Properties of cold and warm air masses

The essence of cold and warm air mass: a single heated air mass controls high temperature, low pressure and weather.

A single cold air mass controls the temperature lower, the air pressure higher, and the weather is clear.

Winter is mainly influenced by the denatured polar continental air mass, which originated in Siberia and Mongolia and is called Siberian air mass. The weather in the area it controls is dry and cold. In addition, tropical marine air masses from the subtropical region of the North Pacific can affect South China, East China and Yunnan. The Arctic air mass can also invade China to the south, resulting in a strong cold wave weather with a sudden drop in temperature.

In summer, Siberian air mass is active in the north and northwest of the Great Wall of China, and the eastern coast of China is mainly affected by denatured tropical marine air mass. The intersection of the above two air masses is the main reason for the regional precipitation in the north and south of China in midsummer.

In addition, tropical continental air masses often affect western China, and severe drought and high temperature will occur in areas under its continuous control. The equatorial air mass from the Indian Ocean can cause a lot of precipitation in the south of the Yangtze River basin.

For different air masses, the speed of denaturation is different. Even for the same air mass, the speed of denaturation is related to the difference between the underlying surface properties and the air mass properties. Generally speaking, cold air masses change quickly when they move to warm areas. In this case, the cold air mass in the lower layer becomes warm and unstable, and turbulent convection is easy to develop, which can quickly transfer heat from the bottom to the upper layer.

On the contrary, when the warm air mass moves to the cold area, its cooling speed is slow, because the cooling at the lower level tends to be stable, turbulence and convection are not easy to develop, and its cooling process mainly depends on radiation.