]> That portion of the total potential energy that may be converted to kinetic energy in an adiabatically enclosed system. The maximum energy available to an ascending parcel, according to parcel theory. The height within which some parameter, such as pressure or density, decreases by a factor 1/e. The pressure of a vapor in equilibrium with its condensed phase (liquid or solid). The vapor pressure of a system, at a given temperature, for which the vapor of a substance is in equilibrium with a plane surface of that substance's pure liquid or solid phase; that is, the vapor pressure of a system that has attained saturation but not supersaturation. The pressure exerted by the molecules of a given vapor. The transport of mass motion momentum solely by the random motions of individual molecules not moving together in coherent groups. The use of the hydrostatic equation as the vertical equation of motion, thus implying that the vertical accelerations are small without constraining them to be zero. An instability due to the buoyancy force of heavy fluid over light fluid overcoming the stabilizing influence of viscous forces. The ability of a fluid at rest to become turbulent or laminar due to the effects of buoyancy.