Atmospheric pressure is a fundamental concept in meteorology and climatology, influencing weather patterns, wind systems, and climate zones. It is the force exerted by the weight of the atmosphere on a surface area and varies with altitude, temperature, and humidity

Definition

Atmospheric pressure, also known as barometric pressure, is the force exerted by the weight of the air above a given point on Earth's surface. It is a critical factor in determining weather conditions, air movement, and climate patterns.

1.Concept of Force per Unit Area: Atmospheric pressure is defined as the force per unit area exerted by the weight of the atmosphere above a particular point. It is measured in terms of the height of a column of mercury (in millimetres or inches) or in units of pressure such as pascals (Pa) or bars. At sea level, the average atmospheric pressure is approximately 1013.25 hPa (hectopascals) or 29.92 inches of mercury (Hg). This value represents the weight of the column of air from the Earth's surface up to the top of the atmosphere.

i.Mathematical Expression: Atmospheric pressure (P) can be expressed mathematically as:

where F is the force exerted by the atmosphere and A is the area over which the force is distributed. The weight of the air above creates this force, which is why atmospheric pressure decreases with altitude.