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| Titel |
Halogenated source gases measured by FTIR at the Jungfraujoch station: updated trends and new target species |
| VerfasserIn |
Emmanuel Mahieu, Whitney Bader, Benoît Bovy, Bruno Franco, Bernard Lejeune, Christian Servais, Justus Notholt, Mathias Palm, Geoffrey C. Toon |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101900
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| Publikation (Nr.) |
 EGU/EGU2015-1166.pdf |
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| Zusammenfassung |
| The atmospheric abundances of chlorine and fluorine increased very significantly during the
second half of last century, following large emissions of long-lived halogenated source gases
used in numerous industrial and domestic applications. Given the phase-out schedule of
ozone depleting substances adopted by the Montreal Protocol, its Amendments and
Adjustments, the loading of the CFCs in the Earth’s atmosphere is now slowly decreasing. In
contrast, their first replacement products, the HCFCs, are still on the rise, with current
rates of increase substantially larger than at the beginning of the 21st century. As
potent greenhouse gases, a suite of fluorinated compounds are targeted by the Kyoto
Protocol. At present, they continue to accumulate in the atmosphere (Montzka et al.,
2011).
Given their environmental impacts, continuous monitoring of the abundances of these
gases is of primary importance. In addition to the in situ networks, remote sensing techniques
operated from space, balloon or from the ground provide valuable information to assess the
long-term tropospheric and lower stratospheric trends of an increasing number of halogenated
source gases, as well as of the reservoirs resulting from their photolysis in the stratosphere
(e.g. Mahieu et al., 2014a).
In this contribution, we will present decadal time series of halogenated source gases
monitored at the high altitude station of the Jungfraujoch (46.5Ë N, 8Ë E, 3580 m asl) with
Fourier Transform Infared (FTIR) spectrometers, within the framework of the Network for
the Detection of Atmospheric Composition Change (NDACC, see http://www.ndacc.org).
Total column trends presented in previous studies for CFC-11, -12 and HCFC-22
(Zander at al., 2008), CCl4 (Rinsland et al., 2012), HCFC-142b (Mahieu et al., 2013),
CF4 (Mahieu et al., 2014b) and SF6 (Zander et al., 2008) will be updated using
the latest available Jungfraujoch solar observations. Investigations dealing with
the definition of approaches to retrieve additional halogenated source gases from
FTIR spectra will also be evoked. Our trend results will be critically discussed and
compared with measurements performed in the northern hemisphere by the in situ
networks.
Acknowledgments
The University of Liège contribution to the present work has primarily been supported by
the AGACC-II project of the SSD program funded by the Belgian Federal Science Policy
Office (BELSPO), Brussels. E. Mahieu is Research Associate with the F.R.S. – FNRS.
Laboratory developments and mission expenses at the Jungfraujoch station were funded by
the F.R.S. – FNRS and the Fédération Wallonie-Bruxelles, respectively. We thank the
International Foundation High Altitude Research Stations Jungfraujoch and Gornergrat
(HFSJG, Bern) for supporting the facilities needed to perform the observations. We further
acknowledge the vital contribution from all the Belgian colleagues in performing the
Jungfraujoch observations used here.
References
Mahieu, E., S. O’Doherty, S. Reimann, et al., First retrievals of HCFC-142b from
ground-based high-resolution FTIR solar observations: application to high-altitude
Jungfraujoch spectra, poster presentation at the “EGU 2013 General Assembly”, 07-12 April
2013, Vienna, Austria, 2013. [http://hdl.handle.net/2268/144709]
Mahieu, E., M.P. Chipperfield, J. Notholt, et al., Recent Northern Hemisphere
stratospheric HCl increase due to atmospheric circulation changes, Nature, 515, 104-107,
doi:10.1038/nature13857, 2014a.
Mahieu,ÂE., R. Zander,ÂG.C. Toon,Âet al., Spectrometric monitoring of atmospheric
carbon tetrafluoride (CF4) above the Jungfraujoch station since 1989: evidence of
continued increase but at a slowing rate, Atmos. Meas. Tech., 7, 333-344, 2014b.
[http://hdl.handle.net/2268/154767]
Montzka, S.A., S. Reimann, A. Engel, et al., Ozone-Depleting Substances (ODSs) and
Related Chemicals, Chapter 1 in Scientific Assessment of Ozone Depletion: 2010, Global
Ozone Research and Monitoring Project-Report No. 52, 516 pp., World Meteorological
Organization, Geneva, Switzerland, 2011.
Rinsland, C.P., E. Mahieu, P. Demoulin, et al., Decrease of the Carbon Tetrachloride
(CCl4) Loading above Jungfraujoch, based on High Resolution Infrared Solar Spectra
recorded between 1999 and 2011, J. Quant. Spectrosc. Radiat. Transfer, 113, 1322-1329,
10.1016/j.jqsrt.2012.02.016, 2012. [http://hdl.handle.net/2268/121150]
Zander, R., E. Mahieu, P. Demoulin, et al., Our changing atmosphere: Evidence based on
long-term infrared solar observations at the Jungfraujoch since 1950, Sci. Total Environ., 391,
184-195, 2008. [http://hdl.handle.net/2268/2421] |
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