Ozone detection in Houston – by land, air and sea

TCEQ air quality experts participate in NASA-led research project

It’s no big news flash that scientists love their computer models. Modeling is an essential part of the modern scientific method in diverse pursuits such as medicine, economics, engineering, architecture, meteorology, and numerous other disciplines. Models create an abstract or ‘virtual’ version of something in the real-world; the more accurate the model, the closer it matches real-life.

But no matter how well they’re designed, models can’t do it all. There’s nothing like field work to validate computer-generated data and confirm – or refute – the latest predictive modelling.

With that in mind, two experts in TCEQ’s Air Quality Division – Doug Boyer and Raj Nadkarni – recently participated in a research project led by NASA and DOE to learn more about how air pollution (especially ozone, aka smog) forms in Houston and along the Gulf coast.

Emissions from industrial facilities and vehicles can produce levels of surface ozone concentrations which can be harmful to human health.

Researchers deployed an array of equipment and technologies to monitor regional air quality on the land, in the air and at sea. Their work focused primarily on tracking ozone, but the team also collected data on sulfur dioxide, nitrogen oxides, formaldehyde, particulate matter, and volatile organic compounds.

“We’re trying to determine how pollution develops during the day so that we can better understand the timing and duration of pollution episodes” Nadkarni said.

The data will be particularly useful in developing TCEQ’s State Implementation Plan to bring the Houston area into attainment under EPA’s National Ambient Air Quality Standards.

One project goal was to validate model predictions of elevated ozone over Galveston Bay and the Gulf of Mexico, where measurements do not exist, Boyer noted.

Researchers also sent specially equipped vessels 35 miles into the Gulf of Mexico and launched balloons to gather ozone and meteorological data vertically through the atmosphere. Mobile sampling laboratories from the University of Houston and Baylor University, and stationary air monitors operated by TCEQ, further tracked ozone closer to the ground.

Preliminary data collection results confirmed a key finding that computer modeling conducted by the TCEQ and others had suggested: ozone formed onshore often drifts off to sea, only to eventually blow back onto land.

“We did see significant ozone offshore, in the Gulf of Mexico,” Boyer said, “and at times with the land-sea breeze effect, it can blow back onshore.”

One surprising observation was the number of container ships that were anchored offshore awaiting passage into the Houston Ship Channel, he added.

While the scientists involved in the Houston-area work will continue to analyze the data collected during the recent project – that’s what they do, ad infinitum – they’ll also compare their findings to results derived from future research.

For example, TCEQ researchers are eagerly awaiting a scheduled launch of NASA’s TEMPO geostationary satellite in 2022. That project will take hourly measurements of ozone, nitrogen dioxide and formaldehyde, along with tiny atmospheric particles called aerosols, from 22,000 miles above the Earth’s surface.

The TEMPO satellite has the potential to dramatically expand scientists’ knowledge of how ozone and other compounds interact and improve our understanding of conditions that lead to harmful air quality in urban areas, Nadkarni said.

Photo credit: Laura M. Judd NASA/Langley Research Center

Doug Boyer, Air Modeling and Data Analysis

Doug Boyer is an atmospheric scientist who has 20+ years of experience analyzing and modeling air quality with TCEQ. He’s a proud husband, dutiful dad, and climber of rocks.



Raj Nadkarni, Air Modeling and Data Analysis

Raj Nadkarni is a planner who has 17+ years of experience field studies, data analyzing, GIS and general air quality modeling with TCEQ. Raj is a graduate of the University of Texas at Austin, interests are in travel around the world anywhere there is a beach, with his girlfriend and their two dogs.