OceanRep
The potential impacts of a sulfur- and halogen-rich supereruption such as Los Chocoyos on the atmosphere and climate.
Brenna, Hans, Kutterolf, Steffen , Mills, Michael J. and Krüger, Kirstin (2020) The potential impacts of a sulfur- and halogen-rich supereruption such as Los Chocoyos on the atmosphere and climate. Atmospheric Chemistry and Physics, 20 (11). pp. 6521-6539. DOI 10.5194/acp-20-6521-2020.
Preview |
Text
acp-20-6521-2020.pdf - Published Version Available under License Creative Commons: Attribution 4.0. Download (9MB) | Preview |
Preview |
Text
acp-20-6521-2020-supplement.pdf - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (9MB) | Preview |
Abstract
The supereruption of Los Chocoyos (14.6°N, 91.2°W) in Guatemala ∼84kyr ago was one of the largest volcanic events of the past 100000 years. Recent petrologic data show that the eruption released very large amounts of climate-relevant sulfur and ozone-destroying chlorine and bromine gases (523±94Mt sulfur, 1200±156Mt chlorine, and 2±0.46Mt bromine). Using the Earth system model (ESM) of the Community Earth System Model version 2 (CESM2) coupled with the Whole Atmosphere Community Climate Model version 6 (WACCM6), we simulated the impacts of the sulfur- and halogen-rich Los Chocoyos eruption on the preindustrial Earth system. Our simulations show that elevated sulfate burden and aerosol optical depth (AOD) persists for 5 years in the model, while the volcanic halogens stay elevated for nearly 15 years. As a consequence, the eruption leads to a collapse of the ozone layer with global mean column ozone values dropping to 50DU (80% decrease) and leading to a 550% increase in surface UV over the first 5 years, with potential impacts on the biosphere. The volcanic eruption shows an asymmetric-hemispheric response with enhanced aerosol, ozone, UV, and climate signals over the Northern Hemisphere. Surface climate is impacted globally due to peak AOD of >6, which leads to a maximum surface cooling of >6K, precipitation and terrestrial net primary production decrease of >25%, and sea ice area increases of 40% in the first 3 years. Locally, a wetting (>100%) and strong increase in net primary production (NPP) (>700%) over northern Africa is simulated in the first 5 years and related to a southward shift of the Intertropical Convergence Zone (ITCZ) to the southern tropics. The ocean responds with pronounced El Niño conditions in the first 3 years that shift to the southern tropics and are coherent with the ITCZ change. Recovery to pre-eruption ozone levels and climate takes 15 years and 30 years, respectively. The long-lasting surface cooling is sustained by an immediate increase in the Arctic sea ice area, followed by a decrease in poleward ocean heat transport at 60°N which lasts up to 20 years. In contrast, when simulating Los Chocoyos conventionally by including sulfur and neglecting halogens, we simulate a larger sulfate burden and AOD, more pronounced surface climate changes, and an increase in column ozone. By comparing our aerosol chemistry ESM results to other supereruption simulations with aerosol climate models, we find a higher surface climate impact per injected sulfur amount than previous studies for our different sets of model experiments, since the CESM2(WACCM6) creates smaller aerosols with a longer lifetime, partly due to the interactive aerosol chemistry. As the model uncertainties for the climate response to supereruptions are very large, observational evidence from paleo archives and a coordinated model intercomparison would help to improve our understanding of the climate and environment response.
Document Type: | Article |
---|---|
Keywords: | aerosol, atmospheric chemistry, concentration (composition), halogen, optical depth, particulate matter, sulfur, volcanic eruption, Guatemala |
Research affiliation: | OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS |
Refereed: | Yes |
Open Access Journal?: | Yes |
Publisher: | Copernicus Publications (EGU) |
Date Deposited: | 22 Jun 2020 07:32 |
Last Modified: | 08 Feb 2023 09:41 |
URI: | https://oceanrep.geomar.de/id/eprint/49919 |
Actions (login required)
View Item |
Copyright 2023 | GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel | All rights reserved
Questions, comments and suggestions regarding the GEOMAR repository are welcomed
at bibliotheksleitung@geomar.de !