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Correlation Between Cosmic Rays and Ozone Depletion
Correlation between Cosmic Rays and Ozone Depletion
Phys. Rev. Lett. 102, 118501 (2009)
Q.-B. Lu
Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
Received 7 August 2008; published 19 March 2009
This Letter reports reliable satellite data in the period of 1980–2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR-driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008–2009 and probably another large hole around 2019–2020, according to the 11-yr CR cycle.
March 27th, 2009 at 6:28 am
For the halogenated-challenged, what does halogenated mean? Are these molecules of Montreal Protocol-banned substances?
C3H Editor
March 27th, 2009 at 6:41 am
The Montreal Protocol should have banned cosmic rays. Also:
Nature 449, 382-383 (27 September 2007)
Chemists poke holes in ozone theory
Quirin Schiermeier
Reaction data of crucial chloride compounds called into question.
Extract:
As the world marks 20 years since the introduction of the Montreal Protocol to protect the ozone layer, Nature has learned of experimental data that threaten to shatter established theories of ozone chemistry. If the data are right, scientists will have to rethink their understanding of how ozone holes are formed and how that relates to climate change.
Long-lived chloride compounds from anthropogenic emissions of chlorofluorocarbons (CFCs) are the main cause of worrying seasonal ozone losses in both hemispheres. In 1985, researchers discovered a hole in the ozone layer above the Antarctic, after atmospheric chloride levels built up. The Montreal Protocol, agreed in 1987 and ratified two years later, stopped the production and consumption of most ozone-destroying chemicals. But many will linger on in the atmosphere for decades to come. How and on what timescales they will break down depend on the molecules’ ultraviolet absorption spectrum (the wavelength of light a molecule can absorb), as the energy for the process comes from sunlight. Molecules break down and react at different speeds according to the wavelength available and the temperature, both of which are factored into the protocol.
So Markus Rex, an atmosphere scientist at the Alfred Wegener Institute of Polar and Marine Research in Potsdam, Germany, did a double-take when he saw new data for the break-down rate of a crucial molecule, dichlorine peroxide (Cl2O2). The rate of photolysis (light-activated splitting) of this molecule reported by chemists at NASA’s Jet Propulsion Laboratory in Pasadena, California, was extremely low in the wavelengths available in the stratosphere — almost an order of magnitude lower than the currently accepted rate. “This must have far-reaching consequences,” Rex says. “If the measurements are correct we can basically no longer say we understand how ozone holes come into being.” What effect the results have on projections of the speed or extent of ozone depletion remains unclear.
The abstract of the original paper is here:
http://pubs.acs.org/doi/abs/10.1021/jp067660w
CCNet’s take:
CCNet 161/2007 – 27 September 2007 — Audiatur et altera pars
SCIENTIFIC CONSENSUS ON MAN-MADE OZONE HOLE MAY BE COMING APART
As the world marks 20 years since the introduction of the Montreal Protocol to protect the ozone layer, Nature has learned of experimental data that threaten to shatter established theories of ozone chemistry. If the data are right, scientists will have to rethink their understanding of how ozone holes are formed and how that relates to climate change.
–Quirin Schiermeier, News@Nature, 26 September 2007
If the measurements are correct we can basically no longer say we understand how ozone holes come into being.
–Markus Rex, News@Nature, 26 September 2007
Our understanding of chloride chemistry has really been blown apart.
–John Crowley, Max Planck Institute of Chemistry, 26 September 2007
Until recently everything looked like it fitted nicely. Now suddenly it’s like a plank has been pulled out of a bridge.
–Neil Harris, University of Cambridge, 26 September 2007
The new measurements raise “intriguing questions”, but don’t compromise the Montreal Protocol as such, says John Pyle, an atmosphere researcher at the University of Cambridge. “We’re starting to see the benefits of the protocol, but we need to keep the pressure on.” He says that he finds it “extremely hard to believe” that an unknown mechanism accounts for the bulk of observed ozone losses.
–Quirin Schiermeier, News@Nature, 26 September 2007
March 27th, 2009 at 10:39 pm
I’m currently reading Maureen Christie’s “The Ozone Layer – A philosophy of science perspective”.
It’s fascinating for many reasons not just the O3 bit, but also it looks at inter-disciplinary expertise which has direct parallels to the IPCC etc.
She takes a good look at many aspects – the science, the philosophy and the rhetoric with the only possible bias that she takes the consensus position on the science for obvious reasons. It’ll be even more fascinating if the GCR theory is upheld.
There’s a review here with more info. if you’re interested:
http://www.joachimschummer.net/papers/2002_Rev-Christie_Hyle.pdf
March 30th, 2009 at 12:57 am
[...] Research News has an interesting piece on the correlation between cosmic rays and ozone depletion. As everyone may remember, the old [...]
April 1st, 2009 at 5:34 am
Yes, compounds like CFC (containing chlorine) and methyl bromide (not banned).
Essentially Lu is claiming that electrons from cosmic rays are what cause halogenated molecules to disassociate, freeing chlorine and bromine to do their O3 breakup trick.
He’s saying “I’ve found out how CFCs lead to ozone depletion”, not “CFCs don’t lead to ozone depletion”.
April 1st, 2009 at 5:37 am
Banning CFCs was much more practical, and leads to the same result since Lu’s claiming that CRs and CFCs work together to destroy ozone.
April 1st, 2009 at 6:32 am
My posting of the Nature article as a comment above, and a link to the original paper suggests that the science of Ozone hole depletion might not be as settled as we thought, although I don’t know if there have been any more developments since that confirm or deny this.
Lu’s paper is here
http://www.science.uwaterloo.ca/~qblu/Lu-2009PRL.pdf
Story here:
http://www.exchangemagazine.com/morningpost/2008/week38/Thursday/091811.html
April 2nd, 2009 at 5:06 am
There are questions about exactly HOW halogenated molecules end up causing ozone depletion, but there’s no question that they do.
I take statements like this:
To imply that there was no need to ban CFCs, because cosmic rays are the problem. Lu’s paper provides no basis for such a conclusion.
If I misunderstood you, I apologize, though I’d argue that it’s a reasonable interpretation of the comment.
April 2nd, 2009 at 5:32 am
That was just my little (obviously not funny) joke! But to be serious, I think ozone holes are a natural phenomenon made (much?)bigger by CFC’s. Ozone chemistry doesn’t seem to be as settled as we thought – as I posted above:
http://pubs.acs.org/doi/abs/10.1021/jp067660w
and the related Nature article.
I don’t know where we are with this, or if cosmic rays help reconcile these discrepancies.
April 2nd, 2009 at 6:09 am
Here’s an exchange I had with someone form the British Antarctic Survey on CCNet about the Nature article:
(8) RE: CHEMISTS POKE HOLES IN OZONE THEORY
Jonathan Shanklin [jdsh@bas.ac.uk]
This slightly revised comment is from the BAS ozone web page.
The September 27th Nature news item (rather than a letter) calls into question existing theories that explain the formation of the ozone hole. The note details research which shows that the rate of photolysis of the chlorine monoxide dimer may be an order of magnitude lower than previously thought. Whilst this needs further investigation and verification by other groups, it does not invalidate previous work which shows an unequivocal link between the abundance of chlorine monoxide and ozone depletion. The news note does not mention bromine monoxide, which also plays a significant part in ozone depletion.
Jonathan Shanklin
j.shanklin@bas.ac.uk
Head of Meteorology and Ozone Monitoring Unit
British Antarctic Survey, Madingley Road, Cambridge CB3 0ET, England
http://www.antarctica.ac.uk/met/jds
http://www.ast.cam.ac.uk/~jds
Dear Benny,
Re: Letter from Jonathan Shanklin [jdsh@bas.ac.uk] CCNet 2nd October 2007
CHEMISTS POKE HOLES IN OZONE THEORY
Whilst Jonathan Shanklin correctly points out that the original paper referred to in the Nature news article ‘Chemists poke holes in ozone theory,’ doesn’t mention bromine monoxide, it clearly states:
“The results of this study are in major disagreement with recent conclusions of various modeling and field work studies, which find good agreement only when using the extrapolated cross sections of Burkholder et al. The calculated photolysisrate differs between the two studies by a factor of about 9. This difference will be further enhanced at higher solar zenith angles. Because photolysis of ClOOCl is the rate limiting step in the loss of polar ozone, the adoption in atmospheric models of the cross sections determined in the present study will lead to a large reduction in the calculated chemical ozone depletion. New photolytic and/or reactive pathways will be required to obtain closer agreement between models and measurements.”
So, photolysis of the chlorine monoxide dimer (ClOOCl) is the rate limiting step in the loss of polar ozone, rather than bromine monoxide.
The original paper can be found here:
http://pubs.acs.org/cgi-bin/abstract.cgi/jpcafh/2007/111/i20/abs/jp067660w.html
J. Phys. Chem. A, 111 (20), 4322 -4332, 2007
Regards,
Paul Biggs
April 2nd, 2009 at 10:19 am
That’s reasonable. Note that Lu’s being quoted by many as being evidence that cosmic rays RATHER THAN CFCs are the cause of ozone depletion.
Anthony Watts, for instance, headlines:
Sometimes its hard to separate out those who just have an interest in the science, and those who will grasp at any straw to show that any science with political implications they dislike must be wrong … fraudulent … etc.