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| Titel |
Satellite observations of stratospheric carbonyl fluoride |
| VerfasserIn |
J. J. Harrison, M. P. Chipperfield, A. Dudhia, S. Cai, S. Dhomse, C. D. Boone, P. F. Bernath |
| 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 ; 14, no. 21 ; Nr. 14, no. 21 (2014-11-13), S.11915-11933 |
| Datensatznummer |
250119156
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| Publikation (Nr.) |
 copernicus.org/acp-14-11915-2014.pdf |
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| Zusammenfassung |
The vast majority of emissions of fluorine-containing molecules are
anthropogenic in nature, e.g. chlorofluorocarbons (CFCs),
hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). These
molecules slowly degrade in the atmosphere, leading to the formation of HF,
COF2, and COClF, which are the main fluorine-containing species in the
stratosphere. Ultimately both COF2 and COClF further degrade to form HF,
an almost permanent reservoir of stratospheric fluorine due to its extreme
stability. Carbonyl fluoride (COF2) is the second-most abundant
stratospheric "inorganic" fluorine reservoir, with main sources being the
atmospheric degradation of CFC-12 (CCl2F2), HCFC-22 (CHF2Cl),
and CFC-113 (CF2ClCFCl2).
This work reports the first global distributions of carbonyl fluoride in the
Earth's atmosphere using infrared satellite remote-sensing measurements by
the Atmospheric Chemistry Experiment Fourier transform spectrometer
(ACE-FTS), which has been recording atmospheric spectra since 2004, and the
Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument,
which recorded thermal emission atmospheric spectra between 2002 and
2012. The observations reveal a high degree of seasonal and latitudinal
variability over the course of a year. These have been compared with the
output of SLIMCAT,
a state-of-the-art three-dimensional chemical transport
model. In general the observations agree well with each other, although MIPAS
is biased high by as much as ~30%, and compare well with SLIMCAT.
Between January 2004 and September 2010 COF2 grew most rapidly at
altitudes above ~25 km in the southern latitudes and at altitudes
below ~25 km in the northern latitudes, whereas it declined most
rapidly in the tropics. These variations are attributed to changes in
stratospheric dynamics over the observation period. The overall COF2
global trend over this period is calculated as 0.85 ±
0.34 (MIPAS), 0.30 ± 0.44 (ACE), and
0.88% year−1 (SLIMCAT). |
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