• Journal of the Korean earth science society
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• v.37 no.1
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• pp.21-28
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• 2016

Mountains have significant influences on the atmospheric environment. The Korean Peninsula consists of approximately 70% mountainous area with numerous mountain ranges and peaks. The initial classification of mountains in Korea was made by a Japanese scientist from 1900 to 1902. In fact, the Japanese study created too many names of mountains to maintain, which led to confusions. The purpose of this study aims to simplify the previous names and classification of mountains in the Korean Peninsula so that they can be utilized for educational and general purpose of the society and educational institutions. Through this study, we name various mountains as one name "Korea Mountains" which is classified as the secondary world-mountain class stretching from the Korean Peninsula to northeast China (southern Manchuria). The Korea Mountains connect the third class regional medium-scale mountains of Jirin, Hamkyoung, Taebaek, and the fourth mountain class, 8 small-scale ranges including the Liaoning, Yaenbaen, Hambeuk, Pyoungbeuk, Whanghae, Charyoung, Kyoungsang and Namhae Mountains. The major mountains in the Korean Peninsula are normally influenced by the general circulation of the atmosphere of the world. The atmospheric conditions are modified on the up-stream and down-stream sides; there is a need for continuous monitoring of the atmospheric environment which impacts the ecosystem and human society.

• Journal of Environmental Impact Assessment
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• v.4 no.3
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• pp.73-86
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• 1995

This paper demonstrates Environmental Impact Assessment (EIA) has to be applied for development projects with regard to the ecological, economical and social aspects before any decisions made in the project. Korea has confronted various environmental problems during the last fifteen years, even though EIA has been enacted since 1981. The role of impact assessment in planning and policy processes should be emphasized to investigate the magnitude and intensity of the adverse influences of economic development. In the Seoul Metropolitan Region, it is necessary to apply EIA all urban projects to reduce the adverse effects of urbanization. Special attention should be given to the climatological effects throughout the urbanization process in Korea to keep the urban area energy-efficient. This study intends not only to establish basic data for national-and regional-based land-use policy in the environmental aspects, but also to provide the basic data for the possible climate model (scenarios) that may provide spatial and temporal variability by analyzing the actual climatic record. There is a noticeable impact of urbanization on the atmospheric environment in the Seoul Metropolitan Region. In this sense, the climatic aspect must be taken into consideration in the process of EIA to mitigate the well-known climatic alterations of urbanization. Moreover, the techniques of assessment should be improved by developing geo-reference data sets to build models of the global climate in response to the man-made environmental change.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.1-14
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• 2015

This study investigates the impact of enhanced regional meteorological fields on improvement of wind energy forecasting accuracy in the southwestern coast of the Korean Peninsula. To clarify the effect of detailed surface boundary data and application of analysis nudging technique on simulated meteorological fields, several WRF simulations were carried out. Case_LT, which is a simulation with high resolution terrain height and land use data, shows the most remarkable accuracy improvement along the shoreline mainly due to modified surface characteristics such as albedo, roughness length and thermal inertia. Case_RS with high resolution SST data shows accurate SST distributions compared to observation data, and they led to change in land and sea breeze circulation. Case_GN, grid nudging applied simulation, also shows changed temperature and wind fields. Especially, the application of grid nudging dominantly influences on the change of horizontal wind components in comparison with vertical wind component.

• Atmosphere
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• v.17 no.4
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• pp.365-379
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• 2007

Global warming may shift the properties and dynamics of ENSO. We study the changes in ENSO characteristics in a coupled general circulation model, ECHO-G/S. First, we analyse the mean state changes by comparing present day simulation and various high $CO_2$ climates. The model shows a little El Nino-like changes in the sea surface temperature and wind stress in the eastern tropical Pacific. As the mean temperature rises, the ENSO amplitude and the frequency of strong El Ninos and La Nina decrease. The analysis shows that the weakening of the oceanic sensitivities is related to the weakening of ENSO. In addition to the surface changes, the remote subsurface sea temperature response in the western Pacific to the wind stress in the eastern Pacific influences the subsequent ENSO amplitude. However, ENSO amplitude does not show linear response to the greenhouse gas concentrations.

• Atmosphere
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• v.27 no.4
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• pp.499-509
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• 2017

Possible links among cosmic ray, cloud, and climate have scientific uncertainties. The reputed topics have been highly controversial during several decades. A link between the atmospheric ionization by galactic cosmic rays (GCR), which is modulated by solar activities, and global cloud cover was firstly proposed in 1997. Some researchers suggested that the GCR can stimulate the formation of cloud condensation nuclei (CCN) in the atmosphere, and then the higher CCN concentrations may lead to an increase of cloud cover, resulting in a cooling of the Earth's climate, and vise versa. The CLOUD (Cosmic leaving outdoor droplets) experiment was designed to study the effect of GCR on the formation of atmospheric aerosols and clouds under precisely controlled laboratory conditions. A state-of-the-art chamber experiment has greatly advanced our scientific understanding of the aerosol formation in early stage and its nucleation processes if the GCR effect is considered or not. Many studies on the climate-GCR (or space weather) connection including the CLOUD experiment have been carried out during the several decades. Although it may not be easy to clarify the physical connection, the recent scientific approaches such as the laboratory experiments or modeling studies give some implications that the research definitively contributed to reduce the scientific uncertainties of natural and anthropogenic aerosol radiative forcing as well as to better understand the formation processes of fine particulate matters as an important parameter of air quality forecast.

• Wind and Structures
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• v.30 no.1
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• pp.99-117
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• 2020

This paper focuses on the processes of wind flow in atmospheric boundary layer, to produce realistic full scale pressures for design of low-rise buildings. CFD with LES turbulence closure is implemented on a scale 1:1 prototype building. A proximity study was executed computationally in CFD with LES that suggests new recommendations on the computational domain size, in front of a building model, apart from common RANS-based guidelines (e.g., COST and AIJ). Our findings suggest a location of the test building, different from existing guidelines, and the inflow boundary proximity influences pressure correlation and reproduction of peak loads. The CFD LES results are compared to corresponding pressures from open jet, full scale, wind tunnel, and the ASCE 7-10 standard for roof Component & Cladding design. The CFD LES shows its adequacy to produce peak pressures/loads on buildings, in agreement with field pressures, due to its capabilities of reproducing the spectral contents of the inflow at 1:1 scale.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.214-224
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• 2007

A three-dimensional computational fluid dynamics (CFD) model with the renormalization group (RNG) $k-{\varepsilon}$ turbulence model is used to examine the effects of difference in building height on flow and pollutant dispersion in asymmetric street canyons. Three numerical experiments with different street canyons formed by two isolated buildings are performed. In the experiment with equal building height, a portal vortex is formed in the street canyon and a typical recirculation zone is formed behind the downwind building. In the experiment with the downwind building being higher than the upwind building, the ambient flow comes into the street canyon at the front of the downwind building and incoming flow diverges strongly in the street canyon. Hence, pollutants released therein are strongly dispersed through the lateral sides of the street canyon. In the experiment with the upwind building being higher than the downwind building, a large recirculation zone is formed behind the upwind building, which is disturbed by the downwind building. Pollutants are weakly dispersed from the street canyon and the residue concentration ratio is largest among the three experiments. This study shows that the difference in upwind and downwind building height significantly influences flow and pollutant dispersion in and around the street canyon.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.E3
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• pp.95-105
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• 2005

The concentrations of sulfur dioxide ($SO_{2}$) were measured from seven major cities and nine provinces in Korea for the period covering 1998 to 2003. Its concentration data were analyzed to explore the possible influences of spatial and temporal factors on the $SO_{2}$ distribution characteristics. Examination of spatial trends of $SO_{2}$ distribution and behavior indicated several interesting features. Although its annual trends appeared to be affected by the changes in the surrounding environmental conditions (e.g., regulation on the use of S-containing fuels), the seasonal trends indicated a cyclic and systematic pattern that may be characterized as: a gradual decrease in concentrations across winter, spring, fall, and summer. The results showed the generally enhanced mean concentrations of $SO_{2}$ from Ulsan, Busan, and Daegu with 12.8, 10.1, and 8.80 ppb, respectively. On the other hand, notably reduced $SO_{2}$ concentrations were seen from Gwangju and Jeju sites with its mean values of 5.43 and 3.88 ppb, respectively. The overall results of our study indicate that a decrease in $SO_{2}$ concentration levels continued through time, while its spatial distribution appears to be affected most sensitively by such factor as city scale and industrial activities.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.941-952
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• 2009

The urban microscale wind field around the air quality monitoring station was investigated in order to check how a building complex influences it. For this study as the high density areas Jwa-dong and Yeonsan-dong monitoring sites in Busan were chosen. As the direction of inflow which is perpendicular to the building of the monitoring station was expected to cause the considerable variation of the wind field, that direction was selected. The model Envi-met was used as the diagnostic numerical model for this study. It is suitable for this investigation because Envi-met has the microscale resolution. After simulating it, on the leeward side around a building complex the decrease of flow velocity and some of vortexes or circulation area were discovered. In addition, on the edge of the top at the building and at the back of the building the upward flow was developed. If the sampling hole of monitoring site were located in this upward flow, it would be under the influence of upward flow from the near street.

• Atmosphere
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• v.18 no.1
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• pp.43-53
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• 2008

A new proposition on the definition of the tropical cyclone (TC) which influences the Korean Peninsula (KP) is presented. The definition is based upon the TC track and intensity, 34 wind swath considering the TC size, and the line of 200 nautical mile (NM) from the KP shore which is the boundary of the official warning of Korea Meteorological Administration. Four types are proposed. First type is TC that hits the KP inland. Second is TC that falls within the 200-NM boundary. Third type is TC that passes outside the 200-NM boundary but large enough to significantly influence the KP. Last, the cases for a TC which are downgraded to the midlatitude cyclone and hit the KP are included. 30-year reanalysis reveals that 21 tropical cyclones should be included in the TC list that influenced the KP during the period from 1977 to 2006, which corresponds to 3.93 TCs per year. Among them, number of type I, II, III and IV TCs turn are to be 36, 47, 10, and 16, respectively. The net increase found in the current reanalysis is 2, 5, 7, and 7 for each type.