An Optimal model to Estimate Solar Radiation Received by Earth in Bojnourd

Estimation of solar radiation is one of the most important parameters in different planning such as meteorological, agricultural, hydrological, architectural, energy  and etc. In this research, we are trying to find a suitable model for estimating the intensity of solar radiation received on the surface of the earth that can be used to determine the mean daily total solar radiation in the area where the total solar radiation data is not available. Most previous studies have used regression equations or angstrom models to estimate solar radiation. In this study ، an optimal model using sunshine parameter was used to estimate the amount of solar radiation received on the earth's surface. The optimal model obtained in this study is a combination of angstrom model and linear regression method. Information of the sunshine parameter and the monthly average amount of ground radiation have been obtained from 2005 to 2019 Bojnourd meteorological station data. The results of this study were compared with other models using bias mean error (MBE) and root mean square error (RMSE) indices. The results show that the current research model compared to other existing models has high accuracy and less error.