Global Monitoring of Volcanic SO2 Degassing Using Sentinel-5 Precursor Tropomi

We present here the TROPOMI SO
2
product, which is publicly available since April 2018. We describe the capabilities and limitations of the product for the monitoring of volcanic SO
2
degassing. With several examples, we illustrate the benefit of a small satellite pixel of 3.5 x 5.5 km
²
. Owing to its improved detection limit, the data can be used to generate time series of SO
2
mass over number of volcanoes, with a large range of SO
2
emissions. We use Nyiragongo as a show case and correlate the SO
2
mass data with lava lake level estimates and local measurements of the seismicity. This paper also presents on-going developments to further improve the performance of the product for weak SO
2
loadings using a new algorithm, COBRA.