• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.4
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• pp.263-271
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• 2000

To investigate the distribution of air pollutants dispersion in the horizontal wind fields, a chaff release experiment was carried out by an airplane. The temporal and spatial variations of a chaff plume from an elevated point source using the WSR-88D(NEXRAD) radar. The observed profiles of radar reflectivity were compared with the Gaussian diffusion model at slightly unstable atmospheric condition. The present study shows that the distributions of radar reflectivity from chaffs and their concentration by the model are in general agreement with time variation. The dispersion coefficients in downwind($\sigma$(sub)x) and crosswind($\sigma$(sub)y) spread data exceeded what has generally been found at Pasquill and Brigg\`s estimates. As a result, it was clearly shown that horizontal and vertical diffusion coefficients are more accurately determined as compared with theoretical coefficients. At longer diffusion distances(than 10km), a radar observation provided the determination of maximum range and diffusion height more qualitatively, too.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.877-882
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• 2008

The purpose of this study is to analyze the characteristics of outdoor thermal environment of flat-type apartment houses and tower-type apartment houses in summer by numerical simulation. After inputting a building condition at CAD, we calculated the surface temperature for two apartments by using the numerical simulation of a clear sky day in summer in Seoul. The results indicated that the variation in Heat Island Potential(HIP) of tow apartments were not only in the day but also in the night. According to form of apartment the flat-type apartment houses appeared $1.3^{\circ}C$ more highly tower-type apartment houses.

• Journal of Environmental Science International
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• v.13 no.4
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• pp.367-376
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• 2004

In urban area, thermal pollution associated with heat island phenomena is generally regarded to make urban life uncomfortable. To overcome this urban thermal pollution problem, urban planning with consideration of urban climate, represented by the concept of urban ventilation lane, is widely practiced in many countries. In this study, the prevailing wind ventilation lane of a local winds in Daegu during the warm climate season was investigated by using surface wind data and RAMS(Reasonal Atmospheric Model System) simulation. The domain of interest is the vicinity of Daegu metropolitan city(about 900 $km^{2})$ and its horizontal scale is about 30km. The simulations were conducted under the synoptic condition of late spring with the weak gradient wind and mostly clear sky. From the numerical simulations, the following two major conclusions were obtained: (1)The major wind passages of the local circulation wind generated by radiative cooling over the mountains(Mt. Palgong and Mt. Ap) are found. The winds blow down along the valley axis over the eastern part of the Daegu area as a gravity flow during nighttime. (2)After that time, the winds blow toward the western part of Daegu through the city center. As the result, the higher temperature region appears over the western part of Daegu metropolitan area.

• Journal of Astronomy and Space Sciences
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• v.29 no.4
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• pp.397-405
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• 2012

Astronomical Observations at Chungbuk National University Observatory (CBNUO) with an 1 m telescope have begun since April 2008, and Near-Earth Space Survey observations also have been started since November 2010, with a 0.6 m wide field telescope developed by Korea Astronomy and Space Science Institute. To improve observational efficiency, we developed a weather monitoring system enabling automatic monitoring for the weather conditions and checking the status of the observational circumstances, such as dome status. We hope this weather monitoring system can be helpful to more than 100 Korean domestic observatories, including public outreach facilities. In this paper, we present the statistic analysis of the weather conditions collected at CBNUO for 3 years (2009- 2011) and comparisons were made for clear nights between using only humidity data and both humidity and cloud data.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.43-47
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• 2003

Air temperature was continuously measured in hilly pear orchards at 4 sites with elevations of 10, 49, 104 and 253 m above sea level. The mean air temperature, averaged over the 10-month period from August 2001 to June 2002, decreased as the site elevation increased by 0.2$^{\circ}C$ per 100 m. This weak lapse condition was amplified during daytime by sun-slope geometry. But on most days an inversion condition began by sunset and persisted until the next sunrise. During the observation period, daily minimum temperature at the valley bottom was lower than that of the hilltop on 67% of the days, and the average temperature difference was 1.4$^{\circ}C$. Inversion of daily minimum temperature under clear sky conditions was stronger in spring and autumn than in winter with a maximum of 6$^{\circ}C$. Lapse condition was predominant in daily minimum temperature on rainy days, and the lapse rate was strongest in winter.

• Journal of East-West Nursing Research
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• v.2 no.1
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• pp.96-106
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• 1997

In Chinese medicine, the activities of removing and solving the inner cause are called the regimen in preventing the disease and the good condition of mind emphasizes us to practice ourselves the doctrine of regimen of the mind to promote the health and long life of the living body, in other words, it means we should have clean mind, less desire, less thought, less agony and widely open our emotion and will, and it also means the raising of good nature, the moral cultivation, and we can be healthy when we live by good virtus as the root of regiem. The meaning of the Qi has been expanded more and more since its origination throught the process of practice and perception of man. 1) Matter is changed to the smoke when burned, the energy of water becomes the rain in the sky and the rain raises all living creatures by making them wet. Throught these changes of circulation, men could realize the energy to be the common and original matter of forming all the creatures. 2) The direction of showing the breathing of men in and out has been expended. 3) It was widely understood as the meaning of showing vitality of men, and it was the original root of chinese medicine. 4) It was expended to be showing spirit of nature such as the sun, moon, star, sky, land, mountain and the moral spirit of men as peacefullness. By the original meaning of the word of energy expanded to the wider side of sky, land, men and things, nature, society, man and the moral spirit could get the unified basis of the matter. As the above, the word of Qi has been used in wider meaning at this time from the past. In other words, all things in the universe come into being and extinct by the chang of motion of the Qi and it is recognized to be the living activity in human body. The Qi-kong based on this energy and the motion applied to our daily life are very extensive (Lee, Hye - lung, 1997). Here are the summaries of the effect of the Qi-kong ; 1) The physical constitution is strenthened, physiological function is prosperous and we are free from various geriatric disease and psychosomatic disease not to mention the cold and indigestion. 2) It maintains the clear spirit, elevates intelligence, strengthens the spiritual power and demonstrates the potentiality at the amximum. 3) It maintain beautiful figure and clean skin never losing the charm but full of energy and vitality. 4) It keeps the balanced body never suffering from the unbalance of the bones, various and neuralgia. 5) It maintain the spiritual comfort, the natural posture in everything and real happiness (Lee, Hye-Jung, 1997 : Suh, Yong Kyu, 1989). Chinese medicine mentions the motion by Qi with Qi - kong. But the motion does not require special method in Western medicine. I t is the only way of living of our ancestor indaily life. It is maintaining the healthy lifr by training the Qi, and it is the motion of being with the nature with the open mind in breathing rather than artificially restricting our daily life, it is the motion of the body.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.135-142
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• 2016

The aim of this study was to confirm the improvement of efficiency for temperature estimation at 0600 and 1500 LST by using a simple method for estimating temperature lapse rate modulated by the amount of clouds in comparison with the case adopting the existing single temperature lapse rate ($-6.5^{\circ}C/km$ or $-9^{\circ}C/km$). A catchment of the 'Hadong Watermark2,' which includes Hadong, Gurye, and Gwangyang was selected as the area for evaluating the practicality of the temperature lapse rate estimation method. The weather data of 0600 and 1500 LST at 12 weather observation sites within the catchment were collected during the entire year of 2015. Also, the 'sky condition' of digital forecast products of KMA in 2015 ($5{\times}5km$ lattice resolution) were overlapped with the catchment of the 'Hadong Watermark2,' to calculate the spatial average value within the catchment, which were used to simulate the 0600 and 1500 LST temperature lapse rate of the catchment. The estimation errors of the temperatures at 0600 LST were ME $-0.39^{\circ}C$ and RMSE $1.45^{\circ}C$ in 2015, when applying the existing temperature lapse rate. Using the estimated temperature lapse rate, they were improved to ME $-0.19^{\circ}C$ and RMSE $1.32^{\circ}C$. At 1500 LST, the effect of the improvements found from the comparison between the existing temperature lapse rate and the estimated temperature lapse rate were minute, because the estimated lapse rate of clear days is not very different from the existing lapse rate. However, the estimation errors of the temperatures at 1500 LST during cloudy days were improved from ME $-0.69^{\circ}C$, RMSE $1.54^{\circ}C$ to ME $-0.51^{\circ}C$, RMSE $1.19^{\circ}C$.

• Proceedings of the KSRS Conference
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• v.2
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• pp.664-667
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• 2006

Seasonal threshold values for fog detection over the ten airport areas in the Korean Peninsula have been derived, using the satellite-observed data of polar-orbit (Aqua/Terra MODIS) and geostationary (GOES-9) during two years. The values are obtained from reflectance at 0.65 ${\mu}m$ $(R_{0.65})$ and the difference in brightness temperature between 3.7 ${\mu}m$ and 11 ${\mu}m$ $(T_{3.7-11})$. In order to examine the discrepancy between the threshold values of two kinds of satellites, the following parameters have been analyzed under the condition of daytime/nighttime and fog/clear-sky, utilizing their simultaneous observations over the Seoul Metropolitan Area. The parameters are the brightness temperature at 3.7 ${\mu}m$ $(T_{3.7})$, the temperature at 11 ${\mu}m$ $(T_{11})$, and $T_{3.7-11}$ for day and night. The $R_{0.65}$ data are additionally included in the daytime. The GOES-9 thresholds over the nine airport areas except the Cheongju airport have revealed the accuracy of 60% in the daytime and 70% in the nighttime, based on statistical verification as follows; FAR, POD and CSI. However, the accuracy decreases in the foggy cases with twilight, precipitation, short persistence, or the higher cloud above fog.

• Atmosphere
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• v.22 no.2
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• pp.137-147
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• 2012

The technique of Brightness Temperature Difference (BTD) between 11 and $12{\mu}m$ separates yellow sand dust from clouds according to the difference in absorptive characteristics between the channels. However, this method causes consistent false alarms in many cases, especially over the desert. In order to reduce these false alarms, we should eliminate the background noise originated from surface. We adopted the Background BTD (BBTD), which stands for surface characteristics on clear sky condition without any dust or cloud. We took an average of brightness temperatures of 11 and $12{\mu}m$ channels during the previous 15 days from a target date and then calculated BTD of averaged ones to obtain decontaminated pixels from dust. After defining the BBTD, we subtracted this index from BTD for the Yellow Sand Index (YSI). In the previous study, this method was already verified using the geostationary satellite, MTSAT. In this study, we applied this to the polar orbiting satellite, MODIS, to detect yellow sand dust over Northeast Asia. Products of yellow sand dust from OMI and MTSAT were used to verify MODIS YSI. The coefficient of determination between MODIS YSI and MTSAT YSI was 0.61, and MODIS YSI and OMI AI was also 0.61. As a result of comparing two products, significantly enhanced signals of dust aerosols were detected by removing the false alarms over the desert. Furthermore, the discontinuity between land and ocean on BTD was removed. This was even effective on the case of fall. This study illustrates that the proposed algorithm can provide the reliable distribution of dust aerosols over the desert even at night.

• Atmosphere
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• v.19 no.4
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• pp.319-329
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• 2009

The intensive dust observation experiment has been performed at Korea Global Atmosphere Watch Center (KGAW) in Anmyeon, Korea during each spring season from 2007 to 2009. Downward and upward hyper-spectral spectrums over the dust condition were measured to understand the hyper-spectral properties of Asian dust using both ground-based Fourier Transform Infrared Spectroscopy (FT-IR) and space-borne AIRS/Aqua. To understand the impact of the Asian dust, a Line-by-Line radiative transfer model runs to calculate the high resolution infrared spectrum over the wave number range of $500-500cm^{-1}$. Furthermore, the radiosonde, a $PM_{10}$ Sampler, a Micro Pulse Lidar (MPL), and an Aerodynamic Particle Sizer (APS) are used to understand the vertical profile of temperature and humidity and the properties of Asian dust like concentration, altitude of dust layer, and size distribution. In this study, we found the Asian dust distributed from surface up to 3-4 km and volume concentration is increased at the size range between 2 and $8{\mu}m$ The observed dust spectrums are larger than the calculated clear sky spectrums by 15~60K for downward and lower by around 2~6K for upward in the wave number range of $800-1200cm^{-1}$. For the characteristics of the spectrum during the Asian dust, the downward spectrum is revealed a positive slope for $800-1000cm^{-1}$ region and negative slope over $1100-1200cm^{-1}$ region. In the upward spectrum, slopes are opposed to the downward one. It is inferred that the difference between measured and calculated spectrum is mostly due to the contribution of emission and/or absorption of the dust particles by the aerosol amount, size distribution, altitude, and composition.