There are many theories about the origin of the name "Typhoon". It is generally believed that it evolved from Cantonese "gale", and it is also said that it evolved from Minnan "wind screen". Some people think that the ancients didn't know the origin of typhoons, and thought that they came from Taiwan Province Province, so they were called "typhoons".
Actually, typhoon is a kind of tropical cyclone. The so-called tropical cyclone refers to the strong atmospheric vortex that occurs in the tropical ocean. Its intensity is based on the maximum average wind speed near the bottom center. According to international regulations, when the maximum wind force near the center is 12 or above, it is called typhoon (hurricane in the West Indies and Atlantic Ocean). Strong tropical storm with wind force 10 ~ 1 1; Tropical storms with winds of 8-9 are called tropical storms; 6 ~ 7 winds are called tropical depression.
As the "big brother" of tropical cyclone family, the horizontal range of typhoon is about several hundred kilometers to several thousand kilometers, and the vertical range is from the ground to the lower stratosphere. The maximum average wind speed near the center of the bottom of the typhoon is about 30 ~ 50m/s, and sometimes it can even exceed 80m/s. In the process of advancing, the typhoon advances at sea or lands on land while spinning strongly, causing severe weather such as strong winds, heavy rains, huge waves and storm surges, and causing great damage to ships at sea and coastal towns.
Tropical ocean is the "hometown" of typhoons. Typhoons are usually generated on the vast tropical warm ocean surface with water temperature of 26℃ ~ 27℃. There, the sea surface temperature is high, the water vapor content in the air is high, and the air constantly releases heat during convection. Under the influence of the earth's rotation deviation, a rotating warm-hearted gas column gradually formed and eventually developed into a typhoon.
On average, there are about 45 typhoons in the global ocean every year. What are the names of these typhoons? Earlier, tropical cyclones always used international numbers. For example, Tropical Storm No.9608, which was generated in 1996, was called Typhoon No.9608 when it continued to develop into a typhoon. However, naming tropical cyclones by numbers is not easy to remember, and it is not convenient for meteorological departments to give early warning. Therefore, the Typhoon Committee of the International Meteorological Organization 3 1 decided that tropical cyclones in the northwest Pacific Ocean and the South China Sea will adopt a new naming method from 2000 10.
At present, the Typhoon Committee has been named 140 names, which are provided by 14 members in the Asia-Pacific region, including China, Viet Nam, Japan, the United States and Hongkong, China. Each member contributed 65,438+00 names. 140 names are divided into 14 groups according to each group, which are recycled in order. The names contributed by each member have their own characteristics. The names of 10 typhoons named by China are Dragon King, Poseidon, Dian Mu, Yutu, Wukong, Fengshen, Haima, Haiyan, Rhododendron and Haitang.
The actual naming of the typhoon was entrusted to the Japan Meteorological Agency in this area. Whenever the Japan Meteorological Agency determines a tropical cyclone in the northwest Pacific or the South China Sea as the intensity of a tropical storm, it will give it a name according to the list and give it a four-digit number. The first two digits of the number are the year, and the last two digits are the order of tropical storms in that year. For example, tropical storm No.8 this year, its four-digit number is 0608, and according to the typhoon naming table, it should be "Sang Mei". When "Sang Mei" reached the typhoon intensity, it was called Typhoon No.0608 "Sang Mei".
Experts from the Central Meteorological Observatory believe that there are two main reasons why typhoons frequently patronize the southeast coast of China this year: first, the global temperature rises, which is easy to form cyclones, leading to an increase in extreme weather phenomena; Second, the high sea surface temperature and strong air pressure in the western Pacific this year have caused typhoons to move westward and frequently land on the coast of China.