ENSO and NAO Linkage to Strong Volcanism and Associated Post-Volcanic
High-latitude Winter Warming
Abstract
High-latitude winter warming was observed following strong tropical
volcanism, which has long been believed to be due to the
volcanic-induced positive NAO phase. However, recent works argue that
this warming is caused by ENSO variability. Moreover, controversies
exist about the sensitivity of ENSO to volcanism. Therefore, to better
resolve the controversies related to post-volcanic ENSO and NAO
sensitivity and associated high-latitude winter warming, we conducted
ENSO-preconditioned volcanic experiments using GFDL-CM2.1 coupled model.
Our simulations strongly suggest that the post-eruption Eurasian winter
warming is caused by a post-eruption positive NAO phase and not by
coexisting ENSO-preconditioned variability. Additionally, we find that
the El Niño-preconditioned volcanic eruption enhances the El Niño phase;
however, the neutral and La Niña-preconditioned volcanisms do not lead
to ENSO–like response. These findings are helpful to better understand
volcanic-induced circulation impacts and have important implications for
the interpretation of model results and for post-volcanic prediction.