Hassan Ghasemi Mobtaker - Department of Biosystems Engineering, University of Tabriz, Tabriz, Iran
Yahya Ajabshirchi - Department of Biosystems Engineering, University of Tabriz, Tabriz, Iran
Seyed Faramarz Ranjbar - Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran
Mansour Matloobi - Department of Horticultural Science, Faculty of Agriculture,, University of Tabriz, Tabriz, Iran
Morteza Taki - Department of Agricultural Machinery and Mechanization, Ramin Agriculture and Natural Resources University of Khuzestan, Mollasani, Ahvaz, Iran

Precise knowledge ofthe amount of global solar radiation plays an important role in designing solar energy systems. In this study, by using ۲۲-year meteorologicaldata, ۱۹ empirical models were tested for prediction of the monthly mean daily global solar radiation in Tabriz. In addition, various Artificial Neural Network (ANN) models were designed for comparison with empirical models. For this purpose, the meteorological data recorded by Iran Meteorological Organization (۱۹۹۲–۲۰۱۳) was used. These data include: monthly mean daily sunshine duration, monthly mean ambient temperature, monthly mean maximum and minimum ambient temperature and monthly mean relative humidity.Theresults showed that the yearly average solar radiation in the region was ۱۶.۳۷ MJ m .Among the empirical models, the best result was acquired for model (۱۹) with correlation coefficient (r) of ۰.۹۶۶۳. Results also showed that the ANN model trained with total meteorological data in input layer (ANN۵) produces better results in comparison to others. Root Mean Square Error (RMSE) and r for this model were۱.۰۸۰۰ MJ m-۲ and ۰.۹۷۱۴, respectively. Comparison betweenthe model ۱۹ and ANN۵, demonstrated that modeling the monthly mean daily global solar radiationthrough the use of the ANNtechnique, yields better estimates. Mean Percentage Errors (MPE) for these models were ۷.۴۷۵۴% and ۱.۰۰۶۰%, respectively. -۲ day-۱

Solar Energy, Meteorological Data Sunshine Hours, prediction, Artificial Neural Networks