Top-down estimation of ammonia emissions from pig farm area using Backward Lagrangian Stochastic model

Ammonia (NH₃) emitted into the atmosphere contributes to increase in fine particulate matter concentrations through secondary formation and affects human comfort through unpleasant odors. Pig farms are a significant source of ammonia, but the actual emissions are highly variable depending on facility types, meteorological conditions, and operational practices, causing high uncertainty in estimating emissions. In this study, hourly atmospheric ammonia concentrations were measured in Yongji, Gimje, South Korea, a region well known for its large-scale old pig farming, over all four seasons from September 2023 to July 2024. Using the data, seasonal ammonia emissions from pig farms were simulated with the WindTrax Backward Lagrangian Stochastic model. Our findings will be presented. This can provide a foundation for validating bottom-up estimates of ammonia emissions and valuable insights on reducing uncertainties associated with ammonia emissions from pig farms.