Lockdown puts increased pressure on coal-fired power plants in Central-Western India, satellite data shows
NEW DELHI, Dec 27 (The CONNECT) - Parts of central-western India and north India showed an increase in pollution whereas reduction of economic activities during the pandemic-related lockdown had resulted in decrease of air pollution in most parts of India.
Based on state-of-the-art satellite observations, scientists have identified that regions in the central-western part of India and north India are prone to higher air pollution exposure and hence are exposed to greater risk of respiratory problems than other regions.
In the study published in ‘Environmental Science and Pollution Research’ led by Prajjwal Rawat, a senior research fellow at ARIES Nainital, along with his research supervisor Dr. Manish Naja, showed that ozone, carbon monoxide, and NO2 showed an increase of about 15% over the central-western part of India.
The vertical distribution in CO shows a systematic increase (as high as 31%) in the lower troposphere, middle troposphere, and upper troposphere over the majority of Indian regions, including over the thermal power plants regions. This feature was more prominent over the western regions.
An increase in CO and NO2 during the lockdown period is suggested to be largely due to increased power production in coal-based thermal power plants (TPPs) that has also induced an increase in ozone.
Lockdown had provided a good opportunity to assess the impact of the coal-based thermal power plants in India, when the majority of other emissions were at nominals.
Multi-satellite remote sensing of air pollutants has evolved dramatically over the last decade. Synergic measurements of satellite and in-situ observation provide a more comprehensive understanding of air pollution episodes.
In 2020, a complete nationwide lockdown was imposed over India to impede the spread of coronavirus disease. This enormously disrupted the economy with a single positive side effect, a short-term improvement in the air quality near the surface.
The satellite-based observation of toxic trace gases, -- ozone, NO2, and carbon monoxide near the surface and in the free troposphere mostly showed
Details the study can be see here
reduction of the pollutants over India. However, over some regions like western - central India, some parts of Northern India, and Remote Himalaya, an increase of ozone and other toxic gases was observed. This could have aggravated respiratory health risks around those regions during the pandemic.
Scientists at the Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institute under the Department of Science & Technology (DST), Govt. of India, utilized the EUMETSAT and NASA satellite observations for the year 2018, 2019, and 2020, and investigated the influence of significant cutoff of anthropogenic activities on the changes in the vertical and columnar distribution of ozone, CO, and NO2 during the lockdown period.
According to the results, carbon monoxide showed a consistent increase (as high as 31%) of concentration at higher heights during the lockdown. The long-range transport and downward transport from the stratosphere significantly increased ozone concentrations over north India during the lockdown, and remote regions like the Himalayas and coastal cities showed the bare minimum influence of lockdown in air quality, with a tendency to increase in criteria air pollutants.
The ARIES team explains ozone production and loss are constrained through the complex photochemistry involving its precursor gases like NOx and VOCs. A decrease in its precursor gases could also lead to enhancement of ozone, depending upon the chemical environment. Moreover, ozone concentrations are also altered via ambient meteorology and dynamics, including the downward transport of ozone-rich air from the stratosphere to the troposphere.
According to the ARIES team, this study helped to identify the regions prone to higher air pollution exposure hence can identify areas at a greater health risk. The team previously, with scientists from the ISRO, showed INSAT-3D as a valuable Indian geostationary satellite to study ozone pollutions over India; however, for other criteria air pollutants (i.e., NO2, SO2, CO, VOCs, etc.), India is lacking in space-based observations and need air quality monitoring indigenous satellite in orbit.
