What is the atmospheric pressure?

A standard atmospheric pressure is1.013x105pa.

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. Therefore, "hectopascals" are used as the air pressure unit in the world. After conversion: a standard atmospheric pressure = 1 .013x105pa,1standard atmospheric pressure =760mm mercury column height.

Extended data:

Atmospheric pressure is related to altitude, atmospheric temperature and atmospheric density, and generally decreases exponentially with altitude. The air pressure changes every day and every year. In a year, the air pressure in winter is higher than that in summer. In a day, the air pressure has a maximum value and a minimum value, which appear at 9 ~ 10 and 15 ~ 16 respectively, and the second high value and the second low value appear at 2 1 ~ 22 and 3 ~ 4 respectively.

The daily variation of air pressure is small, generally 0. 1 ~ 0.4 kPa, and decreases with the increase of latitude. The change of air pressure is closely related to wind and weather, so it is an important meteorological factor. The commonly used units of air pressure are Pa, mmHg and millibar.

Baidu encyclopedia-air pressure