What are pressure gradients?

Pressure gradients refer to variations in atmospheric pressure over a given distance. The correct answer, which explains pressure gradients, centers on the spacing of isobars. Isobars are lines drawn on weather maps that connect points of equal atmospheric pressure. When these lines are close together, it indicates a steep pressure gradient, meaning there is a rapid change in pressure over a short distance. This steep gradient can often lead to strong winds, as air moves from areas of high pressure to low pressure.

When considering other options, differences in altitude across a region pertain to topography rather than pressure. The force exerted by the atmosphere is a broader concept encompassing atmospheric pressure but does not specifically describe the gradient. Changes in temperature at different altitudes relate to atmospheric conditions and stability but do not directly address pressure differences. Thus, the spacing of isobars is the definitive aspect of pressure gradients, making it the most accurate choice.