Air pollution monitoring is not a new activity but tracking pollutants from the realms of space is a first. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) system, launched on April 6, 2023, has generated its first data maps documenting air pollution hot spots throughout North America.

TEMPO, a collaboration between NASA and the Smithsonian Astrophysical Observatory, makes hourly daytime scans of the lower atmosphere over North America from the Atlantic Ocean to Pacific coast and from roughly Mexico City to central Canada. The primary instrument is an advanced spectrometer that detects pollution normally hidden within reflected sunlight. From its orbit 22,000 miles above the equator, TEMPO is the first space-based instrument designed to continuously measure air quality with the resolution of a few square miles.

The first maps from the mission show concentrations of nitrogen dioxide gas from pollution around large cities and major transportation routes in North America. According to NASA, the visualizations show six scans made between 11:12 a.m. and 5:27 p.m. EDT on August 2. The data were gathered during July 31 to August 2, when mission controllers opened the spectrometer to look at the sun and Earth and start a variety of tests and solar calibrations.

Observations by TEMPO are expected to improve studies of pollution caused by rush-hour traffic, the movement of smoke and ash from forest fires and volcanoes and the effects of fertilizer application on farmland. In addition, TEMPO data will help scientists evaluate the health impacts of pollutants and aid in the creation of air pollution maps at the neighborhood scale, improving understanding of disparities in air quality within a community.