What causes sandstorms?

1. Natural conditions, weather conditions that are conducive to strong winds or strong winds, favorable sand and dust source distribution and favorable air instability conditions are the main reasons for the formation of sandstorms or strong sandstorms. Strong wind is the driving force for sandstorms, and sand and dust sources are the material basis of sandstorms. Unstable thermal conditions are conducive to the increase in wind power and the development of strong convection, thereby entraining more sand and dust and carrying it higher.

2. Physical factors, under extremely favorable large-scale environment, high-altitude dry cold jet stream, strong vertical wind speed, wind shear and thermally unstable stratification conditions, cause the generation and development of small- and medium-scale systems near the frontal area. , intensifying the pressure and temperature gradients before and after the frontal zone, forming a huge pressure-temperature gradient before and after the frontal zone. Under the simultaneous action of momentum downward transmission and gradient deviation wind, the near-surface wind speed rises sharply, kicking up surface sand and dust, forming sandstorms or strong sandstorms.

3. Environmental factors. With the efforts of experts from the Cold and Arid Regions Environment and Engineering Institute of the Chinese Academy of Sciences, a sandstorm wind tunnel simulation experiment was specially set up to explore the initiation and transmission mechanism of sand and dust materials. Done successfully. Through experiments, experts found that soil wind erosion is the primary link in the occurrence and development of sandstorms. Wind is the most direct driving force of soil, among which the nature of air flow, wind speed, and related conditions of wind force during soil wind erosion are the most important factors. In addition, soil moisture content is also one of the important reasons affecting soil wind erosion.

4. Human factors. The occurrence of sandstorms is not only the product of specific natural environmental conditions, but also has a corresponding relationship with human activities. Man-made overgrazing, deforestation of forest vegetation, industrial and mining transportation construction, and especially man-made excessive reclamation destroy ground vegetation, disturb the ground structure, and form large areas of desertified land, which directly accelerate the formation and development of sandstorms.

5. Meteorological factors. The formation of sandstorms is based on the special atmospheric circulation in East Asia and is closely related to the winter monsoon. Its occurrence is mainly driven by the Siberian-Mongolian high pressure in the winter half. It is related to the passage of the cold front below and is a cold front type sandstorm.