Dry adiabatic laps rate: the rate of temperature change with altitude in a dry parcel of air with, possibly, water vapor, but without liquid moisture in the form of fog, droplets, or clouds. Calculated according to special equations. Average DALR is 5 K/km.
Environmental lapse rate: the rate of temperature decrease with increasing altitude in the stationary atmosphere. From sea level to 11 km the ELR for "international standard atmosphere" is 6.49 K/km.