Wintertime photochemistry of acyl peroxynitrates and ozone in South Korea during the ASIA-AQ campaign

作者：Young Ro Lee, Linda Arterburn, Masayuki Takeuchi, David J. Tanner, James M. Roberts, Behrooz Roozitalab, Daun Jeong, Alan J. Hills, Rebecca S. Hornbrook, Eric C. Apel, Simone Meinardi, Barbara Barletta, Nicola J. Blake, Donald R. Blake, Saewung Kim, Wojciech Wojnowski, Felix Piel, Armin Wisthaler, Katherine Ball, John D. Crounse, P. O. Wennberg, Jason A. Miech, Yonghoon Choi, Joshua P. DiGangi, Glenn S. Diskin, Abby E. Sebol, Erin R. Delaria, Reem A. Hannun, Jason M. St. Clair, Glenn M. Wolfe, Changmin Cho, Courtney Owen, Kirk Lesko, Alessandro Franchin, Edward L. Winstead, Luke D. Ziemba, Richard H. Moore, Elizabeth B. Wiggins, Guy Symonds, Dongwook Kim, Douglas A. Day, Pedro Campuzano‐Jost, J. L. Jiménez, Kirk Ullmann, Samuel R. Hall, James H. Crawford, L. G. Huey · 发表于：Atmospheric chemistry and physics · 年份：2026 · DOI：10.5194/acp-26-8695-2026 · 研究领域：Atmospheric chemistry and aerosols、Atmospheric Ozone and Climate、Indoor Air Quality and Microbial Exposure

Abstract. Wintertime photochemical air pollution in East Asia remains poorly constrained despite its impact on regional air quality. Sources and formation pathways of acyl peroxynitrates (PANs) and ozone (O3), key photochemical products, are not well understood, hindering effective mitigation strategies. We investigate PANs and O3 over South Korea using observations from the ASIA-AQ campaign (February–March 2024). PANs reached 5.5 ppbv, strongly correlating with formaldehyde and particulate matter, indicating active winter photochemistry. Median PANs were higher in the mid-southern peninsula (MS; 990 pptv) and Yellow Sea (1200 pptv) than the Seoul Metropolitan Area (840 pptv). Elevated homologue-to-acetyl peroxynitrate ratios over the MS, with enhanced acryloyl peroxynitrate, acrolein, and ethylene oxide, provided tracers for petrochemical emissions and their impacts. Acetaldehyde contributed 53 %–80 % of PAN production. Ethanol was a major precursor of acetaldehyde (∼ 50 %). Strong correlations (r2 > 0.8) of ethanol and halocarbons indicate industrial and solvent sources under-represented in inventories. Formaldehyde and C2+ aldehydes contributed ∼ 30 % to ozone production. Low ozone production efficiency (< 10) and radical termination dominated by nitric acid and PANs (> 80 %) indicate VOC-limited conditions. The fractional PANs contribution to NOx loss increased with decreasing OH reactivity ratio of NO2 to aldehydes, suggesting spatial increases in ozone producti...