why does air cool when it rises through the atmosphere?

Answer 1

Take a unit of air and lower the pressure and the temperature will go down - if all other variables remain constant. As air rises in our atmosphere, pressure drops.

By the way, there are phenomena where temperature is higher at a higher elevation in a given region...

Answer 2

Note to ruvierejale:
It appears to me that people have given you a lot of inaccurate information in their responses. If you care about the accuracy of the information, you should do some on-line checking to make sure that you are not misled by people sharing their misunderstandings with you.
Good luck!

Now, here's what I believe is the correct explanation. This is based on the meteorology I studied during my flight training.

1. As a mass of air rises, it is moving into an area of lower pressure. (The air above it is less dense, hence the pressure is lower. So as the air mass rises it is moving into an area of lower pressure.)

2. Because the pressure on the air mass is decreasing, the air mass will expand.

3. When the air mass expands, it is doing work on the gases around it. (If you squeezed this air mass into a smaller area, you would be doing work on it as you compress it. When it expands, the opposite is happening. It is doing work on its surroundings.)

4. Because the air mass is doing work on the gas around it, it is giving up some of its energy. Specifically, its internal energy, or heat, is reduced. As a result, its temperature decreases.


Note: If the air is rising because it is hotter than (and therefore lighter than) the surrounding air, the cooling effect has an interesting result. If the air cools fast enough when it rises, it will become cooler than the air it is rising into. When this happens, it will tend to settle (dexcend), and will reach an equilibrium altitude where it stays.

However, althought the air's temperature decreases when it rises, sometimes it does not cool fast enough to make it cooler than the air it rose into. (Usually the air above is cooler, but it can be either a lot cooler or only a little cooler ... or sometimes warmer, if we have what's called an "inversion").

If the rising air is not cooling fast enough, it continues to be warmer than the air it rises into, and continues rising. Eventually it will rise high enough that it will have cooled to its "dew point," which is the lowest temperature at which it can contain the amount of humidity that is currently in it. After that, as the air mass continues to rise, it will cool further and its moisture will start to condense and form clouds.

When the rising air starts to form clouds, it does not cool as quickly (the condensing moisture gives up heat to the air, which reduces the rate of cooling). As a result, it tends to rise even faster, making more and more dense clouds. If this effect is strong enough, the clouds build into a thunderstorm.

Answer 3

heres a straight forward answer:

The sun's direct rays can't heat air, no-one really knows why, but when the sun's rays hit the ground, the reflection can heat air!! strange?
anyway thats why the air closer to the ground gets hot, and it gets thinner, therefore it rises

the reason it cools down when it rises is because all the air up high is cool (because the sun's rays can't heat it) and this cool air cools down the hot air.

Answer 4

Radiation of heat from the molecules. Heat is radiated out into space. The air pressure at higher altitudes is also lower, which also causes cooling. There is a greater space between the air molecules, this extra distance causes heat loss.

Answer 5

In a nutshell, statistical mechanics has it that molecules' speed is associated with their kinetic energy. A measure of their kinetic energy is temperature. The more energy there is in molecules' displacements, the hotter the gas is. When left to themselves like in atmosphere, a number of these molecules are statistically bound to go upwards, and fight gravity in so doing, hence losing kinetic energy. When this decreases, temperature decreases, and so does the number of molecules per volume unit. This is why air gets thinner as you climb higher in atmosphere.

Answer 6

It only cools up to an altitude of about 11000m. From 11000m to 21000m it remains stable at about -56deg C, after which it gets warmer with increasing altitude. Weird.

Answer 7

Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly 78% nitrogen, 21% oxygen, 0.93% argon, 0.04% carbon dioxide, and trace amounts of other gases, in addition to water vapor. This mixture of gases is commonly known as air. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night.

There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades away into space. Three quarters of the atmosphere's mass is within 11 km of the planetary surface. In the United States, persons who travel above an altitude of 50.0 miles (80.5 km) are designated as astronauts. An altitude of 120 km (75 mi or 400,000 ft) marks the boundary where atmospheric effects become noticeable during re-entry. The Karman line, at 100 km (62 mi), is also frequently used as the boundary between atmosphere and space.

The temperature of the Earth's atmosphere varies with altitude; the mathematical relationship between temperature and altitude varies between the different atmospheric layers:

>troposphere: From the Greek word "tropos" meaning to turn or mix. The troposphere is the lowest layer of the atmosphere starting at the surface going up to between 7 km (4.4 mi) at the poles and 17 km (10.6 mi) at the equator with some variation due to weather factors. The troposphere has a great deal of vertical mixing due to solar heating at the surface. This heating warms air masses, which then rise to release latent heat as sensible heat that further uplifts the air mass. This process continues until all water vapor is removed. In the troposphere, on average, temperature decreases with height due to expansive cooling.
>stratosphere: from that 7–17 km range to about 50 km, temperature increasing with height.
>mesosphere: from about 50 km to the range of 80 km to 85 km, temperature decreasing with height.
>thermosphere: from 80–85 km to 640+ km, temperature increasing with height.
>exosphere: from 500-1000 km up to 10,000 km, free-moving particles that may migrate into and out of the magnetosphere or the solar wind.
The boundaries between these regions are named the tropopause, stratopause, mesopause, thermopause and exobase.

The average temperature of the atmosphere at the surface of earth is 14 °C.

Atmospheric pressure is a direct result of the weight of the air. This means that air pressure varies with location and time, because the amount (and weight) of air above the earth varies with location and time. Atmospheric pressure drops by 50% at an altitude of about 5 km (equivalently, about 50% of the total atmospheric mass is within the lowest 5 km). The average atmospheric pressure, at sea level, is about 101.3 kilopascals (about 14.7 pounds per square inch).

Answer 8

because the air becomes thin.......and maybe because the air up there is already cold, also cause it is thin.....i think