Vertical column abundances of COF2 above the Jungfraujoch Station, derived from ground-based infrared solar observations

in Journal of Atmospheric Chemistry (1998), 29(2), 119-134

Total vertical column abundances of carbonyl fluoride (COF2) have been derived from observations made at the International Scientific Station of the Jungfraujoch (ISSJ; altitude 3.58 km, latitude 46.5 ... [more ▼]

Total vertical column abundances of carbonyl fluoride (COF2) have been derived from observations made at the International Scientific Station of the Jungfraujoch (ISSJ; altitude 3.58 km, latitude 46.5 degrees N, longitude 8.0 degrees E), Switzerland. A systematic analysis of two microwindows containing lines of the vi band was performed, based on a large set of high resolution infrared solar absorption spectra recorded with Fourier transform spectrometers, from 1985 to 1995. Examination of the whole available database indicates a significant increase of the burden of COF2 during the 1988-1995 period. The average exponential rate and the average linear rate referenced to 1992, calculated from daily mean measurements, are both equal to (4.0 +/- 0.5)% yr(-1) (one sigma error). The results are also evaluated and discussed within the context of seasonal variability and correlation between carbonyl fluoride and hydrogen fluoride (HF) columns above the ISSJ. [less ▲]

An Overview of NDSC-related activities at the Jungfraujoch through high-resolution Infrared Solar Observations.

(1997)

Observed trends in total vertical column abundances of atmospheric gases from IR solar spectra recorded at the Jungfraujoch

in Journal of Atmospheric Chemistry (1997), 28(1-3), 227-243

Since 1984, about 15 000 high quality infrared solar spectra have been recorded with state-of-the-art grating and Fourier transform spectrometers at the International Scientific Station of the ... [more ▼]

Since 1984, about 15 000 high quality infrared solar spectra have been recorded with state-of-the-art grating and Fourier transform spectrometers at the International Scientific Station of the Jungfraujoch, Switzerland. Nonlinear least squares spectral curve fitting of selected microwindows containing isolated and well characterized lines of 20 telluric gases have allowed to retrieve their total vertical column abundances above the station, leading to observational data bases essential to derive long- and short-term changes experienced by these species during the last 12 years. In this paper, we focus on atmospheric gases of particular interest within the context of the EUROTRACTOR (Tropospheric Ozone Research) project; secular evolution as well as seasonal cycles of the minor constituents CH4, CO and of the trace gases C2H6, OCS, C2H2, HCN and H2CO are reported and discussed. The long-lived N2O is included as a tracer of the dynamic activity of the atmosphere. [less ▲]

Vertical Column Abundances of COF2 measured above the Jungfraujoch Station from ground-based infrared solar observations.

in Proceedings of Atmospheric Spectroscopy Applications (1996)

The solar Spectrum between 16 and 35 µm.

in Sauval, A. J.; Blomme, R.; Grevesse, Nicolas (Eds.) Astronomical Society of the Pacific Conference Series (1995)

Stratospheric changes monitored above the Jungfraujoch - The budgets of inorganic chlorine and fluorine since 1985.

in Proceedings of the 3d International Symposium on Polar Stratospheric Ozone Research (1995)

The appearance energy of C2H+ from C2H2 revisited. A Photoion-Photoelectron Coincidence Spectroscopic Determination.

in Chemical Physics Letters (1995), 236

The dissociative ionization of C2H2 in the C2H+-producing channel has been reconsidered. The photoion-photoelectron coincidence (PIPECO) technique has been used. The C2H+/e coincidence rate has been ... [more ▼]

The dissociative ionization of C2H2 in the C2H+-producing channel has been reconsidered. The photoion-photoelectron coincidence (PIPECO) technique has been used. The C2H+/e coincidence rate has been recorded between 16.2 and 21.2 eV. The lowest appearance energy determined for C2H+ is 17.35+/-0.04 eV. A second appearance energy is measured at 18.40+/-0.04 eV. At both energies ethynyl ions are produced through a predissociation mechanism at the expense of the C2H2+(A2Ag) state at 17.35 eV and C2H2+(B2Sigma+/g) at 18.40 eV. These results are in good agreement with the most recent TPIPECO experiments and dissociative electroionization results. This comparison leads to the exclusion of any contribution of autoionization phenomena to the C2H+ ion production between 16.2 and 21.2 eV. Investigations of C2H+ through the ion-pair formation channel (and dissociative electron attachment producing C2H- and H-) in C2H2 are reported and its contribution to C2H+ ion production below 17.3 eV must be discarded. [less ▲]

The solar spectrum between 16 and 40 microns. Atlas solaire et atmosphérique.

Report (1994)

Spectroscopic Measurements of Atmospheric Changes (SMAC), Belgian Impulse Programme GLOBAL CHANGE

in Proceedings of the Symposium of Belgian Impulse Programme "Global Change" (1993)

About the Double Ionization of NH3 and CO2. A Comparison between Photoionization and Electron Impact.

in Dalagarno, A.; Freund, R. S.; Lubell, M. S. (Eds.) et al 16th Internatioanl Conference on the Physics of Electronic and Atomic Collisions: Abstracts of Contributed Papers. (1989)

Using synchrotron radiation the double ionization of NH3 and CO2 is measured. The results are compared with those obtained by electron impact.