Category: Applied Research Overview

The project will analyze air quality and meteorology data collected during the 2024 Utah Summer Ozone Study (USOS) to investigate the role of atmospheric boundary layer dynamics in summertime ozone in the Salt Lake City region. One main task is to conduct a comprehensive analysis of boundary layer dynamics using airborne Doppler lidar measurements and evaluate the NOAA High-Resolution Rapid Refresh (HRRR) model performance. The second task involves using case studies to relate spatial and temporal variations in ozone to its meteorological drivers.

The project aims to improve Biogenic Volatile Organic Compound (BVOC) Emissions Modeling for the Wasatch Front, which is essential for developing effective air pollution control strategies for the region’s ozone nonattainment. The scope of work includes synthesizing an updated BVOC emission factor database, enhancing rural landcover inputs for the MEGAN model using datasets like LANDFIRE and USFS FIA, and updating MEGAN species mappings to chemical mechanisms, including support for CB7 with VCP. Key deliverables and outcomes include improved MEGAN model inputs, a more accurate regional BVOC emissions inventory, and quantification of stress-induced and lawn-mowing BVOC emissions, all to be provided to UDAQ.

The goal of this study is to assess summertime ozone sensitivity to volatile organic compounds (VOCs) and oxides of nitrogen (NOx), as well as the impact of changing conditions like wildfire smoke and drought, on ozone concentrations in the Northern Wasatch Front. The core methodology will focus on the Formaldehyde-Nitrogen Ratio (FNR), derived from TROPOMI and TEMPO satellite data, as a key indicator of whether ozone production is NOx-sensitive or VOC-sensitive. The project will utilize an existing Google Earth Engine (GEE) platform and develop new Utah-specific tools within GEE to integrate various satellite and surface data, using machine learning to categorize ozone events and model effects.

The shrinking Great Salt Lake exposes over 750 square miles of potentially metal-contaminated lakebed dust, and this project aims to quantify community exposure to the resulting airborne PM10 in Wasatch Front communities. The methodology involves a combination of continuous PM monitoring, analysis of particle size, oxidative potential, and metal/organic carbon composition. These measurements will be coupled with statistical analysis and HYSPLIT wind trajectory modeling to support the Utah Division of Air Quality’s priority for Great Salt Lake Dust composition measurements and community impact assessments.

To meet ozone standards in the Wasatch Front, this project analyzes the role of local and non-local emissions, especially from wildfires. Researchers will assess wildfire impacts on ozone and PM2.5 levels using satellite and in-situ data, and study ozone sensitivity to NOx and VOCs through formaldehyde-to-NO2 ratios. Insights from this work will inform emission reduction strategies for high ozone days.

Using drones and portable ozone monitors, this research will capture detailed pollutant data near the Great Salt Lake to complement existing ground and airborne measurements. Coordinated with the Utah Summer Ozone Study (USOS), the project will gather crucial information on ozone and other pollutants to address research goals on ozone sources and vertical oxidant exchange.

Focused on the unique atmospheric chemistry of Salt Lake City, this study investigates the influence of regional halogen emissions on ozone and particulate matter. By measuring chlorine-induced reactions with volatile organic compounds, researchers will quantify the extent of halogen-driven oxidation. The findings will provide essential data on how regional industrial emissions contribute to air quality issues.

This project examines the dust exposure risks from the receding Great Salt Lake, using models to simulate dust emissions and transport across the Wasatch Front. It will evaluate the impact of different water levels on dust exposure, providing Utah DAQ with data to determine dust source contributions and identify communities at risk.

This study examines the impact of soil nitrogen oxide (NOx) emissions on air quality in the Northern Wasatch Front, with a focus on refining NOx emissions modeling. By updating inputs in the Berkeley-Dalhousie Soil NOx Parameterization (BDSNP) for the MEGAN biogenic emissions model, the project aims to improve NOx emission estimates. Results will enhance understanding of soil contributions to air pollution, aiding in regulatory strategies for cleaner air.

This project uses high-resolution modeling to explore how international and regional ozone is transported into the Northern Wasatch Front. By analyzing vertical transport patterns, the study will provide a mechanistic understanding of ozone levels in the area, supporting regulatory planning. The findings are crucial for refining air quality models and informing future policy demonstrations.

The National Oceanic and Atmospheric Administration (NOAA) is leading a large-scale campaign that will increase our understanding of ozone chemistry and emissions sources. During the Utah Summer Ozone Study (USOS), NOAA will be deploying two mobile labs and an aircraft that contains an exhaustive suite of instrumentation to measure the meteorology and ozone precursors that drive harmful summertime pollution in

The University of Washington, Utah State University and the University of Montana will conduct a detailed study of ozone (O3) and fine particulate matter (PM2.5) in the Salt Lake Valley (SLV). Using new VOC observations, plus existing measurements of NOx, CO and PM2.5, they will use a variety of analyses to understand O3 formation and the sources of PM2.5 in the SLV during the summertime season. In addition, they will conduct photochemical modeling and statistical/machine learning analyses to improve our understanding of O3 photochemistry. We expect to gain significant new policy-relevant insights on what controls high concentrations of O3 in the SLV during both smoke-influenced and non-smoke conditions.

• Principal Investigator: Dan Jaffe (University of Washington)
• Funded by Science for Solutions Research Grant: $280,516

Though it can be easy to tell that wildfire smoke has negative impacts on urban air quality, there is no tool to quantitatively measure wildfire impacts, nor to identify whether exceedance days are due to wildfire smoke or other emissions. The first scope of this work will develop a new plume rise model to estimate the plume injection heights for larger wildfires, which will improve simulations of smoke transport and downwind air pollution concentrations. The second scope of this work is to use CTM (chemical transport model) ensemble simulations to determine wildfire smoke contributions to local air quality using source apportionment techniques. The last scope of this work is to develop a fast-response tool to identify federal standards (NAAQS) exceedance days with large contributions from wildfire smoke.

• Principal Investigator: Heather Holmes (University of Utah)
• Funded by Science for Solutions Research Grant: $61,738

The goal of this project is to improve numerical predictions of regional ozone and aerosol distributions in the Wasatch Front by developing more accurate estimates of biogenic volatile organic carbon (BVOC) emissions for the urban areas within the Northern Wasatch Front. Specifically, this project will upgrade modeled MEGAN (Model of Emissions of Gasses and Aerosols from Nature) BVOC emission estimates by analyzing high-resolution satellite imagery using machine learning, object-based classifications that are calibrated and assessed by field observations. Such techniques have already successfully been applied in Texas and California. These techniques will improve MEGAN landcover inputs for the Wasatch Front region including time-varying Leaf Area Index (LAI), growth form fractions (tree, shrub, crops, herbaceous plants) and tree species composition (e.g., relative abundance of oaks, poplars, pines, spruce, etc). The benefit of this project will be an improved MEGAN emission model for the Wasatch Front that is available for use in air quality models that are critical for our scientific understanding and the development of effective regulatory strategies.

• Principal Investigator: Tejas Shah (Ramboll US Consulting)
• Funded by Science for Solutions Research Grant: $124,797

The University of Utah will conduct a study intended to significantly reduce uncertainties regarding the temporal, spatial, and particle size distributions of particulate chloride. Through source apportionment, the study will also identify the dominant sources of this important halogen. These results will provide important emission inventory constraints for future air quality modeling efforts performed by UDAQ and others.

• Principal Investigator: Kevin Perry (University of Utah)
• Funded by Science for Solutions Research Grant: $75,735

The University of Utah is conducting a study to determine the meteorological factors that contribute to elevated surface ozone near the Great Salt Lake. The core task for this project is to evaluate from ozone observations and meteorological observations and model analyses the timing of buildup in ozone in the southern Farmington Bay region and subsequent transport into Davis and Salt Lake counties. Completion of this task will provide resources that are likely to enhance operational air quality forecasting and provide critical information to initialize and verify air chemistry models used to identify approaches to meet federal air quality standards.

• Principal Investigator: John Horel (University of Utah)
• Funded by Science for Solutions Research Grant: $63,084