Re: atmospheric blanket / greenhouse effect

[Bernard Cleyet <anngeorg@PACBELL.NET>]

You are correct.  My data implied the absorption above 15 micron was all
due to CO2, and I didn't look at LW's carefully, and missed the rotation
above 15 micron.  The absorption below the 8 => 13 window is only ~ 10%
max. [I'm assuming the earth is a BB at 275 K -- one of your references,
inter alia].  I discounted the absorption in the window, which I
estimate to be as much as 50% *.  So I thought all the absorption was >
15 microns, 50% (of the BB spectrum) and due to CO2.   Water liquid, I
didn't consider (and wrote so) may be an additional large amount in the
window and below.

* my absorption band fig. is for 17 mm water;  the other graphs (solar
absorption spectra) , mine, LW and yours probably, are for 20 mm.  Since
the absorption follows Bouguer's law, the effect is greater than the 17%
difference.  [I think.]

This changes the note I was about to post, which I will anyway.

bc


John S. Denker wrote:

> On 07/29/2003 03:16 AM, Bernard Cleyet wrote:
>
>
> > water vapour doesn't do the heat trapping - CO2 does.
>
> How do we know that?   How sure are we?
>
> Not everyone considers that self-evident, e.g.
>   http://ganesh.colorado.edu/astr3720/exam2_sol.html  (item 11)
>   http://www.etl.noaa.gov/et2/#wv
>   http://astro.gmu.edu/classes/a10594/notes/l13/gif/l13s046.gif
>   http://physicsweb.org/article/world/16/5/7
>   http://www.earth.nasa.gov/visions/in-situ/chap33a.htm
>        "Of the greenhouse gases water vapor is by far the most
>        abundant and therefore the strongest absorber"