Wildfire smoke trends worsening for Western U.S.

The warming climate has made wildfires and smoke increasingly common. Researchers in the Department of Atmospheric Sciences evaluated data from a number of sources to look at air quality trends in the West. A new paper by doctoral student Kai Wilmot with Gannet Hallar and John Lin (GCSC-affiliated faculty) and Derek Mallia (past GCSC fellow) is published in Environmental Research Letters.

 

The following was originally published in At the U:

From the Pacific Northwest to the Rocky Mountains, summers in the West are marked by wildfires and smoke. New research from the University of Utah ties the worsening trend of extreme poor air quality events in Western regions to wildfire activity, with growing trends of smoke impacting air quality clear into September. The work is published in Environmental Research Letters.

“In a big picture sense, we can expect it to get worse,” says Kai Wilmot, lead author of the study and doctoral student in the Department of Atmospheric Sciences. “We’re going to see more fire area burned in the Western U.S. between now and in 2050. If we extrapolate our trends forward, it seems to indicate that a lot of urban centers are going to have trouble in meeting air quality standards in as little time as 15 years.”

Drawing the connection

Many of the West’s inhabitants have seen smoky summer skies in recent years. Last year, dramatic images of an orange-tinted San Francisco Bay Area called attention to the far-reaching problem of wildfire smoke. Wilmot, a native of the Pacific Northwest, has seen the smoke as well and, with his colleagues, looked at trends of extreme air quality events in the West from 2000 to 2019 to see if they correlated with summer wildfires.

Using air measurements of PM2.5, or the amount of particulate matter in the air with diameters less than 2.5 microns, from the Environmental Protection Agency and the IMPROVE monitoring network, along with measurements of fire area burned and the PM2.5 emitted from those fires, the researchers found consistent trends in air quality that correlated with wildfire activity—but that had different spatial patterns in August than in September.

Trends in August and September

Over the years studied, the researchers noticed that the mean air quality was worsening in the Pacific Northwest in the average August when sensors indicated wildfire smoke events.

“That’s pretty dramatic,” Wilmot says, “that extreme events are strong enough to pull the mean up so that we’re seeing an overall increase in particulate matter during August across much of the Pacific Northwest and portions of California. The Pacific Northwest seems like it’s just really getting the brunt of it.”

The reason for that, he says, is that the regions around the Pacific Northwest, in British Columbia and Northern California, both experience wildfires around August. The mountainous Pacific Northwest, Wilmot says, sits in the middle.

But by September, the researchers found, wildfire activity slows in British Columbia and shifts to the Rocky Mountains. The smoke shifts too—the researchers saw emerging trends correlating wildfire smoke with declines in September air quality in Wyoming and Montana. “We see the PM2.5trends start to pick up a bit more in the Rockies and they become more statistically significant, a little bit stronger and more spatially coherent,” Wilmot says.

What about Utah? The study findings show that the magnitude and significance of air quality trends increases as you go from the southern states of Arizona and New Mexico toward the Pacific Northwest. In Utah, Wilmot says, air quality trends are near the edge of statistical significance, with evidence for impact from wildfires, but evidence that’s less robust than in the Pacific Northwest and California. “Thinking about events like the smoke transport from fires in the Bay Area this past summer,” Wilmot says, “I would not be surprised to see trends in Utah become increasingly convincing with additional data.”

Looking to the future

Other researchers in other studies have suggested that the future will bring more fire areas burned in the Western U.S., with an accompanying increase in wildfire smoke exposure throughout the West and the impacts of that smoke on human health.

Wilmot notes that the trends the researchers see in the Pacific Northwest in August are “pretty robust,” he says, while the September trends in Montana and Wyoming are still “emerging.”

“I think the concern is that, given more time, those emerging trends are going to start looking a lot more like what we’re seeing in August,” he says. “I hope that’s not the case, but it seems entirely within the realm of possibility.”

His next step is to develop simulation models to more precisely link wildfire emissions in urban centers to smoke source regions.

“The big picture,” he says, “is aiming to help forest management in terms of identifying wildfire emissions hotspots that are particularly relevant to air quality in the Western U.S., such that if we had funding to spend on some sort of intervention to limit wildfire emissions, we would know where to allocate those funds first to get the most out of it.”

Find the full study here.

John Lin named Earth Leadership Program Fellow

GCSC faculty affiliate John Lin, professor of atmospheric sciences, has been named a 2021 fellow of The Earth Leadership Program. The program recognizes mid-career academic researchers who focus on environmental and sustainability issues and provides them with an opportunity to develop as global leaders to bring their expertise to effect positive change. Dr. Lin will join a global network of scientists, researchers, and innovators engaged in transdisciplinary research that will be needed to support rapid transformations towards sustainability.

Lin has been an innovative and collaborative researcher since being recruited to the U of U (with the help of the GCSC) in 2012. His Land-Atmosphere Interactions Research (LAIR) group studies phenomena that impact climate and the environment such as air quality, greenhouse gases, and wildfire emissions.

Lin says his selection as a fellow reflects the quality of research at the U in studying climate change and air pollution. “As importantly,” he says, “the Earth Leadership Program recognizes the potential for work at the U to provide solutions to these issues by working with stakeholders and the public at large.  This is testament to the efforts in the Department of Atmospheric Sciences as well as the many, many wonderful members of the Global Change and Sustainability Center across campus.” (quoted from an article in @theU. Click link to read further.)

 

This leadership training program “provides opportunities for Fellows to learn leadership skills and to practice them in a dynamic setting. The network of trainers, mentors, and peers promotes relationships that are meaningful and may lead to new professional opportunities. The value for each Fellow is in building these connections and in becoming inspired and confident that our research has purpose and impact on the world.” Sharon K. Collinge, Executive Director of the Earth Leadership Program.

 

Mounting air-quality sensors on light rail saves cities money while improving data

Researchers affiliated with the GCSC have been measuring greenhouse gases in the Salt Lake valley by mounting sensors on TRAX light rail trains. Not only does this greatly improve the data that informs city planners and policy makers, but this method can provide extraordinary cost savings. The cost of one research-grade mobile sensor is about $40,000. To collect data from the same area with stationary sensors would take 30 instruments and would cost more than $1.2 million.

U of U researchers have been monitoring carbon dioxide in the Salt Lake Valley for 20 years. According to John Lin, Professor, Atmospheric Sciences, adding the TRAX-based measurements to stationary monitoring sites makes Salt Lake City one of the best-instrumented cities in the world for observing air pollution.

Read the full story in At the U. Find the publication in Environmental Science & Technology.

Students initiate study on air pollution and unhoused people

Who in city government tracks the environmental effects of air pollution on people experiencing homelessness? When students in the 2019 Global Changes and Society class looked into it, they found that there was not an office with that responsibility. Initially, students set out to change that missing piece. But those efforts have now also resulted in a study published in the International Journal of Environmental Research and Public Health, as part of a special issues “Addressing public health and health inequities in marginalized and hidden populations.”

The project-based course Global Changes and Society (SUST 6000) features guest lecturers with expertise in research related to global changes and sustainability. In this course, students from different disciplines Identify a theme or focus area, begin to learn the language and approaches of other disciplines around the theme, explore perspectives and approaches of different stakeholders, and develop a team project. Recognizing that there are disproportionate environmental impacts on certain socially and geographically vulnerable communities in the Salt Lake Valley, students in the 2019 class developed projects to address some of these issues.

The student group with members including Angelina DeMarco and Rebecca Hardenbrook (GCSC Fellow 2018-19) noted that during poor air quality events such as inversions, wildfires, and heightened ozone periods, residents are urged to stay indoors when possible, but people affected by homelessness don’t have the luxury of escaping indoors on short notice to avoid poor air conditions. But it appeared that no-one had researched the effects of poor air quality on this population.

Read about the research project these students developed with GCSC faculty affiliates Daniel Mendoza (Atmospheric Sciences and City & Metropolitan Planning) and Jeff Rose (Parks, Recreation and Tourism) in At the U.