Use geographical knowledge to answer: Why is the atmospheric pressure lower on rainy days than on sunny days?

On a sunny day, the heat on the ground can be transported outwards relatively smoothly through effective radiation and the upward divergent movement of the troposphere.

On cloudy days, clouds reduce the outward divergent movement of the tropospheric atmosphere. The effect of clouds on conserving heat from the surface and the liquid layer is called the "greenhouse effect."

The atmosphere in cloudy areas expands more strongly, which causes the atmosphere in cloudy areas to spread laterally outward, reducing the density of the air. At the same time, the humidity of the atmosphere in cloudy areas is relatively high, which also reduces the density of the atmosphere. Density decreases. Due to the influence of these two factors, the atmospheric pressure on a cloudy day is lower than that on a sunny day.

The generation of atmospheric pressure is the result of the earth's gravity. Due to the earth's gravity, the atmosphere is "sucked" toward the earth, thus generating pressure. The atmospheric pressure is the highest near the ground. Air pressure in meteorological science refers to the weight of the atmospheric column (atmospheric pressure) per unit area, that is, the pressure exerted by the atmospheric column on the unit area. So why is the atmospheric pressure on rainy days lower than on sunny days?

Atmospheric pressure under normal circumstances:

Scientifically, the pressure equivalent to a 760mm high mercury column (Hg) or 1.013×10 fifth power Pascal is called 1 standard Atmospheric pressure, referred to as atmospheric pressure. ?

Standard atmospheric pressure: 760mm mercury or 1.013X10^5pa.