Affiliation: | 1. CESR, Université Paul Sabatier, 31029 Toulouse, France;2. Polar Geophysical Institute, 184200, Apatity, USSR;3. IZMIRAN, 142092 Troitsk, USSR;4. ESTEC, Noordwijk, The Netherlands;5. Finnish Meteorological Institute, Helsinki, Finland;6. Technical University of Graz, Graz, Austria;7. Royal Institute of Technology, Stockholm, Sweden |