[NatureNS] ozone holes and northern lights: was Re: FW: Historical perspective

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Date: Wed, 8 Nov 2006 19:47:21 -0400
From: "Bruce Stevens" <m.bruce.stevens@gmail.com>
To: naturens@chebucto.ns.ca
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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