Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 3 5 2003 10.5194/acpd-3-4857-2003 http://www.atmos-chem-phys-discuss.net/3/4857/2003/ http://www.atmos-chem-phys-discuss.net/3/4857/2003/acpd-3-4857-2003.html http://www.atmos-chem-phys-discuss.net/3/4857/2003/acpd-3-4857-2003.pdf 4857 4878 2003-09-25 Ground-based FTIR measurements of CO from the Jungfraujoch: characterisation and comparison with <i>in situ</i> surface andMOPITT data B. Barret M. De Mazière E. Mahieu Belgian Institute for Space Aeronomy, Brussels, Belgium Institut de Géophysique et d’Astrophysique, Liège, Belgium CO vertical profiles have been retrieved from solar absorption FTIR spectra recorded at the NDSC station of the Jungfraujoch (46.5&deg; N, 8&deg;<b> </b>E and 3580 m a.s.l.) for the period from January 1997 to May 2001. The characterisation of these profiles has been established by an information content analysis and an estimation of the error budgets. A partial validation of the profiles has been performed through comparisons with correlative measurements. The average volume mixing ratios (vmr) in the 3 km layer above the station have been compared with coincident surface measurements. The agreement between monthly means from both measurement techniques is very good, with a correlation coefficient of 0.87, and no significant bias observed. The FTIR total columns have also been compared to CO partial columns above 3580 m a.s.l. derived from the MOPITT (Measurement Of Pollution In The Troposphere) instrument for the period March 2000 to May 2001. Relative to the FTIR columns, the MOPITT partial columns exhibit a positive bias of 8&plusmn;8% for daytime and of 4&plusmn;7% for nighttime measurements.