Fig. 2: The time series of the stratospheric SO2 (sulfur dioxide) burden.

The blue and red lines are two model cases with and without water injection. The dashed blue line is the SO2_H2O case excluding the SO2 below 0.2 DU (i.e., the approximate OMPS-NM (the Ozone Mapping and Profiling Suite Nadir-Mapper) SO2 detection limit). The circles and triangles are SO2 measurements by OMPS-NM and TROPOMI (the TROPOspheric Monitoring Instrument). The error bars imply an estimated uncertainty of 35% and 30%26 for OMPS-NM and TROPOMI SO2 mass estimates, respectively. The observational data are from https://so2.gsfc.nasa.gov/. The SO2only run has the SO2 injection; the SO2_H2O run has both the SO2 and H2O injections (detailed in Online methods).