Matthew Toohey, GEOMAR, Kiel – Niels Bohr Institute - University of Copenhagen

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Matthew Toohey, GEOMAR, Kiel

Climate impacts of volcanic eruptions: towards a synthesis of ice core data and climate models

Ice cores provide the best records of the history of volcanism on Earth. Using ice core sulfate signals to estimate the stratospheric aerosol loading and associated climate impact resulting from an eruption requires an understanding of the relationships between these quantities. Current generation climate models – especially those which explicitly simulate stratospheric sulfate aerosols – can be used to investigate such relationships. For example, simulations of the Young Toba Tuff eruption (~74 ka BP) and the unknown eruption of ~1258 AD have shed light on the role aerosol size plays in reducing the relative impact of very large volcanic eruptions. Simulations also show how volcanically-induced changes in atmospheric circulation may influence sulfate deposition, and suggest that sulfate deposition to Antarctica is attenuated for the largest eruptions in Earth’s history. With present work producing ice core records of volcanic sulfate deposition of unprecedented quality, climate model results should prove useful in translating ice core data into better estimates of stratospheric sulfur burdens and the associated climate impacts of past eruptions.