Do Southern Hemisphere tree rings record past volcanic events? A case study from New Zealand
<p>Much of our knowledge about the impacts of volcanic eruptions on climate comes from proxy records. However, little is known about their impact on the low to mid-latitudes of the Southern Hemisphere. Using superposed epoch analysis, we investigated whether volcanic signals could be identifie...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-05-01
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| Series: | Climate of the Past |
| Online Access: | https://cp.copernicus.org/articles/18/1169/2022/cp-18-1169-2022.pdf |
| Summary: | <p>Much of our knowledge about the impacts of volcanic eruptions on climate comes from proxy records. However, little is known about their impact on
the low to mid-latitudes of the Southern Hemisphere. Using superposed epoch analysis, we investigated whether volcanic signals could be identified
in annual tree-ring series from eight New Zealand dendrochronological species. We found that most species are reliable recorders of volcanic cooling
and that the magnitude and persistence of the post-event response can be broadly linked to plant life history traits. Across species, site-based
factors, particularly altitude and exposure to prevailing conditions, are more important determinants of the strength of the volcanic response than
species. We then investigated whether chronology selection impacts the magnitude of post-volcanic cooling in tree-ring-based temperature
reconstructions by developing two new multispecies reconstructions of New Zealand summer (December–February) temperature with one reconstruction
from the pool of all available chronologies, and the other from a selected subset shown to be sensitive to volcanic eruptions. Both reconstructions
record temperature anomalies that are remarkably consistent with studies based on instrumental temperature and the ensemble mean response of climate
models, demonstrating that New Zealand ring widths are reliable indicators of regional volcanic climate response. However, we also found that
volcanic response can be complex, with positive, negative, and neutral responses identified – sometimes within the same species group. Species-wide
composites thus tend to underestimate the volcanic response. This has important implications for the development of future tree-ring and multiproxy
temperature reconstructions from the Southern Hemisphere.</p> |
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| ISSN: | 1814-9324 1814-9332 |