• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.577-588
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• 1998

Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion and, in urban area atmosphere, are mainly traffic or heating in origin. Size-segregated aerosol samples were collected on the Eixth story of Shinchon on the Yonsei campus, using a high-volume cascade impactor, between August 1994 and September 1995. Ten PAHs were analyzed by GC/MSD. The size distribution of PAH-containing particulates followed approximately a log-normal relationship with the majority of PAH content associated with particles below 3.0mm. PAHs concentration in submicron particles increased during the winter months. The Mass Median Diameter (MMD) value of annual particulates in the heavy traffic area of Shinchon shows about 1.6 pm. The MMD values of air particulate in winter were the lowest values and similar to that in summer, while MMD values of seasonal PAHs were generally lower than 1.0 pm. Among the PAHs, MMD values of PAHs with the more than 5 benzen ring were averagely lower than those with 4 benzin rings. Especially MMD's of dibenzo (a, h) anthracene in winter was clearly lower than in summer. This reason may be caused by fuels used for heating. In this area, 50∼80% PAHs mass was particles smaller than 1.0mm aerodynamic diameter in size range, and the MMD values of PAHs lower than those of other country's area.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.3
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• pp.347-357
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• 2011

The TSP aerosols were collected at Gosan site of Jeju Island between 2003 and 2007, and their aerosol components were analyzed to examine the variations of chemical compositions with the corresponding pathways of inflowing air parcels. According to the comparison of seasonal aerosol compositions, the soil-originated components showed remarkably high concentrations during spring season. On the other hand, the concentrations of anthropogenic components were somewhat high in spring and summer seasons, but low in fall season. Based on the comparison of TSP compositions in relation to the pathways of inflowing air mass, the concentrations of anthropogenic components (nss-$SO_4^{2-}$, S, $NO_3^-$), soil-originated components (nss-$Ca^{2+}$, Al, Fe, Ca), and the heavy metals (e,g., Mn, Zn, Cr, Pb, Cu, Cd, etc.) have relatively increased with the air mass moving from China continent into Jeju area. Meanwhile, the marine-originated components showed an increasing trend with the air mass coming from North Pacific Ocean. In the seasonal and sectional comparison, the nss-$SO_4^{2-}$, $NO_3^-$, nss-$Ca^{2+}$, and Al showed comparatively high concentrations when the air mass moved from China continent during all seasons. Especially, the $NO_3^-$, nss-$Ca^{2+}$, and Al concentrations were somewhat high when the air mass moved from Korean Peninsula during summer season. It was also recognized that the Na+ concentration were high, when the air mass moved from Pacific Ocean through all seasons.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.3
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• pp.291-302
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• 2011

[ $PM_{10}$ ]measurements were made at two coastal sites, i.e., Taean and Gangneung, for summer to examine the characterization of water-soluble organic carbon (WSOC) and inorganic ionic species, and to investigate their difference between the sites. The fractions of three major inorganic water-soluble components ($NO_3^-$, $SO_4^{2-}$, and $NH_4^+$) at Taean and Gangneung sites were 30.6% (16.2~62.0%) and 25.6% (13.0~52.5%) of the $PM_{10}$, respectively. $SO_4^{2-}$ is the most dominant species of water-soluble ions at both sites, accounting for up to 20.5% (9.1~44.9%) and 16.3% (5.5~34.2%) of their respective PM10 mass concentrations. Using the paired T-test, $PM_{10}$ (p<0.01), $NO_3^-$ (p<0.05), $SO_4^{2-}$ (p<0.01), $NH_4^+$ (p<0.001), and WSOC (p<0.05) concentrations exhibited strong fluctuations on a daily basis between Taean and Gangneung sites. Relationship between the concentrations of $SO_x$ ($SO_4^{2-}+SO_2$) and CO indicates that the slopes of $SO_x$ /CO were 0.007 and 0.019 in the Taean and Gangneung sites, respectively. The smaller $SO_x$/CO slope in the Taean site could be related to the aged air with wet scavenging of $SO_x$ during transport. The correlation between the concentrations of CO and WSOC suggests that WSOC observed in the Gangneung ($R^2$=0.82) be transported from combustion-related sources, while the WSOC at the Taean site could be formed through atmospheric processing of primary volatile organic species during transport.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.4
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• pp.378-384
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• 2015

The long-term variations of ozone and nitrogen oxides in Suwon city, the capital of Gyeong-gi province, were examined from 1991 to 2012. In this period, the annual average $O_3$ concentration increased from 13.8 ppbv to 22.7 ppbv and that of $99^{th}$ percentile increased from 58.0 ppbv to 80.0 ppbv. The monthly average and $99^{th}$ percentile of $O_3$ concentrations were the highest in June. The increase in $O_3$ concentration was the greatest in early summer (May and June) before monsoon season began. While the concentrations of NO and NOx have gradually decreased since 2000, $NO_2$ remained unchanged. As a result, $NO_2/NO_x$ ratio increased from 0.5 to 0.73 in 2012. The monthly $NO_2/NO_x$ ratio was the highest in early summer, when monthly average $O_3$ concentration was the highest. It suggests that the enhanced $NO_2/NO_x$ ratio is intimately coupled with increase in $O_3$ for the last two decades in Suwon.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.4
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• pp.470-482
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• 2008

Seasonal variations of chemical composition and optical properties of aerosols at Seoul and Gosan were investigated using the ground-based aerosol measurements and an optical model calculation. The mass fraction of elemental carbon was $8{\sim}17%$, but its contribution on light absorption was high up to $29{\sim}48%$ in Seoul. In Gosan, the contribution of water soluble aerosols on aerosol extinction was $83{\sim}94%$ due to the high mass fraction of these particles in the range of $56{\sim}88%$. Model calculation showed that the water holding capacity of aerosols was larger in Gosan than in Seoul because of higher relative humidity and temperature along with abundant water soluble aerosols. Difference between measured and calculated aerosol optical depths was the highest in summer. This was because aerosol optical depth calculated from ground-based measurements could not consider aerosol loadings at high altitude in spite of high column-integrated aerosol loadings observed by Sun photometer. Although hygroscopic growth was expected to be dominant in summer, the mass concentration of water soluble aerosols was too low to permit this growth.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.3
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• pp.24-33
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• 2000

The value of beauty and the resources in the southern coastal sea is most important not only ecologically but also economically in Korea. Since 1980s, intensive use and consequent coastal water pollution have caused an increase in the frequency of red tides outbreak in this area. In this study, seawater and sediment were collected in summer and winter of 1998 and 1999, respectively. The status of seawater eutrophication, sediment oxygen demand(SOD), and nutrients release from sediment were measured. There was an obvious trend that COD and total phosphorous concentrations of summer sediments obtained from aquaculture farms were higher than those of winter sediments. It was concluded that sediments accumulated in the shellfish farms of southern coastal sea caused oxygen deficit in the bottom layer of seawater and played an important role for eutrophication.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.2
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• pp.46-52
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• 1987

There are many factors such as airtighteness and high density of merchandises or passengers that contaminate indoor air in underground commercial floor. So it is very important to know air quality and quantity of contamination in underground market increasing in number lately. It was from these viewpoints that gaseous pollutants, dusts and mutagenicity of organic compounds extracted from dusts in an underground market were investigatd. Organic ompounds (tar) were extracted by Soxhlet extractor with benzene as a solvent. Mutagenicities of these extracts were evaluated by the preincubation method using Salmonella typhimurium TA 100 and TA 98 strains with and without S9mix. The results obtained were as follows: It seemed to be under the influence of outdoor air that the concentrations of $CO, CO_2, NO, NO_2$ and dusts were higher in winter than summer. The concentration of $CO_2$ was higher in indoor than outdoor, but the concentration of NOx was similar in both sampling areas. Metal contents in dusts attached to the ventilation ducts were as follows showing in order of high concentration : Fe (9000-22000ppm), Zn(1200-2300ppm) and Pb (280-590ppm). The contents of tar were 6-33% of dusts, and higher than those from dusts collected by high volume air sampler. The extracts from dusts attached to the inlet duct exhibited lower mutagenicity than those from dusts attached to the outlet duct. This finding seemed to suggest that mutagenic substances were in creasing in underground. There was no seasonal difference of mutagenicity toward TA 98. Toward TA 100 in the presence of S9mix, the mutagenicity was about 3 fold higher in winter than summer. The mutagenicities of tar extracted from dusts collected by high volume air sampler were different from those attached to the ventilation ducts. The former showed 2-3 fold higher mutagenicity than the latter toward TA 100. However no difference showed between the former and the latter toward TA 98 in the absence of S9mix, but the former was 4-5 fold higher than the latter in the presence of S9mix.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.1
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• pp.49-60
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• 2000

The concentration of atmospheric mercury(Hg0 and relevent environmental parameters that include both meteorological and criteria pollutant data were dtermined at hourly intervals during two field campaigns covering the periods of September 1997 and May/June 1998. The mean concentrations of Hg for the two study periods were computed as 3.94 and 3.43ngm-3, respectively. Through a separation of these data into both daytime and nighttime periods, we further analyzed diurnal variation patterns for Hg between two different seasons. Using our Hg data sets, we were able to recognize two contrasting diurnal variation patterns of Hg between two diffeerent seasons that can be characterized as: (1) the occurrences of peak Hg concentration during daytime(fall0 and (2) slight reductions in daytime Hg concentration relative to nighttiime Hg data(summer). To study the systematic differences in diurnal patterns between two different seasons, we analyzed Hg data in terms of different statistical approaches such as correlation(and linear regression0 and factor analysis. Results of these analyses consistently indicated that different mechanisms were responsible for controlling the daytime distribution patterns of Hg. The variation of boundary layer conditions betwen day/night periods may have been important in introducing the relative reduction in daytime Hg levels during summer. However, when the relationship between Hg and concurrently determined O3 is concerned, these differences are unlikely to be an effective sink mechanism within the ranges of ozone concentrations determined concurrently during this study, regardless of season. To further provide the general account for short-term variations in Hg distribution data, we should be able to describe the various factors underlying its sink mechanism.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.16-29
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• 2011

The cyclone/annular denuder system/filter pack sampling system (ADS) was used to collect data set of the acidic air pollutants in the vicinity of industrial complexes in Gwangyang. The data set was collected during sixty different days with 24 hour sampling period from January 8, 2008 through November 12, 2008. The annual mean concentrations of $HNO_3$, $HNO_2$, $SO_2$ and $NH_3$ in the gas phase were 1.12, 1.40, 10.2 and 1.28 ${\mu}g/m^3$, respectively. The annual mean concentrations of $PM_{2.5}$ ($d_p$<2.5 ${\mu}m$), $SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ in the particulate phase were 29.2, 8.25, 3.30 and 3.42${\mu}g/m^3$, respectively. $HNO_3$ and $NH_3$ exhibited higher concentrations during the summer, while $HNO_2$, $PM_{2.5}$, $NO_3^-$ and $NH_4^+$ were higher during the winter. The highest level of $SO_2$ was, unlikely, observed in the summer and $SO_4^{2-}$ was not showed seasonal variation. $SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ accounted for 49~57% of the $PM_{2.5}$ mass. $SO_4^{2-}$ was the most abundant component, which constituted 23~40% of $PM_{2.5}$. High correlations were found among $PM_{2.5}$, $SO_4^{2-}$, $NO_3^-$, and $NH_4^+$.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.2
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• pp.181-194
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• 2015

Spatial-temporal meteorological features of the Ulsan metropolitan region (UMR) were analyzed using observations and high-resolution numerical modeling. Long-term trend analysis (1970~2013) showed a significant increase of $0.033^{\circ}Cyr^{-1}$ in the 5-year moving average temperature, although detailed short-term features varied, whereas wind speed and relative humidity over the same period displayed clear decreases of $-0.007ms^{-1}$ and $-0.29%yr^{-1}$, respectively. These trends indicate the effects of regional climate change and urbanization in the UMR. Seasonal variations averaged for the most recent three years, 2011~2013, showed that temperatures in three different regions (urban/industrial, suburban, coastal areas) of the UMR had similar seasonality, but significant differences among them were observed for a certain season. Urban and industrial complex regions were characterized by relatively higher temperatures with large differences (max.: $3.6^{\circ}C$) from that in the coastal area in summer. For wind speed, strong values in the range from 3.3 to $3.9ms^{-1}$ occurred in the coastal areas, with large differences clearly shown between the three regions in September and October. Diurnal variations of temperature were characterized by pronounced differences during the daytime (in summer) or nighttime (in winter) between the three regions. Results from the WRF modeling performed for four months of 2012 showed large variations in gridaverage temperature and winds in the UMR, which displayed significant changes by season. Especially, a clear temperature rise in the urban center was identified in July ($0.6^{\circ}C$ higher than nearby urban areas), and overall, relatively weak winds were simulated over urban and inland suburban regions in all seasons.