This summer, when scientists switched on a device onboard a new satellite, they were soon getting a preview of what would be the country’s first streak of air pollution.
The satellite will be docked over North America and provide scientists with an hourly daytime update on air pollution across the country. On Thursday, researchers released the first images showing changes in nitrogen dioxide pollution in the United States over the course of a day.
“It’s really exciting to see this device working as expected,” said physicist Xiong Liu, deputy mission director of the Center for Astrophysics, which is run by Harvard University and the Smithsonian Institution. A satellite instrument called TEMPO will also be able to measure several other pollutants.
These images were taken during a summer when wildfire smoke blanketed several cities and regions and U.S. air quality was very poor. But even before this summer, Americans have enjoyed improved air quality over the past decade or so, since the Clean Air Act was passed in 1970. was starting to stagnate.
Although air pollution has improved over the years, “a third of Americans still live with unhealthy levels of air pollution,” Dr. Liu said.
Nitrogen dioxide is produced by burning fuels and causes other types of pollution through chemical reactions in the air. The image shows distinct hotspots of gas around major cities, with higher levels in the morning and evening when traffic is heavier.
In addition to gazing down at Earth with the new satellite, scientists will spend July and August this year on foot and surveys in a carefully planned rendition to understand why air quality has stopped improving. I flew all over the country.
Pollutants can travel thousands of miles quickly on the wind, making it difficult for scientists to pinpoint the largest source of pollution on a national scale. TEMPO’s hourly updates are expected to be a “genuine game-changer” in helping researchers track air pollution from its source, said an environmental engineer at the National Oceanic and Atmospheric Administration, who will work with the satellite this summer. said Brian McDonald, who is coordinating the field trip. .
Automobile traffic has historically been one of the biggest contributors to air pollution, but stricter emission standards for cars have reduced air pollution from driving. At the same time, the relative importance of consumer products and materials such as paints and pesticides that emit pollutants known as volatile organic compounds is increasing, explained Dr. McDonald.
These compounds react with nitrogen dioxide in the air to produce harmful ground-based ozone, Still high in some places, especially in California and major metropolitan areas nationwide. The upper ozone layer in the atmosphere protects us from carcinogenic UV rays, but ozone near the ground can exacerbate or cause respiratory diseases such as asthma, bronchitis, and emphysema. There is a nature.
Another persistent problem is particulate contamination. Particulate contamination consists of particles so small that they enter the bloodstream and cause heart and lung disease, stroke and, in severe cases, premature death. Also known as PM2.5, this pollution began to rise again around 2016 after several years of decline.
A study published last fall found that hotter, drier weather caused by climate change, which has increased the frequency and intensity of wildfires, appears to be the main cause of this reversal.
The study relied on older satellites to provide daily readings, said Marshall Burke, a professor of environmental policy at Stanford University and one of the study authors. He and his colleagues now rely heavily on computer models of how pollutants move in the wind to fill the gaps between real observations.
Although Dr. Burke was not involved with the TEMPO mission, he said he was looking forward to getting hourly data from the satellite, which he said would be “close to video.” “The more images we have, the easier it is to map where things came from,” he added.
TEMPO will be able to track air pollution to a resolution of about 4 square miles. So you’ll need to adjust your flights, drives, and walks this summer.
“Data from these field campaigns are being used by decoders on satellite instruments,” said Tracy Holloway, a professor of energy analysis and policy at the University of Wisconsin-Madison who studies air quality but was not involved in the project. It works like a ring.”
One place where scientists are collecting data at a detailed regional level is New York City. Even cities that routinely monitor air do not usually have enough equipment to cover all areas. This is a problem because air pollution tends to be unevenly distributed within individual cities and regions.
Since late July, 12 researchers, led by NOAA’s Audrey Godel and Pratap Ramamurthy, have taken turns in pairs carrying backpacks filled with buzzing air quality sensors. are walking Onlookers often asked if the scientists were going fishing because of the long, thin tube that protruded from the pack to suck air samples.
Every day, one of my colleagues tracked the flight path of a NASA research plane and provided updates on WhatsApp so trekkers could walk under the plane. The datasets will be compared later. The researchers surveyed more than a dozen routes, making sure to include economically disadvantaged areas and areas with large populations of people of color. These regions often face disproportionate air pollution, but little data are available.
“We hope to have better models and better predictions at the street level,” said Josira Ornelas Van Horn, another TEMPO collaborator and professor of environmental health at Columbia University. said.
It will take months to analyze all the data, but the walk itself has already revealed the relationship between climate change and air quality. (Dr Ramamurthy said the many-hour walks in midsummer were “terrible.”) In general, higher temperatures tended to result in higher ozone pollution levels, and on the hottest sampling days, ozone measurements were below national levels. Exceeded standards. Dr. Godel of the Environmental Protection Agency points out:
Data from the TEMPO satellite will be available to the public in spring 2024. During that time, over 400 users, including many state and federal agencies, have signed up as “early adopters.”
Researchers at Mount Sinai Health System in New York will use the TEMPO data to study how air pollutants affect asthma symptoms in children. The Connecticut Department of Air Management plans to use the data to investigate where the state’s unusually high ozone pollution came from.
Dr Ornelas Van Horne hopes this summer’s study will provide policy makers with the information they need to take action on the nation’s lingering air quality problems. “We all agree that air pollution is bad,” she says.