• Journal of the Korean Solar Energy Society
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• v.30 no.5
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• pp.100-106
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• 2010

The purpose of this study is to predict the effective sky temperature on Osan City during the summer. The north latitude, east longitude of Osan City is $37^{\circ}06'$ and $127^{\circ}02'$. The altitude from the sea level is 48m. Empirical relations of the effective sky temperature suggested by Duffie and Beckman are compared on clear days. For the effective sky temperature prediction, data measured by the Korea Meteorological Administration is used as an input to the Bliss model. Both Hottel and Krondratyev model are used to calculate the water vapor emissivity. The results using Hottel's model match well with the empirical relation proposed by Bliss. The results show maximum, minimum, and average values depending on water vapor emissivity model. The maximum deviation is about 10K and is due to total emissivity model.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.227-237
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• 2020

Microclimatic data were measured, and the human thermal sensation was analyzed at 10 local climate zones based on the major land cover classification to investigate the thermal environment of urban areas during summer nighttime. From the results, the green infrastructure areas (GNIAs) showed an average air temperature of 1.6℃ and up to 2.4℃ lower air temperature than the gray infrastructure areas (GYIAs), and the GNIAs showed an average relative humidity of 9.0% and up to 15.0% higher relative humidity. The wind speed of the GNIAs and GYIAs had minimal difference and showed no significance at all locations, except for the forest location, which had the lowest wind speed owing to the influence of trees. The local winds and the surface roughness, which was determined based on the heights of buildings and trees, appeared to be the main factors that influenced wind speed. At the mean radiant temperature, the forest location showed the maximum value, owing to the influence of trees. Except at the forest location, the GNIAs showed an average decrease of 5.5℃ compared to GYIAs. The main factor that influenced the mean radiant temperature was the sky view factor. In the analysis of the human thermal sensation, the GNIAs showed a "neutral" thermal perception level that was neither hot nor cold, and the GYIAs showed a "slightly warm" level, which was a level higher than those of the GNIAs. The GNIAs showed a 3.2℃ decrease compared to the GYIAs, except at the highest forest location, which indicated a half-level improvement in the human thermal environment.