title: Peroxyacetyl nitrate (PAN) in the urban atmosphere.
abstract: Peroxyacetyl nitrate (PAN) in air has been well known as the indicator of photochemical smog due to its frequent occurrences in Seoul metropolitan area. This study was implemented to assess the distribution characteristics of atmospheric PAN in association with relevant parameters measured concurrently. During a full year period in 2011, PAN was continuously measured at hourly intervals at two monitoring sites, Gwang Jin (GJ) and Gang Seo (GS) in the megacity of Seoul, South Korea. The annual mean concentrations of PAN during the study period were 0.64±0.49 and 0.57±0.46 ppb, respectively. The seasonal trends of PAN generally exhibited dual peaks in both early spring and fall, regardless of sites. Their diurnal trends were fairly comparable to each other. There was a slight time lag (e.g., 1 h) in the peak occurrence pattern between O3 and PAN, as the latter trended to peak after the maximum UV irradiance period (16:00 (GJ) and 17:00 (GS)). The concentrations of PAN generally exhibited strong correlations with particulates. The results of this study suggest that PAN concentrations were affected sensitively by atmospheric stability, the wet deposition of NO2, wind direction, and other factors.
authors.affiliation: Seoul Metropolitan Government Institute of Public Health and Environment, Seoul, Republic of Korea.
authors.forename: Jun-Bok
authors.initials: JB
authors.lastname: Lee
authors.forename: Joong-Sup
authors.initials: JS
authors.lastname: Yoon
authors.forename: Kweon
authors.initials: K
authors.lastname: Jung
authors.forename: Seok-Won
authors.initials: SW
authors.lastname: Eom
authors.forename: Young-Zoo
authors.initials: YZ
authors.lastname: Chae
authors.forename: Seog-Ju
authors.initials: SJ
authors.lastname: Cho
authors.forename: Shin-Do
authors.initials: SD
authors.lastname: Kim
authors.forename: Jong Ryeul
authors.initials: JR
authors.lastname: Sohn
authors.forename: Ki-Hyun
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry*; D004784:Environmental Monitoring; D010463:Peracetic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D056910:Republic of Korea; D012621:Seasons; D014919:Wind
chemical_list: D000393:Air Pollutants; D010463:Peracetic Acid; C004185:peroxyacetyl nitrate
keywords: O(3); PAN; Photochemical smog; VOCs