The combustion traces outline a map of settlements and industry in a timely manner, published at the Descartes Labs. The silver plots and threads represent the emissions of nitrogen dioxide, the gas produced during combustion, which contributes to acid rain, fog and lung problems. Although there are natural sources of nitrogen dioxide, people are the main emitters, according to the Environmental Protection Agency. Cars, trucks, power plants, factories and even lawn mowers and construction machinery can pump nitrogen dioxide into the atmosphere. Forest fires and agricultural products can also be burned. "You look at a map that shows where things are burned," says Laura Mazzaro, an atmospheric scientist and environmental engineer at Descartes.
The data comes from satellite Sentinel 5P – a satellite launched in October 2017, which controls the atmosphere. This is part of a family of satellites launched by the European Space Agency, designed to monitor our planet. Other satellites in this series look at things like vegetation, temperature, and even observe cracks in Antarctic ice.
This map is one of the versions of a series of images that Descartes labs released in February, first reported to Axios. To do this, researchers in Descartes created a composite of individual images that the Sentinel 5P satellite captured in August and September 2018, according to Tim Wallace, a graphic design that runs in Descartes. Cloudy days and low-quality images are filtered to create a map of the average amount of nitrogen dioxide in the lowest part of the Earth's atmosphere "any day during these two months," Wallace says.
Nitrogen dioxide does not survive long enough in the atmosphere to travel far from the place where it is produced. So, you expect nitrogen dioxide emissions to be concentrated on cities where more people travel by car. But there are some unexpected sources, says Wallace. "In the middle there are no ships and industrial cities," he explains.
In combination with nitrogen dioxide that shines over cities, these traces, which occur otherwise in dark areas of maps, give a clear idea of how we, people, pollute the air we breathe, almost everywhere we go.