Spatial analysis of particulate matter (PM10) using MODIS aerosol optical thickness observations and GIS over East Malaysia

Even though there are expert monitoring and assessment stations in large cities, air quality monitoring and measurement have a high cost and face significant issues. Data on air pollution can be acquired from remote sensing satellites for large areas and at a reasonable expense to compensate for monitoring stations on the ground. This research presented a method for retrieving PM₁₀ from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Aerosol Optical Thickness (AOT) records. The study depends on a previously established equation to retrieve PM₁₀ over Malaysia in September 2014. In Contrast Reduction Technique, we used Aerosol Robotic Network AERONET AOT to define the reference. The conversion factors, representing the relationship between AOT and PM₁₀ satellite columns, were determined using a mathematical approach. The size and type of aerosol, relative humidity, and boundary layer height vary globally and seasonally, thus the AOT–PM₁₀ relationship fluctuates spatially and temporally. The conversion factor was then applied to the MODIS image to predict the surface level of PM₁₀ concentrations in micrograms via cubic meter (μg/m³). Moreover, the achieved correlation coefficient R² of calculated PM₁₀ based on ground truth data was equal to 0.92. Based on the results obtained from the thematic maps, PM₁₀ levels are significantly higher in specific cities such as Kuala Lumpur and Johor. Where PM₁₀ ranged from (26.5 to 72) µg/m³, while AOT values were between (0.12 and 0.83). It raises concerns about the environmental health threats and their relationship to air quality in these regions as a research topic.