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| Titel |
Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane |
| VerfasserIn |
J. Mühle, A. L. Ganesan, B. R. Miller, P. K. Salameh, C. M. Harth, B. R. Greally, M. Rigby, L. W. Porter, L. P. Steele, C. M. Trudinger, P. B. Krummel, S. O'Doherty, P. J. Fraser, P. G. Simmonds, R. G. Prinn, R. F. Weiss |
| 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 ; 10, no. 11 ; Nr. 10, no. 11 (2010-06-09), S.5145-5164 |
| Datensatznummer |
250008521
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| Publikation (Nr.) |
 copernicus.org/acp-10-5145-2010.pdf |
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| Zusammenfassung |
| We present atmospheric baseline growth rates from the 1970s to the present
for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs)
tetrafluoromethane (CF4), hexafluoroethane (C2F6), and
octafluoropropane (C3F8) in both hemispheres, measured with
improved accuracies (~1–2%) and precisions (<0.3%, or <0.2 ppt
(parts per trillion dry air mole fraction), for CF4; <1.5%, or
<0.06 ppt, for C2F6; <4.5%, or <0.02 ppt, for
C3F8 within the Advanced Global Atmospheric Gases Experiment
(AGAGE). Pre-industrial background values of 34.7±0.2 ppt CF4 and
0.1±0.02 ppt C2F6 were measured in air extracted from
Greenland ice and Antarctic firn. Anthropogenic sources are thought to be
primary aluminum production (CF4, C2F6, C3F8),
semiconductor production (C2F6, CF4, C3F8) and
refrigeration use (C3F8). Global emissions calculated with the
AGAGE 2-D 12-box model are significantly higher than most previous emission
estimates. The sum of CF4 and C2F6 emissions estimated from
aluminum production and non-metal production are lower than observed global
top-down emissions, with gaps of ~6 Gg/yr CF4 in recent years.
The significant discrepancies between previous CF4, C2F6, and
C3F8 emission estimates and observed global top-down emissions
estimated from AGAGE measurements emphasize the need for more accurate,
transparent, and complete emission reporting, and for verification with
atmospheric measurements to assess the emission sources of these long-lived
and potent greenhouse gases, which alter the radiative budget of the
atmosphere, essentially permanently, once emitted. |
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