ADIABATIC LAPSE RATE

The theoretical rate at which the temperature of the air changes with altitude. The temperature change is due to the pressure drop and gas expansion only, and no heat is considered to be exchanged with the surrounding air through convection or mixing. The Dry Adiabatic Lapse Rate for air not saturated with water vapor is 0.98C per 100 meters (5.4F per 1,000 feet). The Wet Adiabatic Lapse Rate for air saturated with water vapor is about 0.60C per 100 meters (3.3F per 1,000 feet).