Köhler theory describes the process in which
water vapor condenses and forms liquid cloud drops, and is based on equilibrium
thermodynamics. It combines the
Kelvin effect, which describes the change in saturation vapor pressure due to a curved surface, and
Raoult's Law, which relates the saturation vapor pressure to the solute. It is an important process in the field of
cloud physics. It was initially published in 1936 by
Hilding Köhler, Professor of Meteorology in the Uppsala University.