What is the impact of dust aerosol on the climate system?

Dust refers to solid particles suspended in the air. Traditionally, there are many names for dust, such as dust, dust, smoke dust, mine dust, sand dust, powder and so on. These terms have no clear boundaries.

Aerosol is a suspension system of liquid or solid particles in air. They can be used as condensation nuclei of water droplets and ice crystals (see atmospheric condensation nuclei, atmospheric ice nuclei), absorbers and scatterers of solar radiation, participate in various chemical cycles, and are important components of the atmosphere. Fog, smoke, haze, light fog (haze), dust and smoke are all atmospheric aerosols caused by natural or man-made reasons.

According to their sources, aerosols can be divided into primary aerosols (directly entering the atmosphere from the source of occurrence in the form of particles) and secondary organic aerosols (produced by the transformation of primary pollutants in the atmosphere).

Aerosol particles have the characteristics of uneven distribution, small change scale and complexity, and are mostly concentrated in the bottom of the atmosphere, which plays an important role in the formation of cloud condensation nuclei, raindrops and ice crystals, and then the formation of precipitation. Aerosols can even change the existence time of clouds, produce chemical reactions on the surface of clouds, determine rainfall and affect atmospheric composition.

Aerosol particles can affect weather and climate in two ways. On the one hand, it can reflect sunlight into space, thus cooling the atmosphere and making the visibility of the atmosphere worse. On the other hand, it can reduce the escape of long-wave radiation on the ground, and heat the atmosphere through particle scattering, diffusion and absorption of part of solar radiation.

Aerosol is an extremely important part of the atmosphere, which not only directly affects human health, but also increases the chemical reaction of the atmosphere, reduces visibility, increases the possibility of precipitation, cloud formation and fog formation, affects the atmospheric radiation budget, and leads to changes in environmental temperature, plant growth rate and material pollution.