This RAPID project supports participation in the 2024 Salt Lake City - Summer Ozone Study (SLC-SOS) field campaign to gain a better understanding of ozone formation throughout the Salt Lake City region. This research will help to determine the conditions under which the ozone formation regime in the region is either limited by concentrations of volatile organic compounds (VOCs) or by concentrations of nitrogen oxides or is in transition between these two regimes. This information is helpful for designing strategies for mitigating ozone pollution in the region.<br/><br/>The objectives of this study are to: (1) measure high time resolution formaldehyde (HCHO) and nitrogen dioxide (NO2) concentrations during SLC-SOS at a stationary ground site, jointly with measurement of ozone (O3) and other O3 precursors; and (2) identify the summertime O3 formation regime over the Northern Wasatch Front (NWF) region in Utah using SLC-SOS data and model simulations. The hypothesis is that the summertime O3 formation regime in the Salt Lake City (SLC) region can be characterized using HCHO/NO2 ratios, gas-phase atmospheric measurements, and model simulations. Two graduate students will participate in the project.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.