Max-Planck-Institut für Kernphysik, P.O. Box 103980, 6900, Heidelberg, Federal Republic of Germany
Abstract:
First mass-spectrometric composition measurements of atmospheric ions between 3250 and 11700 m altitude are reported. They reveal the presence of very massive cluster ions, the majority of which cannot be attributed to a single hydrated ion family like, for example H+(H2O)n. The observed fraction of very massive ions increases with decreasing altitude. Masses as large as about 540 amu were observed at 8200 m altitude. Implications of the observations for ion and nucleation processes are discussed.