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Valley Public Radio Staff
Fri January 18, 2013
NASA Flights Over Fresno, Bakersfield Hope to Predict Air Quality From Space
NASA scientists and aircraft took to the skies above Fresno and Bakersfield today. It's part of a project that one day hopes to predict and air quality from space.
Two aircraft, including a converted Navy P3-B flew repeated loops over various valley cities today, one of them as low as 1,000 feet, to gather air samples. It's part of a program NASA calls DISCOVER-AQ which aims to better understand pollution spikes and how pollutants react with sunlight throughout the day.
"They're flying a circuit repetitive from Bakersfield to Fresno from the north to the south and from Porterville to Huron from east to west," says Jim Crawford, a research scientist at NASA's Langley Research Center in Virginia. He is the principal investigator for the project.
"In the future we hope to use satellites to monitor air quality from space. And the project that we're engaged in right now is a test bed for starting to demonstrate that capability." says Crawford.
But before that can happen, Crawford's team needs to determine just how much of the pollution they see from space is at ground level and how much is higher up in the atmosphere.
"It flies up and down the valley and performs soundings or profiles in the atmosphere over ground sites that the state of California uses to monitor air quality. So what we're trying to do is to demonstrate how much of the polluting material is at the ground level where people are exposed, versus above or ahead where they're really not exposed, but a satellite would also see that portion of the pollution," says Crawford.
Crawford says that by the end of the decade, NASA hopes to have a new satellite in a fixed orbit that can be used to make better air quality predictions.
"Right now most satellites are "sling-shotting" around the globe, so they really only look at California for instance once a day. But you all know as emission are put in the atmosphere in the early morning with people [in] rush hour and people going to work and all the activity that begins, sunlight cooks those emissions throughout the day," says Crawford.
"Air quality is something that's very dynamic. So between the morning, midday and afternoon, most of your severe air quality problems don't exist until much later in the day. By looking all day long from geo-stationary orbit you get the opportunity to watch that unfold in time and try to understand what factors are controlling the air quality problem and hopefully not just be able predict that it's going to happen but start to come up with some strategies for trying to help mitigate the problem."
David Lighthall, with the Valley Air District says the project also will help the district better determine the sources of pollution, especially during wildfires.
"The ability to track with satellite both the particulate matter, as well as the gasses, ozone or NOx [nitrogen oxides], that are being carried by those wildfire plumes are pretty important for the district. What happens is we had very high ozone and PM 2.5 [particulate pollution] in the summer during the 2008 wildfires, and those were creating violations for us, and of course, it was due to conditions outside of our control. So we have to be able to document scientifically to the U.S. EPA that those exceedences were the result of a natural event," says Lighthall.
Crawford says the next step is analyzing the data they gathered this week, comparing it with samples from the ground and existing satellites, and writing computer software that will help scientists better understand the problem for the future.
NASA hopes to take delivery of the new satellite by 2017 and have it operational by 2019 or 2020.