USRA scientists participate in NASA study revealing 30 percent drop in air pollution in Northeast U.S.
Columbia, MD and Washington DC—April 20, 2020. Over the past several weeks, a team of scientists using NASA satellite measurements have revealed significant reductions in air pollution over the major metropolitan areas of the Northeast United States. Similar reductions have been observed in other regions of the world. These recent improvements in air quality have come at a high cost, as communities grapple with widespread lockdowns and shelter-in-place orders as a result of the spread of COVID-19.
Universities Space Research Association’s scientist Lok Lamsal, part of a team of scientists working in collaboration with colleagues from NASA Goddard Space Flight Center in Greenbelt, Maryland, has contributed to process and analyze NASA satellite measurements from the AURA satellite that revealed significant reductions in air pollution. Another USRA scientist Fei Liu, was previously involved in measuring the reduction in pollution over China.
One air pollutant is nitrogen dioxide, primarily emitted from burning fossil fuels (diesel, gasoline, coal) for transportation and electricity generation, and changes in its levels can be used as an indicator of changes in human activity.
This team's research has shown a decrease in nitrogen dioxide as a result of COVID-19 and reduced activity. The images above show average concentrations of atmospheric nitrogen dioxide as measured by the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. The left image in the slider shows the average concentration in March of 2015-19, while the right image in the slider shows the average concentration measured in March of this year.
Though variations in weather from year to year cause variations in the monthly means for individual years, March 2020 shows the lowest monthly atmospheric nitrogen dioxide levels of any March during OMI data record, which spans 2005 to the present. In fact, the data indicate that the nitrogen dioxide levels in March 2020 are about 30% lower on average across the region of the I-95 corridor from Washington, DC to Boston than when compared to the March mean of 2015-19. The choice of the 2015-2019 period as an averaging window is made because of a trend detected in the OMI data during the previous decade, which would make the comparison more difficult to interpret. The reasons for this trend, unrelated to the current study, need to be investigated separately.
Further analysis will be required to rigorously quantify the amount of the change in nitrogen dioxide levels associated with changes in emissions versus natural variations in weather.
For more information, go to : https://www.nasa.gov/feature/goddard/2020/drop-in-air-pollution-over-northeast/
The visual in this article can be downloaded at NASA's Scientific VIsualization Studio.
Founded in 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA) is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs, under Federal funding. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise. More information about USRA is available at www.usra.edu.