Volcanic SO<sub>2</sub> fluxes derived from satellite data: a survey using OMI, GOME-2, IASI and MODIS

Abstract

Abstract. 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 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 ultraviolet-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 us to assess the consistency of the SO2 products from the different sensors used.

The 2011 eruption of Nabro volcano, Eritrea: perspectives on magmatic processes from melt inclusions

“…To the ENE of Dubbi, Kod Ali volcano sits offshore on a small island; its eruptive products contain abundant ultramafic nodules (Hutchison and Gass 1971). When Nabro erupted in 2011, the eruption was widely thought to be from Dubbi until satellite imagery became available (Theys et al 2013).…”

“…1), forming part of an alignment known as the Bidu Massif. The volcano was little heard of until 2011 when it was the site of a substantial explosive and effusive eruption-the first in recorded history-that precipitated a significant humanitarian crisis, disrupted aviation and yielded one of the largest sulphur inputs to the atmosphere since the 1991 eruption of Mount Pinatubo (Goitom et al 2015;Theys et al 2013). Here, we present the first detailed petrological and geochemical study of the eruptive products, focusing on the tephra deposits.…”

Inverting for volcanic SO<sub>2</sub> flux at high temporal resolution using spaceborne plume imagery and chemistry-transport modelling: the 2010 Eyjafjallajökull eruption case study

“…Compared to previous studies (Theys et al, 2013), the strength of our inverse modelling approach is that no a priori knowledge of the volcanic SO 2 flux is required. While this eruption was fairly modest compared to historical Icelandic eruptions, such as the 1783-1784 Laki eruption (Thordarson and Self, 2003), it was able to repeatedly disrupt air traffic over Europe, generating huge economic costs and losses (Harris et al, 2012).…”

Ozone climatology and its variability from ground based and satellite observations over Irene, South Africa (25.5º S; 28.1º E) – Part 2: Total column ozone variations

“…It is a visible spectrometer used for global observation of atmospheric ozone, trace gases as well as UVR. It covers the 240-790 nm wavelength intervals and has a spectral resolution of 0.2-0.5 nm (Theys et al, 2013). An improved GOME-1 satellite, GOME-2 was launched in October 2006 onboard the Meteorological Operational Satellite-A (MetOp-A).…”