Correlation Between Ultraviolet Radiation and Global Radiation in Riyadh, Saudi Arabia

Abstract

The global ultraviolet and global radiation were measured and recorded on an hourly basis in Riyadh, Saudi Arabia (lat. 24.6°N, long. 46.7°) during the period 1984–1989. Global radiation, G, was measured by an Eppley PSP pyranometer (0.285≤λ≤2.8 μm) and an Eppley TUVR radiometer (0.29≤λ≤0.385 μm) was used for the measurement of the ultraviolet radiation, UV. Both instruments were mounted on a horizontal surface. The results showed that the monthly average daily ultraviolet radiation was 197.6 Whm−2. The ratio of the monthly average daily ultraviolet radiation to the monthly average daily global radiation (Ku) varied between 0.031 to 0.037, with a mean value of 0.034. Comparison with results obtained in Kuwait, Dhahran, and Makkah showed that the data of Riyadh are in good agreement with those of Makkah and Dhahran; however, it underestimates Kuwait data. A regression correlation between Ku and KT (the ratio of the monthly average daily values of global radiation to extraterrestrial radiation) is developed. Another regression correlation between ultraviolet and global radiation on an hourly basis is also developed.

Long-Term Monitoring and Analysis of Hourly Solar UV Radiation in the 290-380 nm Range in the Middle Region of Saudi Arabia

“…This is an expected result, since a strong correlation exists between the hourly mean UV irradiance and hourly global radiation H. Such a correlation can be deduced from Table 1. Statistical analysis of previous data 16 shows a similar correlation. A similar trend is obtained for the monthly variation for both K t and K v , as can be seen from the figure.…”

“…The maximum difference between each month in groups 1 and 3 with its corresponding month in groups 2 and 4, respectively, is about 10%. It should be pointed out that a previous work 16 for Riyadh for almost the same period of time showed approximately 20% higher values of the maximum and minimum of hourly mean UV irradiance. This discrepancy must be attributed to the different techniques in data acquisition analysis and evaluation.…”

An improved estimation of daily clear-sky biologically EER from broadband global solar radiation

“…The study of the ratios of biological UV to G has received considerable attention in the past few years so that relationships of this type have been proposed by different investigators, with measurements from Saudi Arabia (Mujahid 1994), Spain (Martinez-Lozano et al 1994FoyoMoreno et al 1998;Foyo-Moreno et al 1999), Egypt (Trabea and Salem 2001), France (De La Casinière et al 2002), Switzerland (Lindfors and Vuilleumier 2005), and Cyprus (Jacovides et al 2006). Similar investigations have also been carried out at some specific cities such as Dharan (Elhadidy et al 1990), Postdam (Feister and Grasnick 1992), and Edmonton (Sadler 1992).…”

Distribution of Ultraviolet solar Radiation at Riyadh Region, Saudi Arabia

“…Accordingly the mathematical expressions from equation (1) to equation (7) will help to determine the total ultraviolet UV solar radiation theoretically. Then the results could be compared with field measurements to find out the accuracy of predicted values of UV radiation as well as the environmental effects at any location in Riyadh area as discussed by Mujahid (1994), Nijeorodov, Luhaga (1998) and Al-Dhafiri et al…”