In the treatment of stability and instability so far, only air that was either dry or saturated was considered. Under normal atmospheric conditions natural air is unsaturated to begin with, but becomes saturated if lifted high enough. However, if the lapse rate for a column of natural air lies between the dry adiabatic lapse rate and the saturation adiabatic lapse rate, the air may be stable or unstable, depending upon the distribution of moisture. Log P diagram.
Positive areas are conducive to instability.
Negative areas are conducive to stability. Conditional instability may be one of three types. For density to increase with altitude, the lapse rate must be equal to or exceed 3.42 C per 100 meters. An example of this condition is found to exist near the surface of the earth in a road mirage or a dust devil. Integrated Publishing's Official Web Page Click here for a current index of everything on this web site.