Spectrometric monitoring of atmospheric carbon tetrafluoride (CF4) above the Jungfraujoch station since 1989: evidence of continued increase but at a slowing rate
E. Mahieu1,R. Zander1,G. C. Toon2,M. K. Vollmer3,S. Reimann3,J. Mühle4,W. Bader1,B. Bovy1,B. Lejeune1,C. Servais1,P. Demoulin1,G. Roland1,P. F. Bernath5,6,C. D. Boone7,K. A. Walker7,8,and P. Duchatelet1,*E. Mahieu et al. E. Mahieu1,R. Zander1,G. C. Toon2,M. K. Vollmer3,S. Reimann3,J. Mühle4,W. Bader1,B. Bovy1,B. Lejeune1,C. Servais1,P. Demoulin1,G. Roland1,P. F. Bernath5,6,C. D. Boone7,K. A. Walker7,8,and P. Duchatelet1,*
1Institute of Astrophysics and Geophysics of the University of Liège, Liège, Belgium
2Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
3Empa, Laboratory for Air Pollution/Environmental Technology, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, Switzerland
4Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, USA
5Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, USA
6Department of Chemistry, University of York, York, UK
7Department of Chemistry, University of Waterloo, Ontario, Canada
8Department of Physics, University of Toronto, Toronto, Canada
*now at: Controlatom, Vilvoorde, Belgium
1Institute of Astrophysics and Geophysics of the University of Liège, Liège, Belgium
2Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
3Empa, Laboratory for Air Pollution/Environmental Technology, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, Switzerland
4Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, USA
5Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, USA
6Department of Chemistry, University of York, York, UK
7Department of Chemistry, University of Waterloo, Ontario, Canada
8Department of Physics, University of Toronto, Toronto, Canada
Received: 14 Aug 2013 – Discussion started: 21 Aug 2013 – Revised: 22 Nov 2013 – Accepted: 17 Dec 2013 – Published: 31 Jan 2014
Abstract. The long-term evolution of the vertical column abundance of carbon tetrafluoride (CF4) above the high-altitude Jungfraujoch station (Swiss Alps, 46.5° N, 8.0° E, 3580 m a.s.l.) has been derived from the spectrometric analysis of Fourier transform infrared solar spectra recorded at that site between 1989 and 2012. The investigation is based on a multi-microwindow approach, two encompassing pairs of absorption lines belonging to the R-branch of the strong ν3 band of CF4 centered at 1283 cm−1, and two additional ones to optimally account for weak but overlapping HNO3 interferences. The analysis reveals a steady accumulation of the very long-lived CF4 above the Jungfraujoch at mean rates of (1.38 ± 0.11) × 1013 molec cm−2 yr−1 from 1989 to 1997, and (0.98 ± 0.02) × 1013 molec cm−2 yr−1 from 1998 to 2012, which correspond to linear growth rates of 1.71 ± 0.14 and 1.04 ± 0.02% yr−1 respectively referenced to 1989 and 1998. Related global CF4 anthropogenic emissions required to sustain these mean increases correspond to 15.8 ± 1.3 and 11.1 ± 0.2 Gg yr−1 over the above specified time intervals. Findings reported here are compared and discussed with respect to relevant northern mid-latitude results obtained remotely from space and balloons as well as in situ at the ground, including new gas chromatography mass spectrometry measurements performed at the Jungfraujoch since 2010.
