Cosmic rays linked to ozone hole

Discussion in 'General Science & Technology' started by wet1, Aug 8, 2001.

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  1. wet1 Wanderer Registered Senior Member

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    From Newscientist:

    Cosmic rays are eating away at the Earth's protective ozone layer, say Canadian radiation scientists Qing-Bin Lu and Leon Sanche of the University of Sherbrooke. They claim to have discovered an important process underlying the growing ozone hole over the southern hemisphere. But atmospheric scientists are not so sure.

    Lu and Sanche analysed ozone and cosmic ray data taken from ground stations, weather balloons and satellites. In a forthcoming paper in Physical Review Letters, they report a strong correlation between cosmic ray intensity and ozone depletion across different levels of the atmosphere and different latitudes. They also found that changes in ozone concentration matched fluctuating cosmic ray intensity between 1979 to 1992.

    They propose that cosmic rays contribute to ozone depletion through their interactions with human-made chlorofluorocarbons (CFCs) in the atmosphere: electrons created by cosmic rays break down CFC molecules, leading to the production of chorine atoms, which in turn break down ozone. Ultraviolet radiation from sunlight destroys ozone in a similar manner.

    Lu and Sanche found evidence for their model in a laboratory simulation of the conditions found in Antarctic clouds. They cooled a metal bar to below -170 °C and condensed water vapour and CFCs onto its surface. When they then bombarded this "cloud" with low-energy electrons like those produced by cosmic rays, chlorine was produced.


    Dark days


    "We believe this could be the major mechanism for the creation of the polar ozone hole," Lu says. For example, he says, the cosmic ray effect could explain why CFC and ozone levels decline during the Antarctic winter, when ultraviolet radiation is scarce.

    However, atmospheric scientists are far from convinced. Neil Harris of the European Ozone Research Coordinating Unit in Cambridge, England says: "It is hard to see how this mechanism would have a significant atmospheric effect."

    Harris says many lines of evidence indicate that the reduction of CFCs in the upper atmosphere during the winter months is due to downward air currents, not chemical processes.

    In addition, he says, since CFCs are not particularly soluble in water, they would not be present in cloud-born ice particles in very high concentrations, so the mechanism Lu and Sanche propose would not dissociate enough CFCs to have a big impact on ozone levels
     
  2. wet1 Wanderer Registered Senior Member

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    Did we misunderstand the causes that created the ozone depletion in the atmosphere? How many jobs were lost in the rush to mandate we DO SOMETHING, NOW!!!!?

    What will be the next item we don't understand fully and think we do? Green house gases?
     
  3. kmguru Staff Member

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    While CFCs are not soluble in water, free chlorine can combine with hydrogen and water vapor to produce Hydrochloric acid (The acid rain!). If we want to neutralize CFCs, we should send several ballons or rockets to the ozone hole and release hydrogen gas, which can mop up the chlorine and fluorine atoms....there may be other polymer based compound that can mop up the free chlorine too.

    We produce more chlorine gas (for bleach, production of aluminum, magnesium etc.) than CFCs on this planet. Just one smokestack in such a plant looses 5000 pounds per hour of chlorine gas to the atmosphere. No body says anything about that. But they somehow get upset only about Freon which is used by third world countries because the patent ran out. Go figure....
     
  4. wet1 Wanderer Registered Senior Member

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    Acid rain does indeed pose a threat to both us and our enviroment. Further it is more wide spread. How many readers here have pools? And out of that, how many need to constantly "sweeten" the water after rains? By sweeten I mean to adjust the PH. And your pool is only a sign.

    Go north and look at all the dead forests. Created by the acid rain. With dead forests come the migration of birds and animals to new areas that supply cover and feed. But they area they onced lived in will not see them coming back.

    Acid rain not only damages the soil. It damages buildings also. So is your home now wrapped in plastic/vinyl? And should the ozone hole widen, how long do you believe that vinyl and plastic will stay whole and in place? Just a thought.
     
  5. kmguru Staff Member

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    Then why are we stuck with CFCs when Chlorine combines with water to produce acid rain (along with SO2)? Something does not jibe....
     
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