UH Atmospheric Sciences Participating
in NASA Air Quality Study
Month-Long Study Targets
Improved Air Quality Forecasting
Throughout September, Houston air quality measurements taken by mobile labs, ground
instruments, airplanes, and a satellite will help scientists understand how to better
interpret and forecast air quality using satellite data and numerical models.
The effort is part of a multi-year NASA air quality study, DISCOVER-AQ, which also
includes measurements in Washington, D.C., Baltimore, Los Angeles, and Denver. University
of Houston atmospheric scientists, Barry Lefer, Robert Talbot, Yunsoo Choi, and adjunct
professor Gary Morris are participating in the project along with 15 UH undergraduates
and graduate students.
Map of Houston 2013 DISCOVER-AQ
Campaign. Two NASA aircraft will fly over the Houston area through September,
one as low as 1,000 feet, to measure air pollution with a number of onboard
science instruments. (Image Courtesy of NASA)
Presently, it is difficult to accurately measure surface air quality based on satellite
data.
鈥淪atellites measure the total amount of pollution in the atmosphere, so the readings
get the upper level pollutants that don鈥檛 affect us as much, as well as the lower
level pollutants,鈥 said Barry Lefer, associate professor in the Department of Earth
and Atmospheric Sciences. 鈥淭he trick is how do you subtract off the stratosphere to
get to the measurements that you want?鈥
Massive Air Quality Data Collection
For 10 to 13 days in September, scientists are collecting an enormous amount of data
similar to what a satellite measuring air pollution would collect.
Two NASA aircraft equipped with scientific instruments are flying a fixed route over
Houston gathering air quality data. Simultaneously, five mobile labs equipped with
similar devices are driving approximately the same route. Measurements are also being
made at stationary locations around Houston and with weather balloons.
The satellite measurements are being made by a fleet of Earth-observing satellites, called the Afternoon Constellation or 鈥淎-train,鈥 which passes over Houston each day at 1:30 p.m.
鈥淯H has two mobile labs, instrumentation at 6 of the 15 ground sites, and daily weather balloon launches gathering ozone measurements,鈥 said Lefer. 鈥淲e are also hosting several monitoring devices from other universities on our rooftop lab at Moody Towers and in our mobile labs.鈥
Members of the UH mobile lab team (from left) James Flynn, Xin Lan, Robert Talbot,
and Barry Lefer with Rice University participant, William Wallace. The sampling area covers the Houston metropolitan area ranging from Conroe in the
north to Galveston in the south. 鈥淭he flight path is sort of a figure eight shape,鈥
Lefer said. 鈥淭he planes fly the route three times each flight day. With 10-13 flight
days, we鈥檙e going to get good statistics; some flights will be on clean air days and
some on dirty days.鈥
One of the NASA planes flies at 26,000 feet taking downward gaseous and particulate
measurements mimicking a satellite. The other plane flies a similar route at lower
altitudes and also makes spirals around eight locations sampling the air at various
levels over those sites. UH鈥檚 Moody Towers is one of the spiral locations.
Moody Towers Measurements
鈥淥n flight days, there are three flights over campus at approximately 10 a.m., 12:30
p.m. and 3 p.m.,鈥 Lefer said. 鈥淭he plane flies around Moody Towers starting at 1,000
feet and making about 3-4 spirals as it climbs to 12,000 feet. The spiral is big,
about 2-1/2 miles in diameter.鈥
Moody Towers also has instrumentation on its roof that is measuring everything the
plane is measuring and more. Some of the instrumentation is there year-round and other
devices belong to visiting scientists from Baylor University, Texas A&M University,
University of Colorado, Pennsylvania State University, Appalachian State University,
the Environmental Protection Agency, NASA, USDA, and NOAA. UH鈥檚 mobile labs also hold
equipment from Chalmers University (Sweden) and Rice University.
On Moody Tower, Talbot鈥檚 instrumentation is measuring carbon dioxide, methane and
mercury, and Lefer is measuring ozone, formaldehyde and four other pollutants.
Adjunct
professor Gary Morris and UH undergraduates Erika Marrero and Daniel
Sierra prepare to launch a weather balloon outfitted with ozone
measuring equipment. Launches from UH occur every day in September.
Choi鈥檚 air quality forecasting model is helping the NASA project team reach its decision
each afternoon on whether to fly the planes the next day. Morris is launching weather
balloons outfitted with ozone measuring equipment each day from campus.
鈥淭he results of this study are going to help us get a better understanding of what
the satellite is showing us,鈥 Lefer said. 鈥淚f we are better able to interpret satellite
data, then we can make more accurate air-quality analyses and forecasts. And, that
will have a big impact on human health.鈥
葫芦影业鈥檚 participation is funded by grants from the Texas Air Quality
Research Program and the Texas Commission on Environmental Quality.
- Kathy Major, College of Natural Sciences and Mathematics