Seasonal and regional variations of atmospheric ammonia across the South Korean Peninsula
Taehyun Park, Rahul Singh, Jihee Ban, Kyunghoon Kim, Gyutae Park, Seokwon Kang, Siyoung Choi, Jeongin Song, Dong-Gil Yu, Min‐Suk Bae, Junyoung Ahn, Hae‐Jin Jung, Yong-Jae Lim, Hyun Woong Kim, Tae Kyung Hwang, Yu Jin Choi, Sooyoung Kim, Hyo Seon Kim, Yu Woon Chang, Hye Jung Shin, Yunsung Lim, Jongtae Lee, Jinsoo Park, Jinsoo Choi, Taehyoung Lee
Abstract
Abstract This study aimed to identify the factors causing NH 3 emissions in the South Korean Peninsula and West Sea region. To analyze the trends of NH 3 and other air pollutants, such as NO x , CO, and NR-PM 1 , we collected samples from six supersites across the peninsula, a roadside in Seoul, and the West Sea over different sampling periods, ranging from 1 month to 1 year. The highest NH 3 concentrations were found at rural areas, ascribed to agricultural activities, particularly NH 4 NO 3 decomposition at high summer temperatures. Areas with low population densities recorded the lowest NH 3 concentrations, attributed to the lack of anthropogenic activities. A roadside field experiment confirmed the close link between ambient NH 3 and vehicle emissions in urban regions by showing a strong correlation between CO and NO x concentrations and that of NH 3 . Moreover, we examined oceanic emissions near the eastern coast of South Korea in the West Sea. Long-range transportation studies confirmed that most of the pollutants (NH 3 , CO, and PM 1 ) were transported by wind from the northeastern region of China. A maritime origin study showed that oceanic emissions and NH 4 NO 3 decomposition in the atmosphere owing to high temperatures were the causing NH 3 pollution. These findings provided valuable insights into the emission sources of NH 3 in primary air pollutants in South Korea, highlighting the contributions of land-based and oceanic sources. Our study can help inform policymakers and stakeholders for developing effective regional air pollution control strategies.