Without knowing which emissions are most culpable or understanding the role of the region’s topography, solutions to Utah’s ozone mess will remain elusive. In collaboration with University of Utah faculty and funding from the state, the National Oceanic and Atmospheric Administration (NOAA) is helping find answers.
A team of NOAA scientists is in Salt Lake City for the next few weeks gathering masses of air quality data that is expected to yield new insights that could help bring relief. Building on a long record of air quality data compiled by U scientists and the Utah Division of Air Quality (DAQ) over several years, this new snapshot data is hoped to illuminate what is driving elevated ozone levels along the Wasatch Front, according to Steven Brown, one of the NOAA research chemists leading the Utah Summer Ozone Study.
John Lin, professor of atmospheric sciences, on the roof of the Browning building where a phalanx of air quality monitoring instruments are stationed. Photo credit: Brian Maffly.
“Every city in the United States has an ozone problem, but every city is also different in terms of the sources that contribute to that ozone. And Salt Lake is no exception in that regard,” Brown said. “We’re certainly trying to understand the influence of wildfires. But then you’ve got this mix of industrial and urban sources in a valley with very unusual meteorology. We’re trying to characterize all those sources. What does that meteorology look like, and how do those things combine to produce the unique ozone problem that affects Salt Lake City?”
NOAA’s multi-platform study is being coordinated with the U’s Utah Atmospheric Trace Gas & Air Quality (UATAQ)) lab, headed by John Lin, a professor of atmospheric sciences. Also involved is Lin’s colleague Gannet Hallar, whose students are launching weather balloons and providing weather forecast briefings most days of the study to support NOAA’s regular overflights.While Utah has made strides reducing the severity of its particulate pollution-trapping winter inversions, summertime ozone has worsened to the point that Salt Lake City is out of attainment of the federal standard.
The primary ozone precursors are volatile organic compounds, or VOCs, which are emitted from countless sources—including oil refineries, gas stations, wildfire, paints, even personal care products, like deodorant—and nitrogen oxides, or NOx, a product of combustion.
“Photons are needed to break up certain molecules, so the reactions typically will not happen without sunlight,” said John Lin, the associate director of the Wilkes Center for Climate Science & Policy. “It essentially chops up those chemical bonds. Then ozone reacts with other things and levels get lower at night.”