From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Newsgroups: sci.environment
Subject: Re: Ozone (A few questions I would like answered.)
Date: 15 Nov 1992 19:15:16 GMT
Organization: HST Wide Field/Planetary Camera
Distribution: world
Reply-To: carl@SOL1.GPS.CALTECH.EDU
NNTP-Posting-Host: sol1.gps.caltech.edu

In article <Bxqy4z.KJu@ucunix.san.uc.edu>, klasmekj@ucunix.san.uc.edu (Kevin J. Klasmeier) writes:
>I have been studying ozone for several months now and have come up with
>some questions I would like answered. If anyone knows about ozone
>depletion, please respone to klasmekj@ucunix.san.uc.edu
>
>1) What is the major source of chlorine into the atmosphere?
>   I have heard that Clorine from the seawater is hands down #1.

I don't know, and the answer to the question as you phrased it is unimportant
to the matter of the ozone layer.  The important question is "What is the major
source of chlorine in the stratosphere?"  You see, the troposphere and the
stratosphere mix with a time constant on the order of decades, and a great many
chlorine compounds can be removed from the troposphere by various processes
before they have a chance to reach the stratosphere.  So in order to cause
problems with the ozone layer, a chemical containing chlorine has to be inert
in the troposphere and subject to breakdown in the stratosphere.  The various
chlorine compounds from seawater are reactive enough that they don't reach the
stratosphere in large amounts.  CFC's, on the other hand, meet both criteria
quite nicely.

>2) Is the formation of ozone (in the atmosphere) responsible for the
>actual absorption of UV light, or is it the breaking apart of ozone from
>UV light, or is it both (or neither?)?

Photodissociation of O2 (which releases elemental oxygen and allows formation
of ozone) absorbs in one band of UV.  O3 absorbs in a different band.  It's
the band in which O3 aborbs that we're concerned about.

>3) Aprox. what percentage of Chlorine to humans omit into the
>atmosphere, and aprox. what percentage does nature itself omit into the
>atmosphere? 

Again, the question is irrelevent.  The relevent question is how much from
which source ends up in the troposphere.  The evidence indicates that it's
man-made compounds that account for most of the stratospheric chlorine.

>I am intrested in ozone depletion. I am not sure, however, if there is a
>problem or not, I have read some pretty powerful evidence on both sides
>and would like to draw a conclusion based on all known facts.

If the "pretty powerful evidence" against it being a problem is what led you to
believe that total atmospheric burden of chlorine is a relevent factor, then
I'd say you've been listening to ill-informed propaganda.
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL

Disclaimer:  Hey, I understand VAXen and VMS.  That's what I get paid for.  My
understanding of astronomy is purely at the amateur level (or below).  So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it.  If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.