gen-define-atmospheric-stability-and-give-one-short-worked-examp-63b7

Define atmospheric stability and give one short worked example.

# Atmospheric Stability **Definition:** Atmospheric stability refers to the atmosphere's resistance to vertical motion. It describes whether an air parcel, once displaced vertically, will continue to rise/sink (unstable), return to its original position (stable), or remain at its new position (neutral). **Key principle:** Compare the temperature of a rising/sinking air parcel to the surrounding environment. - **Stable:** Parcel is cooler (denser) than surroundings → sinks back - **Unstable:** Parcel is warmer (less dense) than surroundings → continues rising - **Neutral:** Parcel has same temperature as surroundings --- ## Worked Example **Given:** - Surface air parcel at 20°C - Environmental lapse rate: 5°C/km - Dry adiabatic lapse rate (DALR): 10°C/km - Parcel rises 1 km **Solution:** *Parcel temperature at 1 km:* - Cools at DALR: 20°C - 10°C = **10°C** *Environmental temperature at 1 km:* - Cools at 5°C/km: 20°C - 5°C = **15°C** **Result:** The parcel (10°C) is **cooler than its surroundings (15°C)**, so it's denser and will sink back down. **Conclusion:** The atmosphere is **STABLE** because the environmental lapse rate (5°C/km) is less than the DALR (10°C/km).