Tracking SO₂ plumes from the Tonga volcano eruption with multi-satellite observations

The Hunga Tonga-Hunga Ha'apai (HTHH) volcano eruption received worldwide attention due to its magnitude and potential effects on environment and climate. However, the operational sulfur dioxide (SO₂) products mis-estimated SO₂ emissions under volcanic conditions due to large uncertainties in the assumptions of SO₂ plume altitude. That might have occurred in previous volcanic eruptions and misled understanding of the evolution of sulfate aerosols in the atmosphere and their impact on global climate. Here, we simultaneously retrieved the volcanic SO₂ and its plume altitude from the Troposphere Monitoring Instrument (TROPOMI) and the Environment Monitoring Instrument-2 (EMI-2), exploring the SO₂ burden, distribution, and evolution from January 14 to 17. We captured multiple eruptions with the second eruption emitting far more SO₂ than the first. Total emissions exceeded 900 kt, significantly higher than those from operational products. Our inferred emission fluxes and injection heights offer valuable references for climate modeling and submarine volcano studies.