ASSESSMENT OF SPATIOTEMPORAL DISTRIBUTION OF UV AEROSOLS IN PORT HARCOURT AND CALABAR FROM 2020-2022 USING SENTINEL-5P

ABSTRACT

Air pollution is a rising global issue and could lead to global warming and climate change and it is as a result of increasing industrial activities, fossil fuel combustion and vehicular emissions. This study assessed the distribution of UV aerosols in Port-Harcourt and Calabar cities of three years with the use of Sentinel-5p. UV aerosols contribute to air quality of the environment; they usually serve as cloud condensation nuclei and when in excess in the atmosphere it could lead to formation of acid rain and secondary photodissociation reaction. The presence of absorbing aerosols in the atmosphere was detected using the ultraviolet (UV) Absorbing Aerosol Index (AAI). This study was done to analyze the values of Ultraviolet Absorbing aerosol index and classify places that have low, moderate, and high levels of UV aerosols in their environment. Raster data was extracted from Google Earth Engine with a script of sentinel-5p made to derive absorbing aerosols index. The raster data was further processed in the ArcMap environment which is one of the Geographic Information System software. The use of remote sensing satellite in air monitoring is beneficial as it helps provide long term trends of pollutant levels and can cover a wide range of area. The mean values of UV aerosols in the year 2020 are -0.03030969, -1.05057148, -1.07843733 as are in the quarters for Port-Harcourt, and compared to the mean values for the year 2022 in quarters are 0.693186744, -0.31411328, -0.20528763, the difference in mean is as a result of lockdown in 2020 which was accompanied with low vehicular emissions and suspension of industrial activities. Same situation goes for the UV aerosol levels in Calabar. The use of Geographic Information System techniques and remote sensing satellite will help greatly in analyzing and maintaining ambient air quality.