1. Research Department; Alfred Wegener Institute for Polar and Marine Research; Potsdam; Germany
2. Jet Propulsion Laboratory; California Institute of Technology; Pasadena; California; USA
3. European Ozone Research Coordinating Unit, Department of Chemistry; University of Cambridge; Cambridge; UK
4. Department of Chemistry and Chemical Biology; Harvard University,; Cambridge; Massachusetts; USA
5. Institut für Umweltphysik; University of Heidelberg; Heidelberg; Germany
6. Atmospheric and Environmental Research, Inc.; Lexington; Massachusetts; USA
7. Service d'Aeronomie-CNRS; Université Pierre et Marie Curie; Paris; France