Abstract:

Measurements of metrological data of maximum, minimum ambient temperature, humidity and sunshine duration for a period of 23 years during the period of 1977-2000, at Tikrit (34. 35°N, 43.37°E), TuzKurmato (34.88°N, 44.64°E), and Kirkuk (35.30°N, 44. 21°E) were used to establish an Angstrom type correlation equations for direct global solar radiation. The diffuse radiation was estimated by using Klien and Page Models. This calculation appears to be sufficient to discriminate each station from the others due to it’s local characteristic of the sites. The overall results shown for TuzKurmato, the received radiation on the plane surface is higher than Tikrit and Kirkuk while the diffuse radiation reversely behaved as for Tiktit is the highest. The developed model can be used for estimating global solar radiation on horizontal surfaces. The monthly average total solar radiation was estimated. The value of correlation coefficient (r) and value of Root Mean Square Error (RMSE), Mean Bias Error (MBE) and Mean Percentage Error (MPE) were determined for each equation

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