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| Titel |
Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends |
| VerfasserIn |
M. Rigby, R. G. Prinn, S. O'Doherty, S. A. Montzka, A. McCulloch, C. M. Harth, J. Mühle, P. K. Salameh, R. F. Weiss, D. Young, P. G. Simmonds, B. D. Hall, G. S. Dutton, D. Nance, D. J. Mondeel, J. W. Elkins, P. B. Krummel, L. P. Steele, P. J. Fraser |
| 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 ; 13, no. 5 ; Nr. 13, no. 5 (2013-03-06), S.2691-2702 |
| Datensatznummer |
250018477
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| Publikation (Nr.) |
 copernicus.org/acp-13-2691-2013.pdf |
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| Zusammenfassung |
| Since the Montreal Protocol on Substances that Deplete the Ozone Layer and
its amendments came into effect, growth rates of the major ozone depleting
substances (ODS), particularly CFC-11, -12 and -113 and CH3CCl3,
have declined markedly, paving the way for global stratospheric ozone
recovery. Emissions have now fallen to relatively low levels, therefore the
rate at which this recovery occurs will depend largely on the atmospheric
lifetime of these compounds. The first ODS measurements began in the early
1970s along with the first lifetime estimates calculated by considering their
atmospheric trends. We now have global mole fraction records spanning
multiple decades, prompting this lifetime re-evaluation. Using surface
measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE)
and the National Oceanic and Atmospheric Administration Global Monitoring
Division (NOAA GMD) from 1978 to 2011, we estimated the lifetime of CFC-11,
CFC-12, CFC-113 and CH3CCl3 using a multi-species inverse method. A
steady-state lifetime of 45 yr for CFC-11, currently recommended in the most
recent World Meteorological Organisation (WMO) Scientific Assessments of
Ozone Depletion, lies towards the lower uncertainty bound of our estimates,
which are 544861 yr (1-sigma uncertainty) when AGAGE data were used and
524561 yr when the
NOAA network data were used. Our derived lifetime for CFC-113 is
significantly higher than the WMO estimates of 85 yr, being
10999121 (AGAGE)
and 10997124
(NOAA). New estimates of the steady-state lifetimes of CFC-12 and
CH3CCl3 are consistent with the current WMO recommendations, being
11195132 and
11295136 yr (CFC-12,
AGAGE and NOAA respectively) and
5.044.925.20 and
5.044.875.23 yr (CH3CCl3,
AGAGE and NOAA respectively). |
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