Seasonal characteristics of ambient volatile organic compounds in Seoul, Korea

Na, Kwangsam; Kim, Yong Pyo

doi:10.1016/s1352-2310(00)00464-7

Cited by 171 publications

(81 citation statements)

References 19 publications

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“…Previous VOC observations in the SMA consistently have shown that toluene is the dominant anthropogenic VOC followed by other aromatic compounds such as xylene and benzene (Kim et al, 2012;Na and Kim, 2001). Na and Kim (2001) reported high concentrations of propane from household fuel use.…”

Section: Observational Resultsmentioning

confidence: 89%

“…Na and Kim (2001) reported high concentrations of propane from household fuel use. However, recent observation results from the photochemical pollution observational network managed by National Institute of Environmental Research of South Korea in the SMA clearly indicate that propane levels have declined and are now much lower than the levels previously observed (NIER, 2010).…”

Section: Observational Resultsmentioning

confidence: 99%

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Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Kim

Lee³

et al. 2015

Atmos. Chem. Phys.

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Abstract. Rapid urbanization and economic development in East Asia in past decades has led to photochemical air pollution problems such as excess photochemical ozone and aerosol formation. Asian megacities such as Seoul, Tokyo, Shanghai, Guangzhou, and Beijing are surrounded by densely forested areas, and recent research has consistently demonstrated the importance of biogenic volatile organic compounds (VOCs) from vegetation in determining oxidation capacity in the suburban Asian megacity regions. Uncertainties in constraining tropospheric oxidation capacity, dominated by hydroxyl radical, undermine our ability to assess regional photochemical air pollution problems. We present an observational data set of CO, NO x , SO 2 , ozone, HONO, and VOCs (anthropogenic and biogenic) from Taehwa research forest (TRF) near the Seoul metropolitan area in early June 2012. The data show that TRF is influenced both by aged pollution and fresh biogenic volatile organic compound emissions. With the data set, we diagnose HO x (OH, HO 2 , and RO 2 ) distributions calculated using the University of Washington chemical box model (UWCM v2.1) with nearexplicit VOC oxidation mechanisms from MCM v3.2 (Master Chemical Mechanism). Uncertainty from unconstrained HONO sources and radical recycling processes highlighted in recent studies is examined using multiple model simulations with different model constraints. The results suggest that (1) different model simulation scenarios cause systematic differences in HO x distributions, especially OH levels (up to 2.5 times), and (2) radical destruction (HO 2 + HO 2 or HO 2 + RO 2 ) could be more efficient than radical recycling (RO 2 + NO), especially in the afternoon. Implications of the uncertainties in radical chemistry are discussed with respect to ozone-VOC-NO x sensitivity and VOC oxidation product formation rates. Overall, the NO x limited regime is assessed except for the morning hours (8 a.m. to 12 p.m. local standard time), but the degree of sensitivity can significantly vary depending on the model scenarios. The model results also suggest that RO 2 levels are positively correlated with oxygenated VOCs (OVOCs) production that is not routinely constrained by observations. These unconstrained OVOCs can cause higher-than-expected OH loss rates (missing OH reactivity) and secondary organic aerosol formation. The series of modeling experiments constrained by observations strongly urge observational constraint of the radical pool to enable precise understanding of regional photochemical pollution problems in the East Asian megacity region.

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Section: Observational Resultsmentioning

confidence: 89%

Section: Observational Resultsmentioning

confidence: 99%

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Kim

Lee³

et al. 2015

Atmos. Chem. Phys.

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“…Variation in source strength has dominating influence on variations in VOC concentrations in close proximity to the source. However, when distance between source and receptor increases, meteorological parameters Yang et al, 2005;Cheng et al, 1997) and photochemical activity (Na and Kim, 2001) may become more important factors affecting variations in VOC concentrations. Diurnal, weekday-weekend, and seasonal variations in VOC concentrations measured in this study are discussed in the following.…”

Section: Temporal Variations Of Vocsmentioning

confidence: 99%

“…Higher summer concentrations at all sites are statistically significant at the 90% confidence level (P < 0.10). Isoprene is a well-known marker for biogenic emissions, and increase in isoprene emissions from plants during summer is frequently reported in the literature (Watson et al, 2001;Na and Kim, 2001;Borbon et al, 2001) and attributed to photosynthetic processes in plant leaves, which are enhanced by increase in solar flux and temperature (Guenther et al, 2000). Isoprene is also emitted from motor vehicles (Borbon et al, 2001;Borbon et al, 2002).…”

Section: Temporal Variations Of Vocsmentioning

confidence: 99%

C5–C12 volatile organic compounds at roadside, residential, and background locations in Ankara, Turkey: Temporal and spatial variations and sources

Kuntasal

Kılavuz

Karman

et al. 2013

Journal of the Air & Waste Management Association

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Concentrations of 91 volatile organic compounds (VOCs) ranging from C5 to C12 were measured at three sites in Ankara, the capital of Turkey, in the summer of 2003 and winter of 2004. Samples were collected at roadside, residential and background stations at consecutive 4-hr intervals over a 24-hr period for six weeks in each season. Air samples were collected onto cartridges packed with Tenax TA and Carbopack B resins and analyzed by thermal desorption, followed by gas chromatography coupled to a mass selective detector (GC/MSD). Time resolved data provided information on ambient levels, temporal and spatial variations and sources of VOCs in Ankara. Toluene is the most abundant compound at all sites with and average concentration of 13.1 ?g m-3. The mean concentrations of benzene are 12.6, 5.2, and 2.4 ?g m-3 during winter at roadside, residential and background stations, respectively. Diurnal variation in the data together with toluene to benzene concentration ratio (T:B) that is close to 2.0 indicated the influence of traffic related emissions at residential and roadside stations during winter season. Higher T:B ratio observed at residential and background stations during summer period and correlation analysis indicated additional VOC sources. Temporal variations and low m,p-xylene to ethylbenzene ratio (mpX:E) indicated that transported air mass is the major VOC source influencing VOC concentrations measured at the background station.Implications: VOC measurement at three sites in Ankara, the capital of Turkey showed that VOC concentrations measured at the roadside station are reasonably higher than concentrations measured at residential and background sites. Diurnal variations of VOC concentrations revealed that traffic emissions at roadside and residential locations are a significant VOC source in Ankara. On the other hand, VOC levels measured at the background site are transported from more polluted parts of Ankara.

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“…The results obtained in this study indicated that there were other factors affecting the seasonal variation, such as source emissions. BTEX mainly originated from vehicle exhaust , solvent usage Yuan et al, 2010) and petrochemical industry (Na and Kim, 2001;Hsieh et al, 2006;Baltrėnas et al, 2011). As discussed above, the emission from vehicles was not obvious from the diurnal variation of BTEX and the solvent usage was negligible in the study area.…”

Section: Ambient Ratios: Sources and Photochemical Removalmentioning

confidence: 83%

One year monitoring of volatile organic compounds (VOCs) from an oil-gas station in northwest China

Zheng

Kong

Xing

et al. 2017

Preprint

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Abstract. Oil and natural gas are important energy supply around the world. The exploring, drilling, transportation, and processing in oil-gas regions can release abundant volatile organic compounds (VOCs). To understand the atmospheric behaviors of VOCs in such region, the fifty-six VOCs designed as the photochemical precursors by the United State 15Environmental Protection Agency were continuously measured for an entire year (September 2014-August 2015) by a set of on-line monitor system at an oil-gas station in northwest China. The VOC concentrations in this study were 1-50 times higher than those measured in many other urban and industrial regions. The VOC compositions were also different from other studies with alkanes contributing up to 87.5% of the total VOCs in this study. According to the propylene-equivalent concentration and maximum incremental reactivity method, alkanes were identified as the most important VOC groups to the ozone 20 formation potential. The photochemical reaction, meteorological parameters (temperature, relative humidity, pressure, and wind speed) and boundary layer height were found to influence the temporal variations of VOCs at different time scales. The positive matrix factorization analysis showed that the natural gas, fuel evaporation, combustion sources, oil refining process, and asphalt contributed 62.6%, 21.5%, 10.9%, 3.8%, and 1.3%, respectively to the total VOCs on the annual average. Clear temporal variations differed from one source to another was observed, due to their differences in source emission strength and 25 the influence of meteorological parameters. Potential source contribution function and contribution weighted trajectory models based on backward trajectories indicated that five identified sources had similar geographic origins. Raster analysis based on CWT analysis indicated that the local emissions contributed 48.4%-74.6% to the VOCs. This research filled the gaps in understanding the VOCs in the oil-gas field region, where exhibited different source emission behaviors compared with the urban/industrial regions. 30

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Seasonal characteristics of ambient volatile organic compounds in Seoul, Korea

Cited by 171 publications

References 19 publications

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

C5–C12 volatile organic compounds at roadside, residential, and background locations in Ankara, Turkey: Temporal and spatial variations and sources

One year monitoring of volatile organic compounds (VOCs) from an oil-gas station in northwest China

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