Houston replaced Los Angeles recently as the city reporting the most days in violation of federal smog standards. Unless Texas dramatically lowers ozone levels in the Houston metropolitan area by 2007, the state faces the loss of $2 billion in federal highway money. To try to improve understanding of the problem and develop cost-effective mitigation strategies, scientists from Battelle and the Battelle-operated Pacific Northwest National Laboratory and Brookhaven National Laboratory joined with more than 30 other organizations in the summer of 2000 to conduct one of the largest-ever air quality studies.

The month-long data collection campaign, the Texas 2000 Air Quality Study, involved more than $20 million and 300 research scientists. Through the U.S. Department of Energy’s Atmospheric Chemistry Program, Battelle-affiliated scientists were involved in overall planning and coordination of the campaign, operation of special meteorological monitoring sites, monitoring from research aircraft, and making measurements from a skyscraper.

The skyscraper measurements were made from the 62nd floor of the Williams Tower in uptown Houston. Working at a height of approximately 830 feet above the ground, teams of scientists from six organizations set up 20 instruments for sampling 24 hours a day, seven days a week. Participant groups included Battelle’s Columbus Operations, Pacific Northwest National Laboratory, Brookhaven National Laboratory, Argonne National Laboratory, State University of New York at Old Westbury, Georgia Institute of Technology, University of California at Davis, and the Texas Natural Resources Conservation Commission.

The skyscraper site made several important contributions to the air quality study. First, a rather complete suite of gas and aerosol measurements was obtained and is being used to characterize the Houston air west of the major emission sources. The elevated measurement site will also contribute to studies of air chemistry above and within the nocturnal boundary layer. Finally, the measurements will be used in the analysis of the role of regional-scale transport during meteorological periods associated with strong advection.

The measurement systems filled two rooms near the top of the office tower. One room was used primarily for gas-phase measurements. Scientists in the other room focused on aerosol characterization and deployed some new techniques for the first time.

One new approach involved an aerosol collector system with a time resolution on the order of minutes. The collected samples are analyzed automatically by scanning electron microscopy with energy-dispersed X-ray analysis and time-of-flight secondary ionization mass spectrometer. Another new instrument operated for the first time in the field was a single particle, time-of-flight mass spectrometer.

Study results are still being analyzed—a process that will likely continue for years as the debate over strategies for controlling Houston’s air quality problems continues. For more information, contact Chet Spicer at (614) 424-5319, spicerc@battelle.org or Carl Berkowitz at (509) 372-6183, Carl.Berkowitz@pnl.gov.