What's the atmospheric pressure, Pa?
A standard atmospheric pressure is equal to the weight of a mercury column with a height of 760mm, which is equivalent to an area of one square centimeter bearing an atmospheric pressure of 1.0336kg. Internationally, "hectopascals" are used as the air pressure unit. After conversion: a standard atmospheric pressure = 10 13 hectopascals (millibars).
Atmospheric pressure is the atmospheric pressure acting on a unit area, that is, it is numerically equal to the gravity of a vertical air column extending upward to the upper limit of the atmosphere. The famous experiment in the Madeborg hemisphere proved its existence. The international system unit of air pressure is Pascal, abbreviated as Pa, and the symbol is PA.
In meteorology, people usually use kilopascals (kPa) or hectopascals (hpa) as units. Other commonly used units are bar (bar, 1 bar = 100000 Pa) and centimeter mercury column (or centimeter mercury column). Air pressure varies not only with height, but also with temperature. The change of air pressure is closely related to the change of weather.
Standard atmospheric pressure. A unit of air pressure, usually the height of a mercury column. For example, a standard atmospheric pressure is equal to the weight of a 760mm high mercury column, which is equivalent to bearing an atmospheric pressure of 1.0336kg in an area of one square centimeter. Because the weight and length units used in different countries are different, and the pressure units are not uniform, it is not convenient to compare and analyze the global pressure.
Basic concepts:
Air pressure is the abbreviation of atmospheric pressure, which is the atmospheric pressure acting on unit area, that is, it is equal to the weight of the vertical air column extending upward to the upper limit of the atmosphere on unit area. Air pressure is related to altitude, temperature and other conditions. It generally decreases with the increase of height. In the horizontal direction, the difference of atmospheric pressure leads to the flow of air.
A unit of air pressure, usually the height of a mercury column. For example, a standard atmospheric pressure is equal to the pressure generated by a mercury column with a height of 760mm, which is equivalent to1.0336kg atmospheric pressure on an area of one square centimeter. After conversion: a standard atmospheric pressure = 10 13 hectopascals (millibars).