Why is it colder at the top of a mountain despite being closer to the sun ?
In: 11
First let’s talk about pressure. Pressure is force divided by area, which is why your cat laying on your lap is much more comfortable than them standing on it, same force (weight), concentrated into a much smaller area. You can kind of think of pressure as “force density.” When it comes to air pressure, you get air pushing against itself, and most of that cancels itself out, except for the force pushing down from gravity. Wherever you are, the air pressure you feel is that of the weight of how much air is above you (divided by the surface area of the top of your head).
Now let’s talk about thermodynamics. There’s a relationship between pressure, density, and temperature. The temperature of air (or whatever) is essentially the average speed of the molecules in it. When pressure goes down, temperature goes down, since pressure is just how hard air molecules are hitting things, and things hit less hard when they’re moving slower.
Putting these together, when you go higher, there’s less air over you because more of it is below you. Less air means less weight, less weight means less pressure, less pressure means lower temperature. This difference is much, much bigger than any other change you’ll get when you climb a mountain.
Latest Answers