Adiabatic processes are those in which there is no net heat transfer between a system and its surrounding environment (e.g., the product of pressure and volume remains constant). Because it is a gas, air undergoes adiabatic heating and cooling as it experiences atmospheric pressure changes associated with changing altitudes. Increasing pressure adiabatically heats air masses, falling pressures allow air to expand and cool.

Adiabatic heating and cooling is common in convective atmospheric currents. In adiabatic heating and cooling there is no net transfer of mass or thermal exchange between the system (e.g., volume of air) the external or surrounding environment. Accordingly, the change in temperature of the air mass is due to internal changes.

In adiabatic cooling, when a mass of air rises—as it does when it moves upslope against a mountain range—it encounters decreasing atmospheric pressure with increasing elevation. The air...