Determination of the Availability and Variation of Surface Downwelling Shortwave Radiation in Saudi Arabia Using EUMETSAT Satellite Imagery

Solar energy is expected to be a viable alternative sustainable energy source in the near future due to diminishing fossil fuel resources and escalating changes in the climate. Surface Downwelling Shortwave (SDS) radiation is an important component for the characterization of energy deposition of the earth’s surface. The monthly means of SDS radiation for Saudi Arabia were extracted from EUMETSAT (SARAH-2.1 climate data record) between 1983 and 2022. The country experienced the lowest level (188 ± 40 W m-2) of SDS radiation in the winter season with a range of 67-271 W m-2. The summer season in Saudi Arabia has the highest level of radiation with a mean value of 304± 27 W m-2, which is 1.62 times the mean of the winter season. The region experienced the highest (10.6 W m-2/10y) and lowest (-10.80 W m-2/10y) levels of a statistically significant upward and downward trend in SDS radiation during the spring and summer seasons respectively in the first decade of the 21st century (2001-2010). During the spring season, there was an upward trend in the availability of SDS radiation across the region, with a magnitude of 3.8 W m-2/10y with a 99% confidence level. In contrast, there was a downward trend in SDS radiation in the summer with a magnitude of 1.0 W m-2/10y with a 90% confidence level followed by the autumn season when the trend was lowest (-0.45 W m-2/10y) and statistically non-significant.