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| Titel |
Recent trends in atmospheric methyl bromide: analysis of post-Montreal Protocol variability |
| VerfasserIn |
S. A. Yvon-Lewis, E. S. Saltzman, S. A. Montzka |
| 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 ; 9, no. 16 ; Nr. 9, no. 16 (2009-08-19), S.5963-5974 |
| Datensatznummer |
250007580
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| Publikation (Nr.) |
 copernicus.org/acp-9-5963-2009.pdf |
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| Zusammenfassung |
| The atmospheric methyl bromide (CH3Br) burden has
declined in recent years, in response to the phaseout of agricultural and
structural fumigation consumption under the amendments to the Montreal
Protocol. The timing and magnitude of this decrease represents an
opportunity to examine our current understanding of atmospheric CH3Br
and its budget, response to the phaseout, and response to interannual
variability in biomass burning and global OH. In this study, simulations
obtained from a time-dependent global model of atmospheric CH3Br
emissions and uptake are compared to observations from the NOAA flask
network. The model includes a detailed gridded ocean model coupled to a
time-dependant atmospheric 2-box model. The phaseout of CH3Br
production for agricultural uses began in 1998, concurrent with the pulse in
biomass burning associated with the 1998 El Niño. The combined effects
of three factors (biomass burning, global OH, and anthropogenic phaseout)
appear to explain most of the observed atmospheric methyl bromide
variability over the 1997–2008 period. The global budget remains imbalanced,
with a large missing source indicated. The missing source does not exhibit a
systematic decline during the phaseout period, and therefore, is not the
result of significantly underestimating non-QPS agricultural CH3Br
emissions. The model results suggest that the oceans should be less
undersaturated than before the phaseout began. |
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