• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.393-393
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• 2001

대기확산모델의 운용을 위한 기상자료는 지면기상과 상층기상으로 구분된다. 지면기상 중 풍향, 풍속은 배출된 대기오염물질의 이송을 결정하는 요소이므로 배출원 위치의 연기상승고도에서 정확한 측정값이 입력되어야 한다. 그런데 풍향, 풍속은 일반적으로 지상풍 측정고도인 10m 높이에서 측정되므로 배출시설의 연기상승고도가 이보다 높은 경우에는 풍속지수식을 이용하여 풍속을 산출하게 된다. (중략)

• Journal of the Korean Solar Energy Society
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• v.36 no.1
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• pp.49-61
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• 2016

The power production using hub height wind speed tends to be overestimated than actual power production. It is because the hub height wind speed cannot represent vertical wind shear and blade tip loss that aerodynamics characteristic on the wind turbine. The commercial CFD model WindSim is used to compare and analyze each power production. A classification of atmospheric stability is accomplished by Monin-Obukhov length. The concentric wind speed constantly represents low value than horizontal equivalent wind speed or hub height wind speed, and also relevant to power production. The difference between hub height wind speed and concentric equivalent wind speed is higher in nighttime than daytime. Under the strongly convective state, power production is lower than under the stable state, especially using the concentric equivalent wind speed. Using the concentric equivalent wind speed considering vertical wind shear and blade tip loss is well estimated to decide suitable area for constructing wind farm.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.E
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• pp.343-356
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• 1994

In this study, a statistical investigation was carried out for the evaluation of any relationship between polycyclic aromatic hydrocarbons (PAHss) associated with ambient aerosols and other air quality parameters under varying meteorological conditions. Daily measurements for PAHs and air quality/meteorological parameters were selected from a data-base constructed by a comprehensive air monitoring in London during 1985-1987. Correlation coefficients were calculated to examine any significant relationship between the PAHs and other individual variables. Statistical analysis was further Performed for the air quality/meteorological data set using a principal component analysis to derive important factors inherent in the interactions among the variables. A total of six components were identified, representing vehicle emission, photochemical activity/volatilization, space heating, atmospheric humidity, atmospheric stability, and wet deposition. It was found from a stepwise multiple regression analysis that the vehicle emission component is overall the most important factor contributing to the variability of PAHs concentrations at the monitoring site. The photochemical activity/volatilzation component appeared to be also an important factor particularly for the lower molecular weight PAHs. In general, the space heating component was found to be next important factor, while the contributions of other three components to the variance of each PAHs did not appear to be as much important as the first three components in most cases. However, a consistency for these components in their negative correlations with PAHs data was found, indicating their roles in the depletion of PAHs concentrations in the urban atmosphere.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.17-20
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• 2003

In a recent paper (Hartwig, ms.) I have shown that it is possible to understand and discuss the changing Austausch (i.e., exchange of air parcels between different atmospheric layers) between the stratosphere and troposphere by means of long-term measurement on series of spallation products. It is well known (Friend 1961; Muet et al. 1966, Hartwig et al. 1969) that there is a seasonal pattern in the 7Be concentration of ground-level air with a maximum during May-June. This maximum is caused by enhanced exchange processes between the atmospheric compartments of the stratosphere and troposphere during this interval. Generally, those exchange processes are a consequence of stability and dynamics of the atmospheric compartments, which themselves result from, among other factors, the distribution of the heat sources in those compartments, namely the ground and the ozone layer. Because of the growing importance of anthropogenic infrared-active gases in the atmosphere, it is to be expected that the relative importance of those original, naturally occurring heat sources will be of lesser significance, thus altering the Austausch. And indeed, it has been shown (Hartwig, ms.) by considering the ratio of the annual maximum and minimum during a 28-yr period of 7Be ground-level concentration at Braunschweig, Germany (10$^{\circ}$33'E, 52$^{\circ}$17'N) (Kolb 1992; Wershofen 1993), that there is a steady decline in that ratio, thus indicating alteration of atmospheric Austausch within the last three decades.(omitted)

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.1
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• pp.35-43
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• 1997

Handling the emergency problems such as Chemobyl accident require real time prediction of pollutants dispersion. One-point real time sounding at pollutant source and simple model including turbulent-radiation process are very important to predict dispersion at real time. The stability categories obtained by one-dimensional numerical model (including PBL dynamics and radiative process) are good agreement with observational data (Golder, 1972). Therefore, the meteorological parameters (thermal, moisture and momentum fluxes; sensible and latent heat; Monin-Obukhov length and bulk Richardson number; vertical diffusion coefficient and TKE; mixing height) calculated by this model will be useful to understand the structure of stable boundary layer and to handling the emergency problems such as dangerous gasses accident. Especially, this simple model has strong merit for practical dispersion models which require turbulence process but does not takes long time to real predictions. According to the results of this model, the urban area has stronger vertical dispersion and weaker horizontal dispersion than rural area during daytime in summer season. The maximum stability class of urban area and rural area are 'A' and 'B' at 14 LST, respectively. After 20 LST, both urban and rural area have weak vertical dispersion, but they have strong horizontal dispersion. Generally, the urban area have larger radius of horizontal dispersion than rural area. Considering the resolution and time consuming problems of three dimensional grid model, one-dimensional model with one-point real sounding have strong merit for practical dispersion model.

• Wind and Structures
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• v.36 no.3
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• pp.201-213
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• 2023

In this study, the effect of sea surface temperature (SST) on the distribution of vertical wind speed in the atmospheric boundary layer of coastal areas was analyzed. In general, coastal areas are known to be more susceptible to various meteorological factors than inland areas due to interannual changes in sea surface temperature. Therefore, the purpose of this study is to analyze the relationship between sea surface temperature (ERA5) and wind resource data based on the meteorological mast of Høvsøre, the test bed area of the onshore wind farm in the coastal area of Denmark. In addition, the possibility of coastal disasters caused by abnormal vertical wind shear due to changes in sea surface temperature was also analyzed. According to the analysis of the correlation between the wind resource data at met mast and the sea surface temperature by ERA5, the wind speed from the sea and the vertical wind shear are stronger than from the inland, and are vulnerable to seasonal sea surface temperature fluctuations. In particular, the abnormal vertical wind shear, in which only the lower wind speed was strengthened and appeared in the form of a nose, mainly appeared in winter when the atmosphere was near-neutral or stable, and all occurred when the wind blows from the sea. This phenomenon usually occurred when there was a sudden change in sea surface temperature within a short period of time.

• Journal of Wetlands Research
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• v.5 no.1
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• pp.29-40
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• 2003

This study was performed to research the relation between airmass thunderstorm and stability index with 12 years meteorological data(1990~2001) at Busan. Also We used the analysed stability indices from University of Wyoming to consider airmass thunderstorm. The frequency of thunderstorm occurrence during 12 years was 156 days(annual mean 13days). The airmass thunderstorm frequency was 14 days, most of those occurrence were summertime(59%). And occurrence hour of airmass thunderstorm was distributed from 1300LST to 2100LST broadly. The highest forecast index for airmass thunderstorm at Busan was K index, the lowest forecast index was SWEAT index. The forecasting of thunderstorms is based primary on the concepts of conditional instability, convective instability, and forced lifting of air near the surface. Instability is a critical factor in severe weather development. Severe weather stability indices can be a useful tool when applied correctly to a given convective weather situation.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.280.2-280.2
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• 2003

The applicability of liquid chromatography-atmospheric-pressure chemical-ionization mass spectrometry (LC-APCI-MS) for the determination of 13C-urea in 13C-urea/PEG capsules has been studied. It is essential to assess the stability of a newly developed low-dose (38 mg) 13C-urea/PEG capsule. which will be used for 13C-urea breath test (13C-UBT) to detect Helicobacter pylori infection. (omitted)

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.5
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• pp.671-683
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• 2004

This study was carried out to understand long-range transport of $SO_2$ using aircraft measurements for the identification of it's horizontal and vertical concentration and distribution pattern. Thirteen missions of aircraft measurements have been done around 37$^{\circ}$00'/124$^{\circ}$30' from October 1997 to November 2001. Concentrations of $SO_2$ was 1.5~2.0 ppb in the below mixing layer, 0.6~1.1 ppb in the above mixing layer. $SO_2$ was found to be relatively higher than marine background level, 0.08~0.2ppb, indicating the western coast being influenced by long-range transport except for the summer season. The vertical distribution of $SO_2$ was classified into 3 groups using its vertical sounding and meteorology pattern; the first is linear decay pattern, the second is exponential decay pattern, and the last is gaussian distribution pattern in the below mixing layer, 2 patterns of linear decay and gaussian distribution patterns in the upper layer. It is founded that vertical distribution pattern is strongly dependent on meteorological condition, for example atmospheric stability and predominant air flow.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.1
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• pp.59-65
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• 2002

The application of local air circulation models in the field of air pollution research has become more and more popular with increasing demands of detailed wind data for obtaining precise information on spatial and temporal variations. However the prediction of air circulation near the surface is generally not a simple task because of intricate interactions between surface and air. Particularly in Korea, many areas are mountainous with a complicated shoreline. Because considerable errors could be introduced into the model predictions, it is necessary to confirm their feasibility by comparing model predictions with observations. In this paper, the results from the evaluation of model predictions in selected publications in Korea as well as their procedures were reviewed. Various aspects of errors in the model predictions. such as possible sources, vulnerable conditions, and reduction methods, were discussed.