Classification of diurnal patterns of particulate inorganic ions downwind of metropolitan Seoul

Lee, Yong Hwan; Choi, Yongjoo; Ghim, Young Sung

doi:10.1007/s11356-016-6125-3

Cited by 11 publications

(5 citation statements)

References 32 publications

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“…However, these variations have rarely been studied, particularly for particulate inorganic ions, because their concentrations have traditionally been measured using filter sampling, which typically provides 24-h averages (McMurry et al, 2004;Solomon et al, 2008). Lee et al (2016) distinguished the five diurnal patterns from the PILS measurement data at Yongin using a hierarchical clustering method: L, low concentration pattern; Mam and Mpm, medium concentration patterns with primary peaks in the morning and afternoon, respectively; H+ and H-, high concentration patterns with increasing and decreasing trends, respectively, during the day (see Fig. 5 for the variations).…”

Section: Ion Sum and Pm 25mentioning

confidence: 99%

Evaluation of Model Performance for Forecasting Fine Particle Concentrations in Korea

Ghim

Choi

Kim

et al. 2017

Aerosol Air Qual. Res.

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The performance of a modeling system consisting of WRF model v3.4.1 and CMAQ model v4.7.1 for forecasting fine particle concentrations were evaluated using measurement data at the surface. Twenty-four hour averages of PM 2.5 and its major components at Bulgwang (located in the northwest of Seoul) during the period February 2012 through January 2013 were compared with predicted concentrations as well as hourly averages of inorganic ions measured at Yongin (located to the southeast of Seoul) in spring 2012. The mean fractional bias (MFB) of -0.37 for PM 2.5 at Bulgwang fell just outside the goal of -0.3, the level of accuracy that the best model can be achieved. Negative values of MFB, especially in winter, along with the correlation coefficient of 0.61 between measured and predicted concentrations showed that the model performance at Bulgwang was closer to that for Europe than that for North America. However, underestimation of SO 4 2-and overestimation of NO 3 -were similarly observed at Bulgwang as in the United States. Although diurnal variations in the measured values showed distinctive features at Yongin according to the classified patterns, most variations in the predicted values typically showed a peak early in the morning followed by an increase at night.

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Section: Ion Sum and Pm 25mentioning

confidence: 99%

Evaluation of Model Performance for Forecasting Fine Particle Concentrations in Korea

Ghim

Choi

Kim

et al. 2017

Aerosol Air Qual. Res.

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“…In Table , AS was regarded as being representative of SII rather than an AS itself. The increased concentrations of AS in January and February can probably be caused by low temperatures, which are favorable for partitioning semi‐volatile SII into the particulate phase [ Lee et al ., , ].…”

Section: Resultsmentioning

confidence: 99%

“…In addition to measure the 24 h average concentrations of particulate components using filter sampling, the concentrations of PM 2.5 inorganic ions and BC were measured using a particle‐into‐liquid sampler (PILS; ADI 2081, Applikon Analytical), coupled with online IC, and a multiangle absorption photometer (MAAP; Model 5012, Thermo Scientific), respectively. The upstream configuration of PILS‐IC was the same as that for the filter sampling [ Lee et al ., ]. Particles activated by supersaturated steam grew up to 5 µm in diameter [ Sorooshian et al ., ], were hit onto the impaction surface, and were collected by the transport liquid to produce a liquid sample every ~25 min.…”

Section: Methodsmentioning

confidence: 99%

Estimation of columnar concentrations of absorbing and scattering fine mode aerosol components using AERONET data

Choi

Ghim

2016

JGR Atmospheres

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Columnar concentrations of absorbing and scattering components of fine mode aerosols were estimated using Aerosol Robotic Network (AERONET) data for a site downwind of Seoul. The study period was between March 2012 and April 2013 including the period of the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)‐Asia campaign in March to May 2012. The Maxwell Garnett mixing rule was assumed for insoluble components embedded in a host solution, while the volume average mixing rule was assumed for the aqueous solution of soluble components. During the DRAGON‐Asia campaign the surface concentrations of major components of fine particles were measured. The columnar mass fractions of black carbon (BC), organic carbon (OC), mineral dust (MD), and ammonium sulfate (AS) were 1.5, 5.9, 6.6, and 52%, respectively, which were comparable to the mass fractions measured at the surface for BC, OC, and secondary inorganic aerosols at 2.3, 18, and 55%. The vertical distributions of BC and AS were investigated by employing the concept of a column height. While the column height for BC was similar to the planetary boundary layer (PBL) height, that for AS was 4.4 times higher than the PBL height and increased with air temperature from March to May. The monthly variations of the columnar mass concentrations during the study period were generally well explained in term of meteorology and emission characteristics. However, certain variations of MD were different from those typically observed primarily because only fine mode aerosols were considered.

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“…Seoul (Yonsei University; 126.93 • E, 37.56 • N, 88 m asl) is a metropolitan city with a population exceeding 10 million along with significant transportation and industrial emission sources, resulting in high levels of urban pollution [48,49]. Yongin (Hankuk_UFS; 127.27 • E, 37.34 • N, 167 m asl) is suitable for monitoring the pollutants transported from Seoul because the site is located in a downwind region (~37 km from Seoul city hall) and has no major emission source except for a four-lane road nearby (~1.8 km) [32,50]. Anmyon (126.33 • E, 36.54 • N, 46 m asl) is one of World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) stations, located on the west coast of South Korea.…”

Section: Study Sites and Periodsmentioning

confidence: 99%

Estimation of Surface Concentrations of Black Carbon from Long-Term Measurements at Aeronet Sites over Korea

et al. 2020

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We estimated fine-mode black carbon (BC) concentrations at the surface using AERONET data from five AERONET sites in Korea, representing urban, rural, and background. We first obtained the columnar BC concentrations by separating the refractive index (RI) for fine-mode aerosols from AERONET data and minimizing the difference between separated RIs and calculated RIs using a mixing rule that can represent a real aerosol mixture (Maxwell Garnett for water-insoluble components and volume average for water-soluble components). Next, we acquired the surface BC concentrations by establishing a multiple linear regression (MLR) between in-situ BC concentrations from co-located or adjacent measurement sites, and columnar BC concentrations, by linearly adding meteorological parameters, month, and land-use type as the independent variables. The columnar BC concentrations estimated from AERONET data using a mixing rule well reproduced site-specific monthly variations of the in-situ measurement data, such as increases due to heating and/or biomass burning and long-range transport associated with prevailing westerlies in the spring and winter, and decreases due to wet scavenging in the summer. The MLR model exhibited a better correlation between measured and predicted BC concentrations than those based on columnar concentrations only, with a correlation coefficient of 0.64. The performance of our MLR model for BC was comparable to that reported in previous studies on the relationship between aerosol optical depth and particulate matter concentration in Korea. This study suggests that the MLR model with properly selected parameters is useful for estimating the surface BC concentration from AERONET data during the daytime, at sites where BC monitoring is not available.

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Classification of diurnal patterns of particulate inorganic ions downwind of metropolitan Seoul

Cited by 11 publications

References 32 publications

Evaluation of Model Performance for Forecasting Fine Particle Concentrations in Korea

Evaluation of Model Performance for Forecasting Fine Particle Concentrations in Korea

Estimation of columnar concentrations of absorbing and scattering fine mode aerosol components using AERONET data

Estimation of Surface Concentrations of Black Carbon from Long-Term Measurements at Aeronet Sites over Korea

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