Combining MODIS, Sentinel-5P, and CALIOP to monitor dust emissions from mining activities

Atmospheric aerosols are a key component of the Earth system, originating from both natural processes and human activities. Mining is a major industrial source of airborne particulate matter, particularly in open-pit operations where blasting, crushing, hauling, and waste management continuously generate dust. Mine waste facilities, such as tailings storage facilities (TSFs) and waste-rock dumps, are among the dominant anthropogenic sources of mineral dust emissions in many mining districts, due to their large exposed surface areas and limited vegetation cover. Mining aerosols typically consist of mineral particles such as silica and metal oxides, often enriched in toxic trace elements, making them relevant from both public health and environmental perspectives. While coarse particles (PM₁₀) tend to deposit near the source, fine particles (PM_2.5 and smaller) can remain suspended and be transported over tens of kilometres, contributing to regional air quality degradation and population exposure.

Monitoring strategies at mining sites primarily rely on in-situ instruments, which provide accurate point measurements but limited spatial context. These observations often do not capture the full extent of dust dispersion or identify preferential transport pathways toward populated areas, particularly in remote or topographically complex regions. Satellite-based aerosol observations offer a valuable complement by providing spatially continuous, long-term, and independent information on aerosol presence, intensity, and transport, yet their application to mining environments remains underexplored.

The MOSMIN project addresses this gap by developing a multi-sensor satellite-based framework to characterise mining-related aerosols across contrasting climatic and surface environments. Satellite products from MODIS MAIAC aerosol optical depth (AOD), Sentinel-5P aerosol index (AI), and CALIOP lidar profiles are combined with meteorological reanalysis to investigate dust emissions, transport, and vertical structure at four pilot sites: Roșia Poieni (Romania), Talabre (Chile), Trident (Zambia), and Aitik (Sweden). Sentinel-5P AI identifies absorbing aerosol hotspots, while MODIS AOD resolves local dust plumes over open pits and TSFs. CALIOP vertical profiles provide complementary information on plume height and vertical structure, improving the interpretation of satellite column measurements.

The combined satellite analysis reveals pronounced site-specific differences driven by meteorology and surface properties. The hyper-arid Talabre site exhibits persistent absorbing aerosol signals and extended plume dispersion, while the Trident mining complex shows strong seasonal contrasts, with enhanced aerosol loading during the dry season and additional contributions from regional biomass burning. At Roșia Poieni, dust emissions show a clear summer maximum linked to increased mechanical activity and boundary-layer mixing, with aerosol accumulation frequently occurring in surrounding valleys rather than directly above the open pit. At the high-latitude Aitik site, mining-related aerosol signals are primarily detectable during the snow-free summer period, when reduced surface brightness allows reliable satellite retrievals of dust transport from exposed mining surfaces.

Overall, the results demonstrate that satellite observations provide essential spatial, temporal, and vertical context for assessing mining-related aerosols, extending monitoring beyond the mine fence and supporting exposure assessment, environmental management, and mitigation planning. In addition, satellite-derived products offer a consistent and accessible basis for communicating dust impact to regulators and other stakeholders, complementing in-situ measurements.