Re: OBC Warning

["Brant M. Miller" <brant@xxxxxxxxxxxxxx>]

An -

At about 38 degF ice can form on a black surface such as a road when the
sky is clear.  When the earth cools at night, the surface will radiate he=
at
into space and chill down.  Most atmospheric gasses are transparent to he=
at
energy, so the air does not participate in the radient cooling.  But the
surface will then chill the air above it by convective cooling.  But sinc=
e
the air is being chilled by the surface, the surface is colder than the
air.  If there is moisture about, ice forms.  So the bong tells you to be=

alert for ice.

Brant

>Date: Tue, 29 Dec 1998 01:53:05 -0500
From: "An Pham Jr." <anp7@domain.elided>
Subject: OBC Warning

Does anyone know why the OBC goes off with the temperature at around 38 d=
eg
F??
An Pham Jr.<

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