1LACy, CNRS, Université de la Réunion, Météo-France, UMR 8105, 15 avenue René Cassin, 97715 Saint-Denis, France
2CNRM/GAME, CNRS, Météo-France, URA 1357, 42, Avenue Gaspard Coriolis, 31057 Toulouse, France
3CREGUR, Université de La Réunion, 15 avenue René Cassin, 97715 Saint-Denis, France
4US140 ESPACE, Centre IRD de La Réunion, BP172, 97492 Saint-Denis, France
Abstract. During April 2007, the Piton de la Fournaise volcano, La Réunion island, entered in its bigger eruption registered at least one century. Due to the absence of rapid captor in the vicinity of the volcano, the estimation of the degassing during the paroxysmal phase of the event has not been estimated. A modeling study that uses the mesoscale chemical model MesoNH-C, the spatial observation from the OMI sensor and the CALIOP spacelidar, have simulated the global mass of SO2 observed and the general shape of the SO2 plume spreading over the Indian ocean. Moreover, an analysis of the budget of the SO2 plume have permitted to estimate the total SO2 release to 159 Kt, the transformation in H2SO4 at 46.9 Kt and the surface dry deposition to 22 Kt and 17.9 Kt of SO2 and H2SO4 respectively. Then, this top down approach has retrieved an estimation of the temporal evolution of the SO2 emission during the most active period of the eruption, where the peak of degassing is estimated to 2000 kg s−1 in the morning of the 6 April. This temporal evolution of SO2 emission, given here, can also be used for more local studies.