What is atmospheric pressure defined as?

Atmospheric pressure is defined as the weight of a column of air above a given point. This concept is fundamental to understanding how pressure is generated in the atmosphere. As you move upwards in the atmosphere, the amount of air above you decreases, leading to a decrease in atmospheric pressure. At sea level, the weight of the entire atmosphere exerts a significant force downwards, which is what we measure as atmospheric pressure.

This measurement is typically expressed in units such as hectopascals (hPa) or inches of mercury (inHg), and it plays a critical role in weather forecasting, climatology, and aviation. Understanding atmospheric pressure allows meteorologists to predict weather patterns, as high pressure is generally associated with clear skies, while low pressure can lead to cloudy and stormy conditions.