title: Time-resolved measurements of PM2.5 carbonaceous aerosols at Gosan, Korea.
abstract: In order to better understand the characteristics of atmospheric carbonaceous aerosol at a background site in Northeast Asia, semicontinuous organic carbon (OC) and elemental carbon (EC), and time-resolved water-soluble organic carbon (WSOC) were measured by a Sunset OC/ EC and a PILS-TOC (particle-into-liquid sampler coupled with an online total organic carbon) analyzer, respectively, at the Gosan supersite on Jeju Island, Korea, in the summer (May 28-June 17) and fall (August 24-September 30) of 2009. Hourly average OC concentration varied in the range of approximately 0.87-28.38 microgC m-3, with a mean of 4.07+/- 2.60 microgC m-3, while the hourly average EC concentration ranged approximately from 0.04 to 8.19 .microgC m-3, with a mean of 1.35 +/- 0.71 microgC m-3, from May 28 to June 17, 2009. During the fall season, OC varied in the approximate range 0.9-9.6 microgC m-3, with a mean of 2.30 +/-0.80 microgC m-3, whereas EC ranged approximately from 0.01 to 5.40 microgC m-3, with a mean of 0.66 +/- 0.38 microgC m-3. Average contributions of EC to TC and WSOC to OC were 26.0% +/- 9.7% and 20.6% +/-7.4%, and 37.6% +/- 23.5% and 57.2% +/- 22.2% during summer and fall seasons, respectively. As expected, clear diurnal variation of WSOC/OC was found in summer, varying from 0.22 during the nighttime up to 0.72 during the daytime, mainly due to the photo-oxidation process. In order to investigate the effect of air mass pathway on the characteristics of carbonaceous aerosol, 5-day back-trajectory analysis was conducted using the HYSPLIT model. The air mass pathways were classified into four types: Continental (CC), Marine (M), East Sea (ES) and Korean Peninsula (KP). The highest OC/EC ratio of 3.63 was observed when air mass originated from the Continental area (CC). The lowest OC/EC ratio of 0.79 was measured when air mass originated from the Marine area (M). A high OC concentration was occasionally observed at Gosan due to local biomass burning activities. The contribution of secondary OC to total OC varied approximately between 8.4% and 32.2% and depended on air mass type.
authors.affiliation: Advanced Environmental Monitoring Research Center (ADEMRC), School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Korea.
authors.forename: T
authors.initials: T
authors.lastname: Batmunkh
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.forename: K Y
authors.initials: KY
authors.lastname: Lee
authors.forename: M G
authors.initials: MG
authors.lastname: Cayetano
authors.forename: J S
authors.initials: JS
authors.lastname: Jung
authors.forename: S Y
authors.initials: SY
authors.lastname: Kim
authors.forename: K C
authors.initials: KC
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Lee
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: L S
authors.initials: LS
authors.lastname: Chang
authors.forename: J Y
authors.initials: JY
authors.lastname: An
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000393:Air Pollutants / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002940:Circadian Rhythm; D004784:Environmental Monitoring; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D056910:Republic of Korea; D013997:Time Factors
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon