• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.168-175
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• 1990

Pasquill stability class (PSC) was evaluated with Monin-Obukhov length (L) using the data observed at a height of 213m meteorological tower in Tsukuba, Japan. PSC was determined with wind speed and insolation (net radiation at night), and L was calculated with the heat flux and the friction velocity obtained at 25m by the eddy correlation method. To evaluate PSC with L, for every class of Pasquill stability (from A to F class), percentiles and median of L were used. Results show that for every class of Pasquill stability, L varies so widely that PSC does not adequately represent the atmospheric stability conditions. The scheme which estimates L using air temperature at two levels and wind speed at single level was developed. Comparison between estimated L by the scheme and observed L reveals that the scheme is better than PSC. Furthermore, the scheme is more advantageous than PSC because it uses air temperature at two levels instead of insolation which is more difficult to observe in the field than air temperature.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.26 no.4
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• pp.260-268
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• 1997

• Ocean Science Journal
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• v.42 no.4
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• pp.211-222
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• 2007

We compare insolation results calculated from two well-known empirical formulas (Socket and Beaudry's SB73 formula and the original Smithsonian (SMS) formula) and a radiative transfer model using input data predicted from meteorological weather-forecast models, and review the accuracy of each method. Comparison of annual mean daily irradiance values for clear-sky conditions between the two formulas shows that, relative to the SMS, the SB73 underestimates spring values by 9 W $m^{-2}$ in the northern Adriatic Sea, although overall there is a good agreement between the annual results calculated with the two formulas. We also elucidate the effect on SMS of changing the 'Sun-Earth distance factor (f)', a parameter which is commonly assumed to be constant in the oceanographic context. Results show that the mean daily solar radiation for clear-sky conditions in the northern Adriatic Sea can be reduced as much as 12 W $m^{-2}$ during summer due to a decrease in the f value. Lastly, surface irradiance values calculated from a simple radiative transfer model (GM02) for clear-sky conditions are compared to those from SB73 and SMS. Comparison with iu situ data in the northern Adriatic Sea shows that the GM02 estimate gives more realistic surface irradiance values than SMS, particularly during summer. Additionally, irradiance values calculated by GM02 using the buoy meteorological fields and ECMWF (The European Centre for Medium Range Weather Forecasts) meteorological data show the suitability of the ECMWF data usage. Through tests of GM02 sensitivity to key regional meteorological factors, we explore the main factors contributing significantly to a reduction in summertime solar irradiance in the Adriatic Sea.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.1
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• pp.73-79
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• 1986

This study is carried out to determine the concentration of the ozone and the factors affecting the variation of ozone concentration in the ambient air in Seoul. The one-hour average concentration of ozone $(O_3)$, sulfur dioxide $(SO_2)$, nitrogen oxides (NO and $NO_2$), suspended particulate (TSP), carbon monoxide (CO) and non-methane hydrocarbon (NMHC) at 5 sites in Seoul measured from September to October in 1983 and 1984 were analysed statistically along with meteorological data for the same period. The results were as follows; 1. The average concentrations of ozone at 5 sites during the period ranged from 3.3 to 9.1 ppb, they were below 20 ppb of the ambient air quality standard of Korea. 2. The maximum hourly concentration of ozone occurred between 2 and 3 p.m. in a day and concentration at night were very low but higher concentrations were observed at around 4 a.m. 3. The concentration ratio between NO and $NO_2$ in Seoul was relatively lower than that for the cities of foreign countries reported so far. 4. The ozone concentration has negative correlationships with the concentration of other primary pollutants$(SO_2, NO, NO_2, CO and NMHC)$ in simple regression analyses. 5. The ozone concentration was positively correlated to wind speed, temperature and insolation intensity but negatively correlated to relative humidity. 6. Stepwise multiple regression analysis of the ozone concentration to the pollutants and meteorological factors indicate that insolation intensity and $[NO_2]/[NO]$ were the primary influencing factors. 7. The three factors of insolation intensity, $[NO_2]/[NO] and NO_2$ concentration had a significant combined effect on the ozone concentration $(r^2 = 0.47-0.57)$.

• KIEAE Journal
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• v.15 no.3
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• pp.5-14
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• 2015

Purpose: Recently, according to climate changes, human health is exposed to danger over the world and they influence all fields of human society. Due to these climate changes, humans can be exposed to more frequent and extreme scorching heat and cold wave than the present. As precautions against these urban higher temperature and dryness, diverse methods are being sought. Among them, as measures to form cold islands, the evaporative cooling effect realistic to social and economic conditions was examined. Method: This study was conducted to analyze effects of temperature reduction and cooling according to injection quantity of minute water particles by using a blast sprayer as one of alternatives of alleviation of urban climate changes in outside space in summer. For this, through temperature difference in accordance with the injection quantity per hour of a day, a time zone representing the value of the highest temperature change was analyzed. Also, by analyzing temperature difference according to the injection quantity per daytime insolation, relation of amounts of insolation and evaporation was investigated. Temperature difference in accordance with distances at the highest temperature with the highest value in temperature changes was analyzed. Result: At the study result, about temperature, as injection quantity increase, temperature reduction was significant statistically at the highest temperature with the most insolation. A factor with the highest influence was judged to be the increase of the injection quantity. According to the injection quantity, it was predicted that $3.1^{\circ}C$ temperature reduction of a daily average in case of 0.16L/min, $3.5^{\circ}C$ temperature reduction of a daily average in case of 0.32L/min, and $4.4^{\circ}C$ temperature reduction of a daily average in case of 0.48L/min.

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.68-76
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• 2012

Since the solar energy resource is the main input for sizing any solar energy utilization system, it is essential to utilize the solar radiation data as an application and development of solar energy system increase. 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 at 16 different locations in Korea and for the more detailed analysis, images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. From the results, the measured data has been collected at 16 different stations and estimated using satellite at 44 different stations over the Korean peninsula from 1982 to 2010. The Result of analysis shows that the annual-average daily global radiation on the horizontal surface is 3.66 $kWh/m^2/day$ and estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.2 to +3.7 % from the measured values.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.52-52
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• 1995

The temporal and spatial distribution of atmospheric transmissivity and depletion rate of solar radiation are investigated, and are compared to the concentration of several components of air pollution. The length of the data span is 11 years from 1983 to 1993. The data of radiation and sunshine rate recorded at 20 meteorological standard stations were used, and in order to investigate a relationship between the depletion rate of solar radiation and air pollution, the concentration data of air pollution observed in Seoul, Pusan, Taegu, Taejon and Kwangju were compiled from 1991 to 1993. Regression coefficient a and b vary from 0.100 to 0.209, from 0.464 to 0.691, and their means are 0.163 and 0.533, respectively. Climatological atmospheric transmissivity is ranged from 0.68 to 0.83, and its mean is 0.75. Atmospheric transmissivity is relatively low in Pusan, Taejon, Kwangju and Inchon which have large population and are highly industrialized. However, that in Chinju, Mokpo, Cheju and Sosan appears to be large compared to the aforementioned stations. Insolation rate of clear days varies from 0.71 to 0.58, and its mean is 0.63. Insolation rate of Kangnung and Chinju are higher than those of Seoul and Pusan by 5%. From the correlation coefficients between depletion rate of solar radiation and air pollution concentration, the most significant factors related to the depletion rate of solar radiation is appeared to be TSP followed by $SO_2$. Ozone shows a negative correlation, End $NO_2$ does not show a obvious correlation with the depletion rate of solar radiation.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.437-446
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• 1995

The temporal and spatial distribution of atmospheric transmissivity and depletion rate of solar radiation are investigated, and are compared to the concentration of several components of air pollution. The length of the data span is 11 years from 1983 to 1993. The data of radiation and sunshine rate recorded at 20 meteorological standard stations were used, and in order to investigate a relationship between the depletion rate of solar radiation and air pollution, the concentration data of air pollution observed in Seoul, Pusan, Taegu, Taejon and Kwangju were compiled from 1991 to 1993. Regression coefficient a and b vary from 0.100 to 0.209, from 0.464 to 0.691, and their means are 0.163 and 0.533, respectively. Climatological atmospheric transmissivity is ranged from 0.68 to 0.83, and its mean is 0.75. Atmospheric transmissivity is relatively low in Pusan, Taejon, Kwangju and Inchon which have large population and are highly industrialized. However, that in Chinju, Mokpo, Cheju and Sosan appears to be large compared to the aforementioned stations. Insolation rate of clear days varies from 0.71 to 0.58, and its mean is 0.63. Insolation rate of Kangnung and Chinju are higher than those of Seoul and Pusan by 5%. From the correlation coefficients between depletion rate of solar radiation and air pollution concentration, the most significant factors related to the depletion rate of solar radiation is appeared to be TSP followed by $SO_2$. Ozone shows a negative correlation, End $NO_2$ does not show a obvious correlation with the depletion rate of solar radiation.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.2
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• pp.1-9
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• 2003

Surface solar radiation over the sea is estimated using the visible and infrared spin scan radiometer (VISSR) data onboard Geostationary Meteorological Satellite(GMS)-5 from January 1997 to December 1997 in clear and cloudy conditions. The hourly insolation is estimated with a spatial resolution of $5km{\times}5km$ grid. The island pyranometer operated by the Japan Meteorological Agency(JMA) is used to validate the estimated insolation. The root mean square error of the hourly estimated insolation is $104W/m^2$ with 0.91 of the correlation coefficient. In the variability of the hourly solar radiation investigated around the Korean Peninsula, the maximum value of solar radiation is found in June at the Yellow Sea and the East Sea, while in August at the South Sea because of low pressure conditions and front in June.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.89-99
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• 2008

In this paper proposes a novel tacking algorithm regarding the power loss when operating a tracking system for a rapidly changing insolation to improve the power of PV hacking system. The tracking system of sensor method used in a conventional PV power station is unable to exactly track a sun position when lacking in the intensity of radiation and has the problem is malfunction of tracking system by a rapidly changing climatic. The tracking system of program method spends too much energy on the unnecessary operation of tracking system because that is unable to adapt itself to a outside factor of climatic environment. In case of tracking an azimuth and altitude of the sun in realtime, therefore, the actual PV power is less increasing than the power of tracking system fixed a specific position. To reduce the power loss, this pap proposes a novel control algorithm of the tracking system. Also, this paper is analyzed efficiency of traditional solar tracking method and proposed method, prove validity of proposed algorithm through demonstrable study.