Atmospheric Ammonia: USU Researchers Looking Into Cache Valley's Ammonia Concentrations

Within our wintertime inversions in the Cache Valley, pollutants and emissions become trapped, and photochemistry begins to combine and condense different chemicals into fine particulate matter — PM2.5, or particulate matter that is 2.5 microns or less in diameter. This size is important because it is the size of particle we can breathe in and that then can get down into our lungs.

The primary chemical species at fault for the formation of this particulate matter? Ammonium nitrate. This chemical compound is formed when gas-phase ammonia and gas-phase nitric acid condense together, and according to the Utah Department of Environmental Quality, ammonium nitrate is responsible for 70 percent or more of the PM2.5 mass in Cache Valley during an inversion.

USU Associate Researcher Randy Martin and his team of undergraduate research assistants are revisiting a study of ammonia levels in Cache Valley — something Martin has been looking into since the mid-2000s. This project will help to determine how the valley’s ammonia concentrations have changed over the past five years since they were last investigated and what can potentially be done to help control the formation of these particles as a result.