Abstract
•A quantitative understanding of the spatial distribution of Erythemal UV.•A quantitative understanding of the temporal variation of Erythemal UV.•The study was based on 25year of TOMS satellite-based measurements.•The results revealed a decreasing trend in the Erythemal UV records.•The results revealed a significant decrease in the total ozone content.
To characterize and reduce the harmful effects of Erythemal ultraviolet radiation (EUV), it is vital to recognize the spatial distribution and temporal variation of EUV radiation under various meteorological conditions. In light of these requirements, the problem we address here is to understand the results of a study performed to assess the influence of stratospheric ozone and aerosol loading on the receipt of EUV at six sites located in Saudi Arabia. The selected sites were chosen to represent the climatic zones of the north, middle, and south of Saudi Arabia. Intensive satellite-based measurements of the atmosphere over the period 1979–2005 obtained from the Total Ozone Mapping Spectrometer (TOMS) website (ftp://toms.gsfc.nasa.gov) were used, with a four year gap from 1993 to 1996. The results hint that, in spite of the significant decrease in stratospheric ozone, there is a clear decreasing trend in the EUV data series due to the increase in the aerosol loading during summer months. For the other months the correlation is not clear and in all cases there was no decrease in the EUV radiation trend outside summer months, with few exceptions.