NASA: Air Pollution in India at 20 year low

On April 22, 2020, NASA (National Aeronautics and Space Administration) announced that Air Pollution in India has reached 20 year low.

Highlights

• According to the data published by NASA, the Aerosol Optical Depth in 2020 has been the least as compared to the average of 2016 to 2019. Aerosol Optical Depth is absorption of light by airborne particles in the atmosphere. When the aerosols are near the surface, the optical depth of 1 or above indicate hazy conditions.
• The AOD was 0.7 in 2016 and has now reached 0.1. The patterns were observed by the MODIS model. MODIS is Moderate Resolution Imaging Spectroradiometer

Aerosol Optical Depth

• The aerosols are particles in atmosphere released due to anthropogenic activities such as industries, vehicles and natural events such as dust storms, fires, etc. The presence of Aerosols in the atmosphere is also affected by particulate matter in the atmosphere.
• The Aerosol Optical Depth is the quantitative measure of aerosols present in the atmosphere. It measures the extinction of light when it passes through the atmosphere. As AOD increases, the rate of extinction of light increases.