Current projects
Emissions and chemical impacts of smoke from wildfire and residential wood burning
Understanding the chemistry in wildfire smoke has important implications for air quality, nutrient cycles, weather, and climate. Atmospheric non-methane VOCs play a crucial role as precursors of ozone and secondary organic aerosol. However, the budgets and distribution of VOCs in the atmosphere are not well understood, particularly in biomass burning influenced conditions which are often more complex than traditionally studied environments in urban, forested, or remote areas. This project will improve our understanding of the sources and atmospheric impacts of VOCs from western U.S. wildfires. The main focus will be on previously understudied VOCs such as furans, which are not represented in current 3D air quality models, but have shown significant hydroxyl radical reactivity in fire smoke plumes. Overall, we will explore: a) which critical VOCs are present in fire smoke and in what amounts; and b) how these VOCs collectively affect tropospheric chemistry on regional through global scales.
Collaborators: WE-CAN Science Team, Bob Yokelson (U Montana), NOAA, NCAR
People: Wade Permar, Damien Ketcherside, Lixu Jin (now at Rutgers)
References: Permar et al. (2021; 2023a; 2023b; 2025); Jin et al. (2023, 2026), Ketcherside et al. (2025)
SMART FIRES (Sensors, Machine Learning, and Artificial Intelligence in Real-Time Fire Science)
The project expands jurisdictional research capacity to address knowledge gaps in prescribed fire usage and its impact on individuals and communities. Prescribed fire is the controlled application of fire to restore ecosystem health and mitigate wildfire risk in the Western U.S. We developed a cutting-edge mobile laboratory to sample and understand prescribed fire emissions. SMART FIRES, which is guided by two foundational questions: 1) How do prescribed fire energy and emissions depend on fuel properties, topography, and environmental conditions? 2) How do the smoke emissions from prescribed fire affect individuals and communities?
Collaborators: UM Fire Center, Bob Yokelson (U Montana), Montana State U
People: Wade Permar, Lu Tan
References: to be updated.
Intermountain urban ozone photochemistry
High ozone mixing ratios are a serious summertime health and economic concern for residents of Utah’s Wasatch Front. We will conduct research flights along the Wasatch Front between July 1 and August 30, 2026 to 1) investigate O3 production and pollutant evolution in thermally driven lake breeze flows over and surrounding Salt Lake City (SLC), 2) quantify the contribution of individual and specific VOC classes to ozone production, 3) characterize differences in the photochemical environment in the SLC region on smoke-impacted versus smoke-free days with daily 8-hour ozone values (MDA8) near or above the standard, and 4) investigate the emissions from specific point and area sources. We are outfitting the University of Wyoming King Air (UWKA) research aircraft with a suite of instrumentation, including our PTR-ToF-MS, optimized for 1) measuring ozone and its precursors, and 2) allowing us to distinguish the presence of wildfire smoke in the local environment.
Collaborators: CSU, U of Wyoming, U of Utah, NCAR, NASA
People: Emily Cope, Amity Deters, Lexie Rhodes
References: Cope et al. (2024)
Previous projects
The Alaskan Layered Pollution And Chemical Analysis (ALPACA)
Biomass burning (BB) emissions from open fires and residential wood combustion are important sources of VOCs to the atmosphere, impacting regional air quality and public health, particularly in the western U.S. and Alaska. Meanwhile, in urban atmospheres, emissions from volatile chemical products (VCPs) have been suggested to be an important VOC source as mobile emissions have steadily declined. Many fundamental issues related to VOC emissions remain unresolved, limiting our capacity for environmental health assessment and management. This project aimed at developing new observational constraints on VOC emissions in two U.S. cities facing serious air pollution challenges. It was built on existing FIREX-AQ efforts in Missoula, MT, and contributed to the ALPACA field campaign in Fairbanks, AK. The data analysis improved mechanistic understanding of VOC emissions and fates in the two urban and in cold/dark environments.
References: Ketcherside et al. (2025)
Factors controlling global tropospheric ozone
Ozone is central to our understanding of tropospheric oxidant chemistry through its driving of radical cycles. In the surface air, ozone is toxic to humans and vegetation. Ozone is also the 3rd most important greenhouse gas in the troposphere. Yet our understanding of factors determining its spatial distribution and the long-term trend is still poor. In collaboration with colleagues at Harvard and NASA GMAO, we used the atmospheric models such as GEOS-Chem chemical transport model as a platform to test our current knowledge of key factors controlling global tropospheric ozone, focusing on the following three projects: 1) Improving our understanding of global tropospheric ozone using integrated recent advancement of knowledge in isoprene chemistry, tropospheric halogen chemistry, lightning NOx source, and deep convection. 2) Modeling global ozone concentration at very-high-resolution to improve the understandings of intercontinental transport of pollution and ozone climate forcing. 3) Investigating factors controlling the variability and trend of tropospheric ozone and OH radical over the last 30 years using the NASA Global Modeling Initiative (GMI) and GEOS-Chem chemical transport models.
References: Christiansen et al. (2022; 2024), Hu et al. (2017; 2018)
Atmospheric chemistry and biogenic VOCs in changing Arctic
The Arctic is experiencing rapid environmental changes due to a warming climate. Its consequences, among many, including lengthening the growing season and ecosystem transformations, are expected to increase atmospheric biogenic VOCs (BVOCs) in the Arctic, thus impacting atmospheric oxidation processes and climate. This NSF-funded project, collaborating with researchers at CU-Boulder and U Minnesota, quantified emissions and ambient concentrations of BVOCs and other important atmospheric compositions like NOx and ozone in the Arctic tundra ecosystem. Our group's role in this project is to utilize atmospheric models and the collected field data to test and improve the current understanding of the fate of air pollutants such as ozone in the changing Arctic.
References: Selimovic et al. (2022)