Solutions To Pollution, Ozone Explored By Atmospheric Scientists

A scientific investigation into the key air quality issues of the eastern half of Texas, TexAQS-II is an initiative led by the National Oceanic and Atmospheric Administration (NOAA), using $2 million appropriated to the Environmental Protection Agency (EPA), to collect and model data in order to develop a more accurate profile of the region's atmosphere. UH's measurement and modeling programs in the department of geosciences are playing a large role in TexAQS-II, leading the way to create a Gulf Coast Air Quality Model.

With one of the most comprehensive measurement ground sites, UH is home to the Moody Tower Atmospheric Chemistry Facility -- one of three super sites that offer the most all-inclusive chemical and meteorological measurement platforms measuring more than 50 variables. During the TexAQS-II initiative, the UH scientists running the Moody Tower facility are collaborating with more than 40 visiting scientists from several different universities and national labs.

As the only ground site of the three super sites, the Moody Tower facility is operational 24 hours a day, seven days a week and offers the most representative sample of what the average person typically breathes in on a daily basis. The other two super sites are NOAA-owned planes and boats, offering observation from the air and water.

"Since we are high up at 18 stories on the roof of UH's Moody Tower dormitory, we can offer a larger footprint of what is actually going on," said Bernhard Rappenglueck, associate professor of atmospheric science at UH. "From up here, we avoid local influences on the ground, such as cars and trucks driving by that would skew results, and can also detect pollutants not just from the Houston area, but even as far away as Mexico."

The Moody Tower vantage point also allows UH scientists to observe and measure the land and sea breeze effects, where during the course of a day aged pollution from the Port of Houston floats to Galveston and then blows back to Houston. The amount and diversity of chemicals measured from this UH super site number in the hundreds, including hydrocarbons from factories burning fossil fuel and from vegetation under environmental stress, carbon monoxide and formaldehyde from vehicle exhaust and a wide range of other harmful elements. The several combinations of these compounds that come together to form ozone, however, receive the most focus from researchers.

"Houston is ripe for ozone," said Barry Lefer, assistant professor of atmospheric science at UH. "Very basically, sunlight, nitrogen oxide and hydrocarbons react to make ozone, and water vapor helps that process along. So, with no short supply of sun and humidity, combined with all the exotic compounds of the chemical industry, Houston is not surprisingly one of the worst with regard to ozone noncompliance levels across the country."

Lefer stresses that the efforts of TexAQS-II will be a good test to see how industry has cleaned up since the first TexAQS initiative six years ago. In this second air quality study, he said, UH scientists are determining what the photochemical processes are, which ones are most important and what the best strategy is to solve the problems.

Along with the myriad measurement tools, gauges and computers on the roof of Moody Tower, weather balloons containing instruments to monitor ozone and other air quality factors are being launched through the end of September and are transmitting data electronically back to labs at UH before parachuting to the ground. From the UH super site, Rappenglueck's students are launching two to six of them each day, while Lefer's graduate students will launch 45 of these weather balloons near various refinery and petrochemical facilities. These balloon launches are a first for Houston, with Lake Charles, La., being the closest until now, and will help with ozone and weather forecasting.

Complementing Lefer and Rappenglueck's Atmospheric Chemistry Measurement Group, UH's modeling and forecasting arm -- the Institute for Multi-dimensional Air Quality Studies -- will extend the Moody Tower super site measurements by running them through UH atmospheric science professor Daewon Byun's sophisticated computational models to pinpoint what works and what doesn't.

If Byun's models accurately work to forecast ozone and other air quality conditions with his measurement colleagues' data, then the existing UH super site and balloon efforts can be applied to other sites. However, if the model does not work properly, then Byun can find out what to fix -- either on the measurement or modeling side -- to perfect the process, such as getting the correct balance of chemistry, emissions and weather measurements.

"The complementary nature of modeling and measurement is key to atmospheric science," Byun said. "One of UH's main goals in the TexAQS-II initiative is for my modeling to extend the measurement efforts of my colleagues so that we can work together to reduce dangerous ozone levels and air pollution."