The Toba supervolcano eruption caused severe tropical stratospheric ozone depletion

Osipov, Sergey ORCIDiD
Stenchikov, Georgiy ORCIDiD
Tsigaridis, Kostas ORCIDiD
LeGrande, Allegra N.
Bauer, Susanne E.
Fnais, Mohammed
Lelieveld, Jos ORCIDiD

DOI: https://doi.org/10.1038/s43247-021-00141-7
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11060
Osipov, Sergey; Stenchikov, Georgiy; Tsigaridis, Kostas; LeGrande, Allegra N.; Bauer, Susanne E.; Fnais, Mohammed; Lelieveld, Jos, 2021: The Toba supervolcano eruption caused severe tropical stratospheric ozone depletion. In: Communications Earth & Environment, 2, 1, DOI: https://doi.org/10.1038/s43247-021-00141-7. 
 
Osipov, Sergey; Max Planck Institute for Chemistry, Mainz, Germany
Stenchikov, Georgiy; King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
Tsigaridis, Kostas; NASA Goddard Institute for Space Studies, New York, USA
LeGrande, Allegra N.; NASA Goddard Institute for Space Studies, New York, USA
Bauer, Susanne E.; NASA Goddard Institute for Space Studies, New York, USA
Fnais, Mohammed; King Saud University, Riyadh, Saudi Arabia
Lelieveld, Jos; Max Planck Institute for Chemistry, Mainz, Germany

Abstract

Supervolcano eruptions have occurred throughout Earth’s history and have major environmental impacts. These impacts are mostly associated with the attenuation of visible sunlight by stratospheric sulfate aerosols, which causes cooling and deceleration of the water cycle. Supereruptions have been assumed to cause so-called volcanic winters that act as primary evolutionary factors through ecosystem disruption and famine, however, winter conditions alone may not be sufficient to cause such disruption. Here we use Earth system model simulations to show that stratospheric sulfur emissions from the Toba supereruption 74,000 years ago caused severe stratospheric ozone loss through a radiation attenuation mechanism that only moderately depends on the emission magnitude. The Toba plume strongly inhibited oxygen photolysis, suppressing ozone formation in the tropics, where exceptionally depleted ozone conditions persisted for over a year. This effect, when combined with volcanic winter in the extra-tropics, can account for the impacts of supereruptions on ecosystems and humanity.


Stratospheric sulfur emissions from the Toba supereruption about 74,000 years ago suppressed ozone formation which caused severe tropical ozone layer depletion and enhanced solar ultraviolet radiation stress, according to Earth system model simulations.