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| Titel |
The sensitivity of stratospheric ozone changes through the 21st century to N2O and CH4 |
| VerfasserIn |
L. E. Revell, G. E. Bodeker, P. E. Huck, B. E. Williamson, E. Rozanov |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 23 ; Nr. 12, no. 23 (2012-12-03), S.11309-11317 |
| Datensatznummer |
250011631
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| Publikation (Nr.) |
 copernicus.org/acp-12-11309-2012.pdf |
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| Zusammenfassung |
| Through the 21st century, anthropogenic emissions of the greenhouse
gases N2O and CH4 are projected to increase, thus increasing their
atmospheric concentrations. Consequently, reactive nitrogen species produced
from N2O and reactive hydrogen species produced from CH4 are
expected to play an increasingly important role in determining stratospheric
ozone concentrations. Eight chemistry-climate model simulations were
performed to assess the sensitivity of stratospheric ozone to different
emissions scenarios for N2O and CH4. Global-mean total column
ozone increases through the 21st century in all eight simulations as a
result of CO2-induced stratospheric cooling and decreasing
stratospheric halogen concentrations. Larger N2O concentrations were
associated with smaller ozone increases, due to reactive nitrogen-mediated
ozone destruction. In the simulation with the largest N2O increase,
global-mean total column ozone increased by 4.3 DU through the 21st
century, compared with 10.0 DU in the simulation with the smallest N2O
increase. In contrast, larger CH4 concentrations were associated with
larger ozone increases; global-mean total column ozone increased by 16.7 DU
through the 21st century in the simulation with the largest CH4
concentrations and by 4.4 DU in the simulation with the lowest CH4
concentrations. CH4 leads to ozone loss in the upper and lower
stratosphere by increasing the rate of reactive hydrogen-mediated ozone loss
cycles, however in the lower stratosphere and troposphere, CH4 leads to
ozone increases due to photochemical smog-type chemistry. In addition to
this mechanism, total column ozone increases due to H2O-induced cooling
of the stratosphere, and slowing of the chlorine-catalyzed ozone loss cycles
due to an increased rate of the CH4 + Cl reaction. Stratospheric
column ozone through the 21st century exhibits a near-linear response
to changes in N2O and CH4 surface concentrations, which provides a
simple parameterization for the ozone response to changes in these gases. |
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