Movement and paths of dust phenomena affecting Najaf Governorate

Abstract

The ability of the air to carry large quantities of sand and dust depends on the wind speed, the size of the sand or dust grains, the degree of soil cohesion, the stability of the atmosphere, and the intensity of the vertical air currents. In general, the movement of dust particles is a function of both the strength of the wind and the characteristics of the granules that carry it from its place.

Dust storms are generated when the wind speed exceeds 7 m / s, as the soil atoms attached to the surface of the earth will lose their bonding strength with their molecules. These atoms begin to move when the wind speed increases, which overcomes the force of friction of the atom with the surface of the earth and the weight of the atom itself.

The phenomenon of rising dust occurs during the day or night, especially in the summer season, as a result of the intense heating of the earth’s surface and the surface air in contact with it, which results in a sharp instability of the surface air layer.