Enter the specific heat of the air or fluid being analyzed and the acceleration due to gravity to calculate the lapse rate.

## Lapse Rate Formula

The following formula is used to calculate a lapse rate.

L = g / Cp
• Where L is the lapse rate (C/km)
• g is the acceleration due to gravity (9.81m/s^2)
• Cp is the specific heat of the gas at constant pressure

To calculate a lapse rate, divide the acceleration due to gravity by the specific heat capacity of the gas.

## Lapse Rate Definition

A lapse rate is defined as the rate at which an atmospheric variable such as temperature changes with a change in altitude.

## Why does lapse rate occur?

A lapse rate occurs because as a change in altitude occurs, a change in air density occurs. The less-dense air causes changes in pressure and temperature. The change in pressure is caused by the effect of gravity acting on the air.

## Lapse Rate Example

How to calculate lapse rate?

1. First, determine the acceleration due to gravity.

On earth this is equal to 9.81 m/s^2.

2. Next, determine the specific heat.

Calculate the specific heat of the gas.

3. Finally, calculate the lapse rate.

Calculate the lapse rate using the equation above.

## FAQ

What is lapse rate?

A lapse rate is a measure of the change in temperature with respect to an altitude of a gas.