American Meteorological Society Certification (AMS) Practice 2025 - Free Practice Questions and Study Guide

The term that describes the pressure difference between two points that drives wind is called a pressure gradient. This pressure gradient represents the change in atmospheric pressure over a given distance. When there is a difference in pressure between two regions, air naturally moves from the area of higher pressure to an area of lower pressure to achieve equilibrium. This movement of air is what we recognize as wind.

Understanding the pressure gradient is crucial for meteorology because it helps explain the formation and strength of winds. A steep pressure gradient indicates a significant difference in pressure over a short distance, leading to stronger winds, while a gradual gradient results in lighter winds.

Other terms present in the question relate to different atmospheric phenomena. Wind shear refers to the change in wind speed or direction with height. The Coriolis effect is the apparent deflection of moving objects due to the rotation of the Earth, which influences wind direction but is not a direct cause of wind itself. A thermal gradient refers to the change in temperature across a distance, which can lead to pressure differences but is not synonymous with the pressure difference that drives wind. Thus, the concept of the pressure gradient is foundational to understanding wind dynamics in meteorology.