Atmospheric Chemistry and Physics (May 2011)
Large scale modeling of the transport, chemical transformation and mass budget of the sulfur emitted during the April 2007 eruption of Piton de la Fournaise
Abstract
In April 2007, the Piton de la Fournaise volcano (Réunion island) entered into its biggest eruption recorded in the last century. Due to the absence of a sensors network in the vicinity of the volcano, an estimation of degassing during the paroxysmal phase of the event has not been performed. Nevertheless, the SO<sub>2</sub> plume and aerosols have been observed by the OMI and CALIOP space sensors, respectively. The mesoscale chemical model MesoNH-C simulates the observed bulk mass of SO<sub>2</sub> and the general shape of the SO<sub>2</sub> plume spreading over the Indian Ocean. Moreover, an analysis of the SO<sub>2</sub> plume budget estimates a total SO<sub>2</sub> release of 230 kt, among of which 60 kt have been transformed into H<sub>2</sub>SO<sub>4</sub>. 27 kt of SO<sub>2</sub> and 21 kt of H<sub>2</sub>SO<sub>4</sub> have been deposited at the surface by dry deposition. With this top down approach, the temporal evolution of the SO<sub>2</sub> emission has been estimated during the most active period of the eruption. The peak of degassing was estimated at 1800 kg s<sup>−1</sup> in the morning of 6~April. The temporal evolution of SO<sub>2</sub> emission presented here can also be used for local studies.