**5. Conclusion**

The daily and monthly variation patterns of the simulated shortwave reflection co-efficient, Hr/Ho, known as albedo, a surface phenomenon, were compared with the corresponding cloudiness index, Hd/H, an atmosphere phenomenon. They were both found to be mirror images of one another. While the shortwave diffuse radiation is toward the Earth's surface, its mirror image, the shortwave reflection radiation is back toward space.

The shortwave solar radiation reflection co-efficient was used to define the Earth's surface albedo which was found to vary daily and monthly in accordance with changes in the atmospheric conditions causing the variations.

The surface albedo according to the analysis, therefore, at Ilorin in year 2000 was found to range between 0.4 and 0.6. These values seem high when compared with the average value of 0.3 obtained for the Earth's surface albedo, but would be considered consistent with the acceptable ones since the values fall within the many possible values averaged statistically to obtain the quoted value for the Earth. The values of albedo can vary from 0 for no reflection to 1 for complete reflection of light striking the surface. For a spot like Ilorin on the surface of the Earth to have values of albedo between 0.4 and 0.6, is not unexpected. Ilorin, in Nigeria, is in the tropical region which is cloudy with different types of clouds most of the time in the year. The atmospheric factors which influence radiation reflection and scattering in the Earth-Atmosphere system most, are clouds and particles, clouds being chief. The Earth and its atmosphere, in this regard, were found most reflective of radiation in August and least reflective in November at Ilorin in year 2000.
