Lapse Rate Calculator:
Enter the values of temperature difference, ΔT(°C) and altitude difference, Δz(km) to determine the value of lapse rate, L(°C/km).
Lapse Rate Formula:
The lapse rate is the rate at which atmospheric temperature declines as altitude increases in the Earth’s atmosphere. It is a key concept in meteorology and atmospheric science. The lapse rate varies based on different atmospheric layers and conditions, such as dry or moist air.
In the troposphere, the standard or average lapse rate is approximately 6.5°C for every kilometer of altitude increase, but this rate can change due to weather patterns, geographical features, or specific conditions in the atmosphere.
There are different types of lapse rates, such as the dry adiabatic lapse rate (DALR), which applies when air is unsaturated, and the moist adiabatic lapse rate (MALR), which applies when air is saturated. The lapse rate is important in understanding weather phenomena such as cloud formation, the stability of the atmosphere, and predicting temperature changes with altitude.
In general, the lapse rate is calculated by the difference in temperature divided by the difference in altitude. The equation can be applied using either a constant rate or a variable lapse rate, depending on the specific conditions. Understanding the lapse rate is crucial for various fields, including aviation, meteorology, and environmental sciences.
The lapse rate, L(°C/km) in degree Celsius per kilometres is calculated as the temperature difference, ΔT(°C) in degree Celsius divided by the altitude difference, Δz(km) in kilometres.
Lapse Rate, L(°C/km) = ΔT(°C) / Δz(km)
L(°C/km) = lapse rate in degree Celsius per kilometres, °C/km.
ΔT(°C) = temperature difference in degree Celsius, °C.
Δz(km) = altitude difference in kilometres, km.
Lapse Rate Calculation:
- An atmospheric temperature decreases from 20°C at sea level to -10°C at an altitude of 3 km. Calculate the lapse rate.
Given: ΔT(°C) = 20 – (- 10) = 30°C, Δz(km) = 3km.
Lapse Rate, L(°C/km) = ΔT(°C) / Δz(km)
L(°C/km) = 30 / 3
L(°C/km) = 10°C/km.
- Given: L(°C/km) = 5°C/km, Δz(km) = 4km.
Lapse Rate, L(°C/km) = ΔT(°C) / Δz(km)
ΔT(°C) = L(°C/km) * Δz(km)
ΔT(°C) = 5 * 4
ΔT(°C) = 20°C.