Spatio-Temporal Analysis of Particulate Matter Based on Ground and Satellite Derived Observations: United Arab Emirates

Abstract

Particulate matter (PM) is a composition of air-borne particles and liquid droplets containing acids. PM is a major air pollutant that causes harm to both human health and the environment. The main categories of PM include coarse particles (PM10), and fine particles (PM2.5). Relying only on ground monitoring stations while assessing PM trends is challenging due to limited data availability. Therefore, satellite remote sensing for Aerosols optical depth (AOD) is essential for the long-term analysis of PM. This research investigates the variation of AOD across the United Arab Emirates (UAE) and to cross-verify results using PM ground monitoring stations data as there is a lack of studies in this region. Yearly satellite images for AOD obtained using Moderate Resolution Imaging Spectroradiometer (MODIS) will be used to demonstrate the change across the UAE for the past 16 years (2005–2020). Moreover, trend analysis of monthly PM 2.5 and PM 10 levels retrieved for the last three years (2018–2020) from several stations located in Abu Dhabi, Al-Ain, and Dubai are compared against satellite-derived AOD across the UAE to verify the outcome. The yearly investigation showed that AOD levels varied throughout the study period and were relatively highest in the coastal region within UAE, elevated AOD levels were detected during the year 2012 whereas the lowest was noticed in the year 2005. Dust storms and other anthropogenic activities may have contributed to the changes detected within UAE. Results show that seasonal analysis using ground-monitoring PM data and satellite-derived AOD are in agreement where the highest levels were detected during summer, followed by spring season, autumn, and finally Winter. Moreover, the correlation conducted to verify the satellite retrieved AOD was carried out by comparing the monthly average of PM from the year 2018 to 2020 obtained at Abu Dhabi, Al Ain, and Dubai city with the monthly average AOD at the same location for each of the 9 ground stations analyzed. It was found that Al Ain city PM levels showed a higher correlation with the AOD retrieved at the same location with an R2 value of 0.719, followed by Abu Dhabi whereas Dubai station data showed the lowest correlation.