Mountain top temps

[1Chavez]

Why does air at lower altitudes tend to be warmer than air at high altitudes?

[rekstout]

This is just a guess...

The grounds absorbs a massive amount of thermal energy which is released back into the air, thus warming it. At higher altitudes, this effect is less noticeable since there is less land mass to radiate thermal energy.

[1Chavez]

Sounds good, but wouldn't a higher altitude absorb more of the sun's energy since it wouln't be filtered through the atmosphere?

[rekstout]

Yes, I though the same thing after I had posted my reply - the only thing I can think of is that the overall insulating effect of the air above contributes to the maintenance of a higher temperature at sea level.

[incitatus]

the effect is complex. the ground has a large effect but the atmosphere plays a part. At high altitudes the atmospheric pressure is lower. Thjis means the numbers of gas molecules per litre of air is less (according to the ideal gas law pv=nrt thus p is proportional to n/v). The gases in air that absorb radiant heat, such as water and co2 are therefore spread out, can absorb less heat, and so are at lower temperature. what heat there is can be reradiated in two directions, up or down if it is reradiated upwards it is almost all lost. if downwards it heats the lower atmosphere.