Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?
Thermodynamics – Why Is There Less Temperature at High Altitude?
atmospheric sciencetemperature
atmospheric sciencetemperature
Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?
Best Answer
Crazy Buddy is quite correct that it's because gas expands and cools as it rises, but there is more to it than that.
For something to be be heated it must either absorb EM radiation, or it must be heated by some hot object it's in contact with. Air doesn't absorb light so it can't be directly heated by sunlight. Instead the sunlight passes through the air and heats the ground, and the ground heats the air.
The expansion comes in because the hot air that is heated by the ground rises. However as it rises it's volume increases and therefore it's temperature decreases. So the decrease in temperature with height is indeed due to expansion, but this is only the case because air is heated from below by the ground.
If air absorbed light directly it would heat up independantly of the ground and we would not see the same temperature variation with height. In fact exactly this effect happens in the stratosphere. In the upper reaches of the stratosphere ozone molecules absorb ultraviolet light and heat up, and in the stratosphere temperature increases with height instead of decreasing.