The top of a mountain is closer to the sun, why is it warmer at sea level?

Question

my husband claims it is thermal conductivity and I don't know what that is and he won't tell me. He says to ask my brother.

Answer 1

This is due to two reasons:

At high altitude, the atmospheric pressure is much less than sea level, because gravity causes most of the atmosphere to settle towards the Earth. In fact, over 50% of the atmosphere resides under the five mile mark above the Earth. As a result, the air is less dense the higher you go.

Now it is true that the sun heats this air, but since there is less pressure, it expands as it rises much more easily than the air does near the Earth. As a result of this expansion, the air cools.

Answer 2

This is a simple, and a complex question. The simple answer is that the 'heat' we generally think about, come from the surface of the earth. The sun irradiates the surface, which re-radiates the atmosphere, but at a lower wavelength. This lower wavelength is what we think of as heat. So the atmosphere is heated from below, primarily.

The second part deals with the equation of state for gases in the atmosphere. You may recall, for an ideal gas

PV = nRT

As pressure decreases in the above, and volume is kept steady, we can either lower the number of molecules (n) or decrease the temperature (T), or both. So as you go up the mountain, the pressure decreases, and the density plus temperature decrease as well.

There are more complicated issues, but that will probably satisfy for your tight lipped (I assume he just doesn't know jack) mate. No offense, but it has very little to do with thermal conductivity.

Added:
One note on 'thermal conductivity' -- At high altitude, with lower pressure and decreased density, the air retains much less moisture. This water vapor is the container of heat. So, under certain conditions, with a nice fleece jacket you may stay warmer longer on top of the mountain than at the base, even though it is colder on top (assuming its very cold at both locations).

Answer 3

As you climb higher the air pressure decreases. This means there is less air. The warm air is a sensation caused by infrared rays that heat up molecules of air. You feel these molecules on your skin and have the sensation of a hot day. Because there is less air at higher altitudes (as I have already stated), there are fewer molecules to heat, and therefore less heat. That is called thermal conductivity because the air molecules conduct the heat, and the fewer molecules there are, the less heat you feel.

Answer 4

I think it has to do with the air being thinner higher up in the atmosphere. The air molecules are spread farther apart so they produce less kinetic energy and thus less heat than at sea level. Kinetic energy is higher at sea level. I am not sure this is right but it is what I thought of, look at the other answers and decide for yourself.

edit kinetic energy is the energy of motion that has the potential to produce heat.

Answer 5

Thermal conductivity is right. The heat are contained in the body of water and the larger the body of water the harder it is to get really cold. That is why it is hard to freeze an ocean

Answer 6

Because the air is thinner at the top of the mountain so it stays colder at a higher altitude.

Answer 7

Sun is actually very far away.. many millions km.. like many!! however did you ever thing there the volcanoes a bit closer?

Warm air can hold more water vapor than cold air.

And if husband cant answer. maybe himself done not know how the answer..

Answer 8

The sun reflects off of the surface. The heat is stronger at that surface. To top of the montain is further away from the reflected rays of the sun.

Answer 9

im sorry, i have no idea what thermal conductivity is, at least not by name. its colder though because there are so fewer air molecules to retain the heat. maybe thats what thermal conductivity is, maybe thats no where close

Answer 10

The water holds heat better than land. And yes, the air is thinner the higher you go, so it is colder.