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Index of Subjects
Index of Subjects ------=_Part_33346_3240771.1163029641208 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline David and all, In answer to your question about the existance of studies on the relationship between solar activity and ozone depletion: There are many papers published on this subject. Ozone depletion became a hot topic when it was discovered that the family of anthropogenic compounds known as CFCs was a vigourous catalyst in this reaction. Unlike many other greenhouse gases, CFCs have a very long residency time in the atmosphere, meaning they take a long time to break down into simple molecules. This is the reason for the advertised delay in observing any effect in reducing the production of CFCs used as refridgerants. A particularly strong Solar Proton Event (SPE) occurred between 26 October and 6 November, 2003, also known as the "Halloween Storm". The magnetic field strength of the Earth's poles causes a preferential depletion of ozon= e at these extreme latitudes, as protons are strongly attracted there. These protons form NOx and HOx compounds that act as catalysts for ozone depletio= n [1]. However, this particular SPE had 1-2% impact on the total ozone column at the poles [2], and therefore a corresponding impact on UV irradiance at the Earth's surface. Unlike CFC residency, the transient nature of these phenomena, coupled with their nearly-decadal frequency, suggests no long-term trend in ozone levels at the poles. [1] Jackman, H. C., et al., *J, Geophys. Res., *110, A09S27, doi:10.1029/2004JA010888, 2005. [2] Rohen, G., et al., *J. Geophys. Res., *110, A09S39, doi:10.1029/2004JA010984, 2005. I hope this answers one question at least! Bruce Stevens On 11/8/06, David & Alison Webster <dwebster@glinx.com> wrote: > > Dear All, Nov 8, 2006 > Further to my question of Sept 10, 2005 (below) I have from day one > doubted the conventional CFC rationale for preferental depletion at the > poles. In spite of most CFC release being at low latitudes the > consequences are seen mostly at the poles, so the rationale goes, > because only over the poles does ozone have the optimum temperature for > the reaction or some such explanation; sure. > > So I was interested to see a few days ago, in an old article on the > northern lights (Smithsonian 7(11):64-69, 1977), that "Chemical changes > in the atmosphere are also provoked by the influx of energetic > particles. In particular, the density of nitric oxide increases. The gas > catalytically destroys ozone...". This influx of particles takes place > at the poles. > > Have there been any studies of possible relationships between polar > ozone thinning on the one hand and auroral activity, solar wind storms > and/or sunspot cycles on the other ? > > The article also mentions in passing the enigma of sound generation by > northern lights. I have read elsewhere that attempts to record sound > produced by the northern lights have recorded only silence [and in > another context, cannon roars recorded for the 1812 Overture by > conventional methods sounded like a soap bubble bursting]. Many people, > including yours truly, have heard the northern lights so one must ask > what form of energy is being 'heard'. > > Is it possible that inner ear papillae can act as detectors for high > frequency radio waves generated by electrical discharges ? > > Yours truly, Dave Webster, Kentville > > > \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ > Hi Jim & All, Sept 10, 2005 > Has anyone examined a possible connection between sunspot cycles and > ozone thinning at the poles ? > DW > > > Jim Wolford wrote: > > > Thanks, Judy! Note no mention of specific areas of the atmosphere, > > e.g. Antarctic vs. Arctic vs. everywhere else. I recall discussions > > about the dreaded CFCs (clorofluorocarbons) in refrigerators etc., and > > that discontinuing or drastically reducing their levels released would > > still not show results for decades because of the lifespans of those > > chemicals in the atmosphere. > > > > Cheers from Jim > > ---------- > > From: Judy Tufts <tandove@ns.sympatico.ca> > > <mailto:tandove@ns.sympatico.ca> > > Date: Fri, 09 Sep 2005 09:13:57 -0300 > > To: Jim Wolford <jimwolford@eastlink.ca> <mailto:jimwolford@eastlink.ca= > > > Subject: Re: Historical perspective > > > > You wrote: > > > > > > > > Historical info' on Herald's page 2 Sept. 8/05: > > > > > > > > TODAY IN HISTORY: > > > > > > > > Canadian scientists with the federal government confirmed 18 years ago > > today, in 1987, that a large hole in the ozone layer had formed above > > the Arctic in the previous year. On Sept. 15, diplomats from around > > the world reached an agreement in Montreal on a pact to protect the > > ozone layer. > > > > > > > > [How effective has that Montreal Protocol been??] > > > > > > > > > > > > Cheers from Jim in Wolfville > > > > > > > > > > > > Hi Jim : > > > > > > You were wondering about the effectivenss of the Montreal ProtocolS( > > > > > > > > I do not know whether you receive =B3E/The Environment Magazine=B2 > > (e.magazine.com) news > > > > on-line but it does give some encouraging news on the Montreal > > Protocol. Thought you would be interested in the following article. > > > > > > > > Judy T. > > > > > > > > >>>>>>>>>>>> > > > > > > > > > > Ozone Layer On the Mend, Thanks to Montreal Protocol > > > > > > September 6, 2005 > > > > Reporting by Roddy Scheer > > > > Researchers monitoring Earth's atmosphere for the National Oceanic and > > Atmospheric Administration (NOAA) report that the ozone layer has > > stopped shrinking and can now make steps toward recovery over the next > > several decades. They reported that while the ozone layer has started > > to thicken in some parts of the world, it is still "well below normal > > levels." These recent findings, reported last week in the Journal of > > Geophysical Research, were based on analyses of satellite records and > > surface monitoring instruments. > > > > > > > > Scientists laud the 1987 Montreal Protocol, an inter