Amid Lockdown: NASA dashboard confirms pollution drop in Delhi

Satellite data records, which show the drop in NO2 levels, have been put together by the three agencies in a Covid-19 Earth Observation Dashboard, which is also tracking changes in environment, economic activity and agriculture caused by the pandemic related restrictions across the globe.

“Air quality changes around the world were among the first noticeable impacts of pandemic-related stay-at-home orders… One air pollutant, nitrogen dioxide, which is primarily the result of burning fossil fuels for transportation and electricity generation, shows up clearly in satellite data,” a press statement by NASA said Thursday.

On April 13, the tropospheric NO2 over Delhi dropped to 31.3 micromoles per square meter (µmol/m2), the lowest level seen since July 9, 2018, as per the data from the dashboard.

In the same period last year, on April 15, the NO2 concentration over the city was 113.9 µmol/m2, more than three times higher than the levels recorded this year.

The concentration began increasing after April 13 but remained much lower than the same period last year. On June 22, the level was 76.7 µmol/m2, as compared to 102 µmol/m2 on June 24, 2019.

The dashboard also highlights how global and local reactions to the pandemic have changed concentrations of carbon dioxide (CO2), a greenhouse gas.

Data shows that in April this year, the concentration of CO2 had almost halved as compared to April 2016 in Delhi.

“These changes are very difficult to attribute to the pandemic because of the large-scale natural CO2 changes seen across India during this season,” the statement said.