Sand haze

From Glossary of Meteorology

sand haze

Reduced visibility in the atmospheric boundary layer caused by suspended particles of soil, mixed into the air during strong winds.

Sand haze is particularly prevalent in desert regions where there is little moisture and few plants to hold the sand grains to the surface. After a sandstorm the larger sand grains will fall out of the air quickly, leaving a sand haze of medium size particles (1–100 μm diameters, including silt and fine sand) and small particles (< 1 μm diameters, including clay particles).
See sandstorm, haboob, aerosol, airborne particulates.