Validation of Near Real‐Time Retrieval of Plume Mass Eruption Rates: The Case of the 2021 Eruption of La Soufrière, St Vincent

Abstract Satellite observations have enabled an important advance in the near‐real‐time quantification of the dynamic parameters of the volcanic plume spreading in the atmosphere. However, the link between these observations and the estimation of eruption source parameters, such as the mass eruption rate (MER), remains a scientific obstacle to be overcome. The previously developed methods to estimate the MER are less efficient for weak eruptions and/or occurring under strong wind conditions, which are the most frequent. Here, we update a 1‐D volcanic column model for the estimation of the MER based on satellite measurements of wind‐impacted plumes. The new model allows predicting the plume geometry as seen from space, and thus linking the source MER to the geometry far from the source. We find that the predictions mostly depend on the wind speed and the MER. We test the model using measurements made on GOES‐16 images during the 2021 eruption of La Soufrière, St Vincent, and find a good agreement between our MER estimates and those found in the literature (with a mean MER of −0.23). We finally test our ability in estimating the MER in near real‐time using the HOTVOLC system and Meteosat‐SEVIRI images of 10 paroxysms from Mt Etna. The GIS‐based tool integrated to HOTVOLC allows easier measurements of the plume growth and will provide a robust tool for a rapid interpretation of satellite data in terms of source conditions, which are necessary inputs for tephra dispersion models, such as those used by the Volcanic Ash Advisory Centers.