Large volcanic eruptions significantly affect the Earth's climate. They inject large quantities of sulfur dioxide (SO2) that form aerosols, which scatter solar radiation. The impact of a volcanic eruption is dependent on whether the eruption reaches the stratosphere, where aerosols have a longer lifetime. Sulfur isotope signatures can provide a new method for identifying stratospheric eruptions in the past. Large anomalies in isotopic signatures of aerosol deposited from volcanic eruptions were observed in ice-core deposits. These signatures were linked to SO2 photo-chemistry that can only occur in the stratosphere.
The successful candidate will simulate the photo-chemical processes that lead to the formation of these isotopic anomalies in stratospheric aerosol from volcanic eruptions. He/She will then use a chemistry-transport model to trace the evolution of these anomalies during transport from the stratosphere to deposition locations at the poles, where the isotopic anomalies were detected. The project involves a close collaboration with the Max-Plank Institute in Mainz, that develops the EMAC model used in this project.