Evaluation of Three Practical Methods for Estimating Daily Solar Radiation in Dry Climates

ABSTRACT

Three practical methods for estimating daily solar radiation in dry climates with air temperature and precipitation data as input were evaluated. The three equations only partially explained second order statistics such as variance and different correlations, so the interdependence with primary weather variables such as the daily maximum and minimum temperatures was not fully captured. The equations, however, may be useful for calculations that require solar radiation as input, such as the daily reference evapotranspiration according to Priestley-Taylor equation using the FAO guidelines expert consultation.