0.03","      1.53","      0.00","     -1.53","    -17.55","    -17.87","    -17.96","    -17.56","    -15.92","    -14.74","    -13.77","    -12.99","    -11.94","    -10.87","     -9.80","     -8.71","     -7.72","     -6.74","     -5.65","     -4.77","     -3.83","     -2.76","     -1.69","     -1.63","     -1.63","     -1.67","     -1.69","     -1.51","     -1.57","     -1.59","     -1.59","     -1.57","     -1.57","     -1.57","     -1.63"

"04/05/2014 05:00","","","","    -18.86","   1009.56","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/05/2014 06:00","","","","    -18.89","   1009.43","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/05/2014 07:00","","","","    -18.99","   1009.29","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

 Inversion, beginning of "ice wall",   horizon risen (possible maximum bottom melt, needs calibration):

"04/05/2014 08:00","     72.5359","   -149.4102","GPS","    -19.21","   1009.16","      0.03","      1.52","      0.00","     -1.52","    -19.39","    -18.88","    -18.71","    -18.12","    -16.10","    -14.74","    -13.71","    -12.93","    -11.94","    -10.87","     -9.86","     -8.77","     -7.79","     -6.80","     -5.71","     -4.77","     -3.83","     -2.76","     -1.69","     -1.63","     -1.57","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.65","     -1.57","     -1.50","     -1.57","     -1.63"

"04/05/2014 09:00","","","","    -19.19","   1008.89","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/05/2014 10:00","","",""," -19.27"," 1008.89","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","" "04/05/2014 11:00","","",""," -19.28"," 1008.55","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

    Sometimes prior, bottom refroze, released latent heat of fusion warming throughout entire ice (ice thickness should be re-confirmed):

 04/05/2014 12:00","     72.5374","   -149.4334","GPS","    -19.28","   1008.48","      0.03","      1.53","      0.00","     -1.53","    -19.13","    -18.76","    -18.52","    -18.00","    -16.17","

---- ----------------------------------------------

   Hypothesis presented here confirmed by buoy.  But buoy data are really good for specific physical details.  Optical data is immediate and comprises all of this same information in general,  but in physical precise terms, all obtained in one swift glimpse….

___________________________________
NASA EOSDIS confirmed clear day :

     April 9 2014,  buoy 2014B:

    Evening prior diurnal cooling:

"04/09/2014 05:00","","","","    -21.08","   1010.85","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 06:00","","","","    -22.22","   1010.99","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 07:00","","","","    -24.69","   1011.12","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/09/2014 08:00","     72.5308","   -149.5788","GPS","    -26.22","   1011.67","      0.05","      1.54","      0.00","     -1.54","    -26.22","    -26.35","    -26.30","    -26.09","    -21.54","    -15.43","    -13.90","    -13.12","    -12.13","    -11.06","    -10.11","     -9.02","     -8.04","     -7.12","     -6.03","     -5.08","     -4.14","     -2.95","     -1.76","     -1.63","     -1.63","     -1.67","     -1.69","     -1.51","     -1.57","     -1.53","     -1.59","     -1.57","     -1.57","     -1.57","     -1.63"

  Next Day Morning cooling continues:

 
"04/09/2014 09:00","","","","    -27.07","   1012.14","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 10:00","","","","    -26.98","   1012.75","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 11:00","","","","    -28.08","   1013.23","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

   Bottom refreeze at about 10:00 UTC.  Note the surface warming. At 12:00 UTC, there was likely a 10 C/100 meter inversion.   This is significant enough to make special optical"effects"
"04/09/2014 12:00","     72.5309","   -149.5794","GPS","    -28.63","   1013.70","      0.04","      1.55","      0.00","     -1.55","    -28.82","    -28.82","    -28.71","    -28.57","    -23.25","    -16.00","    -14.02","    -13.12","    -12.07","    -11.00","    -10.05","     -9.02","     -8.04","     -7.12","     -6.03","     -5.08","     -4.14","     -2.95","     -1.76","     -1.63","     -1.57","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.59","     -1.57","     -1.57","     -1.63","     -1.63"

   Sun -4.7 degrees below the horizon,  sunrise may be visible due to surface to air inversion:
"04/09/2014 13:00","","","","    -29.04","   1014.18","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 14:00","","","","    -29.44","   1014.58","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 15:00","","","","    -29.94","   1014.99","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

    Sun 7.4 degrees above the horizon, enough to warm the snow/ice surface warmer than surface air,  the apparent horizon dropped  a lot, coldest ice layer sinks.  
"04/09/2014 16:00","     72.5309","   -149.5785","GPS","    -29.65","   1015.40","      0.05","      1.54","      0.00","     -1.54","    -29.07","    -29.26","    -29.22","    -29.07","    -24.07","    -16.50","    -14.21","    -13.18","    -12.07","    -11.00","    -10.05","     -9.02","     -8.10","     -7.12","     -6.03","     -5.15","     -4.21","     -3.01","     -1.76","     -1.63","     -1.57","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.59","     -1.57","     -1.57","     -1.57","     -1.57"

    Diurnal warming from sunshine, 

"04/09/2014 17:00","","","","    -29.56","   

1016.21","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 18:00","","","","    -28.92","   1016.48","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 19:00","","","","    -27.78","   1016.89","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

 Sun 22.75 degrees above the horizon, coldest ice layer got deeper below surface,

the horizon was low:

"04/09/2014 20:00","     72.5308","   -149.5734","GPS","    -26.88","   1017.57","      0.04","      1.54","      0.00","     -1.54","    -23.88","    -24.89","    -24.78","    -25.08","    -21.35","    -16.19","    -14.34","    -13.25","    -12.07","    -11.00","    -10.05","     -8.96","     -8.04","     -7.12","     -6.03","     -5.08","     -4.21","     -3.01","     -1.76","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.53","     -1.59","     -1.51","     -1.50","     -1.57","     -1.63"
"04/09/2014 21:00","","","","    -25.81","   1017.98","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 22:00","","","","    -25.17","   1018.59","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/09/2014 23:00","","","","    -24.20","   1018.93","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
  The more than 22 degree in altitude sun significantly warmed the top of snow

by almost 6 degrees, the top ice layers even more, because of twin thermal heating from sun and sea.  

"04/10/2014 00:00","     72.5304","   -149.5623","GPS","    -23.71","   1018.86","      0.04","      1.54","      0.00","     -1.54","    -15.85","    -17.05","    -16.57","    -16.86","    -17.62","    -15.62","    -14.27","    -13.31","    -12.07","    -11.00","    -10.05","     -8.96","     -8.04","     -7.12","     -6.03","     -5.08","     -4.21","     -3.01","     -1.82","     -1.63","     -1.63","     -1.67","     -1.69","     -1.51","     -1.57","     -1.59","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

Lowest horizon,  surface temperature stall,  bottom melting:

"04/10/2014 01:00","","","","    -23.43","   1018.99","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/10/2014 02:00","","","","    -23.47","   1018.99","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/10/2014 03:00","","","","    -24.04","   1019.20","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

 Lower sun. Diurnal cooling well in play, coldest layer rises:
"04/10/2014 04:00","     72.5299","   -149.5554","GPS","    -25.33","   1019.20","      0.04","      1.54","      0.00","     -1.54","    -14.53","    -16.23","    -18.78","    -19.45","    -17.05","    -15.24","    -14.08","    -13.25","    -12.13","    -11.06","    -10.05","     -9.02","     -8.04","     -7.12","     -6.03","     -5.15","     -4.21","     -3.07","     -1.82","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.50","     -1.53","     -1.65","     -1.57","     -1.50","     -1.57","     -1.63"
"04/10/2014 05:00","","","","    -26.97","   1019.20","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/10/2014 06:00","","","","    -28.61","   1019.20","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/10/2014 07:00","","","","    -28.91","   1019.33","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"04/10/2014 08:00","     72.5301","   -149.5535","GPS","    -29.70","   1019.47","      0.05","      1.54","      0.00","     -1.54","    -30.09","    -30.15","    -29.79","    -27.17","    -18.95","    -15.43","    -14.08","    -13.25","    -12.13","    -11.06","    -10.05","     -9.02","     -8.10","     -7.12","     -6.09","     -5.15","     -4.27","     -3.07","     -1.88","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.50","     -1.59","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

Sun elevation -8.9 degrees

"04/10/2014 09:00","","","","    -30.14","   1019.47","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"04/10/2014 10:00","","","","    -30.53","   1019.67","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

Bottom refroze latent heat of fusion released
"04/10/2014 11:00","","","","    -29.99","   1019.47","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

 Sun Elevation -7.2 degrees, entering dawn light, ice bottom froze 2 cm,  the heat produced has changed the diurnal cooling rate, coldest layer back at top of snow, sun and more light will be seen much earlier:
"04/10/2014 12:00","     72.5304","   -149.5509","GPS","    -30.35","   1019.20","      0.05","      1.56","      0.00","     -1.56","    -31.04","    -31.04","    -30.68","    -28.00","    -19.51","    -15.75","    -14.27","    -13.31","    -12.13","    -11.06","    -10.11","     -9.09","     -8.10","     -7.18","     -6.09","     -5.21","     -4.27","     -3.07","     -1.88","     -1.63","     -1.63","     -1.67","     -1.69","     -1.57","     -1.57","     -1.59","     -1.65","     -1.57","     -1.57","     -1.57","     -1.63"

--------------------------------------------------

It seems plausible that a diurnal cooling refreeze may induce further thickness increase than just the earlier melted layer. 

----------------------------------------------------

It is not always that simple,  when the weather is cloudy with some occasional clearing, accretion is chaotic,  here is one example:

VERY SLOW accretion (complicated autumnal action)

Buoy 2013l An October day of data acquisition over Arctic Basin Near Alaska:

"10/12/2013 08:00","","","","     -9.55","   1012.25","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 09:00","","","","     -9.09","   1012.25","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 10:00","","","","     -8.37","   1012.25","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

The ice is thick enough to stop "super accretion" but still most of the time warmer than the air, an adiabatic surface to air interface should increase thickness though:

"10/12/2013 11:00","     75.2560","   -154.5052","GPS","     -8.38","   1012.18","      0.09","      1.00","      0.00","     -1.00","     -6.59","     -5.46","     -4.52","     -3.95","     -3.51","     -3.14","     -2.70","     -2.13","     -1.57","     -1.50","     -1.44","     -1.50","     -1.57","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.57","     -1.38","     -1.38","     -1.50","     -1.44","     -1.44","     -1.44","     -1.50","     -1.50"

Detached diurnal warming all the action is in the air,  there is no sense of temperature direction:
"10/12/2013 12:00","","","","     -8.66","   1012.24","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 13:00","","","","     -9.17","   1012.04","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 14:00","","","","     -9.56","   1012.18","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 15:00","     75.2704","   -154.5744","GPS","    -10.87","   1012.38","      0.10","      1.00","      0.00","     -1.00","     -6.97","     -5.40","     -4.46","     -3.95","     -3.58","     -3.14","     -2.70","     -2.13","     -1.57","     -1.50","     -1.44","     -1.50","     -1.57","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.50","     -1.38","     -1.38","     -1.44","     -1.38","     -1.44","     -1.44","     -1.57","     -1.50"

Probable diurnal cooling (cloud clears):
"10/12/2013 16:00","","","","    -11.59","   1012.45","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 17:00","","","","    -12.38","   1012.39","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 18:00","","","","    -13.77","   1012.38","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 19:00","     75.2808","   -154.6458","GPS","    -13.36","   1012.25","      0.09","      1.00","      0.00","     -1.00","     -8.79","     -5.90","     -4.52","     -4.02","     -3.58","     -3.14","     -2.70","     -2.20","     -1.57","     -1.50","     -1.44","     -1.50","     -1.57","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.50","     -1.38","     -1.38","     -1.44","     -1.44","     -1.44","     -1.44","     -1.50","     -1.50"
"10/12/2013 20:00","","","","    -13.12","   1012.25","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 21:00","","","","    -13.47","   1012.39","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 22:00","","","","    -13.36","   1012.25","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/12/2013 23:00","     75.2940","   -154.7277","GPS","    -12.99","   1011.98","      0.09","      1.00","      0.00","     -1.00","     -9.48","     -6.28","     -4.71","     -4.08","     -3.64","     -3.20","     -2.70","     -2.13","     -1.57","     -1.50","     -1.44","     -1.50","     -1.50","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.57","     -1.38","     -1.38","     -1.50","     -1.44","     -1.44","     -1.44","     -1.50","     -1.50"
"10/12/2013 23:59","","","","    -12.50","   1011.70","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 01:00","","","","    -11.66","   1011.43","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 02:00","","","","    -10.92","   1011.16","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 03:00","     75.3098","   -154.8211","GPS","    -10.40","   1011.02","      0.10","      1.01","      0.00","     -1.01","     -7.79","     -6.09","     -4.83","     -4.20","     -3.70","     -3.20","     -2.70","     -2.20","     -1.57","     -1.50","     -1.44","     -1.50","     -1.57","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.50","     -1.38","     -1.38","     -1.50","     -1.44","     -1.44","     -1.44","     -1.50","     -1.50"
"10/13/2013 04:00","","","","     -9.98","   1010.68","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 05:00","","","","     -9.54","   1010.34","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 06:00","","","","     -8.93","   1010.28","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 07:00","     75.3285","   -154.9179","GPS","     -8.02","   1010.07","      0.09","      1.00","      0.00","     -1.00","     -6.78","     -5.71","     -4.83","     -4.27","     -3.76","     -3.26","     -2.76","     -2.20","     -1.57","     -1.44","     -1.44","     -1.50","     -1.50","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.50","     -1.44","     -1.50","     -1.44","     -1.50","     -1.38","     -1.38","     -1.44","     -1.44","     -1.44","     -1.44","     -1.50","     -1.50"
"10/13/2013 08:00","","","","     -7.09","   1010.07","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

"10/13/2013 09:00","","","","     -6.23","   1009.80","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 10:00","","","","     -5.57","   1009.66","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 11:00","     75.3509","   -155.0021","GPS","     -4.94","   1009.53","      0.09","      1.00","      0.00","     -1.00","     -5.33","     -5.21","     -4.71","     -4.27","     -3.76","     -3.26","     -2.76","     -2.20","     -1.57","     -1.50","     -1.44","     -1.50","     -1.57","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.50","     -1.38","     -1.38","     -1.50","     -1.44","     -1.44","     -1.44","     -1.50","     -1.50"
"10/13/2013 12:00","","","","     -4.55","   1009.32","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 13:00","","","","     -4.06","   1009.19","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 14:00","","","","     -3.81","   1009.11","","","","","

  And so it went on until finally a gain, note the presence of an inversion the horizon rose:

"10/13/2013 15:00","     75.3721","   -155.0279","GPS","     -3.23","   1009.53","      0.09","      1.00","      0.00","     -1.00","     -3.95","     -4.58","     -4.52","     -4.14","     -3.76","     -3.32","     -2.76","     -2.20","     -1.57","     -1.50","     -1.44","     -1.50","     -1.50","     -1.50","     -1.50","     -1.50","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.57","     -1.38","     -1.44","     -1.44","     -1.38","     -1.44","     -1.44","     -1.50","     -1.50"

   Diurnal cooling, sign of cold air advection or clearing sky:
"10/13/2013 16:00","","","","     -4.21","   1009.80","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 17:00","","","","     -5.48","   1010.34","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 18:00","","","","     -6.28","   1010.55","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""

    Note the increase in thickness was somehow tied with the overnight inversion:
"10/13/2013 19:00","     75.3816","   -154.9967","GPS","     -7.24","   1011.16","      0.09","      1.01","      0.00","     -1.01","     -5.90","     -4.71","     -4.33","     -4.02","     -3.76","     -3.32","     -2.82","     -2.26","     -1.57","     -1.50","     -1.44","     -1.50","     -1.57","     -1.50","     -1.50","     -1.57","     -1.57","     -1.63","     -1.57","     -1.44","     -1.57","     -1.44","     -1.50","     -1.38","     -1.38","     -1.44","     -1.38","     -1.44","     -1.44","     -1.50","     -1.50"
"10/13/2013 20:00","","","","     -8.54","   1011.29","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","",""
"10/13/2013 21:00","","","","    -12.53","   

-------------------------------------------------------------

 Thinner ice mixed with clouds makes the analysis difficult,  if observed visually ,  simultaneously at buoy location,  physical processes understanding would be much more comprehensive.  

  WD June 19-20 2014