Volcanic SO₂ fluxes derived from satellite data: a survey using OMI, GOME-2, IASI and MODIS

Nicolas Theys (1) , Robin Campion (2) , Lieven Clarisse (2) , Hugues Brenot (1) , J. van Gent (1) , Bart Dils (1) , S. Corradini (3) , L. Merucci (3) , Pierre-François Coheur (2) , Michel van Roozendael (1) , Daniel Hurtmans (2) , Cathy Clerbaux (4, 2) , Steve Tait (5) , Fabrizio Ferrucci (5)

1 BIRA-IASB - Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique
2 Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique
3 Istituto Nazionale di Geofisica e Vulcanologia
4 TROPO - LATMOS
5 IPGP - Institut de Physique du Globe de Paris

Sulphur dioxide (SO₂) fluxes of active degassing volcanoes are routinely measured with ground-based equipment to characterize and monitor volcanic activity. SO₂ of unmonitored volcanoes or from explosive volcanic eruptions, can be measured with satellites. However, remote-sensing methods based on absorption spectroscopy generally provide integrated amounts of already dispersed plumes of SO₂ and satellite derived flux estimates are rarely reported. Here we review a number of different techniques to derive volcanic SO₂ fluxes using satellite measurements of dispersed and large-scale plumes of SO₂ and investigate the temporal evolution of the total emissions of SO₂ for three very different volcanic events in 2011: Puyehue-Cordón Caulle (Chile), Nyamulagira (DR Congo) and Nabro (Eritrea). High spectral resolution satellite instruments operating both in the UV-visible (OMI/Aura and GOME-2/MetOp-A) and thermal infrared (IASI/MetOp-A) spectral ranges, and multispectral satellite instruments operating in the thermal infrared (MODIS/Terra-Aqua) are used. We show that satellite data can provide fluxes with a sampling of a day or less (few hours in the best case). Generally the flux results from the different methods are consistent, and we discuss the advantages and weaknesses of each technique. Although the primary objective of this study is the calculation of SO₂ fluxes, it also enables to assess the consistency of the SO₂ products from the different sensors used.

Domaines: Volcanologie; Milieux et Changements globaux; Physique Atmosphérique et Océanique [physics.ao-ph]

Nicolas Theys, Robin Campion, Lieven Clarisse, Hugues Brenot, J. van Gent, et al.. Volcanic SO₂ fluxes derived from satellite data: a survey using OMI, GOME-2, IASI and MODIS. Atmospheric Chemistry and Physics, 2013, 13 (12), pp.5945-5968. ⟨10.5194/acp-13-5945-2013⟩. ⟨hal-00768974⟩