He et al. (2026) Comparison of Global Climatic Responses to Large Tropical Volcanic Eruptions over the Last Millennium in Paleoclimatic Reconstructions and Model Simulations

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-01-28
• Authors: Zhaoxiangrui He, Ernesto Tejedor, J. E. Smerdon, M. F. Vuille, Lorenzo M. Polvani, Richard Seager, Ibuki Sugiura
• DOI: 10.1175/jcli-d-25-0179.1

Research Groups

Not explicitly mentioned in the provided abstract.

Short Summary

This study comprehensively intercompared the impacts of major Last Millennium volcanic eruptions on surface air temperature, hydroclimate, and atmospheric circulation across tree-ring reconstructions, data assimilation products, and climate model ensembles, revealing robust global cooling, coherent regional hydroclimate shifts linked to circulation changes, and inconsistencies in El Niño–Southern Oscillation responses.

Objective

• To assess the impacts of major eruptions over the Last Millennium on surface air temperature (SAT), Palmer drought severity index (PDSI), and 500-hPa geopotential height using tree-ring reconstructions, nine data assimilation (DA) products, and two climate model ensembles.

Study Configuration

• Spatial Scale: Global, with specific regional analyses including the western United States, Mediterranean Basin, southern South America, northern and European Russia, central Asia, southern Siberia, mid- to high latitudes, tropics, and Southern Hemisphere.
• Temporal Scale: Last Millennium (referring to major volcanic eruptions within this period).

Methodology and Data

• Models used: Two climate model ensembles (specific names not provided in the abstract).
• Data sources: Tree-ring reconstructions (based on density and width), nine data assimilation (DA) products.

Main Results

• Robust global surface air temperature (SAT) cooling is confirmed, but with significant differences in magnitude and persistence across datasets. Tree-ring density reconstructions show shorter, physically consistent cooling, whereas products dominated by tree-ring widths show longer persistence, likely due to biological memory.
• Palmer drought severity index (PDSI) responses reveal coherent wetting over the western United States, the Mediterranean Basin, and southern South America. Coherent drying is observed over northern and European Russia, central Asia, and southern Siberia, with divergence in other regions.
• El Niño–Southern Oscillation (ENSO) responses differ across products, suggesting that any volcanically forced signal is weak relative to internal variability and highly sensitive to the background climate state.
• Geopotential height anomalies indicate widespread posteruption tropospheric contraction and robust extratropical circulation shifts, including negative height anomalies over mid- to high latitudes and wave-like patterns in the Southern Hemisphere.
• These geopotential height anomalies are dynamically consistent with the spatial patterns of wetting and drying in PDSI, suggesting that volcanic forcing reorganizes large-scale atmospheric circulation in ways that influence hydroclimate.

Contributions

• Presents the first comprehensive intercomparison of volcanic impacts on temperature, hydroclimate, and atmospheric circulation using a diverse set of tree-ring reconstructions, data assimilation products, and climate model ensembles.
• Establishes tree-ring density reconstructions as a physically consistent benchmark for assessing the duration of volcanic cooling, contrasting with the overestimation of persistence by tree-ring width products due to biological memory.
• Connects hydroclimate signals with posteruption atmospheric height anomalies and associated extratropical circulation changes, providing a clearer framework for interpreting how volcanoes impact ocean-atmosphere interactions.
• Identifies priority regions, particularly across the tropics and the Southern Hemisphere, where expanded, high-resolution proxy records could most effectively reduce current uncertainties in understanding volcanic impacts.

Funding

Not explicitly mentioned in the provided abstract.

Citation

@article{He2026Comparison,
  author = {He, Zhaoxiangrui and Tejedor, Ernesto and Smerdon, J. E. and Vuille, M. F. and Polvani, Lorenzo M. and Seager, Richard and Sugiura, Ibuki},
  title = {Comparison of Global Climatic Responses to Large Tropical Volcanic Eruptions over the Last Millennium in Paleoclimatic Reconstructions and Model Simulations},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0179.1},
  url = {https://doi.org/10.1175/jcli-d-25-0179.1}
}