Is the air pressure high in winter or summer? Why?

The air pressure in winter is higher than that in summer.

Air pressure refers to the pressure produced by the air column per unit area on the earth. The air pressure in a place often changes. When the air pressure decreases, it will be rainy, and when the air pressure increases, the weather will turn fine. There are many reasons for the change of air pressure.

The change of temperature is a very important reason for the change of pressure. When the air is cooled, the air contracts, the density increases, the weight of air column per unit area increases, and the air pressure also increases.

Therefore, the arrival of cold air is always accompanied by the increase of air pressure; When warm air comes, the air pressure tends to drop. Winter is a world of cold air and summer is a world of warm air, so obviously, the air pressure is high in winter and low in summer.

Extended data:

Influencing factors of air pressure:

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. The conversion relationship between them is:100pa =1mbar ≈ 3/4 mm mercury column height.

Commonly used instruments for measuring atmospheric pressure in meteorological observation include mercury barometer, empty box barometer and barometer. When the temperature is 0℃ and the pressure is 760mm, the standard atmospheric pressure is first measured by Italian scientist Torricelli.

Baidu encyclopedia-air pressure