## adiabatic lapse rate

in atmospheric chemistry
https://doi.org/10.1351/goldbook.A00144
The rate of decrease in temperature with increase in altitude of an air parcel which is expanding slowly to a lower atmospheric pressure without exchange of heat; for a descending parcel it is the rate of increase in temperature with decrease in altitude. Theory predicts that for dry air it is equal to the @A00051@ of gravity divided by the specific heat of dry air at constant pressure (approximately $$9.8\ ^{\unicode{x26ac}} \text{C}\ \text{km}^{-1}$$). The moist @A00141@ lapse rate is less than the dry @A00141@ lapse rate and depends on the moisture content of the air mass.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2171 [Terms] [Paper]