• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.45-59
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• 2006

In this study, the effects of the surface topographical characteristics on the meteorological fields are examined in a mesoscale meteorlolgical model. We calculated the direct solar radiation using the illumination angle considering the inclination of topography and tried to find out its effect on meteorological fields. In above experiments, we selected two cases for the clear day and the cloudy day to show the effect of weather and represented the results for two cases. In the correction of the direct solar radiation, the results of two cases indicate that there are obvious differences on the steep Taeback and Soback mountains. And on the time-series analysis the east-facing slope of these mountains receives the more direct solar radiation about $10-60W/m^2$ in the morning hours but lesser in the afternoon hours than the horizontal surface while it is opposite on the west-facing slope. And the results mentioned above are more obvious at clear day. With the same analysis method, at clear day, the surface skin temperature is higher at all hours than that on horizontal surface on the both of slope. At cloudy and rainy day, the surface skin temperature on the east-facing slope is higher in the morning hours but lower in the afternoon hours than that on horizontal surface. But on the west-facing slope, it is higher at all hours than that on horizontal surface. In the two cases, the temperature considering the slope of surface is almost higher than that on the horizontal surface. The wind is stronger than that on the horizontal surface with increasing pressure gradient force according as increasing temperature gradient around the Taeback and the Soback mountains.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.417-418
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• 2003

2002년 10월과 11월에는 가을 추수 후 소각이 대기질에 미치는 영향을 조사하고자 광주과학기술원 내에서 에어로졸과 대기 복사 집중 측정 기간을 가졌다. 12시간 또는 일평균 자료만을 제공하는 에어로졸 화학적 특성의 측정과 달리 자외선 영역의 다파장 회전차폐판 복사계 (Ultraviolet Multi-filter Rotating Shadowband Radiometer)를 이용한 에어로졸 광학 깊이(aerosol optical depth)는 1분 간격의 직달 일사량 자료로부터 에어로졸 복사적 특성을 시간에 따른 변화를 볼 수 있다는 장점을 가진다. (중략)

• Journal of the Korean earth science society
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• v.40 no.2
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• pp.119-134
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• 2019

In order to analyze the observational environment of solar radiation stations operated by the Korea Meteorological Administration (KMA), we used the digital elevation model (DEM) and the solar radiation model to calculate a topographical shading, sky view factor (SVF) and solar radiation by surrounding terrain. The sky line and SVF were calculated using high resolution DEM around 25 km of the solar stations. We analyzed the topographic effect by analyzing overlapped solar map with sky line. Particularly, Incheon station has low SVF whereas Cheongsong and Chupungryong station have high SVF. In order to validation the contribution of topographic effect, the solar radiation calculated using GWNU solar radiation model according to the sky line and SVF under the same meteorological conditions. As a result, direct, diffuse and global solar radiation were decreased by 12.0, 5.6, and 4.7% compared to plane surface on Cheongsong station. The 6 stations were decreased amount of mean daily solar radiation to the annual solar radiation. Among 42 stations, eight stations were analyzed as the urgent transfer stations or moving equipment quickly and more than half of stations (24) were required to review the observational environment. Since the DEM data do not include artifacts and vegetation around the station, the stations need a detail survey of observational environment.

• Journal of the Korean earth science society
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• v.38 no.2
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• pp.129-140
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• 2017

Global solar radiation was calculated in this research using ground-base measurement data, meteorological satellite data, and GWNU (Gangneung-Wonju National University) solar radiation model. We also analyzed the accuracy of the GWNU model by comparing the observed solar radiation according to the total cloud cover. Our research was based on the global solar radiation of the GWNU radiation site in 2012, observation data such as temperature and pressure, humidity, aerosol, total ozone amount data from the Ozone Monitoring Instrument (OMI) sensor, and Skyview data used for evaluation of cloud mask and total cloud cover. On a clear day when the total cloud cover was 0 tenth, the calculated global solar radiations using the GWNU model had a high correlation coefficient of 0.98 compared with the observed solar radiation, but root mean square error (RMSE) was relatively high, i.e., $36.62Wm^{-2}$. The Skyview equipment was unable to determine the meteorological condition such as thin clouds, mist, and haze. On a cloudy day, regression equations were used for the radiation model to correct the effect of clouds. The correlation coefficient was 0.92, but the RMSE was high, i.e., $99.50Wm^{-2}$. For more accurate analysis, additional analysis of various elements including shielding of the direct radiation component and cloud optical thickness is required. The results of this study can be useful in the area where the global solar radiation is not observed by calculating the global solar radiation per minute or time.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.151-165
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• 2008

Ground slope and aspect are important parameters for physical deterministic water balance models like BROOK90 or hydrological models which attempt to calculate evapotranspiration, snowmelt, and net radiation. This study constructs a Digital Elevation Model(DEM) and examines how DEM resolution can change the average ground slope and aspect of a river basin and attempts to evaluate the effects on simulation results of BROOK90, a physical deterministic water balance model. The study area is Byungcheon river basin in Korea. DEM has been constructed using a 1:25,000 digital map with the methods of TIN and Topo To Raster. The total of 20 DEMs with 10m~100m resolution have been constructed, with a 10m interval. It was found that the higher the DEM resolution, the steeper the average ground slope value of the Byungcheon river basin. In turn, the direct solar radiation of a hilly area in the model increased the evapotranspiration and reduced the stream runoff in the Byungcheon river basin. On the other hand, a lower DEM resolution tends to move the average aspect from southeast to south in the Byungcheon river basin. Accordingly, it was found that stream runoff was reduced and evapotranspiration increased.

• Journal of the Korean Solar Energy Society
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• v.29 no.4
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• pp.15-21
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• 2009

Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.60 kWh/$m^2$/day and the yearly mean 2.62 kWh/$m^2$/day of the direct normal insolation was evaluated for all days.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.103-116
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• 2004

The mesoscale atmospheric models to produce surface temperature can not generally consider the effect of the sloped terrain for direct solar radiation. These have not showed the regional difference of solar radiation and as a result, have made the big error in the local surface temperature. Therefore, we wished to represent the exact locality of surface temperature by considering the geometric properties of surface as well as the vegetated properties of surface. The purpose of the study is to produce local surface ground temperature in sloped terrain diagnostically using surface Energy Balance Model (EBM) with the use of GRID model in Geographic Information Systems (GIS). In this study, surface inhomogeneity over southeastern part of Korean peninsula are considered in estimation of the absorbed surface solar radiation in terms of the illumination angle, depending on topographical aspect and slope in GRID. Also, the properties of vegetated surface which the major components for the variability of surface temperature are considered in terms of NDVI. The results of our study show the locally changes in the surface ground temperature due to local ground aspect and slope effect and local properties of vegetated surface. The more detailed distribution of local surface temperature may drive the local circulation at lower atmospheric and it may explain better the real local circulation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.3
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• pp.118-134
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• 2017

The radiation observation data will be used importantly in research field such as climatology, weather, architecture, agro-livestock and marine science. The Ieodo Ocean Research Station (IORS) is regarded as an ideal observatory because its location can minimize the solar radiation reflection from the surrounding background and also the data produced here can serve as a reference data for radiation observation. This station has the potential to emerge as a significant observatory and join a global radiation observation group such as the Baseline Surface Radiation Network (BSRN), if the surrounding of observatory is improved and be equipped with the essential radiation measuring instruments (pyaranometer and pyrheliometer). IORS has observed the solar radiation using a pyranometer since November 2004 and the data from January 1, 2005 to December 31, 2015 were analyzed in this study. During the period of this study, the daily mean solar radiation observed from IORS decreased to $-3.80W/m^2/year$ due to the variation of the sensor response in addition to the natural environment. Since the yellow sand and fine dust from China are of great interest to scientists around the world, it is necessary to establish a basis of global joint response through the radiation data obtained at the Ieodo as well as at Sinan Gageocho and Ongjin Socheongcho Ocean Research Station. So it is an urgent need to improve the observatory surrounding and the accuracy of the observed data.

• Journal of the Korean earth science society
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• v.26 no.8
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• pp.790-799
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• 2005

We investigate the optical properties of aerosols over Gongju by an indirect method using the pound measurement, Sky-radiometer. The analysis period is from January to December, 2004. Skyrad. pack.3 is used to estimate the optical properties, such as the aerosol optical thickness (AOT), single scattering albedo (SSA), ${\AA}ngstron$ exponent $({\alpha})$ and size distribution, of aerosols from the ground measured radiance data. And qualify control is applied to minimize the cloud-contaminated data and improve the quality of analysis results. The 12-month average of AOT, ${\alpha}$, and SSA are 0.46, 1.14, and 0.91, respectively. The average volume spectra of aerosols shows a bi-modal distribution, the first peak at fine mode and the second peak at coarse mode. AOT and coarse particles clearly increases while SSA decreases during the Asian dust events. The optical properties of aerosols at Gongju vary with?seasons, but those are not influenced by the wind direction.