Major metropolitan areas in the northeastern United States, due to restrictions and lockdowns as a result of the spread of COVID-19, are experiencing significant reductions in air pollution .
Specifically, nitrogen dioxide pollution falls by up to 30% , as confirmed by NASA satellite measurements .
The images show the average atmospheric nitrogen dioxide concentrations measured by the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite.
One image shows the average concentration in March 2015-19, and the other the average concentration measured in March of this year . Data indicates that nitrogen dioxide levels in March 2020 are approximately 30% lower on average in the I-95 corridor region from Washington, DC to Boston than compared to the March 2015-19 average.
Nitrogen dioxide (NO2) is mainly the result of the burning of fossil fuels for transportation and electricity generation, so it can be used as an important indicator of changes in human activity.
However, further analysis will be required to rigorously quantify the amount of change in nitrogen dioxide levels associated with changes in emissions versus natural variations in climate.