American Meteorological Society Certification (AMS) Practice

The direction of wind is most directly influenced by Earth's spin and the Coriolis effect. As the Earth rotates, the movement of air is affected by this rotation, leading to a deflection of wind patterns. The Coriolis effect is a result of the rotation of the Earth, which causes moving air (and water) to turn and twist rather than move in a straight line. In the Northern Hemisphere, this deflection is to the right, and in the Southern Hemisphere, it is to the left.

The combination of the Earth's rotation and the Coriolis effect helps establish prevailing wind patterns, such as trade winds in tropical regions and westerlies in mid-latitude regions. This is why understanding the Coriolis effect is crucial in meteorology for predicting wind patterns and weather systems.

Other factors like ocean currents, topographical features, and solar radiation do impact weather and climate, but they do not directly influence the fundamental direction of wind as impacted by the Earth's spin and Coriolis effect.