Hi, please could someone explain how a convection current occurs. There are a few different explanations I have come across which in my view are not consistent. Warm air rises, becomes less dense and due to its buoyancy will rise. What mechanism causes the cooler air to replace this air? Some sources say it is 'sucked in' due to pressure differences whilst others say the cooler air from above sinks. I have looked at another thread (https://www.physicsforums.com/showthread.php?t=676317) but its a bit too complex for me but seems to suggest it has nothing to do with pressure differences?