As the summer winds down, data from one of the most comprehensive local ozone studies is starting to filter in.
The state Legislature granted a one-time fund for studying Utah’s air quality during their last session. A chunk of that money went to the Great Salt Lake Summer Ozone Study, or SO3S -- a collaboration between the Division of Air Quality and three local universities.
Ozone forms through reactions between chemicals and sunlight, so levels naturally change during the day as the sun rises and sets. The lake influences wind and weather patterns along the Wasatch Front, which means the lake might influence how ozone moves around. Its dropping levels could be influencing other ozone problems, too.
“The Great Salt Lake Summer Ozone Study resulted in a massive amount of data. It will take months to put a lot of it together and in context,” said John Sohl, a Weber State physics professor who helped with the study.
Weber State staff and students, from left, Jeffrey Page, Alexis Frias, Murielle Shallbetter and Bill Dowell prepare to take air quality measurements using a balloon near the Great Salt Lake as part of a comprehensive ozone study last summer. Photo by Sheri Trbovich.
Even with a grant from state lawmakers, money for the study was tight. Researchers stretched their dollars by taking advantage of air-monitoring tools they already had, like the AggieAir drone at Utah State, a tethered balloon at Weber State and some air quality monitors the University of Utah previously installed on TRAX trains. They attached air monitoring equipment to a KSL News helicopter. They also used existing structures, like the railroad causeway running through the lake.
“We utilized existing infrastructure to collect some really awesome and really unprecedented ozone measurements throughout the Salt Lake Valley, and over the Great Salt Lake,” said Ansley Long, a University of Utah graduate student.
The combined data paints a more comprehensive ozone picture of the Great Salt Lake and its neighboring cities, up and down the air column, at different parts of the valley during different parts of day — at least for one season.
Scientists are still sifting through all the data, but the summer’s extremes were useful, providing two events that capture extremes feeding ozone pollution. June was unusually hot with high pressure, and it also brought a spike in ozone levels.
“We don’t know why June had such high ozone and July didn’t have high ozone,” said said Brian Blaylock, a University of Utah graduate student. “Maybe there’s something with the lake temperature playing a role in that.”
Another ozone spike came in August, as hazy smoke blew in from Western wildfires and spiked ozone levels again.
Lake breezes also had an effect on ozone pollution. Prevailing winds in the Salt Lake Valley blow from the south, but the air-monitoring information found the lake breeze can clash and make ozone get stuck. When it gets stuck, levels start to build and the air becomes unhealthy.
Blaylock said the two summer events will be useful in testing some existing ozone hypotheses for the Salt Lake area. But the lake’s fluctuating levels make understanding local ozone even more complicated. The water levels are on a downward trend overall. That means more lake bed and salt flats that can potentially reflect solar light and create even more ozone.
“We know that Great Salt Lake is changing. We know that there is significantly more ozone over the lake as compared to what we measure in the areas where our population is concentrated,” Sohl said. “The problem is that we know almost nothing about how the changing lake will impact this issue.”
Sohl said even though the summer study produced a hefty amount of good information, more than anything, it underscores the need to fund more Great Salt Lake ozone research.
“It is a bit like trying to understand tourism by doing a major study of winter visitors, but only doing a single winter,” he said. “Without several years of data you cannot measure what a normal fluctuation is or detect any sort of trend — good or bad.”