The Reduction of the Global Irradiance Due to the Asian Dust Aerosols (PM10) Estimated by the Observed Data in the Dust Source Region of Erdene in Mongolia

박순웅,주승진,이인혜,주재원 한국기상학회 2019 Asia-Pacific Journal of Atmospheric Sciences Vol.55 No.3

An empirical method of the PM10 to reduce the global irradiance has been developed with the observed 14-day data in 2009 at the Erdene site in the Asian dust source region of Mongolia. The observed data at a 10-min interval are used to get all parameters for the estimation of the beam and diffuse irradiances except for the properties of Asian dust aerosols such as the single scattering albedo (ω0), scattering transmittance (τa) and transmittance due to aerosol absorption (τaa) using the parametric solar radiation model. To determine these parameters, firstly τa is calculated with the observed global irradiance for a given ω0 value using all sampled data. And then the estimated τas are correlated with observed dust concentration to find an optimal regression equation between τa and the observed dust concentration. The optimal ω0 value is found that the error between the calculated global irradiance using the optimal regression equation and the observed global irradiance becomes minimum. It is found that the single scattering albedo of Asian dust aerosol (ω0) is 0.85 and its reduction rate of the global irradiance is up 34.4% of that of the dust free atmosphere for the heavy dust case. This reduction is mainly contributed by the reduction of the beam irradiance whereas the diffuse irradiance enhances slightly (about 1.8%) the global irradiance. The presently developed optimal regression equation between τa and the observed dust concentration has a great potential to estimate the impact of Asian dust aerosols on the solar irradiance.

천리안 위성 영상 기반 태양자원지도를 활용한 다양한 정의에서의 청천지수 특성 분석

김창기,김현구,강용혁,윤창열 한국태양에너지학회 2019 한국태양에너지학회 논문집 Vol.39 No.3

Clear sky indices were estimated by various ways based on in-situ observation and satellite-derived solar irradiance. In principle, clear sky index defined by clear sky solar irradiance indicates the impacts of cloud on the incoming solar irradiance. However, clear sky index widely used in energy sciences is formulated by extraterrestrial irradiance, which implies the extinction of solar irradiance due to mainly aerosol, water vapor and clouds drops. This study examined the relative difference of clear sky indices and then major characteristics of clear sky irradiance when sky is clear are investigated. Clear sky is defined when clear sky index based on clear sky irradiance is higher than 0.9. In contrast, clear sky index defined by extraterrestrial irradiance is distributed between 0.4 and 0.8. When aerosol optical depth and air mass coefficient are relative larger, solar irradiance is lower due to enhanced extinction, which leads to the lower value of clear sky index defined by extraterrestrial irradiance.

Characteristics of Environmental Solar Ultraviolet Irradiance

Sasaki, Masako,Oyanagi, Takehiko,Takeshita, Shu Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

영농형 태양광 발전 시설 하부의 일사량 분포 모의

정영준,최원,이상익,이종혁,서병훈,김동수,이지민 한국농공학회 2022 한국농공학회논문집 Vol.64 No.2

Agrivoltaic facility is the composite system that the solar panel is installed above the farmland, and it enables crop and electricity productionsimultaneously. Solar panels of the agrivoltaic facilities can block and reduce the amount of solar irradiance arriving at the farmland, but it can helpthe crop growth by preventing excessive solar irradiance. Therefore, to clarify how the agrivoltaic facilities affect the crop growth, precise solarirradiance distribution under the solar panel should be modeled. In this study, PAR (photosynthetically active radiation), radiation from 400 to 700 nm,which crops usually use to grow, was extracted from the total irradiance and its distribution model under various conditions was developed. Monthlyirradiance distributions varied because the elevation of the sun was changed over time, which made the position changed that the local maximum andminimum irradiance appear. The higher panel height did not cause any significant difference in the amount of irradiance reaching below the solar panel,but its distribution became more uniform. Furthermore, the panel angles with the most irradiance arriving below the solar panel were different by month,but its difference was up to 2%p between the irradiance with 30° angle which is usually recommended in Korea. Finally, the interval between panelswas adjusted; when the ratio of the length of the panel to the empty space was 1:2, the irradiance of 0.719 times was reached compared to whenthere was no panel, 0.579 times for 1:1 and 0.442 times for 2:1.

서울지역 일사량 및 외기온도와 단결정 실리콘 태양광 모듈온도의 상관성에 대한 실증분석

윤다은,박형동,이상남,강용혁 한국자원공학회 2017 한국자원공학회지 Vol.54 No.2

This study analyzed photovoltaic module temperature which affects power generation of photovoltaic systems. The influence of irradiance and ambient temperature on the module temperature was confirmed using data measured in Seoul area. The module temperature increased with increasing irradiance and was similar to ambient temperature at night. Also, as a result of regression analysis, it was confirmed that the effect of irradiance on the module temperature was different depending on intervals of solar irradiance. Correlation between irradiance and module temperature was not valid in an irradiance group under 300 W/m2. The effect of irradiance on the module temperature increased between 300–800 W/m2 and decreased over 800 W/m2. This study has potential in prediction models according to intervals of irradiance. It could eventually lead to more accurate prediction of module temperature and solar power generation. 본 연구에서는 태양광 발전 시스템의 발전량에 영향을 미치는 모듈온도에 대한 실증분석을 실시하였다. 일사량, 외기온도 등 서울지역에서 측정한 기상요소와 모듈온도 자료를 이용하여 일사량과 외기온도가 모듈온도에 미치는 영향을 파악하였다. 실험 및 데이터 분석 결과, 모듈온도는 외기온도와 경향이 동일하고 외기온도를 기본 값으로가졌으며, 일사량의 영향이 더해져서 최종 모듈온도가 정의될 수 있음을 확인하였다. 또한, 모듈온도에 대한 일사량의 회귀분석 결과, 일사량 300 W/m2, 800 W/m2을 기준으로 모듈온도와 일사량의 상관성이 없는 구간, 모듈온도에 대한 일사량의 영향력이 증가하는 구간, 감소하는 구간으로 나눌 수 있었다. 이를 토대로 단일 식을 사용하는 기존 모델보다 해당 지역 자료를 이용하여 일사량 구간별 예측 모델을 사용하는 것이 더 적절함을 확인했다. 본 연구는 서울지역의 실측 자료를 이용하였기 때문에 향후 서울지역에 설치될 시스템 설치 환경을 파악할 수 있으며, 일사량 구간에 따른모듈온도 예측모델 제안 가능성을 보여주어 태양광 발전 시스템 설계 및 발전량 예측에 기여할 것으로 기대된다.

Advanced Forecasting Approach to Improve Uncertainty of Solar Irradiance Associated with Aerosol Direct Effects

( Dong Hyeok Kim ),( Jung Woo Yoo ),( Hwa Woon Lee ),( Soon Young Park ),( Hyun Goo Kim ) 한국환경과학회 2017 한국환경과학회지 Vol.26 No.10

Numerical Weather Prediction (NWP) models such as the Weather Research and Forecasting (WRF) model are essential for forecasting one-day-ahead solar irradiance. In order to evaluate the performance of the WRF in forecasting solar irradiance over the Korean Peninsula, we compared WRF prediction data from 2008 to 2010 corresponding to weather observation data (OBS) from the Korean Meteorological Administration (KMA). The WRF model showed poor performance at polluted regions such as Seoul and Suwon where the relative Root Mean Square Error (rRMSE) is over 30%. Predictions by the WRF model alone had a large amount of potential error because of the lack of actual aerosol radiative feedbacks. For the purpose of reducing this error induced by atmospheric particles, i.e., aerosols, the WRF model was coupled with the Community Multiscale Air Quality (CMAQ) model. The coupled system makes it possible to estimate the radiative feedbacks of aerosols on the solar irradiance. As a result, the solar irradiance estimated by the coupled system showed a strong dependence on both the aerosol spatial distributions and the associated optical properties. In the NF (No Feedback) case, which refers to the WRF-only stimulated system without aerosol feedbacks, the GHI was overestimated by 50-200 W m^-2 compared with OBS derived values at each site. In the YF (Yes Feedback) case, in contrast, which refers to the WRF-CMAQ two-way coupled system, the rRMSE was significantly improved by 3.1-3.7% at Suwon and Seoul where the Particulate Matter (PM) concentrations, specifically, those related to the PM₁₀ size fraction, were over 100 μg m^-3. Thus, the coupled system showed promise for acquiring more accurate solar irradiance forecasts.

건물에너지해석용 국내 표준기상자료들의 일사량 비교분석 연구

강은호(Kang Eun-Ho),김동수(Kim Dong-Soo),이효문(Lee Hyo-Mun),윤종호(Yoon Jong-Ho) 한국태양에너지학회 2022 한국태양에너지학회 논문집 Vol.42 No.6

This research paper examined the variation in solar irradiance quantitatively over time by comparing solar irradiance data from domestic Typical Meteorological Year (TMY) records. Solar radiation can produce different TMY records depending on the year of data collection, even for the same region. Therefore, simulation users should take these factors into consideration and select appropriate TMY records based on their specific needs. The results showed that the recently produced TMY records had higher solar irradiance values than those produced in the past. The average annual deviation between different TMY records was 86.1 kWh/㎡yr (6.5%). However, a comparison of TMY records from KIRE and SAREK, which have a significant difference in publication date, demonstrated that the deviation increased to an average of 204 kWh/㎡yr (14.4%), with a maximum of kWh/㎡yr (16.9%). The study also found that the difference in solar irradiance is related to the ratio of direct solar radiation when converting GHI to inclined plane irradiance. The annual cumulative solar irradiance showed significant variations on the southern inclined planes with a high ratio of direct solar radiation, while minimal changes were observed on northern inclined planes with a high ratio of diffusion solar radiation.

한국연안에서 분리한 적조형성 미세조류 10종의 성장에 미치는 온도, 염분, 광도의 영향

이창규,이옥희,이삼근,Lee, Chang-Kyu,Lee, Ok-Hee,Lee, Sam-Geun 한국해양학회 2005 바다 Vol.10 No.1

한국 연안에서 출현하는 주요 적조생물의 적조발생 특성을 알아보기 위해 편모조류 10종을 대상으로 하여 수온과 염분, 광도에 따른 종의 성장률을 조사하였고, 또한 최근 13년간의 적조발생자료와 1999년도 및 2000년도 남해안연안에서 조사한 적조생물의 출현밀도를 비교, 분석하였다. 수온에 따른 적조생물의 성장은 Heterocapsa triquetra, Eutreptiella gymnastica, Alexandrium tamarense의 경우 대체로 $16{\sim}22^{\circ}C$에서 최대성장률을 보였으나, $10{\sim}16^{\circ}C$의 저수온에서도 비교적 높은 성장률을 보였고 $22^{\circ}C$이상의 고수온에서는 오히려 성장률이 급격히 감소되는 것으로 나타나 저온성종의 특성을 보였다. Prorocentrum micans와 Pyramimonas sp.는 $19^{\circ}C$ 이하의 저수온에서는 낮은 성장률을 보였으나 $22{\sim}25^{\circ}C$에서는 높은 성장률을 보여 고온종의 특성을 나타냈으며, Akashiwo sanguinea, Hetemsigma akashiwo Prorocentrum minimum, Scrippsiella tnchoidea는 $16{\sim}25^{\circ}C$의 광범위한 수온 범위에서 비교적 높은 성장률을 보여 광온성종의 특성을 보였다. 또한 이러한 결과는 이 종들이 자연상태에서 적조를 일으키는 수온 범위와도 대체로 일치하였다 염분에 따른 성장은 대부분의 종이 염분 $30{\sim}35$ psu에서 높은 성장률을 보였는데, E. gymnastica는 35 psu 이상의 고염분보다는 $10{\sim}30$ psu의 저염분에서 더 높은 성장률을 나타내 저염성을 보였으며, H. akashiwo, P. minimum, H. triquetra는 $15{\sim}40$ psu의 넓은 염분 범위에서 양호한 성장률을 보여 광염성종의 특성을 보였다. 이종들은 한국 연안에서 강우 직후 염분이 25 psu이하로 하강하는 저염분 상태에서 빈번히 적조를 일으키고 있는데, 이것은 이종들의 저염 및 광염성 특성과 밀접한 관련이 있는 것으로 판단되었다. 광도별 성장은 H. akashiwo, P. minimum, Pyramimonas sp.는 $150\;{\mu}E{\cdot}m^{-2}{\cdot}s^{-1}$의 고광도에서 비교적 높은 성장률을 보였다. A. sanguinea, A. tamarense, H. triquetra는 $150{\sim}100\;{\mu}E{\cdot}m^{-2}{\cdot}s^{-1}$에서 가장 높은 성장률을 보였고 $100\;{\mu}E{\cdot}m^{-2}{\cdot}s^{-1}$ 이상의 고광도에서 는 오히려 성장률이 급격히 감소되는 것으로 나타났다. 전반적으로 수온과 일조량이 높은 시기인 하계에 적조를 일으키는 고온성 종은 고광도에서 성장이 좋은 것으로 나타났고, 수온과 일조량이 낮은 동, 춘계에 적조를 일으키는 저온성 종은 저 광도에서 성장이 양호한 것으로 나타났다. In order to understand growth characteristics of ten major species of microalgae responsible for frequent harmful algal blooms in Korean coastal waters, the growth rates of the isolates were examined in relation with the impacts of water temperature, salinity and irradiance. In addition, their bloom events since 1990 as well as monthly abundance of vegetative cells were analyzed. Heterocapsa triquetra, Eutreptiella gymnastica and Alexandrium tamarense were considered as relatively mid temperature adapted species in that growth rates were comparatively high at low water temperatures of $10{\sim}16^{\circ}C$ and drastically decreased at above $22^{\circ}C$. Prorocentrum micans and Pyramimonas sp. were categorized as relatively high temperature adapted species by showing comparatively better growths at high water temperatures above $25^{\circ}C$. Akashiwo sanguinea, Heterosigma akashiwo, Prorocentrum minimum and Scrippsiella trochoidea were eurythermal species with relative high growth rates in a broad ranges of water temperature, $16{\sim}25^{\circ}C$ were slightly halophobic, showing better growths at low salinities of $10{\sim}30$ psu than at above 35 psu. H. akashiwo, P. minimum and H. triquetra were euryhaline species with remarkable growths in a broad ranges of salinity, 15-40 psu. Frequent algal blooms by these three species at extremely low salinities below 25 psu after rainfall were attributed to their euryhaline and slightly halophobic physiological characteristics. Growth rates of H. akashiwo, P. minimum and Pyraminonas sp. increased with the increase of irradiance within the experimental ranges of $2{\sim}150\;{\mu}E{\cdot}m^{-2}{\cdot}s^{-1}$. However, A. sanguinea, A. tamarense and H. triquetra showed better growths at comparatively low irradiance of $50{\sim}100\;{\mu}E{\cdot}m^{-2}{\cdot}s^{-1}$ and drastic decreases in growth rates above $150\;{\mu}E{\cdot}m^{-2}{\cdot}s^{-1}$ of irradiance. Overall, relatively high temperature adapted species make blooms frequently in high water temperature season with strong natural irradiance, and relatively low temperature adapted species grow better at low water temperature with relatively weak natural irradiance.

Estimation of the PAR Irradiance Ratio and Its Variability under Clear-sky Conditions at Ieodo in the East China Sea

Byun, Do-Seong,Cho, Yang-Ki The Korean Society of Oceanography 2006 Ocean science journal Vol.41 No.4

Determining 'photosynthetically active radiation' (PAR) is a key part of calculating phytoplankton productivity in a biogeochemical model. We explore the daily and seasonal variability in the ratio of PAR irradiance to total irradiance that occurred at Ieodo Ocean Research Station (IORS) in the East China Sea under clear-sky conditions in 2004 using a simple radiative transfer model (RTM). Meteorological data observed at IORS and aerosol optical properties derived from Aerosol Robotic Network observations at Gosan are used for the RTM. Preliminary results suggest that the use of simple PAR irradiance-ratio values is appropriate in calculating phytoplankton productivity as follows: an average of $0.44\;({\pm}0.01)$ in January to an average of $0.48\;({\pm}0.01)$ in July, with average daily variabilities over these periods of about $0.016\;({\pm}0.008)$ and $0.025\;({\pm}0.008)$, respectively. The model experiments demonstrate that variations in the major controlling input parameters (i.e. solar zenith angle, precipitable water vapor and aerosol optical thickness) cause PAR irradiance ratio variation at daily and seasonal timescales. Further, increases (>0.012) in the PAR irradiance ratio just below the sea-surface are positively correlated with high solar zenith angles and strong wind stresses relative to those just above the sea-surface.

Evaluation of Global Horizontal Irradiance Derived from CLAVR-x Model and COMS Imagery Over the Korean Peninsula

Chang Ki Kim,Hyun-Goo Kim,Yong-Heack Kang,Chang-Yeol Yun,Sang-Nam Lee 한국신재생에너지학회 2016 신재생에너지 Vol.12 No.S2

Satellite-derived solar irradiance was evaluated against four ground observations for clear and cloudy skies. The solar irradiance estimated by the CLAVR-x model was positively biased for clear sky and the error metrics increased when clouds exist. The COMS operational products include the solar insolation, which is underestimated when comparing with the clear sky solar irradiance measured at ground stations. The biases for clear sky were correlated with the solar zenith angle and therefore correction factor was formulated as a function of the cosine of the solar zenith angle. After the correction, the solar irradiance estimates were consistent with the observed solar irradiance. For cloudy sky, the CLAVR-x model failed to detect the cloudy pixel for shallow clouds.