NASA, ISRO Confirm Aerosol Layer Over Asian Region

The formation of the aerosol layer has been largely attributed to vehicular pollution, though final analysis of the phenomenon is still due.

New Delhi (Sputnik) — A joint study conducted by the Indian Space Research Organisation (ISRO) and National Aeronautics and Space Administration (NASA) of the USA has confirmed the presence of a layer of aerosol over Asia region.

An aerosol is produced from a variety of man-made and natural processes such as vehicle exhaust, waste-burning, dust, volcanic eruptions and is majorly restricted to the first few kilometers from the surface of Earth's atmosphere called as the upper troposphere and lower stratosphere (UTLS).

The ISRO-NASA study which began after satellite images gave preliminary evidence of aerosol layer has also confirmed the presence of nitrate in the aerosol layer.

"The joint team has confirmed the presence of aerosol layer seen in satellite measurements over the Asian region and it also shows a sharp increase of aerosol concentration near 16.5-18.5 km from Earth's surface," ISRO said in a statement said.

This layer contains particles that are less than 0.25 micron in size and are 90 percent volatile. It appears the aerosol is formed from precursor pollutant gases which are transported via convection from the ground, the statement added.

The statement was issued by the Indian space agency after the National Atmospheric Research Laboratory and a team from NASA monitored and analyzed air quality around India as part of the study. Preliminary chemical analysis of samples collected in this campaign indicates the dominant presence of nitrate.

Presence of nitrate is a new finding and the converging air masses over the northern part of India during Asian monsoon (July-August) has been found to be the main reason which lifts aerosols and trace gases to the UTLS.

Detailed analysis of the phenomenon is still due and additional study during winter months for obtaining the background conditions is planned. The joint team also has plans for multiple studies until 2020 to comprehensively understand the aerosol layer.