A satellite that took off this morning from Florida in the US is equipped with a new NASA instrument that will measure hour-by-hour, neighborhood-by-neighborhood air pollution over North America.

This scientific tool, named TEMPO, will allow the emission of pollutants to be monitored with much greater precision than before, from the source of their emission and throughout their spread by wind.

The data collected will be used primarily by the US Environmental Protection Agency (EPA) and the US National Oceanic and Atmospheric Administration (NOAA), which are responsible for air quality forecasts in the US.

The measurements of this new tool will allow the improvement of warnings issued to residents in the event of poor air quality, the better identification of the points where new detection instruments should be installed on the ground or even contribute to research on the effects of atmospheric pollutants to health.

This new tool will also monitor air pollution caused by wildfires, which are becoming more frequent due to climate change.

About 40% of Americans (137 million people) live in areas where air quality is poor, according to the American Lung Association. Very poor neighborhoods are disproportionately affected.

Air pollution causes about 60,000 premature deaths annually in the US. It also hurts the economy, as it affects the productivity of workers or even crops.

– “All the time” –

The satellites currently used in the US to make measurements of this kind are at an altitude of about 700 kilometers and orbit the Earth about fifteen times a day.

“So every day we can have readings over New York at 1:30 p.m. for example,” Caroline Nowlan, an atmospheric physicist at the Center for Astrophysics, explained at a press conference. But “there’s a lot going on in a day in New York. There are two peak hours where we can’t get metrics,” he said.

TEMPO, which weighs just under 140 kilograms, will be attached to a satellite in geostationary orbit at an altitude of more than 35,000 kilometers. It will therefore rotate around the Earth at the same time that it rotates around itself, which will allow it to always be over North America.

“For the first time we will be able to take measurements around the clock over North America,” added Nowlan, expressing her satisfaction.

Geostationary orbit is very common in telecommunications satellites, and TEMPO was placed on one of them: the Intelsat IS-40e satellite.

– Ozone and nitrogen dioxide –

SpaceX’s Falcon 9 rocket carrying the satellite with NASA’s new instrument blasted off today at 00:30 local time (07:30 Greek time) from the Kennedy Space Center in Florida. It will take about two weeks to get into proper orbit, according to Jean-Luc Freliser, vice president of Intelsat.

Then he can start his business.

TEMPO will work by analyzing the light reflected off the surface of clouds, with the help of a spectrometer. Each gas absorbs light differently, so “we can see what’s in the atmosphere by the colors or wavelengths of the light that’s absorbed,” Nowlan explained.

TEMPO will make three basic measurements.

First, it will measure nitrogen dioxide produced by combustion, mainly from cars running on petrol or diesel, but also from coal or natural gas-fired power stations.

Second, ozone, which when it is high in the atmosphere protects us from the Sun’s radiation, but becomes harmful to health when it is on the ground.

Finally formaldehyde, which can be used to infer the presence of volatile organic compounds. These are “what make certain things smell, like paint, gasoline,” explains Nowlan.

TEMPO, which will be in operation for at least two years, though it is certain to operate for much longer, will join NASA’s roughly 25 Earth-observing missions.

A similar instrument to TEMPO, called GEMS, is already in geostationary orbit to fulfill the same mission over Asia after it launches in 2020.

And another, Sentinel-4, is expected to depart in 2024 to cover Europe.