1Laboratoire de Météorologie Dynamique/Institut Pierre Simon Laplace (LMD/IPSL), Palaiseau, France
2Laboratoire des Sciences du Climat et de l'Environnement (LSCE/IPSL), CNRS-CEA-UVSQ Gif-sur-Yvette, France
3Department of Chemistry, University of Waterloo, Ontario, N2L 3G1, Canada
4NASA Langley Research Center, Hampton, VA, USA
5Deparment of Chemistry, University of York, Heslington, York, YO10 5DD, UK
*now at: Laboratoire Inter-universitaire des Systèmes Atmosphériques (LISA), Universités Paris 12 et Paris 7, CNRS, Créteil, France
Abstract. The distribution and budget of oxygenated organic compounds in the atmosphere and their impact on tropospheric chemistry are still poorly constrained. Near-global space-borne measurements of seasonally resolved upper tropospheric profiles of methanol by the ACE Fourier transform spectrometer provide a unique opportunity to evaluate our understanding of this important oxygenated organic species. The comparison with distributions simulated by a state-of-the-art chemistry transport model shows fair agreement during the March 2004 to August 2005 period with about 50% of the measurements reproduced by the model within 50%. However, in the northern hemisphere and during summertime, the satellite measurements reveal that the emissions from the continental biosphere lead to upper-tropospheric methanol concentrations significantly higher than expected.