Large tropical volcanic eruptions have been hypothesized to induce surface warming over Eurasia in winter. Recent studies, however, have questioned the robustness of this claim and highlighted the very large internal variability in that season, which can easily overshadow any forced signal caused by such eruptions. To address uncertainties arising from sparse winter proxy data in previous reconstructions, we here examine a recently developed “online” paleo-data assimilation dataset, LMR Seasonal, in which the analysis from one season is propagated forward as the prior for the next season, allowing information from the dense network of summer-sensitive proxies to better constrain winter climate. We examine Eurasian and Northern European temperatures first following the 20 largest tropical eruptions of the last millennium, each exceeding the magnitude of the 1991 Pinatubo event and then, separately, following the largest extra-tropical eruptions over the same period. Irrespective of latitude, we find no evidence of statistically significant wintertime post-eruption warming – or cooling – and correlation analyses show no significant relationship between volcanic stratospheric sulfur injection and subsequent winter temperature anomalies. These findings are corroborated with two additional datasets (WinTEDA and ModE-RA). In addition, analysis of individual eruptions reveals considerable spread across datasets for many events, leading us to question the validity of superposed epoch analysis, which can yield erroneous conclusions even on continental scales.
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