Trends in Global NO2 Emissions in the First Quarter of 2020

NASA Satellite Data Visualization

April 16, 2020
Recently, NASA published data on NO2 emissions in the atmosphere over China in January and February 2020. The “significant decrease” in February NO2 emissions was “at least partly related to the economic slowdown following the outbreak of coronavirus.” 1; Using data collected separately,2 we noted similar trends in China for January and February (see Figure 1). For March 2020, we observed an increase in NO2 emissions—possibly related to resumed industrial activities and consistent with China’s rise in manufacturing purchasing managers Index (PMI) in March³ — though NO2 emissions had not returned to what they were in January 2020.

Figure 1 China

Figure 1: China NO2 tropospheric column density, screened for Cloud Fraction <30%( 1e+14 molec/cm2) for the first quarter (Q1),2020


In Italy, NO2 emissions data followed a different pattern than in China. In February, NO2 emissions were only marginally lower than in January. However, consistent with manufacturing shut downs, March 2020 data showed visible decreases in NO2 emissions (see Figure 2).

Figure 2 Italy

Figure 2:  Italy NO2 tropospheric column density, screened for Cloud Fraction <30%( 1e+14 molec/cm2) for the first quarter (Q1),2020.

In the United States, the atmospheric NO2 emissions are substantially lower than in China (Figure 3; note the scale differences in Figures 1 and 3). NO2 emissions decreased between January and February and again, between February and March. Example locations with visible decreases in atmospheric NO2 emissions were around Houston, the New York City area, and Los Angeles. The mid-Atlantic region had NO2 emissions similar to January 2020.

Figure 3: United States NO2 tropospheric column density, screened for Cloud Fraction <30%( 1e+14 molec/cm2) for the first quarter (Q1),2020


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Sources

1 https://earthobservatory.nasa.gov/images/146362/airborne-nitrogen-dioxide-plummets-over-china?utm=carousel

2 Source data: Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite (https://disc.gsfc.nasa.gov/)

3 https://www.marketwatch.com/story/caixin-china-manufacturing-pmi-rebounds-in-march-2020-03-31

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