Nonlinear Responses of Droughts Over China to Volcanic Eruptions at Different Drought Phases

Abstract

Abstract Previous studies show that volcanic eruptions can intensify and extend drought events triggered by internal variability over Eastern China. However, it has remained unclear whether volcanic eruptions occurring in different drought phases have different impacts. Here, based on multiple reconstructions, simulations, as well as volcanic sensitivity experiments with volcanic forcing imposed in the early and late phases of droughts, we propose a nonlinear effect of volcanic eruptions on drought events. Late‐phase volcanic eruptions exert greater impact on drought persistence and intensity while early‐phase volcanic eruptions induce modest and weaker impacts. The evolutions of drought differ substantially from the typical volcanic‐only influence or the linear combination of the drought triggered by internal variability and volcanic‐only influences, which are hypothesized to be associated with positive feedbacks of soil moisture to precipitation, as well as its interaction with the evolution of the East Asia Summer monsoon.