• Journal of Korean Society for Atmospheric Environment
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• v.33 no.3
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• pp.233-240
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• 2017

To distinguish between high particulate matter (HPM) and light Asian dust (LAD) events, aerosol optical properties from GOCI were investigated in Seoul from 2014 to 2016. The poor air quality case caused by fine atmospheric particulate matter (i.e., 80<$PM_{10}$<$400{\mu}g/m^3$) is clearly separated from the case of heavy Asian dust that generally shows the $PM_{10}$ concentration more than $400{\mu}g/m^3$. In this study, we have found eight cases for the poor air quality and divided them into the two events(i.e., HPM and LAD). In case of aerosol optical depth (AOD), there was no big difference between two events. However, Angstrom exponent (AE) for HPM events was greater than 1, while that for LAD events less than 1. As a result of comparing aerosol type, non-absorbing fine mode aerosols were dominant for HPM events, but coarse and absorbing coarse mode aerosols for LAD events. Therefore, AE and aerosol type from GOCI can be used to distinguish between two events effectively.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.97-107
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• 2017

Columnar aerosol properties retrieved from solar radiation were investigated at the Yongin (YGN) SKYNET site over seven years from October 2008 to October 2015. Hourly averages were calculated when the data were available, and back trajectories were calculated to examine the effects of regional transport. Data recovery rate was low at 6.6%, primarily because solar radiation was measured only under daytime clear-sky conditions. Mean values of the fine-mode volume fraction (FMVF) as well as its seasonal variation were similar to those of $PM_{2.5}/PM_{10}$ although the coarse-mode fraction of column aerosols tended to be slightly larger. The values of single scattering albedo (SSA) and FMVF were lower in spring due to the effects of mineral dust, and higher in summer due to secondarily-formed inorganic ions. Back trajectories were grouped into five clusters according to the directions of transport paths. Aerosol loading was highest for Cluster 2 from the northwest, but SSA and FMVF were not particularly high or low because aerosols were composed of various materials with different properties. Aerosol loading was lowest for Cluster 5 from the Pacific Ocean passing through the south end of Japan, whose SSA and FMVF were highest as secondarily-formed inorganic ions were mixed.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.2
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• pp.168-180
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• 2011

The variation of the physicochemical properties of atmospheric aerosols in coexistence of the heavy Asian Dust and Haze observed from $15^{th}$ to $17^{th}$ March 2009 in Seoul was scrutinized through the mass and ion concentration observations and synoptic weather analysis. Although the ratio of PM1.0/PM10 was constant at 0.3 (which is typical during Asian Dust period in Korea) during the measurement period, both PM10 and PM1.0 mass concentrations were 3~6 times and 2~4 times higher than that of clear days, respectively. Water-soluble ion components accounted for 30~50% of PM10 and 50~70% of PM1.0 mass concentration. One of the secondary pollutants, $NO_3^-$ was found to be associated with $Ca^{2+}$ and $Na^+$ in coarse mode indicating that the aerosol derived from natural source was affected by anthropogenic pollutants. While the acidity of the aerosols increased in fine mode when the stagnation of weather patterns was the strongest (March $16^{th}$), the alkalinity increased in coarse mode when new air masses arrived with a southwestern wind after ending a period of stagnation (March $17^{th}$). In the selected case, SOR (Sulfur Oxidation Ratio, $nSO_4^{2-}/[nSO_4^{2-}+nSO_2]$) and NOR (Nitrogen Oxidation Ratio, $nNO_3^-/[nNO_3^-+nNO_2]$) values of ion components were higher than the general values during Asian Dust period. These results imply that dust aerosols could be mixed with pollutants transported from China even in heavy Asian Dust cases in Korea.

• Asian Journal of Atmospheric Environment
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• v.6 no.4
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• pp.275-280
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• 2012

To understand the effect of aerosols on the growth and physiological conditions of trees in forests, it is important to know the state of aerosols that are deposited on the surface of the leaves or needles. In this study, we developed methods of visualization of submicron-sized aerosols that were artificially deposited from the gas-phase or liquid phase onto tree leaves or needles in trees. Firstly, we used field-emission scanning electron microscopy (FE-SEM) to observe black carbon (BC) particles that were artificially sprayed onto the leaves or needles. The distribution of BC particles deposited on the leaves and needles were distinguished based on the size and morphological features of the particles. The distribution and agglomerates size of BC particles differed between two spraying methods of BC particles employed. Secondly, we tried to visualize gold (Au) particles that were artificially sprayed onto the leaves using energy dispersive X-ray spectrometry (EDX) coupled to FE-SEM. We detected the Au particles based on the characteristic X-ray spectrum, which was secondarily generated from the Au particles. In contrast to the case of BC particles, the Au particles did not form agglomerates and were uniformly distributed on the leaf surfaces. The present results show that our methods provide useful information of adsorption and/or behavior of fine particles at the submicron level on the surface of the leaves.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.109-127
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• 2011

Atmospheric aerosols, small particles in the atmosphere, are one of the important parameters in climate change and human health. Additionally, accurate estimates of aerosol species are increasingly important in environmental impact assessment studies. Recent advances in global satellite remote sensing provide powerful tool for air quality monitoring. This study explores the potential usage of satellite derived data such as atmospheric aerosols for air quality monitoring as well as climate change study. The objectives of this study is to understand the general features of the global distribution of type dependent aerosols. A detailed spatio-temporal variability of the each different satellite dataset shows the variation of the global zonal average and specific geographical regions where the strong emission sources are located. Especially, significantly large aerosol amounts are observed in Asia and Africa because of the desert dust storm, anthropogenic and biomass burning emissions.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.1-12
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• 2016

Numerous researchers have proposed that surface area is a more appropriate indicator than mass for evaluating pulmonary inflammatory responses caused by exposure to fine and ultrafine particles. In this study, measurements of surface area concentrations of aerosols were conducted in Yokohama, Japan, using the diffusion charging method. $PM_{2.5}$ mass concentration and black carbon concentration in $PM_{2.5}$ were also measured. The 24-hour continuous measurement campaigns were conducted 39 times from March to November, 2014. The surface area concentration was more closely correlated with the black carbon concentration than with the $PM_{2.5}$ mass concentration. It is considered that the abundance of black carbon particles significantly affects the surface area concentration of $PM_{2.5}$. The strength of the correlation between the surface area and black carbon concentrations varied considerably among the measurement campaigns. A relatively weaker afternoon correlation was observed compared with the other time zones (morning, evening, and night). We consider that these phenomena are due to the transportation/formation of the particles other than black carbon that affects surface area concentration and/or the variation of the surface condition of the black carbon particles.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.380-391
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• 2010

Airborne in-situ measurements of aerosol/cloud number concentrations were analyzed to investigate the effects of aerosols on warm cloud formation in the Pacific Dust Experiment (PACDEX) during April and May 2007. In the air masses originating from the Asian continent, high concentrations of fine particles including black carbon (BC) were observed when compared to other regions. A strong correlation (r=0.88) between condensation nuclei (CN) having sizes ranging from 0.1 to 1.0 mm ($CN_{0.1-1.0}$) and cloud condensation nuclei (CCN) at 0.4% supersaturation ($CCN_{0.4%}$) suggests that most of the $CN_{0.1-1.0}$ can contribute to cloud formation. The possibility of a cloud droplet formation by BC particles was expected at the high water vapor mixing ratio (WVMR) and the abundance of water-soluble components at the low altitude less than 3 km.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.41-48
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• 2000

This study has been carried out to determine the seasonal characteristics of concentration of various ionic (CI-, NO3-, SO42-, Na+, NH+, K+, Ca2+) and heavy metallic (Pb, Mn, Cu, Ni) species in Pusan from August 1997 to April 1998. The concentrations of CI-, Na+, K+ were higher during summer with 2.98 ${\mu}{\textrm}{m}$/㎥. Seasonal variation of total concentration of but the concentration of NH4+ was higher during winter with 2.46${\mu}{\textrm}{m}$/㎥. Seasonal variation of total concentration of heavy metals(Pb, Cu, Mn, Ni) were 186.0 ng/㎥ in summer, 222.6 ng/㎥ in autumn, and 135.83 ng/㎥ in winter. Over the seasons inspected, the concentration of Mn was higher in coarse particles than fine particles and concentration of Ni was higher in fine particles than coarse particles. during yellow sand period, the concentration of TSP was increased about two times than that of other period. SO42-, Ca2+ concentrations were higher than other ionic components because of soil particles. The concentration of Ni showed 94.62ng/㎥ was increased about 4~5 times than other period. Principal component of the yellow sand, SO42-, Ca2+ could be discreased by rainfall and washout effect of atmospheric aerosol was higher in coarse particles than fine particles. Results from PCA(principal component analysis) showed that major pollutant was NaCl by seasalt particulate and (NH4)2SO4.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.699-708
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• 2005

To characterize the elemental composition of fine particles in urban area, $PM_{2.5}$ was collected by a 3-stage DRUM impactor at Gwangju during spring and summer. Time and size resolved concentrations for 19 trace elements were obtained by synchrotron X-Ray fluorescence analysis. Trace elements in summer were distributed in smaller size range compared to those in spring. Almost trace element concentrations in fine particles were highly increased during the Asian dust. In spring, soil elements such as Si, K, Ca, Ti and Fe had low enrichment factors indicating the dominant influence of soil dust. However, all elements had high enrichment factors in summer implying that these elements could be emitted from the anthropogenic sources. Factor analysis was conducted with the elemental composition data in order to identify anthropogenic sources of aerosols in urban area during spring and summer. Fine particles in spring have several sources such as soil dust originating from China continental region, coal and oil combustion, biomass burning, sea salt, ferrous and nonferrous metal sources. On the other hand, fine particles in summer were influenced by road dust, gasoline vehicle as well as coal and oil combustion, sea salt, ferrous and nonferrous metal sources.

• Journal of Environmental Science International
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• v.19 no.3
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• pp.331-342
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• 2010

Aerosol physical properties have been measured at Pusan National University by using the 16-channel LPC(Laser Particle Counter), and particle characteristics have been examined for the period from Aug. 4 2007 to Dec. 30, 2008. Annual total average, seasonal average, and other averages of the meteorologically classified four categories such as Asian dust, precipitation, foggy, and clear days are respectively described here. Both annually and seasonally averaged number concentration show three peaks at the particle diameter of 0.3, 1.3, and $4{\mu}m$, respectively. However, the first peak for summer season tends to be shifted toward smaller size than other seasons, implying the strong fine particle generation. Meteorological condition shows strong contrast in aerosol concentrations. In Asian dust case, relatively lower number concentrations of fine particles (i.e., smaller than $0.5{\mu}m$) were predominant, while higher concentrations of coarse particles were found particularly for the size bigger than $0.5{\mu}m$. In precipitation day, number concentrations were decreased by approximately 30% due to the removal process of precipitation. Foggy day shows significantly higher concentrations for fine particles, implying the importance of the aerosol condensation process of micro-fine-particle growing to fine-particle. Finally the regressed particle size distribution function was fitted optimally with two log-normal distribution, and discussed the similarities and differences among four categorized cases of the Asian dust, precipitation, foggy, and clear days.