UV Index for Public Health Awareness Based on OMI/NASA Satellite Data at King Abdulaziz University, Saudi Arabia

Exposure to ultraviolet radiation (UV) is essential for good health and formation of vitamin D while overexposure poses a risk to public health. Therefore, it is important to provide information to the public about the level of solar UV radiation. The ultraviolet index (UVI) is used to help avoid the negative effects of ultraviolet (UV) radiation on humans and to optimize individual exposure. There is limited ground measurement of solar UV radiation, but satellite Ozone Monitoring Instrument (OMIs) satellite products with a spatial resolution of 1 ° × 1 ° can be used to create UV index climatology at local noon time. In this study, we utilize OMI satellite products collected over the campus of King Abdulaziz University (KAU) (21.5° North and 39.1° East), Jeddah, Saudi Arabia, to estimate changes in exposure to UV over a period of 15 years (2004-2020). The results indicate a significantly increasing trend in UV index over this period. Between 2004 and 2020, daily “extreme” UV ( UVI > 11 , as defined by the World Health Organization (WHO)) occurred on 46.60% of days. The frequency of low UVI ( UVI < 2 ) was only about 0.06%. These results imply dangerous exposure levels to solar UV radiation on the KAU campus and call for safety measures to increase awareness and decrease direct exposure; for example, by implementing the United States Environmental Protection Agency (EPA) general guidelines.

Variability of Solar UV Radiation and Its Relationship to Pollutants in Baghdad City

The atmospheric constituents generated by the activities of an urban area may affect UV radiation reaching the ground. In this study, two areas were chosen in Baghdad city (Zafaraniyah and Abu Ghraib). Parameters of the pollutants data (Total column NO2 and Total column CO) and UV radiation for specific bands were collected and analyzed for the period of three years (2017-2019) were taken hourly from the European Center for Medium-Range Weather Forecasts (ECMWF) for each parameter through the years. The results show that the concentrations of pollutants in Zafaraniyah higher than Abu Ghraib throughout the year, Where total column NO2 reaching to about 9.6 * 10-5 kg m-2 in 2019 for Zafaraniyah and 8.48 * 10-5 kg m-2 for Abu Ghraib. While total column CO reaching to about 45 * 10-4 kg m-2 in 2019 for Zafaraniyah and 43 * 10-4 kg m-2 for Abu Ghraib in the same year. While the values of UV radiation in Abu Ghraib higher value 487.3W/m2 than 443.7 W/m2 Zafaraniyah throughout the year.

Dependence of UVB-UVA Solar Radiation in the 280–400 nm Range on Changes in the Total Magnetic Field of the Sun

The study presents the results of the correlation analysis for the average seasonal values of intensity of solar UV radiation (297–330 nm), as well as for the energy of the lines of solar spectral irradiance with total solar irradiance and total magnetic field of the Sun for the period of 2008–2018 (the 24th cycle of solar activity). The analysis is carried out using the spectral observations of solar UV radiation at Novolazarevskaya station (Antarctica), the SORCE spacecraft and WSO (Wilcox Solar Observatory) data. The dependence of the UVB-UVA radiation of 280–315 nm (UV-B) and 315–400 nm (UV-A) on changes in the total magnetic field of the Sun is revealed.