EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Pattern of volcanic degassing at open-vent volcanoes using TROPOMI SO2 time-series from COBRA retrievals

Jordi Van Mieghem1, Hugues Brenot2, Benoît Smets1,3, and Nicolas Theys2
Jordi Van Mieghem et al.
  • 1Vrije Universiteit Brussel (VUB), Department of Geography, Belgium
  • 2Royal Belgian Institute for Space Aeronomy (BIRA-IASB)
  • 3Royal Museum for Central Africa (MRAC-KMMA)

Sensitive and accurate detection of SO2 from remote sensing is essential to monitor volcanic degassing. The main objective of this study is to understand the dynamics of SO2 gas emissions at open-vent volcanoes between major eruptive events, using Sentinel-5P TROPOMI-based SO2 measurements.

Time-series of SO2 mass are analysed at 10 open-vent volcanoes (Ambrym, Erebus, Erta Ale, Kilauea, Masaya, Nyamuragira, Nyiragongo, Stromboli, Villarica, Yasur) using a newly developed TROPOMI SO2 product generated by the Covariance Based Retrieval Algorithm (COBRA; Theys et al., 2021). Compared to the current operational SO2 TROPOMI product (which uses the Differential Optical Absorption Spectroscopy technique), the COBRA dataset has improved performances and reduce both the noise and bias on the data, allowing a more refined study of degassing from open-vent volcanoes.

Time-series have been obtained for SO2 emissions over a period from 2018 to early 2023. For the 10 selected persistently active volcanoes, the SO2 behaviours are analysed and compared, showing cyclic and sporadic variations, as well as peaks of emission when a flank or major eruption occur. Patterns in SO2 time-series during and between major eruptive events are discussed to assess the potential use (and limitations) of these measurements as a tool for early warning and volcanic crisis management.


Theys, N., Fioletov, V., Li, C., De Smedt, I., Lerot, C., McLinden, C., Krotkov, N., Griffin, D., Clarisse, L., Hedelt, P., Loyola, D., Wagner, T., Kumar, V., Innes, A., Ribas, R., Hendrick, F., Vlietinck, J., Brenot, H., Van Roozendael, M. (2021). A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources. Atmospheric Chemistry and Physics, 21(22), 16727-16744.

How to cite: Van Mieghem, J., Brenot, H., Smets, B., and Theys, N.: Pattern of volcanic degassing at open-vent volcanoes using TROPOMI SO2 time-series from COBRA retrievals, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14820,, 2023.