# Pseudoadiabatic lapse rate

From AMS Glossary

## pseudoadiabatic lapse rate

It is given by where Γ

_{ps}is the pseudoadiabatic lapse rate,*g*is gravitational acceleration,*r*_{v}is the mixing ratio of water vapor,*c*_{pd}and*c*_{pv}are the specific heats at constant pressure of dry air and water vapor,*L*_{v}is the latent heat of vaporization,*R*is the dry air gas constant, ε ≈ 0.62 is the ratio of the gas constants of dry air and water vapor, and*T*is temperature. The above lapse rate is usually within 1 percent of those shown under moist-adiabatic lapse rate and reversible moist-adiabatic lapse rate.