Saturday, March 17, 2018

High Arctic sea ice First Melt 2018 earliest in short monitoring history

~First melt 2018 predicts a coming great sea ice melt with a high degree of confidence..  
~Very latest discoveries unveils largely invisible moisture capable of bouncing back Long Wave Radiation much like clouds.  
~This affects sea ice horizon readings without affecting the theory behind "First Melts" observations. 

When the sea ice horizon comes back down to astronomical horizon elevation after always being above that altitude throughout the entire High Arctic winter, this event is called "First Melt". When accretion stops, bottom sea ice may be fragile and or melt. This happens when the temperature top of sea ice/snow is equal to surface air. During the dark season , ice accretes when interface sea water looses heat towards space, this heat loss stops when temperature of top sea ice/snow is same as surface air some weeks after long night sunrise with sun high enough to warm up the top of ice sheet. Astronomical horizon is reached as long as the sun warms the top of ice, and then when daily sun lowers towards setting, sea ice horizon rises. The degree of horizon elevation fluctuations depends on sea ice thickness and how porous the Arctic atmosphere to short and long wave radiation. Overcast skies can theoretically create first melt conditions, but this was hardly observed. First Melts usually occur a few hours after local apparent noon when sunny with rays well above 5 degrees elevation. With thinner sea ice, the core minima temperature of sea ice column is not as strong and expansive as with very thick multiyear sea ice, the sun can warm top of sea ice quicker, likewise, and this is a very latest discovery, if the atmosphere is very porous to long and short wave radiation, the First Melt would tend to arrive later than usual, if the atmosphere blocks and bounces back all radiations, First Melts may come earlier, because it is not really a matter of temperature, but a matter of no temperature difference between surface air and top of sea ice. In simpler terms, a long Arctic night with a long term persistent more saturated or moist atmosphere is not good for sea ice accretion, sea ice would become thinner under these conditions with less radiation having escaped towards space.

First Melts in brief history:

2017 April 25,   In earliest Chronology:   2012  ~ 2012 PIOMAS peak to peak max. volume loss  
2016 March 18,                                           2016      2010                                                 
2015 March 26,                                           2010      2016
2014 April 10,                                             2013       2011           
2013 March 23,                                           2015       2015
2012 March 17,                                           2014       2013
2011 April 15,                                              2011       2017
2010 March 19.                                           2017       2014

        March 2016 was corrected upon verification of data, was off by 0.2 arc minutes. 2011 was the only outlier on otherwise largely predictive powers of First Melt data with respect to conditions of not only sea ice, currently near or at record thinness, but also atmospheric conditions, in particular how persistently moist or how dry the Arctic long night atmosphere was. This explains 2011 as it was very likely a drier long night, this has something to do with circulation patterns, unlike 2018 where we have had a continuous onslaught of Cyclonic intrusions from both the North Pacific and Atlantic. Furthermore 2011 Arctic winter occurred during a very deep La-Nina which was ideal for lesser clouds. 2011 equally had record number of very damaging tornadoes further South, along with very cold stratosphere, on "steroids" as I wrote.

     2018 First Melt happened March 14, the earliest on record since monitoring has started. Throughout the long night the sea ice horizon of the Central North West passage tended to be low. Not always, but more often low than higher. This was an indication of a largely pervasive moist atmosphere, which is an anti-accretion process during the dark season. The two geophysical processes go hand and hand, thinner sea ice is the product of a warmer more moist atmosphere during winter, snow adds on to this process, more snowfall replaces ice thickness, because a thick snow layer is fairly good insulation. The current over all sea ice thickness of the Arctic may be much thinner for a very large area of the Arctic Ocean given that South Cornwallis Island is a representative area of sea ice conditions extending well beyond the Canadian Arctic Archipelago, mainly because the stated prolonged moist atmosphere came mainly from the North Atlantic by way of the North Pole. WD March 17,2018

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