Why do air masses not flow in direct paths between the equator and the poles?

Air masses do not flow in direct paths between the equator and the poles primarily due to the Earth's rotation, which causes the Coriolis effect. This effect deflects moving air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, creating curved wind patterns. Additionally, the temperature differences between the equator and poles lead to varying air pressures, further influencing the movement of air masses and resulting in complex circulation patterns, such as the trade winds and jet streams.