S-5P/TROPOMI-Derived NOx Emissions From Copper/Cobalt Mining and Other Industrial Activities in the Copperbelt (Democratic Republic of Congo and Zambia)

We have analyzed Sentinel-5 Precursor TROPOspheric Monitoring Instrument (TROPOMI) data over the Copperbelt mining region (Democratic Republic of Congo and Zambia). Despite high background values, annual 2019-2022 means of TROPOMI NO2 (nitrogen dioxide) show local enhancements consistent with six point sources (four copper/cobalt mines, two cities) where high-emission industrial activities take place. We have quantified annual NOx (nitrogen oxides) emissions from these point sources, identified temporal trends in emissions, and found strong correlations with production data from colocated mines and one oil refinery. The Copernicus Atmosphere Monitoring Service Global Anthropogenic (CAMS-GLOB-ANT) version 5 inventory underpredicts TROPOMI-derived emissions and lacks the temporal trends observed in TROPOMI and mine/refinery production. These results demonstrate the potential for satellite monitoring of mining and other industrial activities, often unreported or underestimated, which impact the air quality of local communities. This is particularly important for Africa, where mining is increasing aggressively.

Automated summary

We analyzed TROPOMI data over the Copperbelt mining region and identified six point sources of high emissions. We quantified the emissions and observed strong correlations with production data from mines and one refinery. The CAMS-GLOB-ANT inventory underestimated emissions and lacked temporal trends. These results demonstrate the potential of satellite monitoring for tracking mining and industrial activities.