What is the cause of sandstorm weather?

The driving force of sandstorm is mainly strong wind, and its material basis is dust source. Unstable thermal conditions are conducive to the increase of wind power and the development of strong convection, thus carrying more dust and rising higher.

In addition, the special weather background of sandstorm formation is drought and lack of rain in the early stage, warming weather and rising temperature; The convective cells before the ground cold front develop into clouds or squall lines, which is a small and medium-sized system conducive to the development and strengthening of sandstorms. The narrow tube effect of topography is also one of the favorable conditions for the formation of sandstorms. 1. Chemical mechanism of sandstorm formation

The main component of soil and yellow sand is silicate. When there is less rain and the air temperature becomes warmer, the silicic acid on the silicate surface loses moisture, that is, H2SiO4 = SiO3-2+H2O (gas) ↑. In this way, the surface of silicate soil micelles and sand particles will be negatively charged and repel each other, becoming aerosols that cannot be aggregated together, thus forming sand blowing, that is, sandstorms. Therefore, sandstorms are essentially silicate aerosols with negative charges.

2. Physical mechanism of sandstorm formation

The physical mechanism of sandstorm formation is due to the high-altitude dry and cold jet, strong vertical wind speed, wind direction shear and thermal instability stratification conditions, which cause the formation and development of small and medium-scale systems near the front area, aggravate the pressure and temperature gradients before and after the front area, and form huge pressure and temperature gradients before and after the front area. Under the joint action of momentum downward transfer and gradient deviation wind, the wind speed in the near-surface layer rises sharply, causing dust on the surface and forming sandstorm or strong sandstorm weather.