NASA's launching a new mission this summer designed to better understand air pollution.
Crawford says traditionally most air quality measurements have been taken from the ground and only in a few locations.
"With that kind of information, it's easy to tell when we have poor conditions, but it's difficult to paint a complete picture of how those conditions play out across the area," he says.
NASA will fly two aircraft over the ground locations that are generally used to monitor air quality, set up by the Maryland Department of the Environment. One will fly at a lower altitude to sample the air around it, and the other will fly at a higher altitude to look at pollution below it. Crawford says flights at different altitudes will offer information about the pollution at the surface, "where it influences people," and the pollution that's higher in the atmosphere, which is currently difficult for satellites to monitor.
"Trying to distinguish between the two is a particular difficulty," he says.
By integrating satellites, Crawford says scientists could forecast poor air quality conditions. Satellite technology could also help scientists analyze where pollution comes from and then figure out how to mitigate it.
Crawford says this is the first deployment over an urban area, but NASA scientists have plans to do three more deployments over the next four years. Each site has pollution for distinct reasons.
The aircraft in the Baltimore-Washington experiment will only fly during the day. Test flights begin next week, but the entire project will last through the end of July.