From: SCHLOERER@rzmain.rz.uni-ulm.de (Jan Schloerer)
Subject: Re: Ozonloch
Organization: University of Ulm, Germany
Date: Mon, 31 Aug 1992 12:32:32 GMT
X-News-Reader: VMS NEWS 1.23

In   <311@lynx1.lynx.north.de>   schreibt
     sirius@lynx1.lynx.north.de (Kai-Peter Ernst)

> ...
> 
> Aus Freizeit Revue, Nr. 34 vom 13. August 1992:
>
> O Z O N L O C H  -  ein Jahrhundertschwindel?

  [Artikel aus der Freizeit Revue geloescht]

Die Behauptungen der Freizeit Revue stammen im Wesentlichen von dem
konservativen "talk-radio host" Limbaugh und von Dixy Lee Ray (beide USA).
Ray ist oder war Limbaughs "science advisor" und hat ein  -  zumindest in
puncto Ozon  -  schlecht recherchiertes Buch "Trashing the planet" oder
so aehnlich verfasst.

Robert Parson hat den Ozon-Teil des Buches in einem langen Artikel kriti-
siert, den ich nicht mehr on line habe. Ausserdem hat er vor einiger Zeit
eine Reihe serioeser neuerer Artikel zu den Ozonverlusten in der Strato-
sphaere zusammengestellt, die vielleicht manche interessant finden. Ich
habe sie seinerzeit etwas umeditiert, um sie leichter lesen zu koennen,
und ein paar Tippfehler beseitigt. Der Inhalt ist unveraendert.

Wer nur Zeit / Lust fuer einen einzigen Artikel hat, nimm wohl am besten 
  "Polar Stratospheric Clouds and Ozone Depletion",
  O. Toon and R. Turco, _Scientific American_ June 1991.
  Sollte auch in Spektrum der Wissenschaft zu finden sein, vielleicht
  1 oder 2 Monate spaeter.

-----

   From:         parson_r@cubldr.colorado.edu (Robert Parson)
   Newsgroups:   sci.environment
   Subject:      Ozone depletion references
   Date:         15 May 92 20:08:15 GMT
   Organization: University of Colorado, Boulder

I thought the following list might be useful to readers of this group.
The sources deal with scientific, rather than public-policy, issues, and
are written by active researchers in the field, but none is excessively
technical.  Because of my own background the emphasis is on atmospheric
chemistry and physics  -  perhaps readers who are familiar with
biological, ecological, medical/epidemiological, or economic aspects can
add appropriate references.  With 2 exceptions (Rowland's review and the
textbook by Wayne), I have limited myself to publications that should be
readily available (the local public library is not likely to carry
_Journal of Geophysical Research_, but one should be able to get hold of
_Science_ or _Nature_).  Otherwise, there is nothing systematic about
these choices, they are just the ones I find useful.

GENERAL:

"The Antarctic Ozone Hole",  Richard Stolarski,  _Scientific American_
  Jan. 1988.  This is a good place to start. This article is somewhat
  out of date, since it was written before the results of the crucial
  1987 Airborne Atmospheric Ozone Experiment (AAOE) were released.

"Polar Stratospheric Clouds and Ozone Depletion",  O. Toon
  and R. Turco,  _Scientific American_ June 1991.  A good sequel
  to the above.

"Stratospheric Ozone Depletion", F. Sherwood Rowland, _Ann. Rev.
  Phys. Chem._ _42_, 731-768 (1991).  Very comprehensive review.

_Chemistry of Atmospheres_ 2nd. ed.,  by R. P. Wayne,  Oxford, 1991.
  Good for both general background and up-to-date information.

SPECIFIC TOPICS:

"Free Radicals within the Antarctic vortex: the role of CFC's
  in Antarctic Ozone Loss",  J. Anderson, D. W. Toohey, and
  W. H. Brune, _Science_ _251_, 39  (4 Jan. 1991).  This describes
  the AAOE "smoking gun" results (first published in 1988) which
  convinced most scientists that the Antarctic ozone hole was due
  to the buildup of CFC's in the atmosphere.

"The dynamics of the stratospheric polar vortex and its relation
  to springtime ozone depletions",  M. Schoeberl and D. L. Hartmann,
  _Science_ _251_, 46  (4 Jan. 1991, same issue as the above).
  Describes the unusual dynamical behavior of the antarctic air mass.

"Progress towards a quantitative understanding of Antarctic ozone
  depletion",  Susan Solomon, _Nature_ _347_, 347 (27 Sept. 1990)
  Describes the current state-of-the-art in modelling these processes.

"Polar stratospheric clouds and the ozone hole", P. Hamill and O. Toon,
  _Physics Today_ December 1991.  More detailed than the Sci. American
  article mentioned above.

"Contribution of Cl and F-bearing gases to the atmosphere by volcanoes",
  R. B. Symonds, W. I. Rose, and M. H. Reed, _Nature_ _334_, 415 (1988).
  Surveys data taken from a number of recent volcanic eruptions. Their
  contribution to stratospheric chlorine turns out to be much less than
  that due to CFC's, disposing of a common myth.

-----

   From:         parson_r@cubldr.colorado.edu (Robert Parson)
   Newsgroups:   talk.environment,sci.environment
   Subject:      Re: OZONE INFO (3)
   Date:         31 May 92 00:49:14 GMT
   Organization: University of Colorado, Boulder

A geophysicist with a rather alarming surname ;) has estimated the HCl
output of some historical eruptions    (H. Sigurdsson, Evidence of 
volvanic loading of the atmosphere and climate response. Palaeogeography,
Palaeoclimatology, Palaeoecology 89, 277-289 (1990)  [Aren't electronic
lit. databases wonderful!].  He considers his results (obtained by
examining Cl in melt inclusions) to be lower limits.  Combining this
with the review of Symonds et. al. (_Nature_ 4 Aug. 1988):

  Laki,      1783:    1.6    Tg HCl   fissure eruption - limited
                                         stratosph. penetration
  Krakatoa,  1883:    3.75   Tg
  El Chichon,1982:    0.04   Tg       measured directly in stratosphere

  Annual CFC prod.:   2.28   Tg Cl    contribution
  Natural CH3Cl:    1.4-3.5  Tg "     contribution;  fairly reactive;
                                         most lost in troposphere

So even these big blasts don't really compare with present-day loads.
There's one exception, however:
  Tambora,   1815:   64      Tg HCl   (!!)
This was the biggest eruption in 10,000 years; as y'all know, it is
believed to have trigerred the notorious "year without a summer" in
1816.  The above figure represents 28 years worth of CFC production.
Most of this would have reached the stratosphere although some was
probably washed out quickly (since much would be absorbed on dust
particles).  The dust and aerosols would also have provided reaction
sites for conversion of HCl to ClO, as presently occurs on polar
stratospheric clouds.  On the other hand, the dust and aerosols would
also absorb a lot of UV themselves, at least in the first year or so.
On the third hand, the stratosphere must have warmed, which would offset
this.  After a few years the HCl would be washed out.  Very different
scenario from the present, even though the gross amounts are similar.
Hard to say which is worse.

It'd be hard to separate effects of increased UV (e.g. crop destruction)
from the well-known losses due to reduced sunlight and lowered
temperatures.                                         Robert

-----

PS :  Eventuell interessant sind auch

Richard Stolarski et al :  Measured trends in stratospheric ozone
    Science 17. April 1992, 342 ff
  Kenneth M. Towe  &  Richard Stolarski : Stratospheric ozone trends
    Science  7. August 1992, 727-728
  Seit etwa 1980/85 Anzeichen fuer Abwaertstrend in mittleren und
  hoeheren Breiten. In Aequatornaehe bisher kein erkennbarer Trend.
  Towe bringt einige haeufige Einwaende, auf die Stolarski antwortet.
  
Smith, R.C.,  B.B. Prezelin,  K.S. Baker  &  10 weitere Autoren
   Ozone depletion:  ultraviolet radiation and
   phytoplankton biology in Antarctic waters.
   Science 255 (21 February 1992), 952-959
   In der Umgebung der Antarktis im (suedlichen) Fruehling 1990 Anzei-
   chen fuer einen Produktivitaets-Rueckgang des Phytoplanktons um etwa
   2-4 %.  Natuerliche Variabilitaet wird auf etwa +/- 25 % geschaetzt.
   Nicht unmittelbar alarmierend, aber auch kein Grund zur Beruhigung.

-----

Gruss,  Jan Schloerer

schloerer@rzmain.rz.uni-ulm.de
Klinische Dokumentation           Uni Ulm
Postfach 3880     DW-7900 Ulm     Germany