Extreme Tibetan Plateau cooling caused by tropical volcanism

Extreme cooling during boreal winter in Tibetan Plateau (TP) poses great threats to local environment and people’s live safety, and it has usually been attributed to climate internal varaibility. Here we show that the recent five large tropical volcanic eruptions since 1863  induced an extreme TP cooling up to -0.8 K in the first boreal winter post-eruptions, much larger than the global average terrestrial cooling of -0.3 K. This extreme TP cooling response (-0.79 K)  to tropical eruptions is simulated by the multimodel ensemble mean of the Phase 6 Coupled Model Intercomparison Project when realistic sea surface temperature is specified for the atmospheric models, and it is much larger than the direct aerosol cooling (-0.36 K) simulated by the historical runs. The positive North Atlantic Oscillation during the post-eruption winter plays the key role in amplifing the TP cooling through atmospheric teleconnection, which overwhelms the warming response associated the frequently occurring El Niños. Results from this study put into perspective the potential volcanic contribution in certain extreme Tibetan Plateau cooling events.