What weather system is a typhoon?

A storm with special properties near Taiwan Province Island is called typhoon or wind from Taiwan Province Province. In the past, China used to call tropical cyclones with SST higher than 26℃ on the tropical ocean surface typhoons. According to its intensity, tropical cyclones can be divided into six grades: tropical depression, tropical storm, strong tropical storm, typhoon, strong typhoon and super typhoon. Since 1989, China has adopted the international tropical cyclone name and grade standard. According to international practice, tropical cyclones occurring in the northwest Pacific Ocean and the South China Sea of China are divided into tropical depression and maximum wind speed.

Typhoon is a powerful and deep cyclone vortex and a mature typhoon. Its bottom layer is divided into three areas according to the convergent airflow speed: ① Outer ring: also known as windy area, with a radius of about 200-300km from the edge of typhoon to the outer edge of vortex area. Its main feature is that the wind speed increases sharply to the center, and the wind power can reach more than 6 levels. ② The middle circle, also known as the vortex area, has a radius of about 100km from the edge of the windy area to the eye wall of the typhoon, which is the area with the strongest convection, wind and rain and the most destructive force. ③ The inner ring is also called typhoon eye area, with a radius of about 5-30km. Most of them are round, and the wind speed decreases rapidly or the wind is calm.

Weather system is an atmospheric movement system with certain spatial structure characteristics of meteorological elements such as temperature, pressure or wind.

The characteristic scales of various weather systems in the atmosphere vary greatly, from tens of thousands of kilometers such as ultra-long waves and subtropical high to hundreds of meters such as tornadoes. According to the characteristic scale, it can be roughly divided into five categories, namely: planetary scale weather system, weather scale weather system (planetary scale weather system and weather scale weather system are collectively called large-scale weather system), mesoscale weather system (sub-synoptic scale weather system), mesoscale weather system and small-scale weather system.

Planetary-scale weather system-The wavelength found on the high-altitude weather map is equivalent to that of radius of the earth.

Weather-scale weather system-the average distance between ground observation stations is about 200 ~ 300 kilometers. According to the observed data, the high and low pressure systems are analyzed.

Large-scale weather system-The general name of planetary scale weather system and weather scale weather system.

Mesoscale weather system-a system in the range of 2000 km to 200 km

Mesoscale weather system-a system with horizontal scale from 2000 km to 2 km.

Mesoscale alpha weather system of 200 ~ 2000 km, including typhoons and fronts;

Mesoscale β weather system of 20 ~ 200 km, including tornado and squall line;

Mesoscale gamma weather system with a distance of 2-20km, including thunderstorm cell.

Small-scale weather system-a weather system with a horizontal range of several hundred meters to dozens of kilometers and a life span of only a few tens of minutes to two or three hours.

Typhoon belongs to mesoscale weather system.