What Is Atmospheric Pressure?
Atmospheric pressure is the force exerted on a surface by the weight of the air in the atmosphere above it. Because you are at the bottom of an ocean of air, it is constantly pushing down on you and everything around you from all directions.
Section 2: How It's Created
This pressure is created by the gravitational pull of the Earth on the gas molecules that make up our air. Imagine a column of air stretching from the ground to the edge of space; the weight of all the air in that column is the source of atmospheric pressure at that location.
Section 3: A Practical Example
A clear example is the change in pressure with altitude. At sea level, the column of air is very tall, so its weight is high, resulting in higher atmospheric pressure. On top of a mountain, the column of air above is shorter and contains fewer air molecules, so its weight is lower, leading to lower atmospheric pressure.
Section 4: Importance in Weather
Atmospheric pressure is crucial for weather forecasting. Areas of high pressure are typically associated with clear skies and calm weather, as the sinking air prevents cloud formation. Conversely, areas of low pressure often bring clouds, wind, and precipitation as air rises and cools.