Correlation Between Global Solar Radiation, Ambient Temperature and Sunshine Hours for Makurdi, Nigeria
Abstract
The global solar radiation on any surface is influenced by the hours of sunshine, ambient air temperature and relative humidity of the location (Montero et al., 2009: Polo et al., 2009). Many models have been developed to estimate the global solar radiation using these factors. The Angstrong-Page equation used the hours of bright sunshine (Yohanna et al., 2011) while the Hargreaves model uses the difference between the maximum and minimum ambient temperature (Taiwo, 2010). Other models use the maximum ambient temperature (Sanusi and Aliyu, 2005). The Angstrong-Prescot-Page model uses the hours of bright sunshine and relative humidity (Aliyu and Sambo, 1991; Husaaini et al, 2005). Agbo et al (2006) used relative humidity models. The correctness of these models in estimating the global solar radiation depends largely on the correlation between the global solar radiation and these parameters. A low correlation usually indicates the poor predictability of the resulting model.