Volcanic impacts on East Asian climate since 1400: insights from climate reconstructions and paleoclimate reanalysis

This study analysed volcanic impacts on East Asian temperature and precipitation (wetness/dryness) anomalies and investigated the consistency of climate responses between the REACHES reconstruction and paleoclimate reanalysis product (ModE-RA) from the 15th to 20th centuries. Volcanic events were compiled from the eruption chronology based on ice-core sulphate data, and 10 major eruption events were identified. For each event, the eruption year was designated as t0 and used as the reference year for event alignment. Superposed epoch analysis was applied with a ± 8-year window to compare post-eruption years (t = 0–8) against pre-eruption baselines (t = −8–−1) by a significance t-test. For identifying whether extreme years (percentile thresholds from the top 5%–25% in temperature and precipitation fields) are attributed to volcanic forcing or natural variability, we adopted Bayes’ conditional probabilities and applied an exact binomial test to perform reverse inference. Both datasets showed robust post-eruption cooling signals, the strongest being within t0 +3 years. Precipitation responses were controversial: REACHES revealed overall wetting, whereas ModE-RA suggested drying, indicating a consistent cooling effect of major volcanic eruptions and divergent responses in hydroclimates. Future analysis should focus on the hydroclimatic effects of volcanic eruptions using high-resolution reconstruction data and simulations.