Details

Autor(en) / Beteiligte

• Dee, Sylvia G.
• Steiger, Nathan J.

Titel

ENSO’s Response to Volcanism in a Data Assimilation‐Based Paleoclimate Reconstruction Over the Common Era

Ist Teil von

• Paleoceanography and paleoclimatology, 2022-03, Vol.37 (3), p.n/a

Ort / Verlag

Hoboken: Blackwell Publishing Ltd

Erscheinungsjahr

2022

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• The tropical response to explosive volcanism remains underconstrained in the paleoclimate record. While the atmosphere cools due to aerosol forcing following volcanic eruptions, modeling evidence suggests that the tropical Pacific responds with compensatory warming. Given the rarity of large volcanic eruptions and the short instrumental record, these modeling results require independent verification. Here, we test for links between volcanism and tropical Pacific dynamics using the newly developed Paleo Hydrodynamics Data Assimilation product (PHYDA), which spans the past 2,000 years. Using Pacific sea surface temperature fields from PHYDA and coincident volcanic eruptions, we test the response of the El Niño–Southern Oscillation (ENSO) to large, tropical volcanic eruptions. We identify a weak El Niño‐like response of the tropical Pacific in the year following sufficiently large, tropical volcanic eruptions. While the response is not significant at the 95% confidence level using superposed epoch analysis (SEA) and self‐organizing maps, a significant result does emerge when employing probability density functions. Our results indicate that the widely used SEA approach, based on composite averaging, may not be sufficiently sensitive to capture an ENSO response in the presence of large internal variability. We additionally conclude that inconsistencies in both the spatial patterns and magnitudes between climate models and PHYDA results indicate that current models overestimate the regional tropical response to volcanic forcing. Key Points The relationship between ENSO and volcanic eruptions is tested in a new paleoclimate data assimilation product, PHYDA, spanning 1–2000 CE A weak El Niño‐like warming emerges in frequency‐based analyses, but not when using commonly employed superposed epoch analysis Comparisons between GCMs and paleoclimate data using frequency analyses such as self‐organizing maps could reduce data–model discrepancies