Burning produces various gases and particulates. Particulates containing carbon are called carbonaceous aerosols.
Example of human activities resulting in biomass burning:
  •     Agriculture activities: burning of agriculture wastes; burning of forests to extend agriculture land, etc.
  •     Cooking and heating.
It is generally believed that the vast majority (>90%) of biomass burning is human initiated and that biomass burning has increased significantly over the last 100 years.




    Mineral dust is injected into the atmosphere by surface winds from dry soils where the vegetative cover is low and sparse.
The classification of mineral dust as "natural aerosol" is misleading if "natural" is interpreted as "not influenced by human activity", because the production of atmospheric mineral dust without doubt increases in areas where the soil surface is disrupted by agricultural activities or new soil surfaces are exposed to wind erosion through deforestation and shifting desert boundaries.

    Dust flux from disturbed sources may be stronger than dust flux from natural sources for two main reasons:

  • freshly exposed soil can contain more fine material like silt (which contributes the major part of mineral aerosol) than "aged" soil surfaces, where fine particles is likely to have been blown out already. For example, stabilized sand dunes do not act as dust sources. 
  • Also, in cultivated areas the soil surface is in general disrupted by agricultural practices, in which case a lower threshold surface wind speed is sufficient to start dust removal compared to undisturbed soil surfaces.


    Global sulfur emissions to the atmosphere have natural (volcanic, soils and plants, biomass burning, oceanic) and anthropogenic sources (industry, biomass burning).



    It is basically salt from sea spray and bursting bubbles. Therefore, it is going to depend on the wind fields.

Back to Aerosols

Back to Lecture 26