Simulation of the eruption of Piton de la Fournaise in 2007 (c) LACy

The facts & the project

Volcanos are regarded as one of the biggest sources of natural pollution and we need a better understanding of their impacts on populations, ecosystems and on the climate. The problem in representing the lifecycle of volcanic plumes arises from the huge number of different processes involved and their multi-scale and transdisciplinary characteristics.

An innovative modelling tool has been developed as a result of a number of programmes and collaborations between laboratories, coupling together two models: a surface model (FOREFIRE) making it possible to reproduce the evolution of the lava and the associated thermodynamic and chemical flows during its propagation (burning vegetation, entry of the lava into the sea); an atmospheric model (MesoNH) including a volcanic convection module and a three-phase reactional model (gas, aerosol, microphysics) for tracking the transport and chemical transformation of the sulphur and volcanic halogens and the formation of acid precipitation.

The results

By simulating the 3 April 2007 eruption of Piton de la Fournaise on Reunion Island, the team of Pierre Tulet from the LACy (Laboratoire de l’Atmosphère et des Cyclones) reproduced the sulphur pollution levels observed at the surface of the lava and highlighted the extreme sensitivity of the sulphur distribution to meteorological conditions, the relief and the properties of the eruption.

This extremely high definition simulations (100 and 500 metres, 2 kilometres) would not have been achievable without the numeric capacities of Jade at Cines (440,000 hours).