Why/how does uneven atmospheric heating create pressure differences in the atmosphere, causing wind? Maybe it's because everything we studied in thermodynamics involved a series of equilibrium states, but I just can't get my head around it. If you heat a closed cylinder of gas, it makes sense why the pressure of the gas increases, faster molecules on average means more forceful impacts with the walls. But if you slowly heat a cylinder of gas closed with a piston that is free to move, the pressure inside the cylinder remains the same. I know tiny pressure differences exist in natural convection, but it's all jumbled up in my head.
Can /sci/ help a confused anon out?
I'm going to sleep now but I'll check back tomorrow morning.