The sulfur- and halogen-rich super eruption Los Chocoyos and its impacts on climate, environment, and circulation

Kirstin Krüger

Meteorology Oceanography Section, Department of Geosciences. University Oslo, Norway

Abstract:

The Los Chocoyos super eruption happened ~81 kyrs ago in Guatemala, and was one of the largest eruptions of the past 100,000 years. The eruption emitted enormous amounts of sulfur, chlorine and bromine with consequences for the global climate, environment and atmospheric circulation.

Using the Earth System Model CESM2(WACCM6) we simulate the impacts of this super eruption on the pre-industrial Earth System. Our model results show that the ozone layer nearly collapses, with large impacts on UV and the biosphere, and the surface climate cools globally with >6 K. Recovery to pre-eruption ozone levels and climate takes 15 and 30 years respectively. The quasi-biennial oscillation (QBO), an oscillation of the zonal winds in the tropical stratosphere with ~28 month periodicity, reveals a 10 year disruption before returning to QBO conditions with a slightly prolonged periodicity. Different model ensembles, volcanic forcing scenarios and comparison with other models are used to test the robustness of our results.