Atmospheric pressure

Atmospheric pressure

Atmospheric pressure is the weight of air on the Earth's surface in a given area. It is caused by the accumulation of different gases at one point of the atmosphere. These gases are

1. oxygen,
2. hydrogen,
3. nitrogen, and
4. carbon dioxide.

Atmospheric Pressure and Its Measurement

Atmospheric Pressure and Wind Formation

Atmospheric pressure varies from one place to another due to differences in the amount of gases present in the atmosphere. Even within the same area, atmospheric pressure can change depending on the increase or decrease in the quantity of gases accumulated.

Relationship Between Atmospheric Pressure and Wind

1. When the temperature increases, the atmospheric pressure decreases.
2. Differences in temperature between two places create a pressure difference.
3. Air moves from a high-pressure area to a low-pressure area.
4. This movement of air is called wind.

Measuring Atmospheric Pressure

Atmospheric pressure is measured in millibars (mb) using an instrument called a barometer.

Types of Barometers

There are two main types of barometers:

1. Mercury Barometer – A larger and more commonly used instrument in weather stations.
2. Aneroid Barometer – A compact and portable instrument that also records atmospheric pressure.

Both barometers perform the same function of measuring atmospheric pressure, with the mercury barometer being more frequently used in professional weather stations.

An aneroid barometer