Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.414
IF 5-year value: 5.958
IF 5-year
CiteScore value: 9.7
SNIP value: 1.517
IPP value: 5.61
SJR value: 2.601
Scimago H <br class='widget-line-break'>index value: 191
Scimago H
h5-index value: 89
Volume 8, issue 23
Atmos. Chem. Phys., 8, 6865–6886, 2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Results from the European project UFTIR, Time series of Upper...

Atmos. Chem. Phys., 8, 6865–6886, 2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

  01 Dec 2008

01 Dec 2008

Evaluation of tropospheric and stratospheric ozone trends over Western Europe from ground-based FTIR network observations

C. Vigouroux1, M. De Mazière1, P. Demoulin2, C. Servais2, F. Hase3, T. Blumenstock3, I. Kramer3, M. Schneider3, J. Mellqvist4, A. Strandberg4, V. Velazco5, J. Notholt5, R. Sussmann6, W. Stremme6, A. Rockmann6, T. Gardiner7, M. Coleman7, and P. Woods7 C. Vigouroux et al.
  • 1Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
  • 2Institut d'Astrophysique et de Géophysique, University of Liège (ULg), Liège, Belgium
  • 3Institute for Meteorology and Climate Research (IMK-ASF), Forschungszentrum Karlsruhe and University of Karlsruhe, Karlsruhe, Germany
  • 4Chalmers University of Technology, Göteborg, Sweden
  • 5Institute of Environmental Physics, University of Bremen, Bremen, Germany
  • 6Institute for Meteorology and Climate Research (IMK-IFU), Forschungszentrum Karlsruhe, Garmisch-Partenkirchen, Germany
  • 7National Physical Laboratory, Teddington, UK

Abstract. Within the European project UFTIR (Time series of Upper Free Troposphere observations from an European ground-based FTIR network), six ground-based stations in Western Europe, from 79° N to 28° N, all equipped with Fourier Transform infrared (FTIR) instruments and part of the Network for the Detection of Atmospheric Composition Change (NDACC), have joined their efforts to evaluate the trends of several direct and indirect greenhouse gases over the period 1995–2004. The retrievals of CO, CH4, C2H6, N2O, CHClF2, and O3 have been optimized. Using the optimal estimation method, some vertical information can be obtained in addition to total column amounts. A bootstrap resampling method has been implemented to determine annual partial and total column trends for the target gases. The present work focuses on the ozone results. The retrieved time series of partial and total ozone columns are validated with ground-based correlative data (Brewer, Dobson, UV-Vis, ozonesondes, and Lidar). The observed total column ozone trends are in agreement with previous studies: 1) no total column ozone trend is seen at the lowest latitude station Izaña (28° N); 2) slightly positive total column trends are seen at the two mid-latitude stations Zugspitze and Jungfraujoch (47° N), only one of them being significant; 3) the highest latitude stations Harestua (60° N), Kiruna (68° N) and Ny-Ålesund (79° N) show significant positive total column trends. Following the vertical information contained in the ozone FTIR retrievals, we provide partial columns trends for the layers: ground-10 km, 10–18 km, 18–27 km, and 27–42 km, which helps to distinguish the contributions from dynamical and chemical changes on the total column ozone trends. We obtain no statistically significant trends in the ground-10 km layer for five out of the six ground-based stations. We find significant positive trends for the lowermost stratosphere at the two mid-latitude stations, and at Ny-Ålesund. We find smaller, but significant trends for the 18–27 km layer at Kiruna, Harestua, Jungfraujoch, and Izaña. The results for the upper layer are quite contrasted: we find significant positive trends at Kiruna, Harestua, and Jungfraujoch, and significant negative trends at Zugspitze and Izaña. These ozone partial columns trends are discussed and compared with previous studies.

Publications Copernicus
Final-revised paper