Abstract
A unified approach to the thermodynamics of cloudy air, cloud-clear air mixing processes, atmospheric thermodynamic equilibrium structure and instability is formulated, using a new concept: the Saturation Point. This permits the representation of mixing processes and virtual potential temperature isopleths for clear and cloudy air on a thermodynamic diagram (a tephigram is used here), and their comparison with the atmospheric stratification. Illustrative examples will be given for evaporative mixing instability and convective equilibrium structure for stratocumulus, cumulus and cumulonimbus convection and convection in the incipient severe storm atmosphere.
