What is the ups and downs?

Floating dust weather, that is, the lowest intensity sandstorm, is a weather phenomenon formed by the generation and transmission of long-distance sandstorms or local sand blowing weather. The strength is weakened, and after the coarse particles in the dust settle by gravity, the fine particles are continuously transported and float in the air. When the wind speed continues to decrease, the suspended dust particles will settle to the ground, so it is commonly known as "falling yellow sand".

In dusty weather, distant objects are khaki and the sun is pale or yellowish; The wind speed is not very high, below level 4; Visibility is less than 10 km and greater than 10 km. Floating dust and falling dust worsen the surrounding environment and have an important impact on human health, especially the respiratory system.

Region:

The area of floating dust weather is similar to that of sandstorm, but the scope is larger. In China, sandstorms and floating dust weather mainly occur in the northwest arid areas, deserts and the Loess Plateau. In winter and spring, due to the strong wind transport of cold air in northwest China, sandstorms and floating dust weather can occur in most parts of northern China.

When sandstorms begin to occur, there may be strong updraft at the same time, and some dust may enter the upper air, be transported by rapids for a long distance, and then fall to form floating dust weather. Therefore, there are reports of floating dust weather in South China such as Nanjing, Shanghai, Chengdu and Lhasa.

Refer to the above content: Baidu Encyclopedia-Floating Dust