Spatial and temporal dynamics of air quality on the Red Sea – Application of satellite observations and back trajectory analysis

Abstract

The Red Sea, lying between Asia and Africa, is a significant eco-region and the habitat of many marine species. It is an essential route for marine transportation, and it also provides many ecosystem services. Therefore, assessing the spatial and temporal distributions of air quality parameters over the Red Sea and assess temporal trends is important. This study investigated observations of multiple satellites to collect different meteorological and tropospheric columns of aerosols, trace gas including carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3), and meteorological data. The tropospheric columns of trace gases and aerosol index exhibit seasonal and regional characteristics over the Red Sea. The correlation coefficient for air pollutants (NO2, SO2, and O3) and meteorological parameters showed a positive medium and low correlation, whereas a negative correlation was found between O3, Aerosol Index (AI), and wind speed. The back trajectory transport of air mass component using Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model showed long-range trajectory pattern. AI, trace gases concentrations, and meteorological data were investigated through Principal Component Analysis (PCA) with varimax rotation to find a discerning relationship and co-variance between air pollutants and meteorological data. This showed a relationship between meteorological data and CO and O3. Although the satellite observations have some inherent limitations compared to in-situ measurements, this study provides an overall landscape of air pollution over the Red Sea, which will benefit policymakers and researchers.