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Author Topic: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs  (Read 4977 times)


  • Frazil ice
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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #50 on: October 11, 2019, 06:52:55 PM »
Snow is an insulator and a reflector. It prevents the earth losing heat and increases albedo. I foot of snow is equivalent to R15 insulation. It doesn't matter if the year was a "cold" or "warm" one, the difference is that the surface of the ground is insulated against emitting heat into space, the "ground" surface doesn't drop to -40 C or what ever the ambient temperature is. The contrast one has to consider for the analysis is the difference between winter and summer temperatures, not year on year changes.

Albedo is more important when the balance of heat loss prevented by the insulation throughout the day is less than the amount of heat added from insolation. If snow cover DOES persist into the summer then one, clearly, can make an argument that heat into the earth from insolation is going to decrease. From Shared Humanities post, the evidence is that this is not happening. Snow is melting out rapidly in the spring.

Basically we apply a nice reflective blanket in the cold of the night, to keep the heat in, then we pull it off as soon as there is enough warm sunshine to heat up the ground. My guess is its a strong positive feedback loop into warming the earth.

There will be nice deep early snowfalls from a meandering jet stream and an increasingly wet atmosphere, the latitudes that the snow will persist into spring will move north. The permafrost that relies on winter heat loss will thin and decline in extent, releasing more methane and CO2 and feeding the increasingly warm wet cycle towards an equitable climate.

The above are some of the feedbacks that amplify Milankovitch cycle variations. The cycles themselves don't change the heat input into the earth enough to cause the variations that we observe in previous interglacials. We are in a Milankovitch interglacial now and have accelerated the feedbacks by the release of gigatons of CO2.


  • Nilas ice
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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #51 on: October 16, 2019, 07:29:28 AM »
This would be a TAD EARLY though it is way off in la la land.