The main causes of sandstorm formation

The weather situation favorable to strong winds or strong winds, favorable distribution of dust sources and favorable air instability conditions are the main reasons for the formation of sandstorms or strong sandstorms.

2. Physical factors

Under the favorable conditions of large-scale environment, high-altitude dry and cold jet, strong vertical wind speed, wind shear and thermal instability stratification, the generation and development of small and medium-scale systems near the front area intensified the pressure and temperature gradients before and after the front area, forming a huge pressure and temperature gradient before and after the front area.

3. Environmental factors

With the efforts of experts from the Institute of Environment and Engineering in Cold and Arid Regions, Chinese Academy of Sciences, the wind tunnel simulation experiment of sandstorm was successfully completed to explore the starting and transport mechanism of sandstorm materials.

4. Human factors

The occurrence of sandstorm is not only the product of specific natural environmental conditions, but also has a corresponding relationship with human activities. Man-made overgrazing, deforestation, industrial and mining traffic construction, especially man-made overgrazing, have destroyed the ground vegetation and disturbed the ground structure.

5. Meteorological factors

The formation of sandstorm is based on the special atmospheric circulation in East Asia, which is closely related to the winter monsoon.

Extended data

Morphological characteristics of sandstorm;

1, the sand wall stands.

Most of the strong sandstorms on the mainland come from the northwest or west, and a few from the east. When almost all sandstorms come, we can see a black sand wall moving rapidly and getting closer and closer in the direction of the wind.

2. It is already dark.

When a strong sandstorm occurs, due to the strong wind of magnitude 8 or above, the wind is very strong and can roll up stones and sand. As more and more dust flies into the air, the thick dust is overwhelming, blocking the sun and making people see nothing for a period of time, just like at night.

3。 Roll and rush

Black wind blows, the air near the ground is unstable, the heated air below rises, and the surrounding air flows to supplement, causing the air to roll up and down with a lot of dust, forming countless dust clouds of different sizes to meet and rush in the air.

4. smart

The upper layer of sand wall is often yellow to red, the middle layer is gray-black and the lower layer is black. The reason why the upper layer is yellow-red is because the dust on the upper layer is so thin that sunlight can almost shoot down through the dust.

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