Articles | Volume 8, issue 13
Atmos. Chem. Phys., 8, 3483–3508, 2008
Atmos. Chem. Phys., 8, 3483–3508, 2008

  02 Jul 2008

02 Jul 2008

Technical Note: New ground-based FTIR measurements at Ile de La Réunion: observations, error analysis, and comparisons with independent data

C. Senten1, M. De Mazière1, B. Dils1, C. Hermans1, M. Kruglanski1, E. Neefs1, F. Scolas1, A. C. Vandaele1, G. Vanhaelewyn1, C. Vigouroux1, M. Carleer2, P. F. Coheur2, S. Fally2, B. Barret3,*, J. L. Baray4, R. Delmas4, J. Leveau4, J. M. Metzger4, E. Mahieu5, C. Boone6, K. A. Walker6,7, P. F. Bernath6,8, and K. Strong7 C. Senten et al.
  • 1Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
  • 2Service de Chimie Quantique et Photophysique (SCQP), Université Libre de Bruxelles (ULB), Brussels, Belgium
  • 3formerly at: BIRA-IASB and SCQP/ULB
  • 4Laboratoire de l'Atmosphère et des Cyclones (LACy), Université de La Réunion, France
  • 5Institute of Astrophysics and Geophysics, University of Liège, Liège, Belgium
  • 6Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
  • 7Department of Physics, University of Toronto, Toronto, Ontario, Canada
  • 8Department of Chemistry, University of York, Heslington, York, UK
  • *now at: Institut d'Aérologie, Toulouse, France

Abstract. Ground-based high spectral resolution Fourier-transform infrared (FTIR) solar absorption spectroscopy is a powerful remote sensing technique to obtain information on the total column abundances and on the vertical distribution of various constituents in the atmosphere. This work presents results from two FTIR measurement campaigns in 2002 and 2004, held at Ile de La Réunion (21° S, 55° E). These campaigns represent the first FTIR observations carried out at a southern (sub)tropical site. They serve the initiation of regular, long-term FTIR monitoring at this site in the near future. To demonstrate the capabilities of the FTIR measurements at this location for tropospheric and stratospheric monitoring, a detailed report is given on the retrieval strategy, information content and corresponding full error budget evaluation for ozone (O3), methane (CH4), nitrous oxide (N2O), carbon monoxide (CO), ethane (C2H6), hydrogen chloride (HCl), hydrogen fluoride (HF) and nitric acid (HNO3) total and partial column retrievals. Moreover, we have made a thorough comparison of the capabilities at sea level altitude (St.-Denis) and at 2200 m a.s.l. (Maïdo). It is proved that the performances of the technique are such that the atmospheric variability can be observed, at both locations and in distinct altitude layers. Comparisons with literature and with correlative data from ozone sonde and satellite (i.e., ACE-FTS, HALOE and MOPITT) measurements are given to confirm the results. Despite the short time series available at present, we have been able to detect the seasonal variation of CO in the biomass burning season, as well as the impact of particular biomass burning events in Africa and Madagascar on the atmospheric composition above Ile de La Réunion. We also show that differential measurements between St.-Denis and Maïdo provide useful information about the concentrations in the boundary layer.

Final-revised paper