Model consistency for the underlying mechanisms for the Inter-decadal Pacific Oscillation-tropical Atlantic connection

Abstract Modeling evidence suggests that the Inter-decadal Pacific Oscillation (IPO) can remotely affect tropical Atlantic sea surface temperature (SST) variability. However, root causes of IPO-tropical inter-basin teleconnections are not fully understood. Using idealized pacemaker experiments wherein observed IPO-SST anomalies specified, we show a warm-phase anomaly drives basin-wide SST warming over Atlantic. The trans-basin connection is established via tropospheric mechanism and atmospheric bridge teleconnections. An IPO positive-phase initiates anomalies, leading to more humid atmosphere increasing longwave radiation downward into By comparison, reduced Walker circulation mid-latitude Rossby wave responses cause trade winds strengthen, acting suppress through Bjerknes positive feedback mechanism. Thus, similar previous studies, widespread ultimately traced back effects generated by water vapor-longwave radiation-SST feedback, which, contrary overwhelms cooling associated with intensified winds. Our results highlight model dependence on details mechanisms connect decadal timescales.