Monday, May 14, 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


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