Common weather systems in high school geography

1, the cold air mass is generally dense, below the front; The density of warm air mass is small, above the front.

2. Cold air mass and warm air mass are relative concepts, which are compared with the temperature of the area where the air mass reaches. Don't think that the temperature of the cold air mass must be low, and the temperature of the warm air mass must be high.

3. The concepts of three typical fronts: the cold air mass actively acts as a cold front, the warm air mass actively acts as a warm front, and the cold and warm air masses are quite quasi-static fronts.

4.？ When the front passes, it will definitely bring about weather changes, but it will not necessarily produce precipitation. When the warm air mass on the front is dry, precipitation cannot be formed. Such as sandstorm weather in winter and spring in northern China.

5.？ The influence and scope of cold front in China are relatively large, and the obvious warm front appears less in China, mostly accompanied by cyclones. In winter and autumn, it generally appears in the Jianghuai Basin and Northeast China, and it mostly appears in the Yellow River Basin in summer.

. Specific case:

(1) cold front: rainstorm in summer and cold wave in winter in northern China.

(2) Warm front: a spring rain and a warm, "back to the south".

(3) Quasi-static front stop: rainy weather in the middle and lower reaches of the Yangtze River (May-June).