• Journal of Korean Society for Atmospheric Environment
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• v.24 no.6
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• pp.682-692
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• 2008

Fine particles ($PM_{2.5}$) were collected and analyzed from November 2005 through August 2007 in Chuncheon, Korea to investigate the characteristics of $PM_{2.5}$ and its ionic constituents. The average $PM_{2.5}$ concentration during the study period was $39{\mu}g/m^3$, which is almost two times higher than the annual US NAAQS $PM_{2.5}$ standard of $15{\mu}g/m^3$. $PM_{2.5}$ concentrations were higher in spring and winter than in summer and fall. During spring, Asian Dust events dramatically enhanced $PM_{2.5}$ concentrations, and long-range transport of $PM_{2.5}$ emitted in industrial area of China often occurred during winter based on trajectory analysis. Contribution of $PM_{2.5}$ to $PM_{10}$ concentrations ranged from $72{\mu}g/m^3$ during Asian Dust events to $457{\mu}g/m^3$, indicating that a large portion of $PM_{2.5{\sim}10}$ was transported from China during Asian Dust events. Among the major ionic constituents ${SO_4}^{2-}$ showed the highest concentration, followed by ${NH_4}^+$, ${NO_3}^-$ and ${NO_2}^-$. Chuncheon appeared to be ${NH_4}^+$ rich environment, indicating that $(NH_4)_{2}SO_4$ and ${NH_4}{NO_3}$ were the predominant forms of ${NO_3}^-$ and ${SO_4}^2$ in $PM_{2.5}$. Haze has frequently occurred in Chuncheon since So-Yang dam was constructed in 1973. Haze events were observed on 23 days during sampling period, and the average $PM_{2.5}$ concentration was approximately 1.6 times higher during haze events than during non-haze events. This result suggests that haze enhances the secondary aerosol formation because the aerosol spontaneously absorbs water to form a saturated salt solution, deriving a significant increase in the mass of the particle.

• 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 Environmental Science International
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• v.29 no.2
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• pp.177-189
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• 2020

We analyzed the recent characteristics of Particulate Matter (PM) including PM₁₀ (PM with diameter of less than 10 ㎛) and PM_2.5 (PM with diameter of less than 2.5 ㎛) observed in Busan metropolitan area, and compared them with those measured in Seoul metropolitan area. This analysis includes the monthly, seasonal, and annual variations and differences, in emissions and chemical compositions observed in both Busan and Seoul areas. Synoptic meteorological conditions were investigated at the time when high PM concentrations occurred in each of the two areas. The results showed clearly decreasing trends of annual mean concentrations with strong seasonal variations: lower in summer and higher in winter in both areas. In comparison with Seoul, the seasonal variation in Busan demonstrated relatively lower, but showed greater summer fluctuations than in Seoul metropolitan area. This is implying the importance of secondary generation of PM in summer via active photochemical reaction in Busan area. In high concentration days, Busan's chemical composition of sulfate was higher than that of nitrate in summer, whereas nitrate was higher than sulfate in Seoul. The ratios of NO₃^- to SO₄^2-(N/S ratio) showed lower in Busan approximately by a factor of 1/2(half of N/S ratio) in Busan compared with that in Seoul. Others such as synoptic characteristics and emission differences were also discussed in this study.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.551-556
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• 2018

In recent years, drones have been used to measure aircraft flights data and weather information. Related applications include the measure for low-altitude atmospheric data, the measure for atmospheric fine dust, and the measure for air pollution. However, the mounting position of the atmospheric measurement sensor should be mounted by considering the effects of propeller flow, the EMI effects, and the changes in the weight of the drone. Among these, the upper flow of the propeller affects the wind speed and direction, so the optimal position should be selected. This study deals with the proper height of the atmospheric data measurement sensor. Through the flow analysis, we study the flow characteristics of around a drone and suggest the proper sensor mounting height.

• Smart Media Journal
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• v.7 no.4
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• pp.44-51
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• 2018

The purpose of this research is to collect atmospheric environmental information at specific altitudes in a range of 0 to 1 km above the surface and to monitor it using drones. The corresponding temperature and humidity were measured with the meteorological factors, and the amounts of fine dust and $CO_2$ were observed by the environmental factors so that they could receive the normal values. Monitoring the status of atmospheric gas emission in specific enterprises, industrial complexes and regions through the measurement is meant to help establish policies to reduce pollution factors. In conventional means previously practiced, exhaust gas detection accompanies a great deal of risks in terms of safety because the surveyor is directly exposed to the source of contamination such as the holes installed in the chimney. However, in our proposed method, the drone can collect information in a wide range under safe circumstances, which can be utilized through wide industrial areas.

• Journal of Astronomy and Space Sciences
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• v.25 no.2
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• pp.101-112
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• 2008

Systematic CCD observations of times of minimum lights for eclipsing binaries has been carried out from 2002 to 2007 at Campus Station of Chungbuk National University Observatory which is located in Cheongju city, Korea. As a by-product of our observations, photometric data for stars in CCD images taken from 2005 to 2007 were used to determine 1st order atmospheric extinction coefficient (hereafter AEC) and seasonal and yearly variations of the AECs were studied. Total nights used for determination of AECs were 57 days in 2005, 51 days in 2006, and 63 days in 2007. As a result the annual mean value of the AECs per air mass is calculated as $0.^m34{\pm}0.^m18$ for 2005, $0.^m38{\pm}0.^m19$ for 2006, and $0.^m45{\pm}0.^m20$ for 2007. These values show that the AECs and their standard deviations are two and four times, respectively, larger than those of normal observatories which are not located near large cities. Annual comparison between concentration of atmospheric fine dust and coefficient of atmospheric extinction show strong correlation between two quantities of which time variations show similar patterns. The AECs for the east sky show larger than those for the west sky. It can be easily understood by the reasonable possibility that air pollutants remain more in the east sky than in the west because the east area of Cheongju city has been more developed than the west one. In conclusion the atmospheric extinction of the night sky of Cheongju city has an annual trend of increase of $0.^m06\;airrnass^{-1}\; year^{-1}$ implying that it may take only about 13 years for Cheongju city to have 2 times brighter night sky than the present one. Our study highlights that variations of AEC can be used as an important indicator of air pollution to monitor night skies.

• Journal of Korea Port Economic Association
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• v.38 no.1
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• pp.129-142
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• 2022

In the past, interest in air pollution was concentrated on greenhouse gases, but in recent years, interest in fine dust has been increasing. The media and environmental organizations continue to emphasize air pollution caused by fine dust. The awareness of fine dust is increasing, and air pollution generated at ports is analyzed to be serious as a domestic factor excluding foreign inflows. Recognizing this, in order to reduce air pollution generated at ports, special laws on improving air quality, such as port areas, have been enacted in Korea, and attempts are being made to curb air pollution caused by ports. In this law, it is a policy that regulates air pollutants generated not only by ships but also throughout ports such as vehicles and unloading machines, and representative are ECA, VSR, and AMP. This study attempted to analyze the effects of these eco-friendly policies at Incheon Port. First of all, a study was conducted to calculate emissions assuming that there was no policy, analyze each policy, and finally calculate and compare actual emissions reflecting all policies. The methodology presented by the European Environmental Administration and the U.S. Environmental Protection Agency was used, and pollutants to be analyzed were analyzed for sulfur oxides (SO_X), carbon monoxide (CO), nitrogen oxides (NO_X), total floating substances (TSP), fine dust and ultrafine dust (PM₁₀, PM_2.5) and ammonia (NH₃). As a result of the analysis, it was analyzed that the actual emission reflecting all policies was about 4,097 tons/year, which had an emission reduction effect of about 760 tons/year compared to about 4,857 tons/year when the policy was not reflected. When the effects of each policy were analyzed individually, it was found that ECA 4,111 tons/year, VSR 4,854 tons/year, and AMP 4,843 tons of air pollutant emissions occurred The results of this study can be used as basic data and evidence for policy establishment related to the atmospheric environment at Incheon Port.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.3
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• pp.219-236
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• 2009

Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

• 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.

• Economic and Environmental Geology
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• v.55 no.3
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• pp.281-293
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• 2022

We examined degradation characteristics of lead based pigments(white lead, Red lead, Litharge) according to atmospheric environmet condition, for example atmospheric gas(CO₂, NO₂) and soluble salt. Painted samples not changed material compositions but were occured the color change(𝚫E 4~31) after exposed UV irradiation. All sample were not affected by CO₂ gas not only color but chemical composition. However, samples were remakably changed color exposed NO₂ gas and it was formed secondary product like as lead nitrate. Such as red lead and white lead samples' color difference were 𝚫E 2 and 𝚫 10 respectively and became dark, along with litharge became bright and color difference was 𝚫E 5 after react with NO₂ gas. It confirm that NO₂ was influential factor than CO₂ in the case of same concentration. Furthermore salt spray test was taken to figure out soluble salt influence in fine dust. The result showed noticeable color change and secondary product was formed on samples' surface. The glue film peeled off or hole, and color changed around the secondary products. After salt spray, XRD pattern showed decrease peak intensity and lower crystalinity. As a result of salt spray test, white lead was formed new product litharge and litharge was formed litharge and minium. According to the results, influential atmospheric factors for conservation of paint pigments were UV, NO₂, soluble salt, and litharge was most weakness throughout lead base pigments.