Quantification of Volcanic SO2 Flux from Satellite Imagery and Volcanic Emission Impacts on Aviation

Abstract

Volcanic eruptions pose a significant hazard to mankind. In particular, the gases and ash emitted can be a severe threat both locally and globally. This warrants the use of monitoring instruments to fully understand gas plume dispersion and emission fluxes which in turn help in understanding volcanic activity. One such instrument is the Tropospheric Monitoring Instrument (TROPOMI) on board the Sentinel 5-Precursor satellite which can measure various atmospheric gases including sulfur dioxide (SO2). TROPOMI can be used alongside a back trajectory analysis toolkit known as PlumeTraj to calculate emission flux and determine plume altitude. However, few studies have used TROPOMI to measure low- lying (1.5 – 3 km above sea level) high SO2 emitting eruptions. To investigate the efficacy of TROPOMI and PlumeTraj on these types of SO2 emissions, I used the Kīlauea 2018 eruption which was very well monitored by ground-based instruments, making it a perfect case study for data comparison. Volcanic SO2 can be detrimental to human health, causing respiratory complications, but it can also cause corrosion (known as sulfidation) of jet engine parts once combined with sodium or calcium in the atmosphere. The signs of sulfidation usually take months to years to become visible. But what is the amount of SO2 an aircraft may be exposed to? To answer this, I analysed flights from an aircraft which operated close to the Tajogaite 2021 eruption. The results show that the monitored aircraft was exposed to SO2 in short bursts, which may nevertheless be enough to damage the engines. Additionally, volcanic ash damages engine parts by depositing on engine blades and reducing engine efficiency. Volcanic Ash Advisory Centres (VAAC) produce ash location reports that are ultimately relayed to airlines via third parties. As the reports are advisory in nature, airlines are not legally obligated to require their aircraft to avoid ash. However, to what extent do aircraft avoid ash locations as published in Volcanic Ash Advisory reports? To determine this, I analyse seven different eruptions and nearby flight paths. The vast majority of flights avoid the ash locations as shown in the reports, which suggests the widespread utilisation of such reports.

Date of Award	6 Jan 2025
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Catherine Hayer (Supervisor) & Mike Burton (Supervisor)