Why does the temperature get cooler the higher you go up a mountain?

Answer 1

The sun causes very little direct heating of the air, you can tell by the way that light passes through air.

The light from the sun falls on the ground and, if it is not reflected, heats up the ground (or the sea). Heat is radiated from the ground as infra-red. Some infra-red radiates back into space but many of the constituents of the atmosphere either reflect infra-red back down or absorb it, this causes some heating of the air. Air is also heated by conduction when it is in contact with the ground. So we have the heat source at the bottom of the atmosphere.

The amount of heat energy held by the atmosphere depends upon water content. Wet air holds more heat than dry air. As we go up in altitude, the water vapor content of the atmosphere falls and it's capacity to hold heat also falls.

The combination of all these facts results in the air being warmer at low altitudes.

Answer 2

It all has to do with air pressure. The higher you go in elevation and altitude, the lower the air pressure drops.

But the question is, why does this affect temperature? Temperature is a measurement - believe it or not - of kinetic energy. The more kinetic energy, the higher the temperature, and the less kinetic energy, the lower the temperature. But what does this have to do with pressure? Air has mass, and is made of tiny particles that are constantly moving with kinetic energy. The more you cram the air particles together (with higher pressure), the more they bounce off one another and have higher kinetic energy. The further away you move from the earth's surface (and climb up the mountain), the fewer air particles you'll have (which is why mountain climbers take supplemental oxygen on really high climbs), and the less often they'll bump into one another.

Some people talk about the core of the earth heating the air, and the sun's direct rays, yadda yadda yadda - those effects are insignificant.

Below is a link that explains the chemical/physical relationship between Pressure and Temperature, if you'd like to learn it. Gay-Lussac was one of the scientists whose formula was later used for the Ideal Gas Law (which compares relationships between Pressure, Volume, and Temperature).

I hope this is helpful!

Answer 3

Probably there are more than one reason. One I can think of is the fact that the closer to the ground you are, the more you get the radiating heat from the earth's crust. As the earth itslef produces heat and the sunlight is reflected from the earth's crust, you get more heat when you are on the surface than when you are in air.

Edit: Most of the answers mention something like the radiation from the earth's surface but one claims that it is so insignificant that the only significant factor is the air pressure. I am quite puzzled with that. If the sunlight is so insignificant how do you explain the dramatic temperature changes between seasons? Does the air pressure change that much between winter and summer, or between day and night?

Answer 4

The earth is 92 million miles from the sun, but from outer space to surface of the earth is only about 20 miles. In terms of distance from the sun, they are at the same location.

The air is like a slinky spring when you hold it so the axis of extension is perpindicular to the ground. Its a lot denser at the bottom. Also gasses that are denser than the air, like water vapor, are attracted to the earth, and end up at lower altitudes.

That is meaningful because the energy transfer from the sun is radiative (light carries the energy). The thicker the air is, the more sunlight it can absorb (more atoms in the way). The more stuff there is in the air the more of the sunlight it can absorb. The thicker the air is, the more slowly the heat can leak through it to where ever the cold is.

So its cooler cause theres less air & stuff in the air to soak up the sunlight, and because theres less mass blocking the transfer of that energy back out of the air.

Answer 5

It is because air temperature falls as you gain altitude. I think it goes cooler by about 3 degree Centigrade for each 1000 feet.


This is also why clouds are all at the same level. It is the height at which the air temperature falls to dew point. Dew point is the temperature when the air can no longer hold all the water that's in there so it starts to rain. It often gives clouds that flat underside.

Answer 6

Mainly because of the absorbtion and reflection of the sun's energy.

At ground level there is a large mass available to absorb and radiate the heat, however, as you climb there is less ground mass available and therefore less absorbed and radiated energy.

As you proceed into outer space temperature drops to around absolute zero provided you are not in the direct light of the sun, however if you are in direct sunlight and because there is no insulating atmosphere, the temperature you would feel can be many hundreds of degrees because you are providing the mass to absorb the sun's energy.

Answer 7

Because air cools when it expands and warms when it is compressed. Air flowing up the windward side of a mountain expands as the pressure falls, hence cools. Flowing down the leeward side, it is compressed and warms. The expansion and compression is called adiabatic, meaning that heat is not explicitly added or removed. When air expands, it does work on its surroundings, hence (since energy is conserved) it must get cooler.

Answer 8

Air is cooler at higher altitude because there are fewer molecules at higher elevations than at lower elevations. Since there are fewer molecules, the molecules have to travel farther in order to reach each other. The bumping and rubbing of these molecules creates heat, and since there are more available to bump and rub at lower altitudes than at higher altitudes the temperature at higher altitudes are lower than lower altitudes.

This is also why in space it is freezing cold, but it is several hundred miles closer to the sun than the surface of the Earth. Molecules are very far apart, and they may travel miles before bumping into another molecule to create heat.

The same reason why it is harder to breathe at higher altitudes. Air molecules are too far apart.

Answer 9

The air at the ground is at a higher pressure than air higher up; this is because the air at the ground is compressed by the weight of all the air above it. Air weighs quite a lot: A square column of air one meter across weighs ten tonnes! The air pressure decreases steadily as you go up, since there's less air pressing down from above, until you reach zero pressure, which is outer space.

Answer 10

the earth is a hot thing and teh sky is a cool thing. the base of teh mountain is hot as it is attached to the earth and the top is cool cos it is close to the sky.

no not really.

i think it is something to do with pressure and temperature being linked. i should have paid more attention when i visited the science museum - or perhaps i should just go again sometime...