SMASHING! Unravelling the climate impact of Small-to-Moderate magnitude eruptions through volcanic ASH IN Greenland ice cores
Lead Research Organisation:
QUEEN'S UNIVERSITY BELFAST
Abstract
Volcanoes are one of the most important natural drivers of climate change. Volcanic sulfate emissions reflect incoming sunlight, temporarily cooling the Earth’s surface. These natural effects are now considered as models for potential geo-engineering solutions to anthropogenic climate change, despite an incomplete understanding of volcano-climate relationships. Studying the impacts of past eruptions provides critical insights into how volcanoes interact with climate. Polar ice cores are particularly useful archives of past volcanism because they capture fallout from distant eruptions, including sulfates and volcanic ash (tephra). Although previously thought that very explosive tropical eruptions had the greatest measurable effect on the Earth’s climate, the SMASHING team’s research highlighted that small-to-moderate magnitude eruptions (SMME) contribute 40-60% of long-term volcanic forcing, and that extra-tropical eruption impacts on climate are as important as tropical ones. SMME are harder to detect in conventional ice-core records, however, and are underrepresented in global volcanic databases. This leaves a critical gap in our long-term understanding of SMME distribution in terms of spatial, temporal and magnitude distribution. This knowledge gap hinders both our ability to understand the wide-ranging climate impacts of SMME, as well as the direct hazards they pose such as long-range ash cloud dispersion that can shut down aviation routes.
By studying ash in Greenland ice cores, SMASHING aims to investigate for the first time a continuous record of volcanic activity spanning the last two millennia to identify the occurrence and climate impacts of SMME. To do this, we take advantage of a new and easily accessible ice core (TUNU2022) from northern Greenland and archived ice from central Greenland (Eurocore2015). Within the ice, ash takes the form of minute concentrations of glass shards invisible to the naked eye whose geochemical fingerprint allows us to identify its source volcano. Knowing the source, we will use computer models to estimate the height of the volcanic clouds and how it has been transported to Greenland as this influences the potential climate impact of the eruptions. This approach will also tell us more about the frequency of major ash clouds, and the extent of the area that might be affected by future eruptions. In parallel, we will study the atomic composition of sulphur deposited alongside the ash, providing a second constraint on the height on the sulfate cloud and, in turn, the eruption capability to cool the Earth’s surface. Finally, by combining eruption source, sulfate yield and atmospheric transport, we will model the climatic impacts of these eruptions to evaluate their significance for the climate system. Our Common Era and Northern Hemisphere focus is crucial as climate models can be validated with respect to historical records. Our work is timely as it will deliver new datasets in time to inform the design of climate-forcing datasets for the next generation of climate models.
SMASHING will push the boundaries of environmental science by delivering a new understanding of the cumulative climate impact of smaller eruptions and evaluate an overlooked but potentially significant driver of climate variability. The findings will reduce uncertainties in climate models used to attribute past climate shifts and predict future ones. Ultimately, this project will deliver vital new insights into the far-reaching impacts of volcanic eruptions, including climate impacts and ash-cloud hazards, helping scientists, policymakers, insurance and aviation industries and the public better understand these events across a range of scales.
By studying ash in Greenland ice cores, SMASHING aims to investigate for the first time a continuous record of volcanic activity spanning the last two millennia to identify the occurrence and climate impacts of SMME. To do this, we take advantage of a new and easily accessible ice core (TUNU2022) from northern Greenland and archived ice from central Greenland (Eurocore2015). Within the ice, ash takes the form of minute concentrations of glass shards invisible to the naked eye whose geochemical fingerprint allows us to identify its source volcano. Knowing the source, we will use computer models to estimate the height of the volcanic clouds and how it has been transported to Greenland as this influences the potential climate impact of the eruptions. This approach will also tell us more about the frequency of major ash clouds, and the extent of the area that might be affected by future eruptions. In parallel, we will study the atomic composition of sulphur deposited alongside the ash, providing a second constraint on the height on the sulfate cloud and, in turn, the eruption capability to cool the Earth’s surface. Finally, by combining eruption source, sulfate yield and atmospheric transport, we will model the climatic impacts of these eruptions to evaluate their significance for the climate system. Our Common Era and Northern Hemisphere focus is crucial as climate models can be validated with respect to historical records. Our work is timely as it will deliver new datasets in time to inform the design of climate-forcing datasets for the next generation of climate models.
SMASHING will push the boundaries of environmental science by delivering a new understanding of the cumulative climate impact of smaller eruptions and evaluate an overlooked but potentially significant driver of climate variability. The findings will reduce uncertainties in climate models used to attribute past climate shifts and predict future ones. Ultimately, this project will deliver vital new insights into the far-reaching impacts of volcanic eruptions, including climate impacts and ash-cloud hazards, helping scientists, policymakers, insurance and aviation industries and the public better understand these events across a range of scales.