What types of weather systems are there?

The types of weather systems are frontal system, low pressure system and high pressure system.

1, frontal system

Frontal system, the interface between cold and warm air masses (wind zone), the horizontal range ranges from several hundred kilometers to several thousand kilometers. Include cold front, warm front and quasi-static front. Generally, the cold air mass is under the front and the warm air mass is on the front. There are often clouds, rain, strong winds and other weather near the front.

Cold front refers to the wind in which the cold air mass actively moves to the warm air mass. The front edge of the cold air mass is inserted under the warm air mass, forcing the warm air mass to rise. The warm air mass cools in the process of lifting, and the water vapor in it can easily condense into clouds and rain. If the warm air contains a lot of water vapor, it may bring rain and snow. The cold front moves faster and often brings strong winds. Therefore, when the cold front crosses the border, it is prone to rainy and windy weather.

2, low pressure system

Low pressure, also known as "cyclone", refers to the large vortex in which the horizontal airflow rotates counterclockwise (clockwise) in the atmosphere. At the same height, the air pressure in the center of the cyclone is lower than that around it, which is also called low pressure. It appears as a low-pressure area surrounded by closed isobars on the contour map, and a low-value area surrounded by closed isobars on the contour map.

Cyclones are similar to circles or ellipses, and their sizes vary greatly. Small cyclones have a horizontal scale of several hundred kilometers, and the large ones can reach three or four thousand kilometers, which belongs to the weather scale weather system. In cyclones, the weather often changes dramatically, which is the weather system that people are most concerned about and studied at the earliest.

3. High voltage system

High pressure is also called "anticyclone". Anti-cyclone refers to the horizontal air vortex with the central air pressure higher than the surrounding air pressure, and it is also the high pressure in the air pressure system. The anticyclone in the northern hemisphere, the horizontal airflow in the lower layer diverges clockwise, and the anticyclone in the southern hemisphere diverges counterclockwise. The horizontal scale of anticyclone is greater than that of cyclone. For example, the Mongolian-Siberian high in winter occupies 1/4 of the Asian continent.

Evolution and extinction of weather system;

The weather system is always reborn, developing and dying. Various weather systems have different birth and death conditions and energy sources. Even if the characteristic scales belong to the same system, their birth and death conditions and energy sources are different. For example, the development conditions of extratropical cyclones are mainly determined by the intensity of air divergence caused by vorticity advection over them, and its energy comes from the effective potential energy stored in atmospheric baroclinic.

The mesoscale weather system with strong convection is mainly developed due to the sudden rise of air with unstable potential, and its energy also comes from the release of latent heat. Moreover, the weather system is often not closed, and the air in one system often exchanges with the air in the surrounding system. Through this exchange, momentum and energy between systems are exchanged, which leads to the birth and death of systems and the interaction between systems.