ACE water vapour validation

1 Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Brussels, Belgium 2 Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada 3 Department of Physics, University of Toronto, Toronto, Ontario, Canada 4 Department of Chemistry, University of York, UK 5 Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada 6 Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA 7 Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA