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Re: Dew Formation



At 06:58 AM 3/15/2004, you wrote:
Forum for Physics Educators <PHYS-L@lists.nau.edu> writes:
>I assume that the colder
>air falls to the ground so that by the side windows it is slightly
>warmer. However, for the windshields the "ground" is the hood or rear
>trunk and is just that much cooler.

In a class taken many years ago, I was led to believe that the top of the
car was radiating into space and the sides into the neighborhood. The rate
of radiation is supposed to depend on the differences of the 4th power of
the temperatures (K^4). The clear night sky is much colder than the
neighborhood and thus the top of the car radiates faster dropping to a
lower temperature producing the conditions needed for freezing. It makes
some sense to me and would love to know if that is still a valid
explanation.

Thanks

Ken Fox


That view is still being transmitted in a net-accessible way, as I found
while looking for sky temperature discussion and experiment,
such as these:

Dry Sky Equiv Temp

<http://astro.umsystem.edu/apml/ARCHIVES/OCT03/msg00021.html>

A sky temp instrument
<http://gamweb.in2p3.fr/~javier/auger_icrc01_cloud.pdf>



Brian Whatcott Altus OK Eureka!