• Journal of the Korean earth science society
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• v.44 no.3
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• pp.196-209
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• 2023

The Nishinoshima volcano, located 940 km south of Tokyo, experienced an eruption from June to August 2020. The volcanic gas and ash from the eruption of Nishinoshima that occurred at the end of July 2020 was reported to have the potential to affect the Korean Peninsula. In this study, we used Ash3D, a numerical simulation program for volcanic ash dispersion, to investigate the eruption that occurred at 0:00 local time on July 28, 2020, with a volcanic explosivity index of three. The results showed that the volcanic ash cloud reached Okinawa on the morning of July 30, carried by an east wind. It then moved northward and reached Jeju Island on August 1, eventually circulating in a clockwise direction and reaching southern part of the Korean Peninsula on August 2. The concentration of Particulate Matter 10 (PM₁₀), measured at the Jeju Gosan Meteorological Observatory in Jeju Island, increase from August 1. A similar increase in PM₁₀ concentration was observed at the Gudeok Mountain Weather Station in Busan from August 2. These findings suggested that eruption of the Nishinoshima volcano had an impact on the fine dust concentrations at Jeju Island and southern part of the Korean Peninsula.

• New & Renewable Energy
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• v.16 no.3
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• pp.13-26
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• 2020

This study analyzed whether the diffusion of new and renewable energy contributed to mitigating emissions of various air pollutants, including particulate matter, using panel econometric models. The theoretical foundation of such econometric models is based on the Environmental Kuznets Curve (EKC) hypothesis, which assumes an inverted U-shaped relation between national income and environmental pollution, as originally proposed by Grossman and Krueger. We examined whether there are inverted U-, U-shaped, or N-shaped relations between national income and air pollution. We demonstrate that increases in new and renewable energy significantly mitigated emissions of CO, NO_X, and PM2.5. Additionally, we included NO_X, SO_X, PM10, and VOCs as secondary emission sources of PM2.5 and found that emission of PM10 resulted in the highest PM2.5 emissions, followed by NO_X and SO_X emissions. The impact of new and renewable energy on air pollution varied across regions. Increase of new and renewable energy in the Honam region significantly mitigated CO, NO_X, and TSP emissions, while that in the Youngnam and metropolitan areas did not significantly mitigate air pollution overall. There was a U-shaped relationship between air pollution and national income for CO, NO_X, PM2.5, and SO_X, while an inverted N-shape was observed for PM10.

• Atmosphere
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• v.25 no.1
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• pp.169-177
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• 2015

Vertical distribution of particle mass concentrations was estimated from 8-year elastic-backscatter lidar and sky radiometer data, and from ground-level PM10 concentrations measured in Seoul. Lidar ratio and mass extinction efficiency were determined from aerosol optical depth (AOD) and ground-level PM10 concentrations, which were used as constraints to estimate particle mass concentration. The mean lidar ratio (with standard deviation) and mass extinction efficiency for the entire 8-year study period were $60.44{\pm}23.17$ sr and $3.69{\pm}3.00m^2g^{-1}$, respectively. The lidar ratio did not vary significantly with the ${\AA}ngstr{\ddot{o}}m$ exponent (less than ${\pm}10%$); however, the mass extinction efficiency decreases to $1.82{\pm}1.67m^2g^{-1}$ (51% less than the mean value) when the ${\AA}ngstr{\ddot{o}}m$ exponent is less than 0.5. This result implies that the particle mass concentration from lidar measurements can be underestimated for dust events. Seasonal variation of the particle mass concentration estimated from lidar measurements for the boundary layer, was quite different from ground-level PM10 measurements. This can be attributable to an inhomogeneous vertical distribution of aerosol in the boundary layer.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.118-125
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• 2016

Objectives: The traditional type of residence in used in Mongolia, called a ger, is an important residential form and applies coal combustion for cooking and heating. The combustion of coal in ger is the major source of indoor air pollution. The purposes of this study were to measure indoor air pollution in ger and determine the effect of cooking and heating activities. Methods: Indoor temperature, relative humidity, particulate matter less than $2.5{\mu}m$ ($PM_{2.5}$) and black carbon (BC) were continuously measured for 24 hours in eight ger. The measurements were conducted in January or February 2015. Heavy metals in $PM_{2.5}$ filter samples were analyzed by ICP-MS. Results: Average indoor temperature and relative humidity were $19.6{\pm}4.6^{\circ}C$ and $21.4{\pm}5.2%$, respectively. The average indoor $PM_{2.5}$ concentration in the eight ger was $119.8{\mu}g/m^3$ and ranged from 69.4 to $202.7{\mu}g/m^3$. The peak concentrations of $PM_{2.5}$ and BC during cooking and heating periods were several times higher than the 24- hour average concentration. Conclusion: The major contributor to indoor $PM_{2.5}$ and BC concentrations in the ger was coal combustion for cooking and heating.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.32-41
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• 2016

Particle-phase concentrations were measured at 10, 80, and 200 m from the roadside of a national highway near Seoul in January and May 2008. The highway has two lanes each way, with an average hourly traffic volume of 1,070 vehicles. In January 2008, $PM_{10}$ concentrations decreased from 10 to 80 m but increased at 200 m. Black carbon (BC) decreased only slightly with distance due to the influence of biomass burning and open burning from the surrounding areas. In May 2008, the effect of secondary formation on both $PM_{10}$ and $PM_{2.5}$ was significant due to high temperatures compared with January. Because on-road emissions had little effect on secondary formation for a short time, variations in $PM_{10}$ concentrations became smaller, and $PM_{2.5}$ concentrations increased with distance. The effects of fugitive dust on PM concentrations were greater in May than in January when the mean temperature was below freezing. In the composition variations, the amounts of primary ions, organic carbon (OC), and BC were larger in January, while those of secondary ions and others were larger in $PM_{10}$, as well as $PM_{2.5}$ in May.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.4
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• pp.411-417
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• 2016

Objectives: The aims of this study were to determine the indoor level of environmental tobacco smoke (ETS) and to assess the implementation rate of smoke-free laws at hospitality venues around a university campus by measuring particulate matter smaller than $2.5{\mu}m$ ($PM_{2.5}$) as an indicator of ETS. Materials and Methods: We measured indoor $PM_{2.5}$ concentrations at 20 PC game rooms, 20 pubs, and 20 billiards halls using Sidepak AM510, a direct reading portable real time monitor, from October to December 2015. Results: Smoking was observed in 65% of the PC game rooms, 10% of pubs, and 85% of billiards halls. The average $PM_{2.5}$ concentrations were $98.2{\mu}g/m^3$, $29.0{\mu}g/m^3$, and $134.2{\mu}g/m^3$ at PC game rooms, pubs, and billiards halls, respectively. $PM_{2.5}$ concentrations in PC game rooms and billiards halls were 2 to 2.7 times higher than the 24-hour exposure standard for outdoor $PM_{2.5}$ ($50{\mu}g/m^3$) by the Ministry of Environment. Conclusions: Although a smoking ban has been implemented for PC rooms and pubs, smoking is still taking place in many of these places. More stringent legal action is required for successfully protecting patrons and workers from secondhand smoke exposure. A ban on smoking in billiards halls should be introduced as quickly as possible.

• Korean Journal of Remote Sensing
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• v.36 no.4
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• pp.573-586
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• 2020

PM (particulate matter) is of interest to everyone because it can have adverse effects on human health by the infiltration from respiratory to internal organs. To date, many studies have made efforts for the prediction of PM10 and PM2.5 concentrations. Unlike previous studies, we conducted the prediction of tomorrow's PM10 concentration for the Air Korea stations using Chinese PM10 data in addition to the satellite AOD and weather variables. We constructed 230,639 matchups from the raw data over 3 million and built an RF (random forest) model from the matchups to cope with the complexity and nonlinearity. The validation statistics from the blind test showed excellent accuracy with the RMSE (root mean square error) of 9.905 ㎍/㎥ and the CC (correlation coefficient) of 0.918. Moreover, our prediction model showed a stable performance without the dependency on seasons or the degree of PM10 concentration. However, part of coastal areas had a relatively low accuracy, which implies that a dedicated model for coastal areas will be necessary. Additional input variables such as wind direction, precipitation, and air stability should also be incorporated into the prediction model as future work.

• Atmosphere
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• v.31 no.1
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• pp.29-43
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• 2021

In this study, two-step statistical approach including Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) was employed, and main meteorological factors explaining the high-PM2.5 episodes were identified in two regions: Seoul and Busan. We first performed PCA to isolate the Principal Component (PC) that is linear combination of the meteorological variables observed at two levels: surface and 850 hPa level. The employed variables at surface are: temperature (T2m), wind speed, sea level pressure, south-north and west-east wind component and those at 850 hPa upper level variables are: south-north (v850) and west-east (u850) wind component and vertical stability. Secondly we carried out MLR analysis and verified the relationships between PM2.5 daily mean concentration and meteorological PCs. Our two-step statistical approach revealed that in Seoul, dominant factors for influencing the high PM2.5 days are mainly composed of upper wind characteristics in winter including positive u850 and negative v850, indicating that continental (or Siberian) anticyclone had a strong influence. In Busan, however, the dominant factors in explanaining in high PM2.5 concentrations were associated with high T2m and negative u850 in summer. This is suggesting that marine anticyclone had a considerable effect on Busan's high PM2.5 with high temperature which is relevant to the vigorous photochemical secondary generation. Our results of both differences and similarities between two regions derived from only statistical approaches imply the high-PM2.5 episodes in Korea show their own unique characteristics and seasonality which are mostly explainable by two layer (surface and upper) mesoscale meteorological variables.

• Korean Journal of Remote Sensing
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• v.36 no.6_3
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• pp.1681-1690
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• 2020

A scanning lidar system has been developed. The system has two wavelength observation channels of 532 and 1064 nm and is capable of 360-degree horizontal scanning observation. In addition, an analysis method that can classify the measured particle as an indicator of coarse-mode particle (PM2.5-10) and an indicator of fine-mode particles (PM2.5) and calculate the mass concentration of each has been developed by using the backscatter coefficient at two wavelengths. It was applied to the data calculated by observation. The mass concentrations of PM10 and PM2.5, which showed a distribution of 22-110 ㎍/㎥ and 7-78 ㎍/㎥, respectively, were successfully calculated in the Ulsan Onsan Industrial Complex using the developed scanning lidar system. The analyzed results showed similar values to the mass concentrations measured on the ground around the lidar observation area, and it was confirmed that high concentrations of 80-110 ㎍/㎥ and 60-78 ㎍/㎥ were measured at points discharged from factories, respectively.

• Atmosphere
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• v.33 no.3
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• pp.319-330
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• 2023

As the need for PM type observation increases, Surface Particulate Matter Network (SPARTAN), PM samplers analyzes aerosol samples for PM mass concentration and chemical composition, were recently installed at two sites: Yonsei University at Seoul and Ulsan Institute of Science and Technology (UNIST) at Ulsan. These SPARTAN filter samplers and nephelometers provide the PM_2.5 mass concentration and chemical speciation data with aerosol type information. We introduced the overall information and installation of SPARTAN at the field site in this study. After installation and observation, both Seoul and Ulsan sites showed a similar time series pattern with the daily PM_2.5 mass concentration of SPARTAN and the data of Airkorea. In particular, in the case of high concentrations of fine particles, daily average value of PM_2.5 was relatively well-matched. During the Yonsei University observation period, high concentrations were displayed in the order of sulfate, black carbon (BC), ammonium, and calcium ions on most measurement days. The case in which the concentration of nitrate ions showed significant value was confirmed as the period during which the fine dust alert was issued. From the data analysis, SPARTAN data can be analyzed in conjunction with the existing urban monitoring network, and it is expected to have a synergetic effect in the research field. Additionally, the possibility of being analyzed with optical data such as AERONET is presented. In addition, the method of installing and operating SPARTAN has been described in detail, which is expected to help set the stage for the observation system in the future.