Calculation of the global, diffused, and direct solar radiation in Bahrain

The model introduced by Gopinathan to estimate the global radiation on a horizontal surface was evaluated. The model has been modified in order to allow a better estimation of the global radiation in Bahrain. The annual monthly mean of the global radiation was found to be $\text{19.49±5.11}\text{MJ m}{}^{\mathrm{-2}}\text{d}{}^{\mathrm{-1}}$. However, the calculated annual monthly mean of the diffused and direct radiation using other theoretical models were found equal to $\text{5.52±1.13}\text{and}\text{13.95±4.23}\text{MJ m}{}^{\mathrm{-2}}\text{d}{}^{\mathrm{-1}}$ respectively.