What happens to air pressure as altitude increases?

As altitude increases, air pressure decreases due to the thinning of the atmosphere. At higher elevations, there is less air above any given point, which leads to a reduction in the weight of the air pressing down. This phenomenon occurs because the Earth's atmosphere is composed of a mixture of gases that are held close to the surface by gravity. As one ascends, the density of the air decreases, resulting in fewer air molecules available to exert pressure.

This inverse relationship between altitude and air pressure is critical for aviation. Pilots must take into account the effects of changing air pressure on aircraft performance, such as lift and engine efficiency, as they fly at different altitudes. The decline in pressure also influences weather patterns and the operation of barometric altimeters, which are used to determine altitude during flight. Thus, understanding this concept is essential for safe and effective navigation in aviation settings.