It will also be able to track differences in pollution on a neighborhood scale. Lefer expects this to be particularly useful for exposing environmental injustices, as low-income and racially segregated areas are more likely to be located near emissions sources such as ports or refineries. “And the satellite data can show that,” he says. Weather forecasting would benefit, too: With information continually being collected across greater North America, agencies would be able to infer future conditions more accurately, particularly in places where data is currently only available for a certain period of the day.
But this mission also has its limitations: Satellites only look down, just as ground-based remote-sensing monitors only look up. That’s why this summer NASA will partner with NOAA, the National Science Foundation, and many other institutions to fill in the gaps between space and Earth, says chemist Gregory Frost of the National Oceanic and Atmospheric Administration. Instruments aboard NASA’s DC-8, Gulfstream III, V, and other jet aircraft will characterize trace gases and aerosols over metropolitan areas such as New York City, Los Angeles, and D.C., as well as coastal regions.
These readings will calibrate and add to TEMPO’s space data for areas lacking good coverage from satellites or the ground. Combine all of this data with information from EPA screens and weather models, and scientists will soon be able to analyze the atmosphere from multiple perspectives. “Once we do that,” Frost says, “it will be like a monitoring device for air pollution everywhere.”
Scientists are particularly interested in hunting down pollutants called PM 2.5, or particles less than two and a half micrometers in diameter. Aerosols like these make up less than 1% of the atmosphere. It’s not much, Frost says, but all air quality issues have something to do with these trace components. They harm crops, impair vision, and are small enough to lodge in people’s lungs, which can lead to cardiovascular and respiratory diseases. Smaller particles – less than 1 micrometer wide – can get into the bloodstream.
“Airborne particulate matter is one of the greatest threats to environmental health worldwide,” says David Diener, a NASA planetary scientist. But which types of PM 2.5 are most harmful to humans remains mostly a mystery. “There’s always this question of whether our bodies are more sensitive to the size of these particles, or to their chemical composition,” he says.
To find out, Diner heads up NASA’s first collaboration with major health organizations, including the Centers for Disease Control and Prevention and the National Institutes of Health. In partnership with the Italian Space Agency, they aim to launch next year an observatory called MAIA, or Multi-Angle Imager for Aerosols, that will sample the air above 11 of the most densely populated metropolitan areas on the planet, including Boston, Johannesburg, and Hill. Tel. The imager will measure the scattering of sunlight from the aerosols to get a sense of their sizes and chemical composition. This data will be passed on to epidemiologists, who will combine it with information from ground-based monitors, and compare it with public health records to see which sizes and mixes of particles are associated with various health problems, such as emphysema, pregnancy complications and preterm infants. death.