What is the sign of sandstorm?

The icon of sandstorm is indicated by "S".

Sandstorm icons usually have two forms. One is a yellow triangle, similar to a warning sign, with a black humanoid pattern on it, indicating that people need to pay special attention to protect themselves in sandstorms. The other is a yellow circle with a black cyclone shape in the middle, indicating that a sandstorm is happening.

These icons usually appear in the weather forecast or meteorological information column in public places to remind people to pay attention to prevent the influence of sandstorms. "S" means ups and downs, the upward arrow on "S" means sandstorm, and the right arrow means sandstorm. Sandstorm refers to the weather phenomenon that strong winds blow up a lot of dust on the ground, which makes the air very turbid and the horizontal visibility is less than 1 km.

Necessary conditions for the formation of sandstorms

1, dust

Dust matter on the ground is the material basis for the formation of sandstorms, and dust in desert areas is the main source of dust matter. Only when the dust is dry, loose and easy to transport will it be swept away by the strong wind. Dust particles in consolidated state or dust with high humidity are not conducive to wind transport.

2. Strong wind

Sandstorm is transported by wind, and strong wind (near-surface wind speed is greater than 6, about 12 m/s) is the dynamic basis for long-distance transportation of sandstorm. Frequent and strong wind passing through or coming from material sources is a necessary condition for the formation of sandstorms. In terms of wind speed, the wind speed is high in spring and low in summer, autumn and winter, so spring is the high season for sandstorms.