Transcontinental transport of a massive SO₂ plume from the Tehran refinery explosion in March 2026 observed from space

Abstract. Conflict-induced explosions can inject pollutants into the middle-to-upper troposphere, producing long-range transport with environmental impacts beyond the local scale. In March 2026, airstrikes on Tehran's refinery complex triggered massive explosions and fires, releasing sulfur dioxide (SO₂) and carbonaceous aerosols. This study utilizes the data from a hyperspectral infrared satellite constellation (CrIS, IASI, and HIRAS) to track the explosion-related SO₂ plume with high frequency. The plume was first detected by CrIS at 22:01 UTC on 7 March at approximately 8.2 km altitude. Retrievals yield a peak SO₂ mass of approximately 3 kt, equivalent to the emissions of a minor volcanic eruption. Satellite observations capture the plume's transcontinental transport over roughly four days, demonstrating good agreement with HYSPLIT forward trajectories simulations. Comparison with CAMS SO₂ forecasts reveal that the model reproduces the transport of regional anthropogenic SO₂ but fails to capture the explosion plume. This study highlights the importance of satellite observations in monitoring emissions from conflict-induced extreme events and accurately assessing their long-range environmental impacts. The Tehran event also provides new insights into the potential global atmospheric impacts from a wider conflict.