Decreasing trend in black carbon Aerosol concentrations

TIRUPATI: Scientists at the National Atmospheric Research Laboratory (NARL) have found decreasing trends in the surface (black carbon) aerosol concentrations at several locations in the past one decade.

Aerosols, the tiny particles suspended in the atmosphere, affect life through adverse health effects and have an enormous impact on climate. Aerosol sources include extensive burning of crop residue and forest fires, besides exhaust from vehicles, as also from other aspects of rapid urbanization and industrialisation. Any change in the natural and human activities alters the climate and climate-related impacts.

Gadanki, an autonomous organisation under the Department of Space located in Chittoor district, said the testing was done in its lab.

According to a research paper ‘Changing patterns in aerosol vertical distribution over South and East Asia’ published in the journal ‘Nature- Scientific Reports’, “substantial imprints of aerosols are being noticed over South-East Asia, where extensive amounts of man-made aerosols with complex chemical, physical and optical characteristics are being emitted.”

“Based on long-term satellite measurements, a ‘dipole pattern’ in Aerosol Optical Depth (AOD) has been publicised and it indicated a concurrent increase over India and reduction over China. Scientists have credited the reduction over China to clean air actions. Conversely, over India and adjoining seas, a rapid increase in aerosol loading has been reported,” said NARL scientist and Bhatnagar Awardee Dr. M Venkat Ratnam.

Dr. A.K. Patra, Director, NARL, said that the increasing trend in free tropospheric aerosol has important consequences on the background meteorology and dynamics. “Depending on the aerosol types, they can modify the cloud condensation nuclei (CCN) activity directly and the background instability indirectly, thus affecting convection and/or precipitation processes,” he said.

end-of