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NASA Air Quality Analysis of the COVID-19 Pandemic

NASA’s Air Quality group will regularly produce images from Aura's Ozone Monitoring Instrument data, showing how nitrogen dioxide (NO2), an air pollutant, is changing due to the evolving restrictions during the COVID-19 pandemic. The group will also produce images of other air pollutants, such as sulfur dioxide (SO2).

NO2 is primarily emitted from burning of fossil fuels (diesel, gasoline, coal) while driving cars and generating electricity. If the data are properly processed and interpreted, changes in NO2 levels can be used as an indicator of changes in human activity.

Major anthropogenic activities that emit SO2 include electricity generation, oil and gas extraction, and metal smelting. SO2 is emitted during electricity generation if the coal burned has sulfur impurities that are not removed (or not “scrubbed”) from the plant’s exhaust stacks.

All imagery will be archived on the Air Quality news page, as well as on NASA’s Scientific Visualization Studio website (here and here). These images are free and publicly available.

Latest NO2 Imagery Related to Restrictions in Place Due to COVID-19:

South America: On June 1, the World Health Organization noted that Central and South American countries have become “the intense zones” for COVID-19 transmission. The Ozone Monitoring Instrument (OMI) on board NASA’s Aura satellite provides data that indicate that restrictions on human activity have led to about a 36% decrease in NO2 levels in Rio de Janeiro, Brazil, relative to previous years. Other large cities in South America show similar decreases in NO2: 36% in Santiago, Chile; 35% in São Paolo, Brazil; and 40% in Buenos Aires, Argentina. One notable exception is in Lima, Peru, showing a 69% decrease. The large decrease may partly be associated with natural variations in weather that can, for instance, disperse air pollution more quickly. Additional analysis is required to determine the amount of the decrease of NO2 in Lima that is associated with a decrease in human activity. A notable increase in NO2 occurred in northern South America, which is likely associated with increased agricultural burning in 2020 relative to previous years.

South America 2015-2019 vs 2020

SA 2015 SA 2020

Figure caption: The slider above shows satellite estimates of NO2 from Aura’s Ozone Monitoring Instrument (OMI) as an average of April 15 through May 31 over South America. The image on the left shows the mean of the 230-day period from 2015 through 2019, while the image on the right shows the mean of the 46-day period for 2020. The sliders below show the same information, but zoomed to show five major South American cities. The images are free and publicly-available and may be downloaded.

Buenos Aires slider

Lima slider

Rio de Janeiro & São Paulo slider

Santiago slider

Media Requests: Contact Peter Jacobs.

How does NASA monitor air pollution? Listen to the NASA ARSET introductory webinar, which is intended for the public, journalists, meteorologists, and others new to remote sensing. The webinar was delivered in English and en español.

Technical Experts in Remote Sensing: More detailed information is available for individual world cities, but this information is for technical experts (i.e., not the media or casual viewer) as care needs to be taken when interpreting the data. You may access and visualize the OMI NO2 data.


Original Homepage Begins Here: NASA's Fleet of Earth Observing Satellites: Monitoring Our Planet's Health

NASA has a fleet of Earth-observing satellites whose instruments observe our planet's oceans, biosphere, and atmosphere. Several of these satellites have instruments that observe air pollutants around the world. The data collected are being used by air quality managers and researchers studying the impact of air pollution on human health and agriculture.


Air Pollutants Observed from Space

Nitrogen Dioxide (NO2): NO2 is unhealthy to breathe and is primarily generated during fossil fuel combustion, so thermal power plants and automobiles are the dominant sources.

Ozone (O3) & Precursors: At Earth's surface, O3 is unhealthy to breathe and also negatively impacts plants, reducing crop yields.

Particulate Matter (PM) & Precursors: PM are tiny particles (e.g., smoke and dust) that cause numerous health issues when breathed in.


Impacts of Air Pollution: How Satellite Data Can Help

Human Health: Exposure to outdoor air pollution is responsible for an estimated 4 million premature deaths annually with about another 3-4 million resulting from exposure to indoor air pollution; that is, air pollution is responsible for about 1 in 9 deaths worldwide (WHO, 2018;  Cohen et al., 2017).

Agriculture: The economic impact of crop yield loss due to pollution is significant all over the world. Air pollution causes global crop yield losses for wheat, corn, and soybeans that are estimated to range from $11-18 billion annually, with the greatest economic loss estimated to occur in the United States ($3.1 billion).


Global ABS Visualization for 2005Global ABS Visualization for 2014
Image Credit: 
NASA's Goddard Space Flight Center

The slider above shows satellite data of nitrogen dioxide (NO2) from the Aura Ozone Monitoring Instrument (OMI) data for two years, 2005 (left) and 2016 (right). The data indicate that levels of this pollutant changed significantly over the last decade in many places around the world.  Slide the bar from back and forth to see these changes.  More information on NO2 trends for each region and more than 300 world cities can be found under the Nitrogen Dioxide tab.


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