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Welcome to the website!  Currently, the website is devoted to one air pollutant, nitrogen dioxide (NO2), which is unhealthy to breathe and a necessary ingredient for the formation of unhealthy levels of surface ozone, another important pollutant.  Our intended audience is health and air quality managers, but there is a lot of content that will be of interest to many people, including plots of data for almost 200 world cities!


What is the air quality like in your city and country?  Just click on the "Data" tab above and then "World Regions" to see. 

Before and After: World Nitrogen Dioxide Levels, 2005-2014

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

The animation above shows how levels of Aura Ozone Monitoring Instrument (OMI) NO2 data have changed over the last decade around the world.  More information for each region can be found under the "Data" and then "World Regions" tabs.

Here you can:

  1. Download prepared images ("Maps" tab) and ascii files ("Data" tab) of the Aura Ozone Monitoring Instrument (OMI) NO2 observations for major US & world cities and US power plants;
  2. Browse free data and visualization resources available to the public ("Resources" tab);
  3. Download publications on how the trends and variations in OMI NO2 data compare to those in Environmental Protection Agency (EPA) Air Quality System (AQS) surface data and Continuous Emissions Monitoring System (CEMS) emissions data from power plants ("Publications" tab);
  4. View NASA media related to air quality ("Media" tab).

We value your input!  Please feel free to send your questions and comments to us.

Disclaimer:  We urge users of any scientific data to carefully interpret the data, including the data presented in the figures and tables on this website, so that one does not draw erroneous conclusions.  The overall uncertainty associated with the data is a combination of uncertainties associated with the instrument and those introduced during the creation of the data product, which is a multi-step and sometimes imperfect process that may lead to inaccurate data for some areas (e.g., Duncan et al., 2014).  We attempted to filter these data artifacts.  However, we did not verify all changes in NO2 levels for all cities and regions with independent data, particularly as independent data are oftentimes sparse or nonexistent.

For scientific studies, OMI NO2 data may be downloaded from the following websites:

Level 2 OMI NO2 data:

High resolution L3 data (0.1x0.1):

AQ Managers!  There are two important & free NASA resources: AQAST + ARSET.

AQAST LogoNASA Air Quality Applied Sciences Team (AQAST) - AQAST team members will work with you on your air quality issues using a combination of satellite data, surface data, and models.


ARSETNASA Applied Remote SEnsing Training (ARSET) - The ARSET program offers free webinars and in-person trainings on the use of NASA satellite data for Health and Air Quality Applications.

Please visit the AQAST and ARSET websites for more details.

A Little Bit about the NASA Aura Mission

The NASA Aura satellite has been collecting observations of air pollutants in Earth's atmosphere for more than a decade.  One of the four instruments on the Aura satellite, the Ozone Monitoring Instrument (OMI), collects data on several important air pollutants:  nitrogen dioxide (NO2), sulfur dioxide (SO2) and formaldehyde (HCHO).