What are the weather signs of a figure-eight lying on its upper and lower points?

Represents the weather "haze".

Haze, also known as haze, refers to the turbidity caused by the suspension of a large number of particles such as smoke and dust. The core substance of smog is dust particles suspended in the air, which are called aerosol particles in meteorology. It distinguishes the severity of smog by color, and yellow, orange and red represent mild, severe and extremely severe pollution respectively.

Different from the common signs of sunny and rainy clouds, the meteorological symbols of fog and haze are somewhat "difficult to understand". Fog with water content as high as 90% is marked with three horizontal bars, and haze with water content below 80% is marked with "8", which looks a bit like an infinite symbol in mathematics. When the water content is between 80% and 90%, it is a mixture of fog and haze, but generally speaking, the main component is haze.

In addition, fog and haze can also be distinguished from visibility. When the visibility is reduced to less than 1 km, it is fog; Visibility is between 1 km and1km, which is called light fog or haze. Haze is similar to light fog, with visibility less than 10 km, and is mainly composed of a large number of tiny dust particles, smoke particles or salt particles suspended in the atmosphere.

Extended data:

Sunny day: the cloud cover in the sky is less than 30%.

Sunny to cloudy: the sky is less than 30%, and the sky is 3-80%?

Cloudy: 3-80% of the sky is cloudy?

Yin: The amount of clouds in the sky accounts for more than 90%.

Light rain: the daily rainfall is less than 10 mm?

Moderate rain: daily rainfall 10. 1-24.9mm?

Heavy rain: the daily rainfall is 25.0-49.9mm?

Heavy rain: the daily rainfall is more than 50.0 mm?

Thunderstorm: Intermittent precipitation accompanied by lightning and thunder?

Xiaoxue: The snowfall (melting into water) is less than 2.5 mm per day?

Snow: the daily snowfall (melting into water) is 2.6-4.9 mm?

Blizzard: Does the daily snowfall (melting into water) reach or exceed 5.0 mm?

Hail: With the violent vertical movement in the cumulonimbus cloud, small hail nuclei repeatedly rise, condense, fall and melt.

Small ice cubes (usually 4-5 layers) that grow into transparent and opaque layers fall off?

Frost: When the temperature is lower than 0℃, water vapor condenses into white crystals on the ground and the surface of objects, resulting in hoarfrost. When the water vapor content is low and there is no frost, it is called black frost, which has freezing damage to crops and is collectively called frost.

Fog: refers to a large number of water droplets or ice crystal particles attached to the stratum and suspended in the air. It is called fog when the horizontal visibility distance drops below 1000 meters, and light fog when the visibility distance drops between 1000 meters and 10000 meters. ?

Freezing rain: raindrops freeze on the ground below 0℃, also known as rain storm (frozen by fog drops, called fog storm), and often fall off the power lines, freezing the road surface and affecting communication, power supply and traffic. ?

Fog pine: raindrops freeze on the surface and ground below 0℃, which is called rain pine (if frozen by fog drops, it is called fog pine). It often falls off the power line, freezes the road surface, and affects communication, power supply and traffic.

China Meteorological Bureau-Understanding Weather Symbols