References of "De Mazière, M."
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See detailRecent Evolution of atmospheric OCS above the Jungfraujoch station : implications for the stratospheric aerosol layer.
Mahieu, Emmanuel ULg; Zander, Rodolphe ULg; Demoulin, Philippe ULg et al

in Proceedings of the Atmospheric Spectroscopy Applications. (2005)

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See detailIntercomparisons of MIPAS operational N2O and HNO3 profiles with ground based FTIR data
Vigouroux, C.; De Mazière, M.; Wood, S. et al

Poster (2004, July)

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See detailComparisons between SCIAMACHY Scientific Products and Ground-Based FTIR Data for Total Columns of CO, CH4 and N2O
De Mazière, M.; Barret, B.; Blumenstock, T. et al

Scientific conference (2004, May)

Total column amounts of CO, CH4 and N2O retrieved from SCIAMACHY nadir observations in its near-infrared channels have been compared to data from a ground-based network of Fourier-transform infrared (FTIR ... [more ▼]

Total column amounts of CO, CH4 and N2O retrieved from SCIAMACHY nadir observations in its near-infrared channels have been compared to data from a ground-based network of Fourier-transform infrared (FTIR) spectrometers as well as to data obtained with an FTIR instrument during a ship cruise in January-February 2003, along the African West Coast. The SCIAMACHY data considered here have been produced by two different scientific retrieval algorithms, wfm-doas (version 4.0) and IMLM (version 5.1), and cover different time periods, making the number of reliable coincidences that satisfy the temporal and spatial collocation criteria rather limited and different for both. Also the quality of the SCIAMACHY Level 1 data, and thus of the Level 2 data for the different time periods is very different. Still the comparisons demonstrate the capability of SCIAMACHY, using one of both algorithms, to deliver geophysically valuable products for the target species under consideration, on a global scale. [less ▲]

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See detailValidation of MIPAS N2O Profiles by Stratospherc Balloon, Aircraft and Ground Based Measurements
Camy-Peyret, C.; Dufour, G.; Payan, S. et al

Scientific conference (2004, May)

The ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS is based on a number of balloon-bone, aircraft and ground-based correlative measurements. In particular the ... [more ▼]

The ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS is based on a number of balloon-bone, aircraft and ground-based correlative measurements. In particular the activities of validation scientists were coordinated by ESA within the ENVISAT Stratospheric Aircraft and Balloon Campaign or ESABC. As a companion to a similar paper on CH4 and in parallel to the contribution of the individual validation teams, the resent paper provides a synthesis of comparisons performed between MIPAS N2O profiles roduced by the current ESA operational software (Instrument Processing Facility version 4.61 or IPF v4.61) or by the IMK-FZK scientific processor and correlative measurements obtained from balloon and aircraft experiments as well as from ground-based instruments. [less ▲]

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See detailGround-based FTIR measurements of O3- and climate-related gases in the free troposphere and lower stratosphere
De Mazière, M.; Barret, B.; Vigouroux, C. 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 ▲]

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See detailThe evolution of inorganic chlorine above the Jungfraujoch station: an update.
Mahieu, Emmanuel ULg; Duchatelet, Pierre ULg; Zander, Rodolphe ULg 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 ▲]

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See detailRetrieval and characterization of ozone profiles from solar infrared spectra at the Jungfraujoch
Barret, B.; De Maziere, M.; Demoulin, Philippe ULg

in Journal of Geophysical Research. Atmospheres (2002), 107(D24),

[1] Vertical distributions of ozone from June 1996 to November 2000 have been retrieved from high-resolution Fourier transform infrared (FTIR) solar absorption spectra recorded at the primary Network for ... [more ▼]

[1] Vertical distributions of ozone from June 1996 to November 2000 have been retrieved from high-resolution Fourier transform infrared (FTIR) solar absorption spectra recorded at the primary Network for Detection of Stratospheric Change station of the Jungfraujoch in the Swiss Alps (46.5degreesN, 8degreesE, 3580 m above sea level (asl). The retrievals were performed using the Optimal Estimation Method (OEM), both in a narrow spectral interval (1002.567-1003.2 cm(-1)) and in a broad spectral interval (1000.0-1005.0 cm(-1)) in the O-3 9.6-mum band. A thorough characterization of the retrievals has been performed following the lines of OEM, including an information content analysis, a study of the correlations between retrieved instrumental parameters and retrieved ozone concentrations, and an evaluation of the O-3 profile error budget. It is demonstrated that the information content is significantly higher for spectra in the broad microwindow, resulting in higher vertical resolutions, on the order of 8 km, of the retrieved profiles extending up to 40 km, and less correlations between retrieved parameters. An independent statistical verification of the retrieval results and their characterization has been performed by comparison of the FTIR ozone profiles with independent measurements. These are the ozone profile measurements from balloon soundings at Payerne, from the microwave radiometer at Bern and the lidar at Observatoire de Haute-Provence (OHP), and the total column data from the Dobson spectrophotometer at Arosa. Applying the optimum retrieval procedure in the broad spectral interval, an excellent agreement has been found between the FTIR O-3 profile data and the correlative data. The largest offset of the FTIR data in comparison with the correlative data is found with respect to the lidar data in the 24- to 40-km layer, and is on the order of 5%. No systematic biases have been found in the troposphere, neither in the upper troposphere-lower stratosphere (UTLS) up to 18 km. The dispersion of the relative differences between the data sets, if any, is never larger than half of the natural ozone variability. [less ▲]

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See detailVALIDATION OF ENVISAT-1 LEVEL-2 PRODUCTS RELATED TO LOWER ATMOSPHERE O3 AND NOy CHEMISTRY BY A FTIR QUASI-GLOBAL NETWORK
De Mazière, M.; Coosemans, T.; Barret, B. et al

Scientific conference (2002, December)

A coordinated action involving eleven stations of the ground-based Network for Detection of Stratospheric Change (NDSC) equipped with Fourier transform infrared (FTIR) instruments was conducted to ... [more ▼]

A coordinated action involving eleven stations of the ground-based Network for Detection of Stratospheric Change (NDSC) equipped with Fourier transform infrared (FTIR) instruments was conducted to contribute to the validation of the three atmospheric chemistry instruments onboard ENVISAT, that are MIPAS, SCIAMACHY and GOMOS. The target products for validation are total columns of O3, CH4, CO and some important NOy species (NO2, HNO3, NO) and the source gas N2O. Together the eleven stations cover the latitudes between 79 °N and 78°S, including polar, mid -latitude and subtropical and tropical locations. The goal is to contribute to the assessment of the data quality of the aforementioned ENVISAT instruments, from a quasi-global perspective. The period of intensive ground-based data collection for the benefit of the ENVISAT Validation Commissioning Phase that is dealt with in the present paper is July 15 to December 1, 2002. The FTIR network involved collected a data set corresponding to an equivalent of approximately 400 days of measurements; about three quarter of the data have already been submitted to the ENVISAT Calval database and are included in the present work. Unfortunately, the distribution of ENVISAT data has been slow and limited. Only a limited number of coincidences has been found for making data inter-comparisons. Therefore, the conclusions drawn in this paper are very preliminary and cover only a limited set of data products from SCIAMACHY only. Our findings up to now concerning the above mentioned target products are the following: (1) SCIAMACHY near infrared operational products (CO, CH4, N2O) have no scientific meaning yet, (2), the operational SCIAMACHY total vertical O3 column product derived in the ultraviolet window has undergone some improvements with changing versions of the processor(s) but it still underestimates the column by about 5 – 10 %, (3), the operational SCIAMACHY total vertical O3 column product derived in the visible window is unrealistically large, and (3), the operational NO2 total column product from SCIAMACHY seems to largely overestimate the real column, but very few coincidences and large dispersions of the data do inhibit any further conclusion at present. In a next phase, the same ground-based correlative data set will be exploited to further validate the ENVISAT data as soon as more and reprocessed data will be distributed. [less ▲]

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See detailThe NOy budget above Jungfraujoch: long-term evolution, family partition and model comparison
Demoulin, Philippe ULg; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

in Abstracts presented at the NDSC 2001 Symposium: Celebrating 10 years of atmospheric research (2001)

Based on high-resolution solar spectra recorded with FTIR instruments at the University of Liège laboratory located at the Jungfraujoch NDSC station (Swiss Alps, 46.5ºN, 8ºE, altitude 3580 m), the most ... [more ▼]

Based on high-resolution solar spectra recorded with FTIR instruments at the University of Liège laboratory located at the Jungfraujoch NDSC station (Swiss Alps, 46.5ºN, 8ºE, altitude 3580 m), the most important constituents making up the NOy family have been measured consistently since the mid-1980s. They include HNO3, NO, NO2 and ClONO2, which are analyzed in terms of their vertical column abundances above the site. Related trends have been determined and assessed statistically. Among these, only ClONO2 and NO2 reveal significant long-term trends. The combined column evaluation of NOy indicates a rate of change equal to (0.1+/-0.2) %/year, thus statistically undefined and barely consistent with the evolution of the source gas N2O. Trends derived from the observations will be compared critically with those deduced from a long-term run of a 2-D stratospheric model developed at the University of Oslo. The model includes full gaseous chemistry, PSCs and sulfate particles, which vary from year to year. Comparisons with similar data found in the literature are also discussed. [less ▲]

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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 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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