Atmospheric pressure concept

Atmospheric pressure is called barometric pressure, and it is the force exerted by the column of the atmosphere relative to a unit area, that is, it is the mass of air over a region, and there are several units for measuring atmospheric pressure, including: millimeters of mercury and kilopascals, where the standard pressure at sea level is 760 mm of mercury, and 101,325 kPa, and the differences around these values ​​are very small, as the highest value recorded for pressure at sea level is 813.05 mm in central Siberia, and the lowest value was 657.86 mm in a cyclone in the South Pacific.[1]

atmospheric pressure gauge

Atmospheric pressure is measured through a device called a barometer, which is a scientific instrument used to measure atmospheric pressure, and these measurements can be used to know the weather, as the change in air pressure affects the weather, and this may help meteorologists predict short-term weather changes.[2]

Causes of change in atmospheric pressure

There are several reasons for changes in atmospheric pressure, including the following: [3]

  • Height above sea level: The most common reason for changes in atmospheric pressure is the change in altitude, as the increase in altitude leads to a decrease in the number of air molecules in the surrounding atmosphere, which reduces the density of the air, and thus the pressure decreases, and this change is not noticeable in the first 1.61 km From the atmosphere above sea level, but at high altitudes this is noticeable significantly, as the air pressure decreases logarithmically at sea level.
  • Weather patterns: Different weather patterns can have significant effects on air pressure, and in general, the density of hot air is less than that of cold air, because the particles that make up hot air have a greater velocity, and are farther from each other than they are in cold air. This means that the ambient air pressure depends on changes in temperature, and the most obvious change in air pressure occurs twice a day with the rise and fall of the sun, where midnight is the time when the lowest air pressure measurement is recorded, while the middle of the day is the time when It is noted that the highest air pressure is observed, and this difference is more pronounced in the regions near the equator, and less in the regions around the poles.

the reviewer

  1. ↑ The Editors of Encyclopaedia Britannica (12-1-2018), “Atmospheric pressure”,, Retrieved 7-3-2018. Edited.
  2. ↑ “barometer”,, Retrieved 7-3-2018. Edited.
  3. ↑ “Causes of Atmospheric Pressure changes”,, Retrieved 7-3-2018. Edited.

What is atmospheric pressure

Writing – on the date : – Last updated: 2022-05-11 07:27:01