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See detailFifteen years-trend characteristics of key stratospheric constituents monitored by FTIR above the Jungfraujoch.
Mahieu, Emmanuel ULg; Zander, Rodolphe ULg; Demoulin, Philippe ULg et al

in Harris, N. R. P.; Guirlet, M.; Amanatidis, G. T. (Eds.) Air Pollution Report 73 EUR 19340 (2000)

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See detailLong-term evolution of the loading of CH4, N2O, CO, CCl2F2, CHClF2 and SF6 above Central Europe during the last 15 years
Zander, Rodolphe ULg; Mahieu, Emmanuel ULg; Demoulin, Philippe ULg et al

in J. van Ham (Ed.) Non-CO2 greenhouse gases: scientific understanding, control and implementation (2000)

Long-term monitoring activities of some 20 atmospheric constituents are continuing at the International Scientific Station of the Jungfraujoch, Switzerland, based on remote infra-red solar observations ... [more ▼]

Long-term monitoring activities of some 20 atmospheric constituents are continuing at the International Scientific Station of the Jungfraujoch, Switzerland, based on remote infra-red solar observations with high spectral resolution Fourier transform spectrometers. As a contribution to non-CO2 greenhouse gas investigations, we report the trends observed in the vertical column abundances measured regularly since the mid-1980s for CH4, N2O, CO, CCl2F2, CHClF2 and SF6. With the exception of CO, all species show positive rates of change in their near past atmospheric loading, those of CH4, N2O and CCl2F2 having slowed significantly during the more recent years. The derived rates of change will be compared to findings resulting from ground-level in situ investigations at latitudes similar to that of the Jungfraujoch, and be interpreted in terms of resulting global loading changes. [less ▲]

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See detailVertical column abundances of COF2 above the Jungfraujoch Station: update and consolidation of the database with measurements in the nu4 band region.
Mélen, Francine; Mahieu, Emmanuel ULg; Demoulin, Philippe ULg et al

in Atmospheric Spectroscopy Applications 1999 - Proceedings (1999)

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See detailColumn Abundance measurements of formaldehyde above the Jungfraujoch.
Demoulin, Philippe ULg; Zander, Rodolphe ULg; Mélen, F. et al

in Atmospheric Spectroscopy Applications 1999 - Proceedings (1999)

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See detailRecent Characteristic Budgets of Inorganic Chlorine and Fluorine above the Jungfraujoch Station
Mahieu, Emmanuel ULg; Zander, Rodolphe ULg; Mélen, Francine et al

in Harris, N. R. P.; Kilbane-Dawe, I.; Amanatidis, G.T. (Eds.) Proceedings of the 4th European Symposium on Polar Stratospheric Ozone 1997 (1998)

Within the frame of NDSC (Network for the Detection of Stratospheric Change)-related monitoring activities conducted at the International Scientific Station of the Jungfraujoch (Swiss Alps, 46.5°N, 8.0°E ... [more ▼]

Within the frame of NDSC (Network for the Detection of Stratospheric Change)-related monitoring activities conducted at the International Scientific Station of the Jungfraujoch (Swiss Alps, 46.5°N, 8.0°E, 3580 m a.s.l.), long-term investigations of the inorganic chlorine and fluorine budgets have been pursued during the last years. They are based on the analysis of high-resolution infrared solar spectra, recorded with grating and Fourier transform state-of-the-art spectrometers. Nonlinear least squares fittings of synthetic spectra to the observations are performed over selected intervals, encompassing characteristic absorptions of HCl, ClONO2, HF and COF2; this allows the retrieval of their total vertical column abundances above the Jungfraujoch and the evaluation of their budgets. [less ▲]

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See detailThe current budget of NOy above the Jungfraujoch as derived from IR solar observations
Demoulin, Philippe ULg; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

in Harris, N. R. P.; Kilbane-Dawe, I.; Amanatidis, G. T. (Eds.) Polar stratospheric ozone 1997 (1998)

This paper reports on an investigations of a series of compounds of the NOy family, based on high resolution infrared solar observations made at the ISSJ (International Scientific Station of the ... [more ▼]

This paper reports on an investigations of a series of compounds of the NOy family, based on high resolution infrared solar observations made at the ISSJ (International Scientific Station of the Jungfraujoch), Switzerland (46.55ºN, 7.99ºE, 3580 m a.s.l.). These observations are part of a long-term monitoring effort undertaken by the Liège group since the mid-1970s, and integrated more recently as a contribution to the Network for the Detection of Stratospheric Change (NDSC). Currently, vertical column abundances of over 20 molecules are retrieved from solar spectra recorded under clear sky conditions as regularly as possible, using two high resolution Fourier transform infrared (2 to 15 microns) spectrometers. [less ▲]

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See detailAn overview of NDSC-related activities at the Jungfraujoch through high-resolution infrared solar observations
Zander, Rodolphe ULg; Demoulin, Philippe ULg; Mahieu, Emmanuel ULg et al

in Bojkov, R.; Visconti, G. (Eds.) Proceedings of "The XXVIII Quadrennial Ozone Symposium" (1998)

Since the mid-1970s, infrared remote sensing at the Jungfraujoch, Switzerland, has been performed in response to the need to measure the concentrations and assess the seasonal and long-term changes of an ... [more ▼]

Since the mid-1970s, infrared remote sensing at the Jungfraujoch, Switzerland, has been performed in response to the need to measure the concentrations and assess the seasonal and long-term changes of an increasing number of atmospheric constituents. Currently, the vertical column abundances of over 20 telluric gases are being monitored, based on the analysis of solar spectra recorded regularly between 2 and 14 microns, using two high-resolution Fourier transform spectrometers. In this paper, emphasis is placed on those activities more specifically performed within the framework of the NDSC (Network for the Detection of Stratospheric Change) whose objectives are briefly described in the introduction. [less ▲]

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See detailVertical column abundances of COF2 above the Jungfraujoch Station, derived from ground-based infrared solar observations
Mélen, F.; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

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 ▲]

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See detailThe current budjet of NOy above the Jungfraujoch as derived from IR Solar Observations.
Demoulin, Philippe ULg; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

in Air Pollution Research Report Nr 66 (1998). (1997)

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See detailTotal vertical column abundances of atmospheric gases derived from IR remote solar observations made at the Jungfraujoch Station.
Zander, Rodolphe ULg; Demoulin, Philippe ULg; Mahieu, Emmanuel ULg et al

in Hov, O. (Ed.) Transport and Chemical Transformation of Pollutants in the Troposphere. (1997)

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See detailObserved trends in total vertical column abundances of atmospheric gases from IR solar spectra recorded at the Jungfraujoch
Mahieu, Emmanuel ULg; Zander, Rodolphe ULg; Delbouille, Luc et al

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 ▲]

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See detailVertical column abundance and profile retrievals of water vapor above the Jungfraujoch.
Demoulin, Philippe ULg; Schmid, Beat; Roland, Ginette et al

in Proceedings of Atmospheric Spectroscopy Applications, ASA Reims 96 (1996)

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See detailVertical Column Abundances of COF2 measured above the Jungfraujoch Station from ground-based infrared solar observations.
Mélen, F.; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

in Proceedings of Atmospheric Spectroscopy Applications (1996)

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See detailHow complex can be the Unimolecular Decomposition of a simple Molecule? The case of Acetylene. An Electron Impact and PIPECO Investigation.
Locht, Robert ULg; Servais, Christian ULg

in Zeitschrift für Physikalische Chemie (1996), 195

The dissociative ionization of C2H2, C2D2 and C2HD is presented in this work. Excepting the H2+ formation, all dissociation channels are thoroughly investigated by electron impact. The translational ... [more ▼]

The dissociative ionization of C2H2, C2D2 and C2HD is presented in this work. Excepting the H2+ formation, all dissociation channels are thoroughly investigated by electron impact. The translational energy distribution as a function of the impinging electron energy and the appearance energy as a function of the translational energy are measured for all fragment ions. KE versus AE diagrams are obtained and the isotope effect is examined. All observed thresholds are analyzed in detail and dissociation mechanisms are proposed. For the C2H+ ion the PIPECO technique has also been used. From these discussions the H-C2H, HC-CH and H-C2 binding energy values are proposed, i.e. 5.33+/-0.23 eV, 9.83+/0.10 eV and 5.44+/-0.40 eV respectively. The fragmentation path leading to C+, CH2+ and C2+ are discussed in terms of dissociation mechanisms involving the transient vinylidene structure of the molecular ion as an intermediate. [less ▲]

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See detailStratospheric changes monitored above the Jungfraujoch - The budgets of inorganic chlorine and fluorine since 1985.
Zander, Rodolphe ULg; Mahieu, Emmanuel ULg; Demoulin, Philippe ULg et al

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

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See detailThe solar Spectrum between 16 and 35 µm.
Farmer, C. P.; Delbouille, L.; Roland, G. et al

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

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See detailA new analysis of the OH radical spectrum from solar Infrared observations.
Mélen, F.; Grevesse, Nicolas ULg; Delbouille, L. et al

in ASP Conference Series (1995)

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See detailA new analysis of the OH radical spectrum from solar infrared observations.
Mélen, F.; Sauval, A. J.; Grevesse, Nicolas ULg et al

in Journal of Molecular Spectroscopy (1995), 174

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