Friday, December 23, 2016

Thinner sea ice adds a whole lot of heat to the dark Arctic Ocean lower atmosphere, changing its circulation.

A paper published in 1996 by Steffen and DeMaria:

after measuring Heat fluxes over Barrow Strait  Nunavut Canada within sea ice and upwards in 1980, this paper basically demonstrates how much energy can be unleashed if the sea ice becomes thinner,  in effect about 4 times more heat is dissipated to the atmosphere if sea ice is 32 cm instead of 1.1 meters thick. 

It is the mark of thin Ice to give off more sensible heat.  By conduction and convection at the surface to air interface.    Thus it was November 1980 just South of Cornwallis Island.  Refraction wise, this is seen by a lower horizon.  An impressive mean of 129 W/m2 dissipates upwards.

Radiative heat flux takes over as the main dissipation thermal system as sea ice became thicker,  now some 1.1 meters,  3 months worth of pre 1998 normal cold during the long night of 1980-81.  Insulation from accretion makes it so.   But only 36 W/m2 towards space,  drastically less than 3 months earlier.   All the data from this paper mainly was but in pure darkness  with very low negligible sunlight in February and November.

When the lower Arctic troposphere warms, the entire Upper air profile changes.  So is the natural way of Atmospheric Physics: 

Average Monthly Upper Air Maxima altitude in meters 2011-2015
Southwest Barrow Island.

The height of Upper Air Profile Maxima  increases during winter, reaches a peak by February, then  becomes gradually lower towards the long day until vanishing during summer.    As the Maxima lowers in altitude ,  the surface to air interface upper air lapse rate does the same, it lowers in stability:

North Barrow Strait,  Southwest Cornwallis Island 2011-2015 average surface to air interface Lapse rates per month, excluding June July August,  in degrees C per100 meters

A February +5.4 C/100 meter lapse rate is super stable as opposed to -1 C/100 meters in early summer which is the normal adiabatic lapse rate of the standard atmosphere: 10 C/km.    Very latest data suggests a leaning towards adiabatic lower temperature profile, opposite to winter building up.  A higher temperature profile maxima altitude makes for a steeper surface based inversion because the atmospheric heat source is more distant from the surface.  Steeper inversions cause greater refraction effects which have been extremely rare compared to the same dark season periods going back as recently as the last 2 years. This suggests enormous current heat injections.  

Arctic summer natural effects from no sea ice gives the turning of the extreme  lower troposphere temperature profile from inversions to adiabatic.   In the graph above,  adiabatic lapse rates predominate  between May and September,  during these high in the sky sun days,  air temperatures decrease with height from just off the ground.  For other months; January to April, October to December the lapse rates are positive,  because just above the ground air warms with height instead,   until  becoming adiabatic again till the tropopause, at the altitude where inversion turns adiabatic is the temperature profile maximum.  Surface based Arctic inversions dominate throughout Arctic late Autumn , Winter,  till late Spring.  It is a sign of winter, when
frozen ground and sea ice in darkness radiate heat upwards with air, thermal radiation eventually escapes to space during cloud free nights,  the Arctic having one long night in particular, these inversions are nearly absolutely permanent for 9 months of the year. But lately these common inversions have been reversed to adiabatic profiles,  in deep mid winter darkness,  the amount of heat energy needed requires warmth from the sea.

The impact of less mid-winter sea ice thus cancels the inversion nature of the lower atmosphere.  Once nullified, the temperature profile becomes isothermal or adiabatic again.  As what was happening during the last few days near the North Pole,  in extended darkness,  heat exchanged between open ocean or thinner sea ice to Arctic air, simply enormous,  boosted and sustained from persistent warmer Cyclones,  exacerbating the ongoing positive circulation feedback of the entire Arctic Atmosphere, even more pronounced.  As the lower upper air maintains a Cyclonic nature rather than being laced with  lower inversions, as defined by any High pressure system, an approaching  to North Pole Low pressure system from the Pacific or the Atlantic is not repelled,  but rather joined by the pre-existing more Cyclonic air.  This fuels a further exchange of heat with what is left from the open Arctic Ocean,  slowing down sea ice accretion further,  with vaster thin ice areas having 24 hours a day heat warming surface air more than 100 Watts per square meter, will set up another accommodating invitation for further Cyclonic incursions.  perpetuating the true nature of Arctic temperature amplification during the long dark night.   WD December 24,2016

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