How does the atmosphere rotate with the Earth on its axis? There are no forces acting on it that would be strong enough to keep it moving with the ground. Gravity acts perpendicular to the direction of rotation, so it would not be able to cause this motion. It would only be able to keep the atmosphere from drifting outside of Earth's gravitational field. Viscosity would not be responsible, or else moving anything through the atmosphere would pull the entire atmosphere above it with it. That is, in order for the atmosphere to be pulled with Earth, each point on the ground would be dragging the atmosphere above it. However, if this were the case, then anything like a car or plane would be able to do the same, but they obviously cannot. And even if the atmosphere somehow got forced into this motion by some other means, viscosity/friction would have slowed this motion until there was only a small boundary layer near the surface that was affected at all, while the rest would be moving at high speeds relative to the ground. Imagine water flowing through a pipe, or reverse it so the pipe moves relative to the water to make it more similar to the Earth/atmosphere. If the pipe is moving, then imagine adding pressure to get the water up to the same speed as the pipe, and then remove that pressure, would the water keep moving with the pipe forever like our atmosphere? Furthermore, even if we were to assume that somehow there was a force keeping the atmosphere relatively stationary to the ground, this would create an atmosphere that does not match what we have around us. Each point on the Earth is not the same distance from the axis of rotation, so the speed of rotation is 0 mph at the poles, and increases to over 1000 mph at the equator. This means the atmosphere would have to be moving at different speeds depending on where it was, which would result in a pressure gradient with highest pressure at the poles and the lowest pressure at the equator. This would cause the air to want to flow from high to low pressure, creating constant winds that went from the poles to the equator. This flow could potentially stabilize as the density increased the closer you got to the equator, but we do not see this density variation either. Lastly, since the atmosphere would have to be at different speeds depending on how far you were from the poles, traveling in an airplane would be largely influenced if the destinations were at very different latitudes. They could either gain or lose 100's of mph, but this does not seem to happen or have to be taken into account.