Why cooler higher altitude

At sea level, the pressure is around At five thousand feet it's around While humans are comfortable at either level, that's quite a change in pressure. For gases, a change in pressure means a change in temperature. Depending on the conditions, there can be a lot of ways to look at this. One is that pressure is an outside force, and pumps energy into the thing it is pressurizing.

Looked at that way, it's natural that gas molecules under high pressure would be at a higher energy level than gas molecules under less pressure.

Another is that with a decrease in pressure gas often increases in volume. If the same number of gas molecules are in a bigger space, they don't jostle into each other as much, and their total kinetic energy is spread out over a larger area, lowering the average temperature.

It is this lower pressure at higher altitudes that causes the temperature to be colder on top of a mountain than at sea level. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe.

Forces of Nature. Atmospheric Science. Lower pressure at higher altitudes causes the temperature to be colder on top of a mountain than at sea level. Pictured is Mount Everest behind the mountain of Nuptse. Air pressure can best be described as the weight of the air molecules that press down on the Earth. But as it does, the atmospheric pressure decreases, the air expands, and it cools.

Synopsis: During the summer heat, many vacationers head to the mountains to cool off. But if heat rises and mountains are closer to the sun, why is it cooler at elevation?

At a ski resort at 10, ft altitude, that number drops to In a passenger jet at 40, ft, the air above you only weighs 2. ABC Australia Science. Discover the natural wonders of Earth on over radio stations nationwide. Cooler in the Mountains. Download PDF zip file. Summer snow in the mountains and green crops in the valley illustrate the temperature differences that occur in mountainous regions.

The answer may surprise you. Not exactly. It has more to do with air pressure. Background: Cooler in the Mountains Synopsis: During the summer heat, many vacationers head to the mountains to cool off. Instead, the sun emits solar radiation as electromagnetic energy such as X-rays; radio waves; and ultraviolet, infrared, and visible light.