What does wind force 5 mean?

Level 5 wind in Beaufort scale, also known as breeze, refers to the wind speed of 8.-1.7 m/s. The waves in the sea are getting higher and higher, and the peaks are foaming and occasionally splashing. Small trees with leaves sway on the land, and there are small waves on the inland water surface.

Grade 4 wind is the Beaufort wind with a wind speed of 5.5-7.9m/s, 2-28km/h, also known as gentle wind, with a wind pressure of 18.9-39Pa, which can blow up dust and paper on the ground, and the twigs of trees move slightly. Generally speaking, the wind force is small. When the fishing boat is full of sails, it is a good wind to lean to one side for fishing. The waves on the sea surface are getting higher and higher, the peaks are foaming, the dust and sand on the land are flying, pieces of paper are flying, and small trunks are shaking.

Extended information:

1. Historical origin of wind power

In the Tang Dynasty more than 1 years ago, our people not only recorded weather phenomena such as rain and snow, but also measured the magnitude of wind power. At the beginning of the Tang Dynasty, an accurate instrument for measuring wind speed was not invented, but at that time, the moving speed of the wind could be calculated and the wind grade could be determined according to the characteristics of the wind to objects.

Li Chunfeng's "Phenomenon Play Zhan" has such a record: "Moving leaves are ten miles, singing songs are hundred miles, shaking branches are two hundred miles, falling leaves are three hundred miles, twigs are broken for four hundred miles, big branches are broken for five hundred miles, stones are gone for a thousand miles, and big roots are pulled up for three thousand miles."

This is to estimate the speed of the wind according to the effect of the wind on the trees. "Moving leaves for ten miles" means that the leaves are slightly fluttering, and the speed of the wind is ten miles a day; "Singing" is the rustling of leaves, and the wind speed at this time is hundreds of miles a day.

In addition, some wind grades are determined according to the characteristics of trees, such as "first-class moving leaves, second-class singing, third-class shaking branches, fourth-class falling leaves, fifth-class broken twigs, sixth-class broken branches, seventh-class broken trees, flying sand and stones, and eighth-class pulling up trees and roots".

these eight levels of wind, plus two levels of "no wind" and "gentle wind" (when the wind comes, it is cool and gentle, and the dust can't afford it, which is called gentle wind), can be combined into ten levels. The grades of these winds are not much different from those imported from abroad. This can be said to be the earliest wind level in the world.

more than 2 years ago, there was still no instrument for measuring the magnitude of wind power, and there was no unified regulation. Every country expressed it in its own way. At that time, there was a man named Beaufort in England. He carefully observed the situation of various objects on land and sea in different winds, and accumulated 5 years of experience before dividing the wind into 13 grades in 185, also known as Beaufort scale.

Later, after research and supplement, the original explanation was explained more clearly, and the speed of each wind level was added, which became the "jargon" for forecasting wind power.

II. Definition of Wind Power

In 21, the China Meteorological Bureau issued the Regulations on Typhoon Business and Service, which added typhoons above 12 to 17 according to Beaufort wind scale. Class 12 typhoon is set at 32.4-36.9 m/s; Level 13 is 37.-41.4 m/s; Level 14 is 41.5-46.1m/s, level 15 is 46.2-5.9m/s, level 16 is 51.-56.m/s, and level 17 is 56.1-61.2m/s..

the typhoon in Qionghai 3 years ago, the maximum wind force near the center was 73m/s, which exceeded the highest standard of 17. It is called level 18, and it is also a common saying in the international maritime community about the super typhoon.

Baidu Encyclopedia-Level 4 Wind

Baidu Encyclopedia-Level 5 Wind

Baidu Encyclopedia-Wind Level