Spatial distributions of atmospheric ammonia in a rural area in south korea and the associated impact on a nearby urban area

Ammonia (NH₃) plays an important role in air quality and atmospheric chemistry, yet studies on the characteristics and impacts of NH₃ are limited. Herein, we revealed the spatial distribution of atmospheric NH₃, as measured by passive samplers, at three different sites (R1, R2, and R3) in the rural area (livestock environment) of Jeongeup, South Korea, from September 2019 to August 2020. At site R1, the boundary of a large-scale pig farm, dramatically high daily mean concentrations of NH₃ were observed (118.7 ppb), whereas sites R2 and R3, located ~1 km from R1, exhibited lower concentrations of 18.2 and 30.4 ppb, respectively. In the rural environment, the monthly NH₃ variations showed a peak in June (34.2 ppb), which was significantly higher than in the urban and remote areas. To examine the impact of NH₃ from the rural area on a nearby urban area in June 2020, simultaneous measurements were performed using a real-time instrument in Jeonju. When high NH₃ events occurred in the urban area in June, the results for the NH₃ concentrations and observed meteorological conditions in the rural and urban areas showed that the rural area influenced the NH₃ levels in the adjacent urban area.