Causes and Effects of Stratospheric Ozone Reduction An Update (1982) / Chapter Skim
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A PERTURBATIONS OF THE STRATOSPHERE AND OZONE DEPLETION
A PERTURBATIONS OF THE STRATOSPHERE AND OZONE DEPLETION
Pages 145-158
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From page 145... ...
Chemical catalysis can be an extremely efficient process; some industrial catalysts mediate millions of cyclical reactions before they themselves require regeneration. The number of times that the catalytic cycle proceeds is called the chain length.
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From page 146... ...
showed that natural nitrogen oxides and aircraft-injected NO could have important roles in counterbalancing natural ozone production and providing extra, artificial ozonedestroying capacity, respectively. Earlier the need for identifying unspecified natural loss processes for stratospheric ozone had been noted by Hampson (1964)
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From page 147... ...
The very existence of natural variations affects our ability to detect secular trends in ozone. On human time scales the most pertinent natural perturbations to atmospheric ozone appear to arise from: solar proton events, relativistic electron bombardments, quasibiennial oscillation (and temperature change)
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From page 148... ...
Natural variations in the solar W output may have influenced stratospheric ozone during the recent past when Dobson instruments and satellite instruments have measured ozone. While there is no argument in principle that W irradiance changes would modulate ozone amounts, there is disagreement over the reality of solar cycle variations in W irradiance.
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From page 149... ...
Data suggest that northern hemispheric tropospheric ozone has increased substantially in the last decade; this is discussed below. Instead, he Finally, although explosive volcanoes can in principle affect stratospheric ozone by direct injections of water and chlorine, there are no indications of measurable effects due to volcanoes during the life of the Dobson instrument network.
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From page 150... ...
Field measurements in general have substantiated all elements of the original Molina-Rowland hypothesis; quantitative adjustments to the size of the ozone perturbation have arisen frequently from new or changed laboratory kinetic data. If we focus on the expected reduction in total ozone due to continued release of CF2C12 and CFC1~ at 1~h=; ~ 1 Ode; :~^r~ll~l r:~^c icon it Zi 1 ~ -arc -- -I ~- -any- `~~~ ~ -- Meal r we see that major changes have resulted from altered chemical reaction rates and from the inclusion of previously omitted reactions and species (e.g., ClNO3 and HNO4)
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From page 151... ...
.~ ~ ~ a been a considerable downward revision or one preen cues steady state ozone depletion. With currently accepted chemical reaction rates one calculates steady state, globally averaged ozone reductions of perhaps 6 percent.
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From page 152... ...
. In a research report concerned with the natural origins of tropospheric ozone they found evidence that ozone produced photochemically in the upper troposphere where subsiding stratospheric NOX encounters rising nyarocarbons.
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From page 153... ...
It is possible that as the upper stratospheric ozone decreases and NATO and COD increase, there could be extra ozone production below about 25 km so that the vertical column of ozone could be changed only slightly. In this event there would probably be a significant redistribution of ozone in latitude and altitude, leading to concern over climatic effects.
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From page 154... ...
4. Continue and expand, if possible, in situ measurements of key chemical species and the ratios of key reactive species in spatial regions where the reactants are important and where photochemical time constants are smaller than those for transport.
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From page 155... ...
whole-air sampling is needed to obtain vertical profiles of H2O, CH4, and N2O and other stable trace gases. These are needed to provide ground truth values for overflights of satellite sensors and to begin to acquire a climatology of the upper stratosphere for multidimensional models to employ in validation tests.
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From page 156... ...
(1971) Reduction of stratospheric ozone by nitrogen oxide catalysts from supersonic transport exhaust.
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From page 157... ...
Observations of ozone depletion associated with solar proton events. Journal of Geophysical Research 86:12071-12081.
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From page 158... ...
Rate of reaction of OH with HNO3. Journal of Geophysical Research 86:1105-1110.
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