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If Levi gives an equivalent night sky temperature of 27 degC
how do you suppose ice forms by radiative cooling?
Brian W.
At 10:13 PM 3/13/2004, you wrote:
"Perhaps someone would care to try it?"
Not really.
...
Levi reports the atmosphere's spectral radiance as ~ > 0.8 W / m^2 - sr
- micron from 5 micron => > 20. (any angle)
From ~ 0 to 2 deg. it rises to ~ 10 X ( 8 W ...) between 7 and 14
micron *. by 20 micron it is ~ 3 W / m^2 etc. measured at ~ 3 km, 8
deg. C, and clear night. I assume no moon
...
I suppose this radiance is due to absorption from the earth's
radiation. It approximates a black body at 300 deg. K Would be
interesting to see how it changes with time.
bc
Brian Whatcott wrote:
At 01:04 PM 3/13/2004, John M., you wrote:
If we are to believe John, a vacuum enclosure with a suitablyWhen dew forms on clear nights, it will heavily wet lawns but willThe primary mechanism is radiation exchange with 2 pi steradians of a
hardly ever leave visible moisture on concrete walkways or asphalt
roads. There are many factors that regulate condensation:
temperature, available condensation nucleii, curvature, hydrophilic
surfaces, etc. - but I am having difficulty identifying the primary
one in this case. Any ideas out there?
3 kelvin blackbody plus high resistance thermal conduction pathways
to the ground and the (still) air.
--
John Mallinckrodt mailto:ajm@csupomona.edu
transparent lid would allow a black chromed copper square (say),
if well insulated at sea-level, to cool to 5 or 6 K overnight?
I don't think so.
I think you would find it rather difficult to radiatively
chill any object at sea level to below -100 degC
Perhaps someone would care to try it?
Brian Whatcott Altus OK Eureka!
Brian Whatcott Altus OK Eureka!