AUSTIN, Texas—Scientists and engineers at The University of Texas at Austin have begun a three-year, $750,000 study of the impact of climate change and land-use patterns on the release of airborne chemicals from plants, a poorly studied process believed to affect statewide smog production.
Plants remove pollutants from the atmosphere, but also release chemicals called volatile organic compounds (VOCs) that combine with man-made emissions of nitrogen oxides to produce ozone. VOCs that contribute to air pollution come from both living plants (biogenic) and man-made sources, but biogenic sources account for the majority of these atmospheric chemicals in areas such as eastern Texas that will be considered in the study. In particular, the researchers will focus on Austin, Dallas, Houston and San Antonio.
The university research team is led by Dr. Zong-Liang Yang of the Department of Geological Sciences, Dr. David Allen of the Department of Chemical Engineering, and Dr. Barbara Parmenter of the School of Architecture. The Environmental Protection Agency grant was approved in November 2003, and work on the project began this spring.
The rate of biogenic VOC emissions depends primarily on the types and densities of plant species, but is also influenced by factors that include temperature, sunlight, and ozone and carbon dioxide concentrations.
“This is fundamental research into understanding how meteorological conditions impact the emission rates of biogenic VOCs, which in turn impacts ozone formation,” said Dr. Yang. “We want to be able to forecast when and where the highest ozone concentrations will occur and understand the processes controlling the formation and evolution of ozone.”
A primary goal of the project is to develop and integrate information about biogenic VOC emissions with the Community Land Model (CLM3), a computer simulation that models the exchange of water, carbon and energy between the land surface and atmosphere over time.
Beginning this fall, Yang and Allen will use information from the climate model in models that predict changes in air quality caused by changes in vegetation. The impact of a variety of climate and land-development scenarios also will be considered.
The land-development scenarios will be provided by Parmenter after interviewing urban planners and others in the four cities about local and regional plans that influence land use.
“These decisions, large and small, add up over time to shape our communities and our air quality,” Parmenter said.
Once their system is put in place during the next three years, the researchers plan to investigate the potential impact of changes in climate, land-cover patterns and biogenic VOC emissions on air quality in Texas over the next 50 to 100 years. The findings are considered crucial because Texas has been warming up since the 1960s, which favors ozone formation, and has urban and rural areas with dense vegetation that emits VOCs.
Note: Data analyses for this study will be conducted using high-performance computers at the university’s Texas Advanced Computing Center.
For more information contact: Barbra Rodriguez, College of Natural Sciences, 512-232-0675.
