Replication Data for: Wintertime trends of fine particulate matter (PM2.5) in South Korea, 2012-2022: response of nitrate and organic components to decreasing NOx emissions

This dataset contains: (1) Seoul-specific bulk PM2.5 data from before 2015 with corresponding NO2 and O3 from AirKorea (seoul_PM2.5_O3_NO2_hourly_2011-2022.csv). (2) The synthetic PM2.5 surface network for Korea prior to 2015 described in Pendergrass et al., (2025), reported on the 2x2 km GOCI grid (korea_pre2015_rf_pm25.csv). (3) PM composition data measurements used in this study (pm_composition_data.xlsx).