Recent Evolution of atmospheric OCS above the Jungfraujoch station : implications for the stratospheric aerosol layer.
Mahieu, Emmanuel ; Zander, Rodolphe ; Demoulin, Philippe et al
in Proceedings of the Atmospheric Spectroscopy Applications. (2005)Detailed reference viewed: 5 (0 ULg)
The exploitation of ground-based Fourier transform infrared observations for the evaluation of tropospheric trends of greenhouse gases over Europe
; ; et al
in Environmental Sciences (2005), 2(2-3), 283-293
Solar absorption measurements using Fourier transform infrared (FTIR) spectrometry carry information about the atmospheric abundances of many constituents, including non-CO2 greenhouse gases. Such ... [more ▼]
Solar absorption measurements using Fourier transform infrared (FTIR) spectrometry carry information about the atmospheric abundances of many constituents, including non-CO2 greenhouse gases. Such observations have regularly been made for many years as a contribution to the Network for the Detection of Stratospheric Change (NDSC). They are the only ground-based remote sensing observations available nowadays that carry information about a number of greenhouse gases in the free troposphere. This work focuses on the discussion of the information content of FTIR long-term monitoring data of some direct and indirect greenhouse gases (CH4, N2O, O3 and CO and C2H6, respectively), at six NDSC stations in Western Europe. This European FTIR network covers the polar to subtropical regions. At several stations of the network, the observations span more than a decade. Existing spectral time series have been reanalyzed according to a common optimized retrieval strategy, in order to derive distinct tropospheric and stratospheric abundances for the above-mentioned target gases. A bootstrap resampling method has been implemented to evaluate trends of the tropospheric burdens of the target gases, including their uncertainties. In parallel, simulations of the target time series are being made with the Oslo CTM2 model: comparisons between the model results and the observations provide valuable information to improve the model and, in particular, to optimize emission estimates that are used as inputs to the model simulations. The work is being performed within the EC project UFTIR. The paper focuses on N2O for which the first trend results have been obtained. [less ▲]Detailed reference viewed: 45 (11 ULg)
Intercomparisons of MIPAS operational N2O and HNO3 profiles with ground based FTIR data
; ; et al
Poster (2004, July)Detailed reference viewed: 3 (1 ULg)
Ground-based FTIR measurements of O3- and climate-related gases in the free troposphere and lower stratosphere
; ; et al
in Zerefos, C. S. (Ed.) Proceedings Quadrennial Ozone Symposium (2004)
In the frame of the EC project UFTIR (Time series of Upper Free Troposphere observations from a European ground-based FTIR network), a common strategy for an optimal determination of the chemical ... [more ▼]
In the frame of the EC project UFTIR (Time series of Upper Free Troposphere observations from a European ground-based FTIR network), a common strategy for an optimal determination of the chemical composition in the free troposphere and lower stratosphere with ground-based Fourier-transform infrared (FTIR) spectrometers is being developed. The project focuses on 6 target species that are O3, CO, CH4, N2O, C2H6 and CHClF2 (HCFC-22). The strategy consists in selecting the most appropriate parameters to retrieve vertical concentration profiles from solar FTIR spectra. Among the important parameters are the spectral microwindows: they have been optimised to maximise the information content and to minimize the influence of poorly known spectroscopic data and interfering species. [less ▲]Detailed reference viewed: 10 (1 ULg)
The evolution of inorganic chlorine above the Jungfraujoch station: an update.
Mahieu, Emmanuel ; Duchatelet, Pierre ; Zander, Rodolphe et al
in Zerefos, C. S. (Ed.) Proceedings of the 20th Quadrennial Ozone Symposium (2004)
Within the frame of the NDSC, the total vertical column abundances of HCl and ClONO2, by far the two most important inorganic chlorine reservoirs at northern mid-latitudes, have been further monitored ... [more ▼]
Within the frame of the NDSC, the total vertical column abundances of HCl and ClONO2, by far the two most important inorganic chlorine reservoirs at northern mid-latitudes, have been further monitored above the Jungfraujoch station (Swiss Alps, 46.5ºN, 8.0ºE, 3580m a.s.l.), by analyzing infrared solar absorption spectra recorded with very high-resolution Fourier spectrometers. The mean temporal evolution of the sum of their monthly mean abundance time series indicates that the total stratospheric inorganic chlorine loading (Cly) has decreased slowly (-0.7+/-0.3%/yr, 1-sigma) since it peaked in late 1996, at the limit of being statistically significant at the 2-sigma level. Comparison with model calculations and with the evolution of surface total organic chlorine will also be discussed. [less ▲]Detailed reference viewed: 19 (2 ULg)
Tropospheric and Stratospheric Carbonyl Sulfide (OCS): long-term trends and seasonal Cycles above the Jungfraujoch Station.
Mahieu, Emmanuel ; ; Zander, Rodolphe et al
in EUR 20650 (2003)Detailed reference viewed: 8 (2 ULg)
Monitoring of the variability and long-term evolution of tropospheric constituents by Infrared solar absorption spectrometry at the Jungfraujoch, Switzerland.
Zander, Rodolphe ; Mahieu, Emmanuel ; Duchatelet, Pierre et al
in Borrell, P.; Borrell, P. M.; Burrows, J. P. (Eds.) et al Sounding the Troposphere from Space: A new era for Atmospheric Chemistry. (2003)Detailed reference viewed: 2 (1 ULg)
Updating the Jungfraujoch FTIR databases : current status
Duchatelet, Pierre ; Mahieu, Emmanuel ; Zander, Rodolphe et al
Since the middle of the 20th century, the University of Liège has been active at the International Scientific Station of the Jungfraujoch (ISSJ) in the Swiss Alps (46.5°N, 8.0°E, 3580m asl) to study the ... [more ▼]
Since the middle of the 20th century, the University of Liège has been active at the International Scientific Station of the Jungfraujoch (ISSJ) in the Swiss Alps (46.5°N, 8.0°E, 3580m asl) to study the chemical composition of both the solar photosphere and the Earth’s atmosphere. Since 1989, the ISSJ is an accepted site of the northern midlattitude primary Alpine station of the NDSC (Network for the Detection of Stratospheric Change). This acceptance resulted from earlier monitoring activities by Ulg of a large number of atmospheric constituents. Within the NDSC frame, a special attention and many efforts have been devoted to the monitoring of the most important atmospheric constituents involved both in the erosion of stratospheric ozone and in the greenhouse capacity of the troposphere, after it became clear that human activities have a direct impact on these two processes. Using two high resolution Fourier transform infrared (FTIR) spectrometers, over 25000 wide-band solar spectra encompassing nearly 1700 days since the mid 1980s have been recorded and analyzed to study, quasi simultaneously and repeatedly, local, seasonal and secular variations of some 20 gaseous telluric species. So far, most results have been reported, demonstrating the power of infrared spectrometric solar observations to characterize the chemical composition of the atmosphere. These datas, archived in terms of total vertical column abundances (e.g., at the NDSC-Data Host Facility; http://www.ndsc.ws), are expressed in number molecules per cm2 above the site using best-know input parameters (i.e. spectroscopic-, instrumental-, environmental-) in the retrieval procedure. Meanwhile, more sophisticated algorithms, based on the “Rodgers” optimal estimation method, have been developed, allowing to derive partial tropospheric- and stratospheric columns for various species, including HCl, ClONO2, O3, HF, CO, N2O, CH4, HCN, OCS. This contribution reports related results for HCl and ClONO2. [less ▲]Detailed reference viewed: 22 (4 ULg)
Potential of the NDSC in support of the Kyoto Protocol: Examples from the station Jungfraujoch, Switzerland
Zander, Rodolphe ; Mahieu, Emmanuel ; Servais, Christian et al
in Van Ham, J.; Baede, A. P. M.; Guicherit, R. (Eds.) et al Non-CO2 Greenhouse Gases: Scientific Understanding, Control Options and Policy Aspects (2002)
This paper gives a brief description and “raison d’être” of the Network for the Detection of Stratospheric Change (NDSC) as well as its key research tasks to address the broader goal of monitoring ... [more ▼]
This paper gives a brief description and “raison d’être” of the Network for the Detection of Stratospheric Change (NDSC) as well as its key research tasks to address the broader goal of monitoring atmospheric changes and to identify their causes and related impacts on mankind’s environment. While the Network has primarily focussed, thus far, on monitoring the ozone layer and assessing global compliance with the Montreal Protocol, ongoing implementations and new capabilities have enabled it to adapt to more recent political developments such as the Kyoto Proto-col on substances affecting the climate system. Examples of activities in support of the latter are reported, based on infrared solar observations at the Jungfraujoch station. [less ▲]Detailed reference viewed: 62 (15 ULg)
Monitoring of the variability and long-term evolution of tropospheric constituents by infrared solar absorption spectrometry at the Junfraujoch, Switzerland.
Zander, Rodolphe ; Mahieu, Emmanuel ; Demoulin, Philippe et al
Report (2001)Detailed reference viewed: 12 (6 ULg)