What happens to air pressure as height increases?

As height increases, air pressure decreases due to the diminishing column of air above a given point. This phenomenon occurs because the atmosphere is composed of gases that are influenced by gravity. As one ascends in altitude, there are fewer air molecules stacked above, which means the weight (and therefore the pressure) exerted by the air above decreases.

This concept is fundamental in meteorology and is known as the barometric formula, which mathematically describes how atmospheric pressure decreases with increasing height. In practical terms, this is why at higher elevations—such as on a mountain—people may experience lower air pressure, which also affects various physical phenomena, including weather patterns and human physiology.

The other choices do not accurately represent the behavior of air pressure with respect to height. While air pressure does fluctuate due to weather systems, the overarching trend with height is a consistent decrease.