When Front Range residents look to the skies for the next few weeks, they may see something unusual – a NASA P-3 airplane buzzing just a thousand feet above.
The plane is one of three research aircraft plying the skies, as scientists from NASA and the National Center for Atmospheric Research work to learn more about air pollution in Colorado.
Jim Crawford is the principal investigator for NASA's flight campaign, an experiment called DISCOVER AQ. The long-term goal of this campaign is to learn how to accurately measure air quality from space, via satellite, he said.
"The long term product is the satellite. We expect the satellite that launches by the end of the decade to be better because of what we've done. We expect what we do to impact Colorado's assessment of its [air] monitoring strategy into the future," said Crawford.
The project in Denver is the fourth and final campaign of a five-year, $30 million effort that included flyovers in the Baltimore-Washington area, California's Central Valley, and Houston. Crawford said he chose Denver because it has ozone levels that exceed Environmental Protection Agency standards, has interesting geography and meteorology, and hundreds of expert atmospheric chemists to collaborate with, due to the concentration of federal and university scientists in the area.
For four weeks starting July 15, NASA will be flying two airplanes, each equipped with a number of sensors, over the Denver area. One, a small King Air from Langley Air Force Base, will fly high above the area, at 27,000 feet, measuring air quality as a satellite would. It has Lidar and another instrument, called ACAM that measures a wide range of pollutants.
The other, a P-3B from the NASA Wallops Flight Facility in Virginia, may be the one locals will notice. As it flies, it spirals through the air, getting a three-dimensional profile of air quality. Many of those flights will take place over the foothills, but also from Greeley to Platteville, from Denver to Golden, and from Erie to Denver, flying over existing ground-based air quality monitors, said Crawford.
"We'll be flying as low as 1,000 feet, which means we'll be easily noticeable," he said. "But you won't see us for long because at that altitude once we go over we're out of sight pretty quick."
If all goes well, NASA will eventually learn how to make sure the high-flying measurements from the King Air to match with both ground measurements, which are very accurate, and what the P-3 finds along its profiles.
Joined By Another Collaborative Research Flight
The National Center for Atmospheric Research is also flying its own plane, a C-130, at the same time for a research project focused on ozone. The ability to have three planes taking simultaneous air quality measurements will help scientists better understand air pollution in the area, said Gabriele Pfister, a principal investigator on the NCAR project.
Scientists know that ozone, which can hurt human health and diminish crop yields, is caused by chemicals like nitrogen oxides and volatile organic chemicals reacting with sunlight to form the pollutant. They are less sure, though, which sources of pollutants – whether it be agriculture, oil and gas, or fossil fuel combustion, or some combination – are responsible for ozone forming.
"If we know what are all these different factors, how do they play together, we can find ways to most efficiently address the problem and achieve cleaner air in the Front Range," Pfister said.
Gordon Pierce, of the air pollution control division at the state's Department of Public Health and Environment, agreed.
"It's always been a question of what are really the sources for ozone," he said.
The CDPHE is collaborating very closely with NASA and NCAR, and even put out six additional ozone monitors to support the project. Pierce said he hopes the department will be able to use the information from the research to inform everything from new regulations that reduce pollution to where they decide to locate air quality monitors.
In addition to the flights and ground-based monitors, scientists also have a balloon in Golden, and vans that will travel around monitoring air quality.
Shaun McGrath, administrator for EPA's Region 8, headquartered in Denver, called the campaign and the quantity of measurements a "huge step" for people who care about air quality.
"We're talking about going from black and white to color TVs, or perhaps more accurately, from 2D to 3D," he said.
