Houston Metro Area Serves as Lab to Study Impact of Urban Pollution on Thunderstorm Activity

April 17, 2023

Baylor University researchers Rebecca Sheesley, Ph.D., and Sascha Usenko, Ph.D., associate professors of environmental science, have been awarded an $890,000 grant by the Department of Energy Atmospheric System Research (ASR) to examine the impact of urban pollution on thunderstorm activity. The grant, TRACER-MAP: Mapping Aerosol Processes across Houston during convective cell events, enables researchers to conduct measurements in Houston to tie into an overarching, multi-institution, multi-agency research project called Tracking Aerosol Convection Interactions Experiment (TRACER). The project began in 2021, and data collection continues.

“We are excited that TRACER will bring together scientists from Department of Energy, NASA and numerous academic institutions to work together on atmospheric science and chemistry in Houston,” Sheesley said.

Sheesley and Usenko will work with co-investigators James Flynn and Yuxuan Wang of the University of Houston, Rob Griffin of Rice University and Don Collins of the University of California, Riverside on the three-year grant investigating if urban air pollution affects activity in thunderstorms.

“Some of our questions focus on how these big thunderstorms develop and how do we improve models of these large thunderstorms, called convective cells,” Sheesley said. “Our big addition to the larger TRACER project is that we will be mapping the atmospheric composition, or urban pollution, around the city so that we can connect the chemistry and air pollution to the convective cell studies.”

The Houston metropolitan area was selected for the 2021 TRACER project due to its high convective storm activity and broad range of polluted aerosol conditions. Greater Houston is large in both land area and population, and has a wide range of atmospheric conditions. The project will map the air chemistry conditions across the region while atmospheric scientists working with TRACER will monitor convective storm activity.

“The TRACER-MAP project is a great opportunity for us to do really interesting atmospheric chemistry and processes research right in our backyard. We hope to improve understanding of how urban air pollution changes the dynamics of these storms systems we routinely see affecting Houston,” Sheesley said.

Sheesley and Usenko’s team will conduct a series of aerosol, gas and meteorological measurements during the summer of 2021 that will be matched to measurements from the DOE’s Atmospheric Radiation Measurement Mobile Facilities. All measurements will be taken from established air quality monitoring sites, making the data easily comparable with previous Texas air quality studies.

Further, they will deploy mobile air quality laboratories across the research area to collect detailed atmospheric chemistry measurements. By integrating these measurements into atmospheric modeling of convective cells, the team can evaluate observed differences related to emissions, aerosol processes and convective storm activity.

“We are talking about studying massively complex systems that can change dramatically by the minute. Such an undertaking requires a wide range of expertise and months to years of preparation,” Usenko said. “I’ve really enjoyed the collaboration — the constant learning from all of our collaborators. I think for our participating students, it's just an amazing process because they get to see these mobile labs they built up and how to work with these different collaborations and all these different groups. The science questions being asked and how they can contribute to that is a pretty meaningful experience for them.”

In addition to TRACER-MAP, Sheesley and Usenko have several active air quality projects in Texas over the next year, including the Texas Commission on Environmental Quality (TCEQ)-funded study (BC)2: Black and Brown Carbon in Houston and El Paso, and the Texas Air Quality Research Program-funded study Characterization of Corpus Christi and San Antonio Air Quality During the 2021 Ozone Season.

Sheesley and Usenko are working with federal agencies, TCEQ and Texas and California colleagues to understand the complex dynamics of urban air quality in southern and coastal Texas. This suite of projects in 2021 will give the Baylor researchers the opportunity to improve understanding of the sources and chemistry of urban air quality to improve quality of life for the millions living in Texas cities.

“There's a lot of relevance to what we're doing. It doesn't take people very long to see where our research is interacting with them and their lives,” Usenko said. “We think the ramifications of such a study could have far reaching implications on our understanding of how we as humans are interacting with the environment.”