The effects of simplifications in the derivation of the Köhler equation describing the equilibrium saturation ratio for solution drops as a function of size on the activation of a population of CCN in an updraft are examined. Simulations based on the conventional form of the Köhler equation underestimate the numbers of droplets nucleated in a 2 m s−1 updraft by roughly 10%. The most simplified form of the Köhler equation using the van't Hoff factor for dilute solutions estimated the number of droplets nucleated to within 1%.

This content is only available as a PDF.