Heather Holmes, an associate professor in University of Utah's chemical engineering department, has long studied the changing climate of the Western U.S. (Credit: Courtesy of Heather Holmes).,
Investigating Extreme Heat in Salt Lake City
In Utah, Heather Holmes is working on better forecasting models, especially when heat waves mix with wildfire smoke in rural communities.
Editor’s note: Meet all five winners of our 2024 Women In Science Incentive Prize here.
Not all that long ago – 14 years, to be exact – Professor Heather Holmes was living the outdoor life in Salt Lake City, racing mountain bikes and enjoying the warm summer season with its cool nights. But career took her away, first to Germany and then to Atlanta and Reno, Nevada. When she finally returned to the University of Utah in summer 2021, she was ready to enjoy outdoorsy activities again.
Except temperatures seemed impossibly high, running a daily seasonal average of 81.5 degrees. One June day hit a blistering 107 degrees. “It was miserable and I could not believe it,” says Holmes, an associate professor in UU’s chemical engineering department. She recalls thinking: “This is not normal.”
What Holmes and other Salt Lake City residents experienced has actually become the new normal in Utah, a state that most outsiders associate with snow-capped mountains and ski resorts. Stifling summers are now breaking records, with this past summer seeing daytime highs in Salt Lake City averaging 93.5 degrees, with 20 days above 100 degrees.
The extreme heat has motivated Holmes, who has long studied the changing climate of the Western U.S., to try to answer the question: What’s specifically causing this new weather pattern in Salt Lake City? She’s curious to see if the extreme heat could be linked to the depletion of the Great Salt Lake, which has shrunk by almost half in recent years, a result of drought (made worse by climate change), agricultural use and population growth. A reduction in the lake, for instance, might impact wind patterns that could normally help cool the city, she says. While there are obvious causes of greater heat, including urbanization and more man-made materials, “it’s going to be very sad if the lake is causing heat issues,” she says.
Extreme heat, she says, also compounds other problems plaguing the Western U.S. — specifically, wildfires and air pollution. Holmes has long researched smoke plumes, the tall columns that contain a combination of gases and particles, which are released into the atmosphere. “The way they move is driven by meteorology,” she says. “The combined impacts of extreme heat and smoke exposure on humans is understudied and likely significant.”
Taken just by itself, extreme heat causes danger to humans, in particular pregnant women and the elderly. Many people in the Western U.S. live in older homes that weren’t set up for air conditioning. Many schools don’t have protocols in place for what to do with students on high heat days. But when you mix in wildfires and high levels of toxic pollutants in the air, “there is a critical need to improve atmospheric models for extreme heat and smoke events, especially in the western U.S.,” she says.
To that end, Holmes is currently working on research that may just become a startup. She and her team anticipate that more forecasting models will be needed to predict when and how extreme heat could impact, for instance, outdoor work crews. “Knowing that information in advance will be helpful for anybody that has outdoor workers,” she says, especially if we begin to see “more occupational health standards around heat.” Employers could use specific, reliable forecasting information to shift where and when people work, resulting in “less of an economic drain,” she says.
While a startup would likely serve big clients, it could also provide high-quality data to consumers, too, Holmes says – especially those who live in rural areas. People in smaller communities often have little means or methods for determining whether it’s safe to be outside. That hits home for Holmes, who grew up in small-town southern Idaho. “A lot of my personal motivation with my work is to [help] these rural communities, because they just don’t get as much,” she says.
When it comes to her work, Holmes has won awards, research grants and a slew of admirers. Her application for The Story Exchange’s Women In Science Incentive Prize came with a letter of recommendation signed by eight different scientists or environmentalists from UU, NASA, the Utah Department of Environmental Quality and the Friends of Great Salt Lake, among others. Beyond her “innovative scientific accomplishments,” the letter says, Holmes is committed to mentoring her graduate students and postdocs, more than half of whom identify as women or non-binary. “This is especially impressive considering her faculty appointments have been in departments with less than 25% female PhD students,” the letter says.
For her part, Holmes says she is driven to “create a safe place” for the next generation of STEM professionals. That same term – “safe place” – might also apply to the work she’s doing, helping to create a better world for communities who are finding that climate change “has made the smoke and heat unbearable for them,” she says. ◼️
