"Stephen Davenport" wrote in message
...
On Wednesday, December 12, 2012 12:05:19 PM UTC, ron button wrote:
Excuse my ignorance ,but how much does fog effect minimum temps ?,

Does it act like a cloud blanket obscuring the clear skies above,or does

precipitating rime affect the latent heat factor ? I should know this
really

after 60 years observing !

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Both. Fog is just cloud so acts in much the same way to arrest or slow
temperature fall. And deposition of rime releases latent heat, ~2800 J/g
or 680 cal/g at 0 deg C.


In persistent fogs the screen temperature rises due to heat flux from the
surface combined with fog top cooling setting up weak convection currents
which slowly overturns and mixes the fog.

Will
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