1Belgian Institute for Space Aeronomy, Ringlaan 3, B-1180, Brussels, Belgium
2LOA, Université de Science et Technologies de Lille, Bâtiment P5, F-59655 Villeneuve d'�Ascq Cedex, France
3University of Saskatchewan, 116 Science Place, Saskatoon, SK S7N 5E2, Canada
4Naval Research Lab, 4555 Overlook Ave. SW, Washington, DC 20375 USA
5Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
6Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
7Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7, Canada
Abstract. The Canadian ACE (Atmospheric Chemistry Experiment) mission is dedicated to the retrieval of a large number of atmospheric trace gas species using the solar occultation technique in the infrared and UV/visible spectral domain. However, two additional solar disk imagers (at 525 nm and 1020 nm) were added for a number of reasons, including the retrieval of aerosol and cloud products. In this paper, we present the first validation results for these imager aerosol/cloud optical extinction coefficient profiles, by intercomparison with profiles derived from measurements performed by 3 solar occultation instruments (SAGE II, SAGE III, POAM III), one stellar occultation instrument (GOMOS) and one limb sounder (OSIRIS). The results indicate that the ACE imager profiles are of good quality in the upper troposphere/lower stratosphere, although the aerosol extinction for the visible channel at 525 nm contains a significant negative bias at higher altitudes, while the profiles are systematically too high at 1020 nm. Both problems are probably related to ACE imager instrumental issues.