Measuring volcanic sulphur dioxide degassing with the satellite-based Ozone Monitoring Instrument

This thesis considers the application of a satellite-based ultraviolet (UV) spectrometer, the Ozone Monitoring Instrument (OMI), to the study of volcanic sulphur dioxide (SO 2 ) emissions. The monitoring of volcanic SO 2 emissions is a central component of volcanol- ogy, since SO 2 is a key proxy for volcanic activity. Satellite remote sensing of volcanic emissions has previously focussed on the large gas releases which accompany major ex- plosive eruptions. OMI’s unprecedented sensitivity to atmospheric SO 2 provides a unique opportunity to focus instead on the continuous and persistent gas emissions typical of many volcanoes, which over time constitute the major proportion of global volcanic gas budgets and which have the potential to provide critical information in the build up to eruptions