Lapse rates and stability
10 min read
Three lapse rates
Dry adiabatic (DALR): rising unsaturated air cools about 3 °C per 1,000 ft (9.8 °C per km).
Saturated adiabatic (SALR): rising saturated air cools more slowly, about 1.5–1.8 °C per 1,000 ft low down (0.6 °C per 100 m is the usual average), because condensation releases heat. It gets closer to the DALR higher up and in colder air.
Environmental (ELR): how the real air around us changes with height, measured by radiosondes. ISA uses 2 °C per 1,000 ft.
IN THIS LESSON
- Stable or unstable
- What you see
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