scholarly journals Mapping Global Solar Radiation from Long-Term Satellite Data in the Tropics Using an Improved Model

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
S. Janjai ◽  
I. Masiri ◽  
S. Pattarapanitchai ◽  
J. Laksanaboonsong

This paper presents an improved model and its application for mapping global solar radiation from satellite data in the tropics. The model provides a more complete description of the absorption and scattering of solar radiation in the earth-atmosphere system as compared to the earlier models. The study is conducted in the tropical environment of Thailand. Digital data from the visible channel of GMS4, GMS5, GOES9, and MTSAT-1R satellites collected during a 15-year period (1995–2009) are used as a main input to the model. Satellite gray levels are converted into earth-atmospheric reflectivity and used to estimate the cloud effect. The absorption of solar radiation due to water vapour is computed from precipitable water derived from ambient temperature and relative humidity. The total ozone column data from TOMS/EP and OMI/AURA satellites are used to compute solar radiation absorption by ozone. The depletion of solar radiation due to aerosol is estimated from visibility data. In order to test its performance, the model is employed to calculate monthly average daily global solar radiation at 36 solar monitoring stations across the country. It is found that solar radiation calculated from the model and that obtained from the measurement are in good agreement, with a root mean square difference of 5.3% and a mean bias difference of 0.3%. The model is used to calculate the monthly average daily global solar radiation over the entire country, and results are displayed as monthly and yearly maps. These maps reveal that the geographical distribution of solar radiation in Thailand is strongly influenced by the tropical monsoons and local geographical features.

1970 ◽  
Vol 8 (3) ◽  
pp. 130-139
Author(s):  
Serm Janjai ◽  
Itsara Masiri ◽  
Somjet Pattarapanitchai ◽  
Jarungsaeng Laksanaboonsong

This paper presents an improved model for estimating surface solar radiation from satellite data for Thailand. Digital data from the visible channel of the GOES9 and MTSAT-1R satellites were used as the main input data of the model. This model accounted for the scattering of solar radiation by clouds, absorption of solar radiation by water vapour, ozone and gases and solar radiation depletion by aerosols. Additionally, the multiple reflections between the atmosphere and the ground in satellite band, which were ignored in the original model, were included in the improved model. For testing its validity, the model was employed to calculate monthly average daily global solar radiation at 38 solar monitoring stations in Thailand. It was found that the solar radiation calculated from the model and that obtained from the measurements were in good agreement, with a root mean square difference (RMSD) of 6.1% and mean bias difference (MBD) of 0.3%. The performance of the improved model was better than that of the original model. DOI: http://dx.doi.org/10.3126/jie.v8i3.5939 JIE 2011; 8(3): 130-139


1970 ◽  
Vol 8 (3) ◽  
pp. 32-41
Author(s):  
Itsara Masiri ◽  
Serm Janjai ◽  
Treenuch Jantarach

An algorithm was developed to estimate aerosol optical depth (AOD) from geostationary satellite data. The 6S radiative transfer computer code was employed to generate a look-up table (LUT) which incorporates several combinations of satellite-derived variables including earthatmospheric reflectivity, atmospheric reflectivity and surface albedo. The parameterization of the satellite-derived atmospheric reflectivity accounted for the scattering of solar radiation by clouds, absorption of solar radiation by water vapour, ozone and gases and solar radiation depletion by aerosols. The digital data of the MTSAT-1R satellite were used as the main input of the algorithm. For the validation, the values of AOD derived from this algorithm were compared with those obtained from four sites of Aerosol Robotic Network (AERONET) in Thailand, and a reasonable agreement was found. DOI: http://dx.doi.org/10.3126/jie.v8i3.5929 JIE 2011; 8(3): 32-41


2009 ◽  
Vol 86 (9) ◽  
pp. 1450-1457 ◽  
Author(s):  
S. Janjai ◽  
P. Pankaew ◽  
J. Laksanaboonsong

Solar Energy ◽  
2004 ◽  
Author(s):  
Ramiro L. Rivera ◽  
Karim Altaii

Solar radiation was measured and recorded on a 5-minute, hourly and daily basis at a number of sites on the Caribbean island of Puerto Rico (located from 18° to 18° 30’N latitude and from 65° 30’ to 67° 15’W longitude) over a 24 calendar month time frame. The global solar radiation was measured at four sites (namely: Aguadilla, Ponce, Gurabo, and San Juan). The global solar radiation data was measured by an Eppley Precision Spectral Pyranometer (model PSP) mounted on a horizontal surface. This pyranometer is sensitive to solar radiation in the range of 0.285 ≤ λ ≤ 2.8 μm wavelengths. Statistical analysis such as the daily average, monthly average hourly, monthly average daily, and annual average daily global radiation are presented in this paper. Despite its small size, a 13 percent variation in the global solar radiation has been observed within the island. Reasonable solar radiation values, for solar energy conversion system installation, seem to exist at and possibly around Aguadilla.


Author(s):  
Abdulhamid Yusuf ◽  
Hakeem Bolarinwa ◽  
Lukman Animasahun ◽  
Yinusa Babatunde

An analysis of measured global solar radiation (GR) in Osogbo (7.77oN, 4.57oE, 288m) is presented in the form of hourly average, monthly average and percentage frequency distribution. The experimental data corresponds to a year data of 2017. The results reveal that the monthly average values of daily total radiation exhibit seasonal variation with maximum value in dry season month of March (16.59MJ/m2) and minimum value in wet season month of August (8.98 MJ/m2). The annual average GR value is 14.20 MJ/m2 while the annual cumulative GR is 5122 MJ/m2. The solar radiation climate of Osogbo has also been compared to those reported for a number of locations. The percentage frequency of days possessing irradiation rate greater than 15 MJ/m2 is 14 percent whereas that possessing less than 10 MJ/m2 is 61 percent. We conclude, based upon the above analysis that Osogbo is characterized by relatively low global solar radiation.


1993 ◽  
Vol 3 (6-7) ◽  
pp. 741-745 ◽  
Author(s):  
Mohd.Yusof Hj. Othman ◽  
Kamaruzzaman Sopian ◽  
Baharudin Yatim ◽  
Mohd.Noh Dalimin

2013 ◽  
Vol 770 ◽  
pp. 229-232
Author(s):  
A. Sansomboon ◽  
N. Luewarasirikul ◽  
A. Ittipongse ◽  
W. Phae-Ngam ◽  
S. Pattarapanitchai

Solar radiation is one of mains alternative energy, widely used in present day. Measure solar radiation accurately is an essential for planning in application of used. Universities are the places that have used significant of energy all year long. Therefore, long-term measured solar radiation data is important, for understand in both quantity and variation in time period, for application of the alternative energy in future. The main objective of this research is to investigate solar energy potentials of Suan Sunandha Rajabhat University, Bongkok, Thailand (Latitude 13.46°N, Longitude 100.31°E). A station for solar radiation was installed at Suan Sunandha Rajabhat University. The main equipment is composed of two parts: 1) a pyranometer from Kipp & Zonen Ltd., model CMP11, and 2) a digital data logger from Measurement Systems Ltd. model DX2000. The pyranometer is permanently installed on the top of a building. The data logger is keeping clean and safe inside the building. To analyze the values of the global solar radiations, the computer source code is written in Interactive Data Language version 6.1 (IDL6.1). The results show the variation of the average hourly global irradiance is about 800-900 W/m2 at 12:00 UTC. The maximum monthly average daily global radiation is 21.5 MJ/m2-day in April. The yearly average daily radiation at Suan Sunandha Rajabhat University is found to be 16.55 MJ/m2-day. The information from the monthly and yearly global radiation has relatively high solar energy potentials. Finally, the solar radiation database was also developed for use in solar energy applications in Suan Sunandha Rajabhat University and neighbor areas.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Huashan Li ◽  
Fei Cao ◽  
Xianlong Wang ◽  
Weibin Ma

Since air temperature records are readily available around the world, the models based on air temperature for estimating solar radiation have been widely accepted. In this paper, a new model based on Hargreaves and Samani (HS) method for estimating monthly average daily global solar radiation is proposed. With statistical error tests, the performance of the new model is validated by comparing with the HS model and its two modifications (Samani model and Chen model) against the measured data at 65 meteorological stations in China. Results show that the new model is more accurate and robust than the HS, Samani, and Chen models in all climatic regions, especially in the humid regions. Hence, the new model can be recommended for estimating solar radiation in areas where only air temperature data are available in China.


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