This was asked by my 12 year old daughter while we were driving through the mountains the other day. It was 90° for several hours of our trip, then we reached the Blue Ridge mountains and the temperature dropped about 10 degrees. Seemed to happen once we reached about 2500 feet above sea level. I rather clumsily tried to give her an answer about air at higher altitudes being less dense, but quickly realized I didn’t have all the facts. Hoping someone can help me explain it better, so I can break it down better and explain it to my daughter.
In: Physics
Lots of people think the sun heats the air directly. It doesn’t. The sun heats the ground, then the ground heats the air, and the air acts like a blanket to the coldness of space. As you go higher up, the air gets thinner. Thinner air means a thinner blanket and colder temperatures. Hope this helps!
Temperature is nothing more than the movement speed of molecules. For example, consider a box filled with air. The air molecules fly around in that box and they hit each other and the walls. Each molecule may move at a different speed, but the average speed stays the same.
Now imagine what happens if we make the box smaller, for example by pressing in one of the walls. This will decrease the volume of the box, but the content stays the same, so the density increases.
By pressing in the wall, you will accelerate the molecules hitting that wall, they will bounce back with increased speed. So after the decease in density, the molekules inside the box move faster, they now have a higher temperature.
There is a nice experiment that shows just that, you can take some marbles and put them inside of some rectangle. Shake that rectangle to get the marbles moving, these are the molecules of the gas. Now you increase the density by pushing one of the sides of the rectangle in: the marbles will move a little bit faster. However you have to be quite fast to see that, otherwise they will just slow down because of friction. I somehow can’t find a video of that experiment online..
And just an additional fun fact: There are certain weather events where it’s actullay warmer at higher latitudes. These are called inversions (literally because the temperature profile is inverted). These occur in fall or winter, when fog is forming in the valleys, which doesn’t let the sun through, so it is cool and moist there. Higher in the mountains, there is no fog, so it’s sunny and warm.
Complicated question.
First it gets cooler down to 0′. Then it goes back up super hot in the ionosphere, before cooling back down again in space.
it’s because of the land area.
the sun doesn’t heat the air directly, it heats the ground, and then the ground heats the air. if you go up a mountain, there is simply less ground area for the sun to heat up then if you were, say, in the Great Plains of the Midwest.
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