NASA's Goddard Space Flight Center
These global maps show NO2 levels in the atmosphere as detected by the Ozone Monitoring Instrument aboard the Aura satellite, averaged over 2005 and 2014, respectively.
The impact of technology to reduce emissions of nitrogen dioxide and sulfur dioxide from coal-fired power plants is apparent in satellite imagery, which shows the signal of pollution blink out over time. Still, while air quality is improving, power plant emissions of carbon dioxide – a greenhouse gas – remain an issue.
Pollution builds up along the U.S. East Coast as it passes from one city to the next, particularly in the Northeast Corridor. These cities include Richmond, Washington, Baltimore, Philadelphia, New York City, Boston and all the smaller cities in between. Some of the largest absolute changes in nitrogen dioxide have occurred in this corridor.