Ground-based infrared solar spectroscopic measurements of carbon monoxide during 1994 Measurement of Air Pollution From Space flights

in Journal Of Geophysical Research. Atmospheres (1998), 103(D15), 19317-19325

Results of the comparison of carbon monoxide ground-based infrared solar spectroscopic measurements with data obtained during 1994 Measurement of Air Pollution From Space (MAPS) flights are presented ... [more ▼]

Results of the comparison of carbon monoxide ground-based infrared solar spectroscopic measurements with data obtained during 1994 Measurement of Air Pollution From Space (MAPS) flights are presented. Spectroscopic measurements were performed correlatively with April and October MAPS flights by nine research groups from Belgium, Canada, Germany, Japan, New Zealand, Russia, and the United States. Characterization of the techniques and error analysis were performed. The role of the CO a priori profile used in the retrieval was estimated. In most cases an agreement between spectroscopic and MAPS data is within estimated MAPS accuracy of +/-10%. [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 abundance and profile retrievals of water vapor above the Jungfraujoch.

in Proceedings of Atmospheric Spectroscopy Applications. (1996)

VERTICAL COLUMN ABUNDANCES OF HCN DEDUCED FROM GROUND-BASED INFRARED SOLAR SPECTRA - LONG-TERM TREND AND VARIABILITY

in Journal of Atmospheric Chemistry (1995), 20(3), 299-310

A set of high-resolution IR solar spectra recorded at the International Scientific Station of the Jungfraujoch, Switzerland, from 84/06 to 93/06, and at the National Solar Observatory McMath-Pierce solar ... [more ▼]

A set of high-resolution IR solar spectra recorded at the International Scientific Station of the Jungfraujoch, Switzerland, from 84/06 to 93/06, and at the National Solar Observatory McMath-Pierce solar telescope facility on Kitt Peak, Arizona, U.S.A. from 78/05 to 92/07 have been analyzed to determine the vertical column abundances of hydrogen cyanide, HCN, above the two stations. The analysis was based on least-squares curve fitting of calculated spectra to the observations encompassing the P4 and the P8 lines of HCN respectively located at 3299.5273 and 3287.2483 cm(-1). The results obtained for the two stations indicate that no significant long-term trend affects either of the two databases; however, this analysis reveals variable increases during springtime of up to a factor of 2 in the HCN total column above the Jungfraujoch and even up to 3 above Kitt Peak. The calculated mean vertical column abundances, excluding the spring observations, are equal to (2.55 +/- 0.30) x 10(15) molec./cm(2) (S.D.) and (2.75 +/- 0.30) x 10(15) molec./cm(2) respectively above the Jungfraujoch and the Kitt Peak observatories. Based on a realistic volume mixing ratio profile, these columns translate into mean volume mixing ratios equal to 190 x 10(-12) ppv at the respective altitudes of the stations. [less ▲]

SECULAR TREND AND SEASONAL VARIABILITY OF THE COLUMN ABUNDANCE OF N2O ABOVE THE JUNGFRAUJOCH STATION DETERMINED FROM IR SOLAR SPECTRA

in Journal of Geophysical Research (1994), 99(D8), 16745-16756

Infrared solar spectra recorded at the International Scientific Station of the Jungfraujoch (3580 m altitude), Switzerland, in 1950-1951 and from 1984 to 1992 have been analyzed to determine vertical ... [more ▼]

Infrared solar spectra recorded at the International Scientific Station of the Jungfraujoch (3580 m altitude), Switzerland, in 1950-1951 and from 1984 to 1992 have been analyzed to determine vertical column abundances of nitrous oxide (N2O) above the station. The best fit to the relatively dense set of measurements made between 1984 and 1992 indicates a mean exponential rate of increase equal to 0.36 +/- 0.06% yr-1 (1 sigma) and a seasonal modulation of 7.2% peak to peak, the minimum occurring at the end of the winter and the maximum in early September. The column abundances for April of the years 1951, 1984, and 1992 were found equal to 3.49 x 10(18), 3.76 x 10(18), and 3.87 x 10(18) molecules cm-2, respectively; they translate into N2O concentrations at the altitude of the Jungfraujoch equal to 275, 296, and 305 parts per billion by volume. These results indicate that the exponential rate of increase for 1951-1984 was equal to 0.23 +/- 0.04% yr-1 (1 sigma), thus substantially lower than for the 1984-1992 time interval and that the so-called preindustrial levels of N2O pertained until 1951 with most of the increase in atmospheric N2O occurring thereafter. [less ▲]

SECULAR EVOLUTION OF THE VERTICAL COLUMN ABUNDANCES OF CHCLF2 (HCFC-22) IN THE EARTH'S ATMOSPHERE INFERRED FROM GROUND-BASED IR SOLAR OBSERVATIONS AT THE JUNGFRAUJOCH AND AT KITT-PEAK, AND COMPARISON WITH MODEL-CALCULATIONS

in Journal of Atmospheric Chemistry (1994), 18(2), 129-148

Series of high-resolution infrared solar spectra recorded at the International Scientific Station of the Jungfraujoch, Switzerland, between 06/1986 and 11/1992, and at Kitt Peak National Observatory ... [more ▼]

Series of high-resolution infrared solar spectra recorded at the International Scientific Station of the Jungfraujoch, Switzerland, between 06/1986 and 11/1992, and at Kitt Peak National Observatory, Tucson, Arizona (U.S.A.), from 12/1980 to 04/1992, have been analyzed to provide a comprehensive ensemble of vertical column abundances of CHClF2 (HCFC-22; Freon-22) above the European and the North American continents. The columns were derived from nonlinear least-squares curve fittings between synthetic spectra and the observations containing the unresolved 2nu6 Q-branch absorption of CHClF2 at 829.05 cm-1. The changes versus time observed in these columns were modeled assuming both an exponential and a linear increase with time. The exponential rates of increase at one-sigma uncertainties were found equal to (7.0 +/- 0.35)%/yr for the Junfraujoch data and (7.0 +/- 0.23)%/yr for the Kitt Peak data. The exponential trend of 7.0%/yr found at both stations widely separated in location can be considered as representative of the global increase of the CHClF2 burden in the Earth's atmosphere during the period 1980 to 1992. When assuming two realistic vertical volume mixing ratio profiles for CHClF2 in the troposphere, one quasi constant and the other decreasing by about 13% from the ground to the tropopause, the concentrations for mid-1990 were found to lie between 97 and 111 pptv (parts per trillion by volume) at the 3.58 km altitude of the Jungfraujoch and between .97 and 103 pptv at Kitt Peak, 2.09 km above sea level. Corresponding values derived from calculations using a high vertical resolution-2D model and recently compiled HCFC-22 releases to the atmosphere, were equal to 107 and 105 pptv, respectively, in excellent agreement with the measurements. The model calculated lifetime of CHClF2 was found equal to 15.6 years. The present results are compared critically with similar data found in the literature. On average, the concentrations found here are lower by 15-20% than those derived from in situ investigations; this difference cannot be explained by the absolute uncertainty of +/- 11% assigned presently to the infrared remote measurements. [less ▲]

Monitoring of statospheric changes at the Jungfraujoch station by high-resolution infrared solar observations in support of the Network for Detection of Stratospheric Change (NDSC)

in Chanin, M.-L. (Ed.) The role of the stratosphere in global change (1993)

Infrared remote sensing observations from the ground, using the sun as source of radiation, constitute a powerful tool for monitoring the state of our environment. The observational effort carried out at ... [more ▼]

Infrared remote sensing observations from the ground, using the sun as source of radiation, constitute a powerful tool for monitoring the state of our environment. The observational effort carried out at the International Scientific Station of the Jungfraujoch, Switzerland, is used in this paper as a typical example to stress out the performances achievable by that technique. When based on high spectral resolution and high signal-to-noise observations, it can overcome the bulk of the absorption produced by gases with high concentration in the troposphere and contribute efficiently to the quantification and monitoring of trace gases predominantly concentrated in the stratosphere. [less ▲]