| Abstract: | We propose a new model to estimate daily global radiation from daily temperature range measurements. This model combines that of Majumdar et al. (Sol Energy 13(4):383–394, 1972) to estimate clear sky radiation with a Gompertz function to estimate the relation between temperature range and cloud transmittance. Model parameters are estimated from historical weather data: maximum and minimum temperatures and, if available, relative humidity; no other calibration is required. The model was parametrized and validated using 788 weather stations in Mexico. When calibrated using historical humidity data, daily global radiation was estimated with a mean root mean square error of 3.06 MJ m?2 day?1. The model performed well in all situations, except for a few stations around the Gulf of Mexico and in mountain areas. When using estimated humidity, the root mean square error of prediction was only slightly degraded (3.07 MJ m?2 day?1). Possible theoretical basis and applicability of this model to other environments are discussed. |
