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.
The influence of biogenic emissions on upper-tropospheric methanol as revealed from space