Effect of Stratospheric Ozone in UVB Solar Radiation Reaching the Earth’s Surface at Qena, Egypt

This study describes the relationship between UVB and total ozone column (TOC) at a subtropical location through the period from 2001 to 2005. To analyze the relationship between TOC and UVB, the dimensionless parameter UVB transmission (KtUVB) and slant total ozone column (Z) were estimated. The results show an opposite seasonal behavior for KtUVB and Z in all sky conditions at Qena, Egypt (26.200N, 32.750E, 96 m above sea level). In order to quantify the UV transmission variations produced by slant path ozone changes (Z), a linear regression between these two variables for cloud–free cases were employed. The correlation (r2) of this relationship was equal to 0.7 for the daily values. In addition, this value (r2) was increased for the monthly average (0.8). This study led to the values of UVB Radiation Amplification Factor (RAF) for the daily and monthly mean values in cloudless sky conditions that were equal to 1.0014 and 1.05, respectively.