Question

Why does temperature fall with elevation ?

Answer 1

Answer:

• As you increase in elevation, there is less air above you thus the pressure decreases. As the pressure decreases, air molecules spread out further (i.e. air expands) and the temperature decreases. If the humidity is at 100 percent (because it's snowing), the temperature decreases more slowly with height.

Answer 2

When we move up a hill, we notice a fall in temperature. This fall in temperature with elevation is primarily due to two reasons.

• With increase in elevation, the atmospheric pressure falls. Fall in pressure implies that the temperature also falls [Pressure is directly proportional to Temperature and vice versa].

• With increase in elevation, the concentration of greenhouse gases decrease (Water vapor and carbon dioxide fall sharply with elevation). Hence the heat absorption capacity of atmosphere will also decrease.

This sort of fall in temperature with elevation is called Temperature Lapse and the rate at which it happens is called Temperature Lapse Rate or simply Lapse rate.