Influence of atmospheric pressure on weather

Areas with high ground pressure are often sunny, and areas with low ground pressure are often rainy. The high air pressure and low air pressure mentioned here are relative, not the absolute value of air pressure. An area with a higher atmospheric pressure than the surrounding area is called a high atmospheric pressure area. If the air pressure in a certain area is lower than that in the surrounding area, it is called a low pressure area. On the same horizontal plane, if the air pressure distribution is uneven, the air will flow from the high pressure area to the low pressure area. Therefore, if the air pressure in a certain area is high, the air in that area will flow out horizontally. The air above the high pressure area will drop. Because the atmospheric pressure increases with the decrease of altitude, when the air at high altitude drops, the pressure it receives will increase and its volume will decrease. When the temperature rises, the condensation in the air will evaporate and dissipate. Therefore, the central area of high pressure is not conducive to the formation of clouds and rain, and it is often sunny. If the air pressure in a certain area is low, the surrounding air will flow into the area horizontally, causing the air in the area to rise. The rising air will expand due to the pressure reduction, and the temperature will drop, and the water vapor in the air will condense. So it often rains in the central area with low air pressure.