A multi-year airborne science mission is on its way to Texas to help scientists better understand how to measure and forecast air quality from space.
Two NASA aircraft equipped with scientific instruments will fly over the Houston area throughout September of 2013. One aircraft will fly as low as 1,000 feet off the ground.
The aircraft are part of NASA's five-year DISCOVER-AQ study, which stands for Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality.
Researchers are working to improve the ability of satellites to consistently observe air quality in the lowest part of the atmosphere. If scientists could better observe pollution from space, they would be able to make better air quality forecasts and more accurately determine where pollution is coming from and why emissions vary.
A fundamental challenge for space-based instruments monitoring air quality is to distinguish between pollution high in the atmosphere and pollution near the surface where people live. DISCOVER-AQ will make measurements from aircraft in combination with ground-based monitoring sites to help scientists better understand how to observe ground-level pollution from space.
"DISCOVER-AQ is collecting data that will prepare us to make better observations from space, as well as determine the best mix of observations to have at the surface when we have new satellite instruments in geostationary orbit," said James Crawford, the mission's principal investigator at NASA's Langley Research Center in Hampton, Va. "NASA is planning to launch such an instrument, called TEMPO, in 2019."
Because many countries, including the United States, have large gaps in ground-based networks of air pollution monitors, experts hope satellites can provide a more complete geographic perspective on the distribution of pollutants.
A fleet of Earth-observing satellites, called the Afternoon Constellation or "A-train," will pass over the DISCOVER-AQ study area daily in the early afternoon. The satellites' data, especially from NASA's Aqua and Aura spacecraft, will give scientists the opportunity to compare the view from space with that from the ground and aircraft.
"The A-Train satellites have been useful in giving us a broader view of air pollution than we've ever had before," said Kenneth Pickering, DISCOVER-AQ's project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "DISCOVER-AQ will help scientists interpret that data to improve air-quality analysis and regional air quality models."
Flights are scheduled to start Sept. 4 and continue through the month. A four-engine P-3B turboprop plane from NASA's Wallops Flight Facility in Wallops Island, Va., will carry eight instruments. A two-engine B200 King Air aircraft from NASA Langley will carry two instruments.
Sampling will focus on the Houston metropolitan area ranging from Conroe in the north to Galveston in the south.
The flight path is designed to pass over and complement the air quality information gathered at ground measurement sites operated by the Texas Commission for Environmental Quality and the City of Houston. Many of these sites will be augmented with additional measurements by DISCOVER-AQ and collaborating scientists sponsored by the Texas Air Quality Research Program.
The 117-foot-long P-3B will sample the composition of air outside the aircraft as it spirals between altitudes from 15,000 feet to as low as 1,000 feet over the ground sites. The smaller B200 King Air will collect data looking downward from an altitude of 26,000 feet. The plane's instruments will look down at the surface, much like a satellite, and measure particulate and gaseous air pollution. The two airplanes will fly from NASA Johnson’s facility at Ellington Field.
The DISCOVER-AQ mission is a partnership with the U.S. Environmental Protection Agency and National Oceanic and Atmospheric Administration. Other academic partners include the National Center for Atmospheric Research; the University of Maryland in College Park and Baltimore County; University of Colorado, Boulder; University of California-Berkeley; Pennsylvania State University, State College; University of Innsbruck in Austria; and Millersville University, Millersville, Penn.
Local partners for the Houston campaign include the Texas Commission on Environmental Quality, the City of Houston, University of Houston, University of Texas, Rice University, Baylor University, and Aerodyne Research Inc.
DISCOVER-AQ is an Earth Venture mission, part of the Earth System Science Pathfinder program managed at Langley for the Earth Science Division of NASA's Science Mission Directorate in Washington.
For more information on DISCOVER-AQ, visit:
NASA Langley Research Center