Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 4 2 2004 10.5194/acp-4-385-2004 http://www.atmos-chem-phys.net/4/385/2004/ http://www.atmos-chem-phys.net/4/385/2004/acp-4-385-2004.html http://www.atmos-chem-phys.net/4/385/2004/acp-4-385-2004.pdf 385 389 2004-02-27 Formation of binary ion clusters from polar vapours: effect of the dipole-charge interaction A. B. Nadykto F. Yu Atmospheric Sciences Research Center, State University of New York at Albany, 251 Fuller Road, Albany, NY 12203, USA Formation of binary cluster ions from polar vapours is considered. The effect of vapour polarity on the size and composition of the critical clusters is investigated theoretically and a corrected version of classical Kelvin-Thomson theory of binary ion-induced nucleation is derived. The model predictions of the derived theory are compared to the results given by classical binary homogeneous nucleation theory and ion-induced nucleation theory. The calculations are performed in wide range of the ambient conditions for a system composed of sulfuric acid and water vapour. It is shown that dipole-charge interaction significantly decreases the size of the critical clusters, especially under the atmospheric conditions when the size of critical clusters is predicted to be small.