gen-define-adiabatic-lapse-rate-and-give-one-short-worked-exampl-4975

Define adiabatic lapse rate and give one short worked example.

# Adiabatic Lapse Rate **Definition:** The adiabatic lapse rate is the rate at which atmospheric temperature decreases with altitude when an air parcel rises (or increases when it descends) without exchanging heat with its surroundings. There are two types: - **Dry Adiabatic Lapse Rate (DALR)**: ~9.8°C/km or ~10°C/km (when no condensation occurs) - **Saturated Adiabatic Lapse Rate (SALR)**: ~6°C/km (varies with temperature and pressure; when condensation releases latent heat) ## Worked Example **Problem:** An unsaturated air parcel at ground level (0 m) has a temperature of 25°C. If it rises to an altitude of 2000 m without condensing, what will its temperature be? **Solution:** Using the dry adiabatic lapse rate (DALR = 10°C/km): Temperature change = DALR × altitude change Temperature change = 10°C/km × 2 km = 20°C Final temperature = Initial temperature - Temperature change Final temperature = 25°C - 20°C = **5°C** The air parcel will have cooled to 5°C at 2000 m altitude.