The condition when the lapse rate of air is greater than the dry adiabatic rate of cooling is called?

Correct option is B

Absolute instability occurs when the environmental lapse rate (the rate at which temperature decreases with altitude) is greater than the dry adiabatic lapse rate (DALR), which is 10°C per 1000 meters. In this situation, a rising air parcel will always be warmer than its surroundings, leading to continuous upward movement, which results in unstable atmospheric conditions. This condition promotes strong convection, often leading to thunderstorms and severe weather events.

• Lapse Rate Types:

  • Environmental Lapse Rate (ELR): The actual rate of temperature decrease in the atmosphere.
  • Dry Adiabatic Lapse Rate (DALR): The rate at which dry air cools as it rises (10°C per 1000m).
  • Moist Adiabatic Lapse Rate (MALR): The rate at which saturated air cools (varies from 4°C to 7°C per 1000m).

• Absolute Instability Occurrence:

  • When ELR > 10°C per 1000m, the atmosphere is highly unstable.
  • Leads to convection, cloud formation, and storms.

1. (a) Absolute stability – Incorrect

   • Occurs when ELR < MALR, meaning a rising air parcel is cooler than the surroundings, leading to sinking motion.

2. (c) Conditional instability – Incorrect

   • Occurs when DALR > ELR > MALR, meaning the air is stable for dry air but unstable for saturated air.

3. (d) Neutral equilibrium – Incorrect

   • Occurs when ELR = DALR, meaning the rising air neither accelerates nor sinks back.