Ask A Scientist© Weather Archive

Question pertained to temperature and the altitude in the atmosphere.


You're absolutely right about the lapse rate and the thermodynamic laws
governing temperature change with altitude. I was afraid that that
explanation or discussion might be a little advanced for the person who
asked the question about why the air was warmer near the earth's surface
rather than at the top of the atmosphere, closer to the sun.

   The actual lapse rate as observed by weather balloons, and other sensors,
are of great interest to forecasters, as that is an indication of dynamic
changes taking place in the atmosphere, and that information is very useful
in weather forecasting.

Sorry for any confusion my previous answer may have caused.

Wendell Bechtold, Meteorologist
Forecaster, National Weather Service
Weather Forecast Office, St. Louis, MO
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The general rule of thumb used by meteorologists is
that temperature decreases approximately 3.6 degrees 
F per 1000 feet in the Troposphere (the lowest layer
of the atmosphere, where we live). This is an average
value and varies from season to season.  The decrease
is slightly less in the summer and slightly greater 
in the winter.


David Cook,
meteorologist at Argonne Nat. Lab.
=========================================================
The lapse rate (in the Troposphere) would be much larger
without atmospheric mixing. But convection (the rising of
warmer air parcels, warmed primarily by energy from warm
surfaces below) has to occur since warm air rises.
Horizontal advection of air masses of different
temperatures by the atmospheric circulation also contribute
to the distribution of energy in the atmosphere. Warming
of the atmosphere takes place at all levels, especially
where there is an abundance of water vapor or aerosols to
absorb energy. As air is warmed, it expands and being
lighter than the surrounding air, it wants to rise. This
is called convection. Altogether, these processes result
in the average lapse rate of 3.6 degrees F per 1000 feet
in the troposphere. Thermodynamics, which includes the
ideal gas law and hydrostatic equation (pressure-gradient
force) is only one of the aspects of meteorology that
determine the lapse rate.

David Cook
meteorologist at Argonne Nat. Lab.
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