Stratospheric Ozone Changes From Explosive Tropical Volcanoes: Modeling and Ice Core Constraints ...

• Main Authors: Ming, A, Winton, VHL, Keeble, J, Abraham, NL, Dalvi, MC, Griffiths, P, Caillon, N, Jones, AE, Mulvaney, R, Savarino, J, Frey, MM, Yang, X
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2020
• Subjects: volcanic eruption; ozone; isotopes in ice cores; Samalas; chemistry-climate modeling; Antarctica; Antarctic; Antarc*; ice core
• Online Access: https://dx.doi.org/10.17863/cam.52519; https://www.repository.cam.ac.uk/handle/1810/305439

AbstractMajor tropical volcanic eruptions have emitted large quantities of stratospheric sulfate and are potential sources of stratospheric chlorine although this is less well constrained by observations. This study combines model and ice core analysis to investigate past changes in total column ozone. Historic eruptions are good analogs for future eruptions as stratospheric chlorine levels have been decreasing since the year 2000. We perturb the preindustrial atmosphere of a chemistry‐climate model with high and low emissions of sulfate and chlorine. The sign of the resulting Antarctic ozone change is highly sensitive to the background stratospheric chlorine loading. In the first year, the response is dynamical, with ozone increases over Antarctica. In the high HCl (2 Tg emission) experiment, the injected chlorine is slowly transported to the polar regions with subsequent chemical ozone depletion. These model results are then compared to measurements of the stable nitrogen isotopic ratio, , from a low snow ...