It's called a warm front.
Regions of cold heavy air are called highs. As cool air moves under warm air, the warm air is pushed upward.
Cool air typically flows under warm air due to the principle of convection, where cooler, denser air sinks while warmer, lighter air rises. This creates a cycle of air circulation where cool air replaces warm air near the surface.
The cold air pushes under the warm air.
When a cool air mass invades a warm air mass, it creates a boundary called a cold front. The denser cool air wedges under the warm air, forcing it to rise rapidly. This can result in the formation of thunderstorms, heavy rain, and strong winds along the front as the warm air is displaced.
Actually, cool air tends to be more dense and flow under warm air
The process you are referring to is called convection. Warm air rises because it is less dense than cool air, which causes it to displace the cooler, denser air and sink. This cycle creates a convection current that plays a key role in atmospheric circulation and weather patterns.
This phenomenon is called a temperature inversion. It typically occurs when a stable layer of warm air sits atop cooler air near the surface, preventing vertical mixing and trapping pollutants in the lower atmosphere.
The process of cool air trying to replace warm air creates convection currents, where warm air rises and cool air sinks. This creates a cycle of air movement that helps distribute heat more evenly in a space.
If they are both under the same pressure and are the same in volume, then, yes, warm air has fewer molecules
By solar energy
Because warm air is less dense then cool air.
When a cool air mass meets and replaces a warm air mass, it results in a cold front. The cool air pushes under the warm air, forcing the warm air to rise. This can lead to the formation of clouds, precipitation, and a drop in temperature as the warm air is displaced by the cooler air mass.