What's the weather like with a lot of 8 points down?

The meteorological symbol of multi-point inverted 8 indicates that the weather phenomenon is smog.

The standard weather sign of smog is 8 lying flat, and the smog weather sign issued by some meteorological bureaus (such as Guangzhou Meteorological Bureau) is 8 lying flat and 3 points up and down. The background color of haze weather symbols during the day is blue, and the background color of haze weather symbols at night is black.

The classification items of smog prediction correspond to moderate smog, severe smog and severe smog respectively. That is, the smog warning level is yellow, orange and red from low to high.

Extended data:

Haze is mainly composed of sulfur dioxide, nitrogen oxides and inhalable particles. The first two are gaseous pollutants, and the last particulate matter is the main reason for aggravating smog weather pollution. Together with the fog, they make the sky gloomy in an instant.

The abbreviation of particulate matter is PM, and Beijing monitors fine particulate matter (PM2.5), that is, pollutant particles with aerodynamic equivalent diameter less than or equal to 2.5 microns. This particle itself is not only a pollutant, but also a carrier of toxic substances such as heavy metals and polycyclic aromatic hydrocarbons.

The distribution of haze particles is relatively uniform, and the size of haze particles is relatively small, ranging from 0.00 1 micron to 10 micron, with an average diameter of about 1 ~ 2 micron. Floating particles are invisible to the naked eye. Because the smog is composed of dust, sulfuric acid, nitric acid and other particles, the longer the scattering wavelength, the more the light ratio, so the smog looks yellow or orange-gray.

Baidu encyclopedia-smog