Ferrel worked to develop theories that explained atmospheric circulation at mid-latitudes in great detail. He focused on the properties of warm air and how it acts, through the Coriolis effect, as it rises and rotates.
The meteorological theory that Ferrel worked on was originally created by Hadley, but Hadley had overlooked a specific and important mechanism that Ferrel was aware of. He correlated the motion of the Earth with the motion of the atmosphere in order to show that centrifugal force is created. The atmosphere, then, cannot maintain a state of equilibrium because the motion is either increasing or diminishing. This depends on which way the atmosphere is moving with regard to the Earth’s surface.
Hadley had erroneously concluded that there was a conservation of linear momentum. However, Ferrel showed that this was not the case. Instead, it is the angular momentum that must be taken into account. In order to do this, one must study not just the movement of the air, but the movement of the air relative to the Earth itself. Without looking at the interaction between the two, the whole picture is not seen.
