Smokes from wood burning and combustion are responsible for creating large pollution plumes in form of brown cloud. This occurs when the organic molecules in the smoke interact with ozone and the smokes created the brown cloud.
Two chemists from the University of Kentucky have found that process of smokes created the brown cloud in the atmosphere. The smokes from wood burning, combustion from the power plants and industrial processes are responsible for the brown cloud appearance.
Graduate student Liz Pillar-Little and the Assistant Professor Marcelo Guzman revealed the process of how smokes created the brown cloud in their recent laboratory research. Pillar-Little and Guzman exhibited in their research that the aromatic molecules from the burning process formed the light-absorbing aerosols under a certain high humidity. Moreover, new molecules such as pyruvic acid can be formed following interaction between the smokes and the atmosphere.
The process of smokes created the brown cloud began when the organic molecules in smokes meet the ozone particle in the atmosphere. As these two met, the aerosol particles are created, and the particles suspended in the air. The aerosol particles scattered and absorb the sunlight, resulting in the reduction of visibility and decreasing the air quality.
The presence of sunlight can also trigger another formation of aerosol particles, which explain further of how the smokes created the brown cloud process. This new process of the forming of aerosols may actually become the source of organic components in the aerosols that absorb the sunlight.
Pillar-Little and Guzman have published their research in the journal Environmental Science and Technology. The report explains the detail of chemical transformations from the emission of molecules from forests fires, combustion in power plants, and industrial processes into the large smokes created the brown cloud.
Aerosols particles suspended in the atmosphere include the desert dust and sea salt from the ocean, aside from the smokes created the brown cloud. Watch the short video explaining the aerosol below:
