WHY MOUNTAINS ARE COLDER THAN PLAINS?
The distance to the sun has absolutely nothing to do with this. The fact is that the temperature sinks with altitude with an average of 0.65 C per 100 meter (3 F per 1,000 ft) The reason is: Air doesn’t get warmed up by the sun’s energy. At least, not at our under the stratosphere. What gets warmed up is the ground. That warms up a thin layer of air right above it and since warmer air is lighter, it rises. But because the higher you get, the lesser the atmospheric pressure is, that rising air cools down by the so-called adiabatic effect. This is the same thermodynamic principle that cools down your fridge when a compressed coolant is released through a nozzle. Therefore the higher you get, the colder it is. At the altitude an airliner flies, the outside temperature is around -50 C (-58 F). But sometimes things are different. If there is no wind at all, during the night the cold air from the hills surrounding a valley will sink down because colder air being denser, is also heavier. In f
