# Geographical Distribution of Global Radiation and Sunshine Duration over the Island of Cyprus
## 3 Results and Discussion
### Daily Values
#### 3.1.3 Daily Clearness Index and Relative Sunshine Duration  
The clearness index (\(K_{T}\)) for a particular time interval is defined as the ratio of the global radiation to the extraterrestrial radiation. It is an objective measure of the influence of cloud cover on the solar radiation flux. In this analysis, clearness index is classified in four groups, as it was earlier stated. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c} \hline \hline \multicolumn{10}{c}{**(b)**} \\ \hline
**Athalassa** & \multicolumn{10}{c}{**Descriptive Statistics and Percentiles of Daily Global Irradiation (MJ/m\({}^{2}\))**} \\ \hline
**Month** & **N** & **Mean** & **StDev** & **Min** & **10\%** & **20\%** & **30\%** & **40\%** & **50\%** & **60\%** & **70\%** & **80\%** & **90\%** & **Max** \\ \hline
**1** & 31 & 9.5 & 2.7 & 3.2 & 5.6 & 7.2 & 7.8 & 8.5 & 9.1 & 10.2 & 11.3 & 12.6 & 12.8 & 14.0 \\
**2** & 28 & 14.3 & 3.5 & 3.9 & 9.8 & 11.6 & 12.8 & 14.2 & 14.7 & 15.8 & 16.1 & 17.6 & 18.1 & 18.4 \\
**3** & 31 & 17.8 & 4.2 & 7.6 & 11.5 & 14.5 & 16.7 & 17.2 & 18.3 & 19.2 & 20.0 & 21.8 & 22.7 & 23.8 \\
**4** & 30 & 22.6 & 5.0 & 12.2 & 13.7 & 15.4 & 22.0 & 23.2 & 23.7 & 24.3 & 26.7 & 26.9 & 27.4 & 27.9 \\
**5** & 31 & 27.7 & 1.7 & 22.6 & 25.0 & 26.3 & 26.6 & 27.6 & 28.0 & 28.7 & 28.9 & 29.1 & 29.3 & 29.8 \\
**6** & 30 & 28.3 & 2.7 & 21.1 & 22.6 & 27.2 & 28.4 & 29.1 & 29.2 & 29.4 & 29.8 & 29.9 & 30.5 & 30.9 \\
**7** & 31 & 28.1 & 0.8 & 26.3 & 27.2 & 27.4 & 27.7 & 27.8 & 28.1 & 28.3 & 28.5 & 28.7 & 29.0 & 30.4 \\
**8** & 31 & 25.7 & 1.5 & 21.9 & 23.5 & 24.1 & 25.3 & 25.6 & 25.8 & 26.3 & 26.7 & 26.8 & 27.3 & 27.9 \\
**9** & 30 & 21.0 & 1.4 & 17.4 & 19.0 & 19.7 & 20.2 & 20.5 & 21.1 & 21.4 & 22.1 & 22.4 & 22.6 & 23.0 \\
**10** & 31 & 15.9 & 2.2 & 11.8 & 13.2 & 13.8 & 14.3 & 15.0 & 15.4 & 17.0 & 17.3 & 17.4 & 19.0 & 19.6 \\
**11** & 30 & 9.6 & 2.8 & 2.9 & 6.1 & 7.5 & 7.8 & 8.4 & 10.2 & 11.1 & 11.5 & 12.0 & 12.6 & 13.4 \\
**12** & 31 & 8.7 & 2.5 & 1.9 & 4.1 & 7.6 & 8.3 & 8.9 & 9.3 & 9.8 & 10.7 & 10.8 & 10.9 & 11.2 \\
**Year** & 365 & 19.1 & 7.8 & 1.9 & 8.0 & 11.1 & 13.5 & 16.8 & 19.7 & 22.6 & 25.8 & 27.6 & 28.7 & 30.9 \\ \hline \hline \multicolumn{10}{c}{**(c)**} \\ \hline
**Kambos** & \multicolumn{10}{c}{**Descriptive Statistics and Percentiles of Daily Global Irradiation (MJ/m\({}^{2}\))**} \\ \hline
**Month** & **N** & **Mean** & **StDev** & **Min** & **10\%** & **20\%** & **30\%** & **40\%** & **50\%** & **60\%** & **70\%** & **80\%** & **90\%** & **Max** \\ \hline
**1** & 55 & 9.1 & 3.5 & 2.0 & 4.7 & 5.4 & 6.7 & 7.5 & 8.8 & 10.6 & 11.3 & 12.2 & 13.9 & 16.5 \\
**2** & 56 & 12.3 & 4.5 & 3.1 & 5.7 & 8.4 & 9.7 & 11.4 & 12.3 & 13.3 & 15.5 & 16.9 & 18.2 & 20.8 \\
**3** & 62 & 17.3 & 6.1 & 2.3 & 6.8 & 11.5 & 14.9 & 17.0 & 19.7 & 20.1 & 21.5 & 22.3 & 23.7 & 25.9 \\
**4** & 77 & 22.1 & 6.0 & 6.4 & 13.3 & 16.4 & 18.6 & 21.8 & 23.4 & 25.8 & 27.0 & 27.3 & 28.0 & 29.6 \\
**5** & 92 & 27.4 & 4.3 & 9.1 & 21.4 & 25.7 & 27.3 & 28.2 & 28.8 & 29.2 & 29.7 & 30.0 & 30.9 & 31.9 \\
**6** & 90 & 27.7 & 3.4 & 14.5 & 22.1 & 25.3 & 27.6 & 28.3 & 28.8 & 29.2 & 29.7 & 30.2 & 30.7 & 31.2 \\
**7** & 92 & 28.8 & 1.7 & 19.4 & 27.5 & 28.2 & 28.4 & 28.6 & 28.9 & 29.0 & 29.6 & 29.9 & 30.4 & 31.5 \\
**8** & 93 & 25.9 & 2.2 & 17.2 & 23.2 & 24.4 & 25.4 & 25.8 & 26.1 & 26.6 & 27.0 & 27.4 & 28.4 & 30.0 \\
**9** & 77 & 21.9 & 3.1 & 11.5 & 19.0 & 20.0 & 21.8 & 22.4 & 22.8 & 23.2 & 23.5 & 24.0 & 24.6 & 26.5 \\
**10** & 84 & 16.1 & 4.1 & 3.8 & 10.5 & 12.7 & 14.3 & 15.6 & 16.5 & 17.7 & 19.0 & 20.1 & 21.1 & 22.9 \\
**11** & 56 & 12.1 & 3.4 & 3.5 & 7.4 & 8.8 & 10.1 & 11.0 & 12.3 & 13.6 & 14.5 & 15.3 & 16.5 & 17.0 \\
**12** & 61 & 8.7 & 2 The monthly averages of the clearness index for all the stations are illustrated in Figure 13a. Generally, the coastal and inland plain stations showed higher \(K_{T}\) values throughout the year. The annual average of \(K_{T}\) of the first group was 0.617 and the second group was 0.583.