Lapse Rate

From Aviation Wiki

Environmental Lapse Rate

  • actual change of temperature with altitude for the stationary atmosphere.
  • the negative of the actual change of temperature with altitude of the stationary atmosphere at a specific time and specific location.
  • the ICAO defines an international standard atmosphere (ISA) with a temperature lapse rate of 1.98 °C/1,000 ft from sea level to 11 km .

Dry Adiabatic Lapse Rate

  • negative of the rate at which a rising parcel of dry or unsaturated air changes temperature with increasing height.
  • Unsaturated air has less than 100% relative humidity; i.e. its temperature is higher than its dew point.
  • 3°C/1000'

Saturated Adiabatic Lapse rate

  • When the air is saturated with water vapour (at its dew point), the moist adiabatic lapse rate (MALR) or saturated adiabatic lapse rate (SALR) applies.
  • 1.5°C/1000'



  1. [1]Lapse Rate - Wikipedia

[[Category: Weather]