Changes in air pressure during the day?

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 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.

Extended data:

barometric pressure

Atmospheric pressure is not fixed. In order to compare atmospheric pressure, at the 10th International Metrology Conference in 1954, scientists stipulated a "standard" for atmospheric pressure: at the sea level of latitude 45 and the temperature of 0℃, the pressure generated by a mercury column with a height of 760mm is called the standard atmospheric pressure.

Since it is a "standard", we should pay attention to the accuracy of each physical quantity according to the formula of liquid pressure. According to relevant data, the density of mercury at 0℃ is13.595×10.3 kg/m? The g value of sea level at latitude 45 is 9.80672 N/kg. Therefore, it can be concluded that the pressure generated by a 760mm high mercury column is

P mercury = ρ mercury GH =13.595×10.3 kg/m? ×9.80672N/kg×0.76m = 1.0 1325× 10 5pa。

This is the value of 1 standard atmospheric pressure.

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