William Asher wrote:
Mark & Steven Bornfeld wrote in
news:cSFui.4025$jQ3.1399@trndny06:

William Asher wrote:
Anyway, there is an interesting thing about the homosphere, and that
is that one of the most important greenhouse gases, water vapor, is
not uniformly distributed through it. This is due mainly to the
effect that water freezes at a very high temperature relative to the
other gases in the atmosphere. The relevance to climate forcing is
that while water vapor decreases in mixing ratio as you go up, CO2
doesn't.
You mean, absolute percentage of atmosphere with increased
altitude?

Mixing ratio defined as grams of water vapor per grams of atmosphere.

Contrast the figure in the Mockler reference to the plot of CO2 mixing
ratio, here expressed as ppmv (parts-per-million-by-volume, which is the
same sort of units only multiplied by a factor of 1000 (for ideal gases,
grams per kilogram is equal to parts per thousand by volume)) from he

http://tinyurl.com/3bnyxx

and you can see there is little change of CO2 concentration through the
troposphere, consistent with Ben's analysis.

In terms of a more practical application, consider modern air travel
through the lower stratosphere. The troposphere gets drier with
altitude, which is why in part aircraft travel dehydrates you. (The air
coming into the cabin has extremely low specific humidity to begin with,
which gets amplified in terms of relative humidity when it is warmed.)
Fortunately however, the O2 concentration in terms of grams of O2 per
gram of air is nearly the same as at the surface, so that all they have
to do is compress the outside air, remove the ozone, and it's breathable.
If the O2 mixing ratio decreased, they would have to add oxygen to the
air.



Thanks Bill--appreciate the explanation.

Steve

--
Mark & Steven Bornfeld DDS
http://www.dentaltwins.com
Brooklyn, NY
718-258-5001