Oslo joint seminar in atmospheric, ocean and climate science, Jun. 13
Title: Extratropical volcanic eruptions and climate
Speaker: Matthew Toohey, Geomar
Matthew Toohey, Geomar
Abstract: It is commonly thought that extratropical eruptions have a weaker climatic impact than tropical eruptions. This hypothesis rests on the idea that aerosol resulting from tropical eruptions spreads globally, and has a longer stratospheric lifetime due to a longer transport path from the tropics to removal across the mid- or high-latitude tropopause. In this talk, I will review our understanding of the radiative impacts of volcanic eruptions, and present recent work investigating the role of eruption latitude in the associated radiative forcing based on proxy records and model simulations. Both the climate proxies and model simulations suggest that the impact of extratropical eruptions on NH extratropical temperatures—in proportion to the amount of sulfur emitted by the eruption—can be stronger than that for tropical eruptions. The model results further elucidate how the radiative forcing produced by extratropical eruptions is strongly dependent on the eruption season and the height of the sulfur injection in the stratosphere. These results provide guidance for improved understanding of the climate forcing resulting from past volcanic eruptions, including the extratropical eruption of 536 CE which initiated the most extreme Northern Hemisphere (NH) cold period of the Common Era, as well as for predicting the impact of future volcanic eruptions.
What is the Joint Oslo Seminar (JOS):
Atmospheric and climate sciences have a stronghold in Oslo among the four institutions University of Oslo, the Meteorological Institute, CICERO and NILU. This joint seminar invites renowned international experts to contribute to an informal series of lectures, meant to create interaction with the Oslo atmospheric and climate science community on recent highlights and analysis in the field. All seminars will be held on Thursdays (Noon -1pm) and lunch (sandwiches) will be served on a “first-come-first-served”-basis.