SRI Stories

SRI Stories: Smoke Plumes

Western wildfire smoke plumes are getting taller.

In recent years, the plumes of smoke crawling upward from Western wildfires have trended taller, with more smoke and aerosols lofted up where they can spread farther and impact air quality over a wider area. The likely cause is climate change, with decreased precipitation and increased aridity in the Western U.S. that intensifies wildfire activity.

“Should these trends persist into the future,” says Kai Wilmot, a postdoctoral researcher in the College of Science's Science Research Initiative and in the Department of Atmospheric Sciences at the University of Utah, “it would suggest that enhanced Western U.S. wildfire activity will likely correspond to increasingly frequent degradation of air quality at local to continental scales.”

The study is published in Scientific Reports and supported by the iNterdisciplinary EXchange for Utah Science, or NEXUS, at the University of Utah.


“Given climate-driven trends towards increasing atmospheric aridity, declining snowpack, hotter temperatures, etc. We’re seeing larger and more intense wildfires throughout the Western U.S., and this is giving us larger burn areas and more intense fires.”


Smoke height

To assess trends in smoke plume height, Wilmot and U colleagues Derek Mallia, Gannet Hallar and John Lin modeled plume activity for around 4.6 million smoke plumes within the Western U.S. and Canada between 2003 and 2020. Dividing the plume data according to EPA ecoregions (areas where ecosystems are similar, like the Great Basin, Colorado Plateau, and Wasatch and Uinta Mountains in Utah) the researchers looked for trends in the maximum smoke plume height measured during August and September in each region in each year.

In the Sierra Nevada ecoregion of California, the team found that the maximum plume height increased, on average, by 750 ft (230 m) per year. In four regions, maximum plume heights increased by an average of 320 ft (100 m) per year.

Why? Wilmot says that plume heights are a complex interaction between atmospheric conditions, fire size and the heat released by the fire.

“Given climate-driven trends towards increasing atmospheric aridity, declining snowpack, hotter temperatures, etc., we’re seeing larger and more intense wildfires throughout the Western U.S.,” he says. “And this is giving us larger burn areas and more intense fires.”

The researchers also employed a smoke plume simulation model to estimate the mass of the plumes and approximate the trends in the amount of aerosols being thrown into the atmosphere by wildfires . . . which are also increasing.

The smoke simulation model also estimated the occurrence of pyrocumulonimbus clouds—a phenomenon where smoke plumes start creating thunderstorms and their own weather systems. Between 2017 and 2020, six ecoregions experienced their first known pyrocumulonimbus clouds and the trend suggests increasingly frequent pyrocumulonimbus activity on the Colorado Plateau.

Taller plumes send more smoke up into higher elevations where it can spread farther, says John Lin, professor of atmospheric sciences.

“When smoke is lofted to higher altitudes, it has the potential to be transported over longer distances, degrading air quality over a wider region,” he says. “So wildfire smoke can go from a more localized issue to a regional to even continental problem.”

Are the trends accelerating?

Some of the most extreme fire seasons have occurred in recent years. So does that mean that the pace of the worsening fire trend is accelerating? It’s too early to tell, Wilmot says. Additional years of data will be needed to tell if something significant has changed.

“Many of the most extreme data points fall within the years 2017 -2020, with some of the 2020 values absolutely towering over the rest of the time series,” he says. “Further, given what we know of the 2021 fire season, it appears likely that analysis of 2021 data would further support this finding.”

In Utah’s Wasatch and Uinta Mountains ecoregion, trends of plume height and aerosol amounts are rising but the trends are not as strong as those in Colorado or California. Smoke from neighboring states, however, often spills into Utah’s mountain basins.

“In terms of the plume trends themselves, it does not appear that Utah is the epicenter of this issue,” Wilmot says. “However, given our position as generally downwind of California, trends in plume top heights and wildfire emissions in California suggest a growing risk to Utah air quality as a result of wildfire activity in the West.”

Wilmot says that while there are some things that people can do to help the situation, like preventing human-caused wildfires, climate change is a much bigger and stronger force driving the trends of less precipitation, higher aridity and riper fire conditions across the West.

“The reality is that some of these [climate change] impacts are already baked in, even if we cut emissions right now,” Wilmot adds. “It seems like largely we’re along for the ride at the moment.”

Find the full study at


by Paul Gabrielsen, first published in @theU.

SRI Stories is a series by the College of Science, intended to share transformative experiences from students, alums, postdocs and faculty of the Science Research Initiative. To read more stories, visit the SRI Stories page.

Arctic Adventures

Arctic Adventures

Julie and Rebecca on the ice.

Adventures in the Canadian Arctic.

Rebecca Hardenbrook and Julie Sherman, both graduate students in the Math Department, participated in the Biogeochemical Exchange Process at Sea Ice Interfaces (BEPSII) Sea Ice School May 14-23, 2022, at the Canadian High Arctic Research Station (CHARS) in Cambridge Bay, Canada.

The purpose of the BEPSII program is to provide early-career polar researchers an opportunity to learn field work methods for understanding and analyzing polar sea ice firsthand, as well as building a community in the sea ice research world. Competition for acceptance in the program is competitive—nearly 100 applications were received for 30 spots.

Recently, the Math Department asked Hardenbrook about her adventures in the Canadian High Arctic.

How did you become interested in sea ice research?

I started my college-level educational journey at the U as an undergrad in 2014. I knew that I wanted to pursue a career that would allow me to do something related to studying climate change in some way, but I also found my passion in studying math. I began working with Dr. Ken Golden in my junior year. He works right in that intersection of climate change, specifically sea ice and math. I was lucky enough to be accepted to the U for my Ph.D., which I am grateful for because being able to continue in this research direction has opened my eyes to a lot of really important research questions about things—such as the fact that all living things depend on sea ice to survive, including humans.

Approaching Cambridge Bay.

How did you travel to Cambridge Bay?

We left Salt Lake, flew to Seattle, and then to Edmonton in Canada. After spending the night in Edmonton, we flew to Yellowknife and then to Cambridge Bay. Yellowknife is a beautiful town in the Northern Territories. On all of our flights, I couldn't stop looking outside the window on the plane as the landscape changed slowly from the familiarity of the Wasatch mountains to the flattened landscape surrounding Edmonton to the frozen lakes and dense woods surrounding Yellowknife to the endless snowy and icy terrain of the Canadian High Arctic, which includes the area in the Northwest Territories, Yukon, and Nunavut.

What was it like meeting the other fellow scientists and colleagues?

Meeting other blooming scientists was equally as exciting as actually getting to be on the sea ice for the first time. I now have 30 friends all around the world who are working on exciting and relevant problems relating to polar sea ice, who I can potentially work with in the future. I certainly have never had that sort of network before! The relationships I made with other early-career researchers at the BEPSII Sea Ice School left me with a renewed passion for my own work and for asking questions I haven't thought of before.

Drilling ice cores.

What was a typical day like?

The activities really varied day-by-day, but we did have several lectures from experienced polar researchers that ranged among topics. For example, we heard from experts studying biophysical processes of the ecosystems and organisms living within the Arctic Sea ice. The researchers are investigating the movement and transport of critical nutrients and trace metals in the Chukchi Sea, the optical properties of sea ice, and how snow on the surface comes into play. We did have a few days of field work, the first two primarily were practice days for learning how to drill ice cores, dig snow pits, take snow hardness measurements, make sack holes, and more. We had a lot of free time to explore the area surrounding Cambridge Bay, although we didn't venture too far away from the town itself. You only have to go out 3/4 of a mile or so before you really understand how remote the area is.

What were your living quarters like? What about your meals?

We lived in apartments of eight people each, and within the apartments we shared a room with one person. Our apartments were part of the Canadian High Arctic Research Station (CHARS) campus, and they were very nice. Because the sun was out for most of the day (or for several hours the entire day), our apartments were pretty warm despite the outside temperature being below freezing. Our lunch and dinner were catered by a local business, and our breakfast foods were purchased from the local grocery store. The price of foods that I really take for granted, like fresh produce and even things like peanut butter, in Cambridge Bay are incredibly expensive. As Julie mentioned in her profile, we heard that a single watermelon costs $75, which is an  extreme example, but it was still shocking to me.

Walking on sea ice.

What did you enjoy most about the experience? What was the environment like?

I truly enjoyed the entire experience, but I think selfishly finally getting to be able to walk on the sea ice, see the algae at the bottom of the ice core we took, feel the cold summer Arctic air on my face, and experience that environment was life changing for me. I did get a little emotional when I first stepped out onto the ice, because I've wanted to be able to do that now for the last six years. I am also so grateful to be able to make the friends that I did. The people I met there are so  passionate about their work, and that drives me to continue doing research in this field. The environment was like nothing I've experienced, and it's kind of hard to put into words. We got to be there for several days with no sunset. Even though it was hard to sleep sometimes, I didn't mind because it was so beautiful on the lucky days when the clouds would clear out and the snow would stop falling. The air was incredibly dry despite us being right near the ocean—I mean it's technically a desert up there—so I think the cold felt a little less intense unless it was windy (which it often was). I think the most notable thing for me was just how quiet and flat it is. I could see many miles on a clear day.

There is an Inuit legend about a family of giants who died while crossing Victoria Island looking for food. These giants are the three eskers (a ridge of stratified sand and gravel, deposited by meltwater from a retreating glacier or ice sheet) nine miles outside of Cambridge Bay. They are named Uvayuq (after the father), Amaaqtuq (after the mother, who was pregnant), and Inuuhuktu (after the son). It is so flat that you can see Uvayuq clearly from the town. In fact, some of us actually considered running to it, but we got too nervous about potentially meeting a bear on our way, so we didn’t do it. Luckily, we didn't see any bears (polar or grizzly), but we heard that there was a polar bear 30 miles out from the town somewhere. We did see a few Arctic fox, which was really exciting because early on in our time there, their fur was completely white and they are hard to see. As time went on, we saw Arctic fox that were starting to shed their winter coats. Their summer fur is short and black, so they’re much more visible. We also saw a few Arctic hare, but they are very good at hiding so we didn’t see too many. There were also a lot of birds—unfortunately, I’m not much of a birder at the moment so I couldn't identify them.

What are your plans after you receive your Ph.D.?

I am hoping to get a postdoctoral research and teaching position at a college or university. I love my research, and I also love teaching undergraduate students about math, about sea ice, and about the environments around us. A life where I can continue on with both of my passions would be a good one, and so I hope to do that.

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Air Tracker

Air Tracker

New tool shows air pollution’s path.

On June 13, 2022, Environmental Defense Fund unveiled Air Tracker, a first-of-its-kind web-based tool that allows users to plot the likely path of air pollution. Run on real-time, trusted scientific models and coupled with air pollution and weather data and developed in partnership with the University of Utah and the CREATE Lab at Carnegie Mellon University, Air Tracker helps users learn more about the air they’re breathing, including pollution concentrations and its potential sources.

U professor John Lin, of the Department of Atmospheric Sciences, adapted his research group’s atmospheric model (the Stochastic Time-Inverted Lagrangian Transport model, or STILT) to run as part of Air Tracker.

John Lin

“Air Tracker is designed to trace our potential source regions for pollution. Users can make use of Air Tracker to investigate emission sources with a research-grade atmospheric model at their fingertips.”


“Air quality monitors can show us how polluted our air is, but they aren’t equipped to tell us what is causing the pollution,” says Tammy Thompson, Senior Air Quality Scientist and creator of the tool. “With Air Tracker, we’re able to see likely sources of pollution hotspots, which is especially helpful in cities where a variety of emitters contribute to overall air quality.”

Users can click anywhere on maps of Houston, Salt Lake City and Pittsburgh to create a “source area,” which shows the most likely origin of the air they’re breathing at any given time. They can also click on locations of individual air quality sensors to show real-time and historical fine particle (PM2.5) pollution readings, wind speed and direction.

Relying on STILT, Air Tracker incorporates a variety of weather forecasting models to show how particles move through the atmosphere, allowing the tool to map the probability of pollution’s path. Air Tracker goes beyond common source identification models–which are unable to capture fine-scale air pollution variability–to identify pollution sources at the city block level.

In Houston, for example, where a lack of zoning has allowed industrial sources to operate near communities with homes, schools, churches and hospitals, Air Tracker uses both real-time and historical data to show how different sources contribute to poor air quality at different dates and times.

“Breathing dirty air is bad for our health, and these health effects are not distributed equally,” said Sarah Vogel, EDF Senior Vice President, Healthy Communities. “The poorer and more disadvantaged groups disproportionately suffer the greater exposures and health impacts from air pollution. We hope community leaders and individuals will use this pollution data to hold polluters accountable and advocate for clean air policy change.”

In addition to learning more about the sources likely influencing the air they breathe, Air Tracker users can also use the real-time source area identification to help speed mitigation and help spot and control emissions resulting from accidents and unusual events. Through its “Share” feature, users can take screenshots of source areas to send to regulators and local officials.

Air Tracker is part of EDF’s ongoing work to better understand local air pollution, its behavior and its impacts. Air Tracker can be adapted to include additional pollutants and used in other cities around the world, including those that may not yet feature extensive, hyper-local air quality monitoring programs.

Learn more about Air Tracker, EDF’s Global Clean Air efforts and the project partners here.

One of the world’s leading international nonprofit organizations, Environmental Defense Fund creates transformational solutions to the most serious environmental problems. To do so, EDF links science, economics, law, and innovative private-sector partnerships. With more than 3 million members and offices in the United States, China, Mexico, Indonesia and the European Union, EDF’s scientists, economists, attorneys and policy experts are working in 28 countries to turn our solutions into action. Connect with us on Twitter @EnvDefenseFund.


by Paul Gabrielsen, first published in @theU. Adapted from a release by the Environmental Defense Fund


NIH-SACNAS Virtual Lunch

NIH-SACNAS Virtual Lunch

Everyone is Welcome!

Stay connected with other SACNISTAS and join us for a virtual lunch on Wednesday, June 22. Share a meal, chat, de-stress, and remember you have a community of SACNISTAS you can stay connected to.

This will be online only. Registrants will receive meeting information prior to the event.

>> Register Today <<

Questions? Contact Dr. Moraima Matus-Nicodemos @

Who are we?

We are part of the National SACNAS organization (Society for the Advancement of Hispanics/Chicanos and Native Americans in Science). We welcome everyone to be part of our events. If you are interested in joining the chapter, please sign-up to our list-serv (NIH-SACNAS)

We are a professional SACNAS chapter that provides a supportive and welcoming environment for Hispanics/Chicanos and Native Americans trainees and staff at the NIH to get together, exchange ideas, network, share successes, and strategize about future goals. Our chapter holds monthly meetings focus on scientific communication, networking, outreach, and career development to provide our members with resources and tools to improve and advance their careers.

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Posted in SRI

Hollywood Dinosaurs

Hollywood Dinosaurs

Cinematic dinosaur representation. Accurate?

Have you ever wondered if “Jurassic Park” is realistic? Jeff Goldblum’s sexual magnetism is most certainly accurate, but what of the dinosaurs?

Enter Mark Loewen, a paleontologist at the Natural History Museum of Utah and associate professor in the Department of Geology and Geophysics at the U. In June, Loewen critiqued the accuracy of Hollywood’s depictions of dinosaurs for Vanity Fair in a video that has racked up nearly 2.5 million views on YouTube. You can watch the video below.

Mark Loewen

“I view myself as an evangelist for science. Movies are a sneaky way of showing students how cool these concepts are. I mean, isn’t this one of the most awesome classes you could take? Get a science credit to watch movies and learn about the science!”


“I love these movies—some of them are horrible, but I still love them,” said Loewen. “Before being a paleontologist, I became a geologist because I wanted to time travel. By looking at rocks, you can literally see what past worlds looked like! Seeing dinosaurs reconstructed in movies is the same thing. It’s fun to see how we can use fossils to imagine what these animals could have looked like.”

Loewen is uniquely suited for the job. In the early 2000s, he and his mentor Scott Sampson created a class called World of Dinosaurs, GEO 1040, where students watched movie clips and analyzed the veracity of dino representation. He expanded this idea to create Science and Cinema, GEO 1000, a non-majors science class that analyzes science in movies. By studying the dinosaurs, natural disasters and science fiction presented on screen, students learn science fundamentals while having fun celebrating—or berating—various motion pictures.

An alum of the Science of Cinema class now works at Vanity Fair and recommended Loewen for the video series, which coincides with the release of “Jurassic World: Dominion” (2022). A professional film crew shot his interview in the paleontology collections at the museum. If you watch the video closely, you can see specimens of dinosaurs that Loewen himself has discovered and named. U students can use their UCard to visit the museum for free, and during the museum’s annual Behind-the-Scenes event you can tour the collections and see fossils and specimens not displayed on the main floor.

“I’ve named 13 dinosaurs, and many of them are in the museum,” Loewen said, “My favorite is Lythronax, an earlier cousin of the T-Rex. Lythronax means ‘King of Gore’ or ‘Gore King.’ It’s a big, bloody dinosaur on its way to becoming a T-Rex.”

Loewen cites the Disney classic “Fantasia” (1940) segment, “Extinction of the Dinosaurs,” as an early catalyst for his love of dinosaurs. He analyzes the scene in the Vanity Fair video and gives it props for being the first movie to show dinosaurs living in their ecosystem. He calls it an important movie because it “sets the stage of dinosaurs being these iconic beasts of the past.” However, he explains that the animation reflected people’s understanding of the creatures in the 40s—the animals were sluggish and dragged their tails while moving around. It wasn’t until much later that we understood that many dinosaurs were agile and fearsome hunters.

For all y’all older millennials out there, be relieved–Loewen confirms that fossils of baby long-necked dinosaurs such as Little Foot in “The Land Before Time” (1988) did have big, puppy eyes and delicate little beaks—so they really were as cute as the cartoon. However, Sara the Triceratops and Little Foot the Brontosaurus didn’t co-exist at the same time, so would never have met to become friends.

He also critiques some aspects of the original "Jurassic Park.” However, Loewen does applaud the movie for being accurate based on our understanding in the early 90s.

“’Jurassic Park’ was one of the first accurate depictions of dinosaurs. They’re not acting like lizards. They’re acting like ferocious birds of prey,” said Loewen. “But when it came out, we didn’t know that dinosaurs had feathers. At the time, lots of scientists would have told you that dinosaurs didn’t become birds. Forty years later, 100% of dinosaur paleontologists will tell you that birds are actually dinosaurs, and we have evidence of feathers for almost every type of dinosaur. In the new movies, most of the dinosaurs have feathers.”

Editor’s note on conflict of interest: The author’s favorite movie is “Jurassic Park.”


by Lisa Potter, first published in @theU. Video first published by Vanity Fair.


Cellular Crosslinking

Cellular Crosslinking

Structural signatures of Escherichia coli chemoreceptor signaling states revealed by cellular crosslinking

Motile bacteria are capable of swimming efficiently toward favorable chemical environments and away from inhospitable ones. This behavior–called “chemotaxis”–is frequently used by unicellular organisms for finding food.

Not surprisingly, such behaviors play important roles in establishing beneficial host symbioses and pathogenic infections. The value of understanding in detail this mechanism of directed cell migration in response to extracellular chemical signals cannot be over-stated, and Escherichia coli, commonly referred to as E. coli, has become the paradigm molecular model.

“Despite their tiny size, bacteria have evolved amazingly sophisticated protein machines for detecting and responding to changes in their environment,” says John “Sandy” Parkinson, principal investigator in the School of Biological Sciences. Caralyn Flack, a research associate in the Parkinson Lab, developed a technique for monitoring the behavior of living bacteria before and after she changed the structure of a critical signaling protein inside the cell.

Flack’s new findings were recently published in Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS). The paper, titled “Structural signatures of Escherichia coli chemoreceptor signaling states revealed by cellular crosslinking,” makes an important advance in elucidating the molecular mechanism(s) of signal propagation through chemoreceptor molecules.

Caralyn Flack

"This new cellular crosslinking approach delivers unprecedented insight into receptor structural properties as the receptors function within cells"


“Bacteria are amazing at sensing and responding quickly to changes in their environment,” states Flack. “This makes them a great model for trying to understand transmembrane signaling.” But it turns out that changes that accompany signaling events in chemoreceptors are difficult to follow with traditional structural methods, and those techniques that do work cannot replicate the native cellular environment. To remedy that, the technique Flack developed does three things. First, it assesses behavior. Second, it changes the structure of a protein inside living bacteria, and third, it then watches the signaling behavior change in real-time. The technique, which involves “crosslinking,” she says, has proven to be “really powerful for structure-function analyses of signaling proteins.”

In essence, what Flack did was create receptor proteins with a special amino acid at a position of interest. That amino acid, cysteine, has unique chemical properties that, under the right conditions, allow it to form a covalent bond (to “crosslink”) to a nearby cysteine in the same protein or in another protein. Such crosslinks constrain the structural movements of the proteins and can change its behavior. This is how Flack was able to change the structure, and in consequence, the function of a receptor within a living cell.

The crosslinking reporter sites “enabled us to evaluate receptor output states before and after crosslink formation,” she writes. This new cellular crosslinking approach “delivers unprecedented insight into receptor structural properties as the receptors function within cells” stated one reviewer of the PNAS manuscript. Flack suggests that “similar crosslinking approaches could serve to follow signal transmission in other regions of the chemoreceptor molecule and perhaps in other signaling proteins, as well.”

Work on those topics is ongoing.

Photo: Colorized scanning electron micrograph of Escherichia coli, grown in culture and adhered to a cover slip by NIAID on Flickr


by David Pace, first published in