1. Institute for Atmospheric Science, School of Earth and Environment; University of Leeds; Leeds UK
2. Alfred Wegener Institute for Polar and Marine Research; Research Unit Potsdam; Potsdam Germany
3. Arctic Research Centre; Finnish Meteorological Institute; Sodankylä Finland
4. Institut für Atmosphäre und Umwelt; J. W. Goethe-Universität Frankfurt; Frankfurt Germany
5. Central Aerological Observatory; Moscow Russia
6. Myasishchev Design Bureau; Moscow Russia