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Re: atmospheric blanket / greenhouse effect



Jack Uretsky wrote:

But the earth is a heat source itself, isn't it? So is the
surface temperature dominated by solar heating, or the earth's internal
furnace?


As others have already pointed out, if you compare the amount of incoming
solar radiation to the T^4 radiation coming from the earth's surface, they
are very close. They become even closer when the influence of the atmosphere
is included. The internal furnace is not a major player in determining the
equilibrium _surface_ temperature. Just below the surface, such as in a deep
mine shaft, it determines the temperature profile as one descends, but the
surface temperature is set by radiation balance.

In what is probably a poor analogy, the pressure at the top of a pond is set
by the atmosphere, below the surface the pressure profile is determined by
the density of the water (as well as by it's compressibility and gravity.)

Bob at PC