Fog Formation due to Self Nucleation

Discussing the fog formation in adiabatically expanded dust- and ion-free moist air, the relation between the droplet size, the time required for the growth of droplets and the rate of self-nucleation are derived, based on the assumption of a simple model process. These relations, when applied to the case of adiabatic expansion at the so-called cloud limit, give a plausible order of magnitude for these quantities. In particular, the discrepancy between the current theory of self-nucleation and the known critical expansion ratio 1.37 can be eliminated.