What prevents air from flowing directly from high-pressure areas to low-pressure areas?

The reason the Coriolis force is considered the correct answer to the question lies in its influence on airflow patterns in the atmosphere. The Coriolis force arises due to the rotation of the Earth, causing moving air to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection alters the flow of air, preventing it from moving directly from high-pressure areas to low-pressure areas in a straight line.

Instead of a direct flow, the air moves in a curved path due to this deflection. As a result, the Coriolis force plays a significant role in shaping weather patterns and influencing wind direction. This effect is crucial in understanding how atmospheric circulation operates on a global scale, impacting various weather systems and phenomena.

In contrast, while the pressure gradient force is responsible for initiating air movement from high to low-pressure areas, it does not prevent that movement; rather, it causes it. Surface friction affects wind speed and direction near the ground but is not the primary force that alters the overall pattern of airflow. Humidity levels do have an influence on weather conditions but do not directly affect the airflow dynamics between high and low pressure.