Friday, December 22, 2017

Winter's coldest thermal machine, almost bare ground in darkness

~When a thick snow layer becomes a thermal insulator roof for ground heat

~We explore the 2 current Cold Temperature North Poles of the Northern Hemisphere

   Presently there are 2 CTNP's in the Northern Hemisphere both rated almost as cold as each other:

     The nearly pervasive CTNP's of this cold season,  the CAA (Canadian Arctic Archipelago) and Northeast Siberia.  Taken from CMC 700 mb map 22/0000 UTC this winter solstice day.  Have had an early winter link with extensive snow layerings ,  now in darkness this link is broken,   Arctic locations with less of a snow have become the spawners of extreme cold temperatures:

  We know from a previous article (here),  that snow cover may not exactly be pin pointed correctly,  however the Baker Lake Kiwatin area  has a neat center of more bare land,  source Eisbedeckung und Schneehoehe from Wetterzentrale Dec 22 2017 0600 UTC.   Alaska seems to have a lot of snow, a likely reason for why winter is not becoming one massive Arctic block.  We note with interest Alberta which should be prone to massive cooling given that it is a corridor of no snow.  But here just West of the sea of Okhotsk East Siberia Russia has a similar land based snow lacuna.  Both relatively left unperturbed by weather events are great areas to cool the Northern world further in these highly localized geographies with hardly a sun to warm them.  As we have learned, the cooler the CTNP the more "attractive" it becomes to Cyclones.   They become unstable by their strength,  but come back once perturbed by weather  bondings which can't last due to the very nature of dark rapid cooling in these polar zones. WD Dec 22,2017

Thursday, December 7, 2017

T***<= Ts is probably the greatest winter equation

~Extremely simple to express another matter to explain mathematically.

~Down past the skin, snow layers thermal profiles literally change with weather

~ One can estimate sky conditions by the thermal profile of  a snow drift

         Going back to the Horizon refraction discovery of a few years ago:


              Tice<= Ts,   which has never been disproved optically,  but never been measured physically except from sea ice buoys during the sunless long nights.   The temperature on top of sea ice (including snow)  is always colder of equal to surface temperature,  this discovery,  prompted the question about snow on top of land,  is it the same?

     After many thousand observations with measurements,  T***<= Ts (***= top of snow layer) was very very elusive to measure,  the first problem was sunlight,  some of my readers know ,   sunlight induces a temperature error to all surfaces with a snow layer.  There are no easy,  readily observable  temperature readings with relatively inexpensive instruments.  Temperature stratas in a column of snow  vary with weather,  which is amazing.   On many occasions, optical observations suggested T***=Ts   the top of snow temperature did not confirm so,  when optical observation interpretation  had an obvious inversion,  the snow was warmer than air.   Even in the thick of winter, when everything is more refracted,  snow readings denied what was seen,  in great conflict with horizon sea ice observations.

   Turns out it was the measurement method,  and the crucial understanding which is that snow temperature columns vary in tandem to weather ,  which broke the mystery. 

    What does this mean?

     In particular,  it is the build up formula for winter on planet Earth,    albedo up to 90% renders sunlight heat practically irrelevant,  but winter comes from  a dark world,  where  the sun is forgotten only reminisced by a faint twilight.    It is in this star lit world,  where winter becomes fierce or faint.    If winter starts earlier,  it can only be by pervasive dark moisture rich clouds, which imprints a snow carpet,  nullifying any warming by whatever sunlight gets through.    In the days of anthropogenic enhanced Global Warming,  this frozen moisture should be greater,  therefore more snow should be expected,  as it does happen yearly  more often than not,

"As sea ice shrinks, the Arctic becomes warmer and wetter, study finds8 / 2015 - Present November saw the biggest increases in “skin temperature” (defined as temperature at the Earth’s surface), and air temperature, with an average annual rise of 0.42 degrees Celsius on the surface and 0.32 degrees Celsius in the air, said the study, by Linette Boisvert of the NASA-affiliated Earth System Science Interdisciplinary Center at the University of Maryland."

 except for when major climate event,  such as from ENSO which changes cloud formations.   I recall in the fall of 1998,  a lack of High Arctic snow carpet was ever present:

      EL-Nino creates low stratospheric cloud seeds, which propagate easily throughout the world.  1998 was then the warmest year in history because of an unusualy strong El-Nino,  warmest despite a rapid change to La-Nina within the same year. (as with this October 16 NOAA SST chart) .  The Canadian High Arctic fall in 98 was sunny with hardly any snow on ground as late as early November, with Barrow Strait freezing the latest in 20 years.    ENSO had a long distance impact.  Just like in 2016,   but in 16,  the Arctic fall had more snow because  La-Nina spring trending brutally stopped during summer.   2017 late spring ENSO had an upsurge towards warming,  then now fast trending to La-Nina (with lesser clouds being created worldwide),  therefore less snow on the ground than with autumn 2016 as it is at present.    This late in the year less clouds trending has huge winter implications,  particularly where there is less snow than normal.

     The question is what happens when land areas exceed snow in pure darkness.  The answer is faster cooling tempered by snow cover .   Land surfaces are pretty much like water when it comes to snow or sea ice.    In summer Arctic sea surface water is a near constant in temperature varying quite slowly one day to the next.    In winter, top of permafrost becomes land surface,  a constant which varies at a wider range than surface sea water temperature though,  but varies day to day in similar ways to sea surface.  Depth is key,  in very early winter top of land is very much like open water,  the optical readings suggest warmer land surface than surface temperatures:

                                                                          T *  >Ts   from a sun radiation
                                                     or equality in temperatures morning and evening:

                                                   T * = Ts with low to mid level clouds:
                                                      or         surface cooling at night:  
                                                   T * <  Ts 

            T * is like a snowflake in a wide field,  like a bergy bit in wide open water,  the predominance of land or water is nearly oblivious with scarce presence of snow.    Ts is part and parcel of the air to surface complex, if the surface changes Ts does likewise, a bit of snow on wide land approaches the nature of no snow at all, in darkness or sunshine,  but it can still affect the surface temperature as it can still be measured optically   Then when snow starts to cover the surface more completely , the horizon shifts  to more neutral heights

                                                                          T* * --> = <--  Ts  nearing 50% snow cover tends to make equality in temperatures

          T* * is  near 50 50 area cover snow when  we can literally judge whether the area of snow exceeds land cover or is less than, made more complex  by land temperature differing from top of snow temperature,  if land gains more exposure when warmer than snow,  the horizon drops (the reverse applies).     These small variations are only applicable till cold really sets in especially on top of ground.  When snow carpet approaches 100%,  the optics are all inclined to behave like if snow is the only thing which matters. 

          Then the easiest equation expressing a physical dominance of snow is T*** <= Ts,,  with near or complete snow cover ,  even with sunshine and during Midwinter darkness T***<= Ts,  even during a cooling atmosphere event,  however when low or mid level clouds overcast the sky T***=Ts in all other circumstances T*** is  colder than Ts.


Tuesday, December 5, 2017

CAA returns to prime cold spot despite massive prolonged warm advection event

~The return to Cold Center of the Northern world stems from very complex geophysics

~ CAA had short term very warm atmosphere,  remnants of this warming exists but fall as snowflakes.

~Deeply cold but regionally small CTNP's are unstable by the mere presence of  moderate cyclones. 
600 mb temperature charts of November 20-24 December 2- 3 2017,   NOAA daily composites. They depict an astounding warming of the CAA atmosphere peaking on  about November 24.,  note how fast it went from coldest to hardly an existing cold cell.     600 mb temperatures are very close to the Density Weighted  Temperature of the entire troposphere.    Even more fascinating, even when expected,  was the return on December 3 of Canadian Arctic Archipelago  to coldest DWT,  again it is the Cold Temperature North Pole.   How do we explain this?  It is complex because land skin temperatures vary from snow coverage not uniform at all everywhere.  The quick warming of the CAA demonstrated  its canopy of mixed conditions,  with likely not so much snow on the ground,  the top permafrost and snow cover warmed rapidly.  When the Mega blizzard advection event ceased,    it snowed a lot more than previous recent weeks,  this covered the warmed top landscape slowing the cooling.  But cooling did occur nevertheless,  by radiative cooling of top of snow and slowed sublimation,  because of fresh flaky snow fall  relative humidity remained high diminishing  the sublimation rate.  

     But the atmosphere cooled faster aloft,  mainly oblivious to low clouds,  in other words, 
the clouds cut off heat to the upper mid atmosphere,  enabling its rapid cooling.   Which inevitably exacerbated the cloudiness and extra snow precipitation,  by stronger convection of lower warmer atmosphere.  

     Even though the Northern Hemisphere had one coldest cell over Eastern Siberia (November 24) and the warming event was about 10 days long,  the Jet Stream didn't change that much in position,  because 10 days is apparently not enough to cause major Jet Stream deviations causing disruptive weather or Global Circulation changes.

     Now is the time when little covered or bare Arctic lands start the mega-cooling process,  excess snow cover cooled  some Arctic autumn locations,  this insulation carpet now changes roles  to save the Arctic from extreme deeper freezing.     Areas with very little snow cover will now on start to change the nature of CTNP's,  from 2 current strong ones to a third or fourth  smaller ones.    We look for them around the Urals and Alaska.  Meanwhile CAA cooling along with NE Siberia will undulate the Jet Stream worldwide  WD December 6 2017

Sunday, December 3, 2017

Remote sensing snow cover appears to be not measured accurately

~ It is perhaps a great technical fundamental flaw which disables accurate long term forecasting

~ New refraction technique suggests that snow on ground behaves exactly as on sea ice which is :
Top of  wide span 100% snow layer T*** is always colder or equal than surface Temperature   
       (A snow layer is not freshly fallen snow,  it is a layer on ground more than several days old) 

~ Taken on a wider Global scale we can identify where the areas with most snow cover lay.

None of these Remote sensing current maps are similar in any great way.   We have N18 (Dec 1) which is NOAA,  the German one Wetterzentrale (Dec 2) and Canadian CMC (Dec 1).     CMC has central Quebec with a lot of Snow,  unlike Wetterzentrale  which has a lot of snow on its Eastern side and NOAA looking completely foreign to the 2 others with more but less significant snow cover in Nunavik (Northern Quebec).    Wetterzentrale has a lot of snow in Russian Urals NOAA doesn't at all.  NOAA has a vast layer of expansive thick snow in North central Siberia unlike Wetterzentrale which has a thick snow carpet in NE Siberia.    CMC has a lot of snow in central or the Alaskan interior  unlike Wetterzentrale more like NOAA.    It is hard to make out CMC's Canadian Arctic Archipelago snow cover because of numerous Glaciers on its Eastern side.    NOAA has Canadian boreal forest tree line gap of less snow unlike the other 2 maps.

Confused?    Just where are the areas with most snow cover?   If we go by a simple gathered by optical refraction rule:


           It means that all places with important thick cover will be cooler than normal,  because the sun,  although weaker by low elevation,  would warm the ground more if bare, which was heated up by the summer.  So we look for places with cooler temperature anomalies,  given that even with warm or cold air advection,  time will bring out the cooler locations:

       Last 30 days NOAA reanalysis suggests Wetterzentrale  correct for Northeastern Siberia and NOAA incorrect about the snow gap of the Northernmost tree line (there should be more snow not less there).    However there was a huge anomalous advection of warm air throughout the CAA,  as reported on previous article below.   We must go prior to November 22 to get a better picture:

   NOAA temperature anomaly October 22-November 22 .   We can note the CAA appears cooler before the warm air advection,    the cold was indeed in Northeastern Siberia and the Canadian tree line,  suggesting that these lands are laced with thick snow layer.    But there was a normal CAA cooling despite greater open water:

  The tree line bit was not as cold as NE Siberia and the CAA which prior to November 22 was the coldest place on Earth.   There was early snow over much of the CAA which sublimated and gradually diminished in thickness before the Arctic mega blizzard.    In conclusion ,  there is a lot of snow Northeastern Siberia,  but need to confirm the tree line bit.  December 3, 2017