Contribution to the Relationship Between Solar Radiation and Sunshine Duration in the Tropics: A Case Study of Experimental Data at Ilorin, Nigeria

Authors : S O UDO

Pages : 229-236

View : 17 | Download : 13

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :From monthly average daily values of clearness index and relative sunshine spanning a period of two years, two equations insert ignore into journalissuearticles values(linear and quadratic); of the Angstrom-Prescott model have been developed for the estimation of global solar irradiation at Ilorin insert ignore into journalissuearticles values(Lat. 8°32`N, Long. 4°34`E);, a tropical location. Comparison of the regression coefficients of the linear type model showed that the values are quite consistent with those quoted in the literature for the Tropics. The predictive efficiencies of these two models are also compared with those which are believed to be applicable globally, and those developed for the Nigerian environment. Although some of the models seem fairly adequate for this location, their predictive efficiencies in terms of Mean bias error insert ignore into journalissuearticles values(MBE);, mean absolute bias error insert ignore into journalissuearticles values(MABE); and root mean square error insert ignore into journalissuearticles values(RMSE); are poorer than those models developed in this study. Everything, therefore, seem to point to the fact that the Angstrom-Prescott model, whether in a linear or quadratic form, is locality dependent.
Keywords : Turk J Phys, 26, 2002, 229 236 Turk J Phys, vol 26, iss 3