Svensmark, Henrik1; Enghoff, Martin Andreas Bødker1; Pedersen, Jens Olaf Pepke1
1 National Space Institute, Technical University of Denmark2 Solar System Physics, National Space Institute, Technical University of Denmark3 Sunclimate, National Space Institute, Technical University of Denmark
In experiments where ultraviolet light produces aerosols from trace amounts of ozone, sulfur dioxide, and water vapor, the relative increase in aerosols produced by ionization by gamma sources is constant from nucleation to diameters larger than 50 nm, appropriate for cloud condensation nuclei. This result contradicts both ion-free control experiments and also theoretical models that predict a decline in the response at larger particle sizes. This unpredicted experimental finding points to a process not included in current theoretical models, possibly an ion-induced formation of sulfuric acid in small clusters.
Physics Letters a, 2013, Vol 377, Issue 37, p. 2343-2347