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| Titel |
First retrievals of carbon tetrafluoride (CF4) from ground-based FTIR measurements: production and analysis of the two-decadal time series above the Jungfraujoch |
| VerfasserIn |
Pierre Duchatelet, Rodolphe Zander, Emmanuel Mahieu, Jens Muhle, Philippe Demoulin, Bernard Lejeune, Ginette Roland, Christian Servais, Olivier Flock |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250051267
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| Zusammenfassung |
| Carbon tetrafluoride (CF4 or PFC-14) is a potent greenhouse gas that is almost 7400 times
more effective (100-yr horizon) than CO2 on a per molecule basis (IPCC, 2007). This high
global warming potential, coming from its medium absorbance combined with a very long
atmospheric lifetime (>50000 years; Ravishankara et al., 1993), makes CF4 a key species
among the various greenhouse gases targeted by the Kyoto Protocol. In the Northern
hemisphere, current atmospheric CF4 concentrations are close to 78 pptv, with a large
fraction (around 35 pptv, Mühle et al., 2010) coming from natural processes like lithospheric
emissions (Harnisch and Eisenhauer, 1998). In addition, CF4 has been used increasingly
since the eighties in electronic and semiconductors industry. The primary aluminum
production processes have also been clearly identified as an important anthropogenic source
of CF4 emissions. The partitioning between these two main sources is however
problematic, principally due to lacking or incomplete CF4 emission factors from
inventories performed in industrial fields (e.g. International Aluminum Institute,
2009).
Recent in situ ground level measurements of CF4 in the Northern hemisphere (Khalil et al.,
2003; Mühle et al., 2010) or remotely from space (Rinsland et al., 2006) have indicated a
significant slowdown in the increase rate of atmospheric CF4. This probably results from
measures adopted by the aluminum industry aiming at the reduction of the frequency and
duration of “anode effects” and therefore of related PFCs emissions (International Aluminum
Institute, 2009).
The present contribution reports on the long-term evolution (1990-2010) of the atmospheric
carbon tetrafluoride total vertical abundance derived from ground-based Fourier transform
infrared (FTIR) solar spectroscopy observations around 1285 cm-1 at the Jungfraujoch
(46.5°N, 8.0°E, 3580m asl) and compares our findings with results available in the literature.
To our knowledge, no equivalent time series (i.e. based on ground-based FTIR technique)
has been published to date.
Acknowledgements:
The University of Liège contribution to present work has primarily been supported by the
SSD and PRODEX programs funded by the Belgian Federal Science Policy Office, Brussels.
We thank the International Foundation High Altitude Research Stations Jungfraujoch
and Gornergrat (HFSJG, Bern) for supporting the facilities needed to perform the
observations.
References:
Harnisch, J. and A. Eisenhauer, Natural CF4 and SF6 on Earth, Geophys. Res. Lett., 25,
2401-2404, 1998.
International Aluminum Institute, The International Aluminum Institute Report on the
Aluminum Industrys Global Perfluorocarbon Gas Emissions Reduction Programme –
Results of the 2007 Anode Effect Survey, International Aluminum Institute, London,
2009.
IPCC, Climate change 2007: The scientific basis, Tech. rep., Intergovernmental Panel on
Climate Change, IPCC/WMO/UNEP, 2007.
Khalil, M. A. K., R. A. Rasmussen, J. A. Culbertson, et al., Atmospheric perfluorocarbons,
Environ. Sci. Technol., 37, 4358-4361, 2003.
Mühle, J., A. L. Ganesan, B. R. Miller, et al., Perfluorocarbons in the global atmosphere:
tetrafluoromethane, hexafluoromethane, and octafluoropropane, Atmos. Chem. Phys., 10,
5145-5164, 2010.
Ravishankara, A. R., S. Solomon, A. A. Turnispeed and R. F. Warren, Atmospheric lifetimes
of long-lived halogenated species, Science, 259, 194-199, 1993.
Rinsland, C. P., E. Mahieu, R. Zander, et al., Long-term stratospheric carbon tetrafluoride
(CF4) increase inferred from 1985-2004 space-based solar occultation measurements,
Geophys. Res. Lett., 33, L02808, doi:10.1029/2005GL024709, 2006. |
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