Optimal Growth of IPV Lags AMV Modulations by up to a Decade

Abstract

AbstractThe Interdecadal Pacific Variability (IPV) has global climate effects but its decadal prediction is a challenge. Here, we use linear inverse models to study the optimal growth of the IPV and reveal important precursor patterns. We find that the optimal growth of the IPV exists in observations due to interference among various sea surface temperature (SST) decadal variations. Small SST anomalies extending from the northeastern subtropical Pacific to the central tropical Pacific, in concert with thermocline dynamics, can develop into a mature phase of the IPV after ∼3 years. Furthermore, the initial SST anomalies lag the Atlantic Multidecadal Variability (AMV) by up to a decade, suggesting the potential importance of the AMV in IPV decadal predictability. As climate models commonly underestimate the AMV trans‐basin effect, our study calls for more efforts on reducing the model bias to improve IPV decadal prediction.