Analysis of SO₂ Emissions and Dispersion from the Fire at the Oil Storage and Refining Plant in Tehran, Iran, in March 2026

On the evening of 7 March 2026, oil depots and refining facilities in Tehran, Iran, were damaged, triggering explosions and fires that released large amounts of SO₂ into the atmosphere. In this study, satellite remote sensing was performed using ultraviolet and infrared hyperspectral data to investigate the SO₂ pollution event and its subsequent evolution by the Chinese FengYun-3 (FY-3) series and European Sentinel-5P. The SO₂ column concentrations retrieved from the Ozone Monitoring Suite-Nadir instrument on FY-3F were further compared with TROPOMI ultraviolet observations on Sentinel-5P, showing generally consistent spatial patterns and variation trends, with a bias of 0.4 DU. By combining multi-satellite observations, the spatiotemporal evolution of the SO₂ plume was recorded. The major emission event lasted approximately 1–2 days. On 8 March, SO₂ column concentrations over Tehran and the surrounding areas increased markedly, with regional mean values rising from about 0.8 DU to 2.0 DU. The affected area reached approximately 3.0 × 10⁵ km², with peak values of up to 10.8 DU, and the total SO₂ emissions were estimated to be about 2.98 × 10⁴ tons. Rainfall over the Tehran region likely enhanced wet deposition of atmospheric SO₂, while prevailing northeasterly winds contributed to the transport and subsequent dissipation of the pollution plume by 9 March. These results demonstrate the capability of FY-3 satellite observations for rapid assessment of sudden SO₂ pollution events and highlight their value in environmental emergency monitoring.