Influence of decadal sea surface temperature variability on northern Brazil rainfall in CMIP5 simulations

摘要: The Amazonia and Northeast regions of northern Brazil are characterized by very different rainfall regimes but have certain similarities in terms their variability. precipitation variability both is strongly linked to the tropical Atlantic sea surface temperature (SST) gradient Pacific SST anomalies, which at decadal timescales modulated Multidecadal Variability (AMV) Interdecadal Oscillation (IPO) modes SST, respectively. On other hand, it has been found that state-of-the-art models from fifth phase Coupled Model Intercomparison Project (CMIP5) able reproduce some characteristics low-frequency modes. In this work we analyze how CMIP5 simulate observed response AMV IPO atmospheric mechanisms involved. Results show that, simulations observations, opposite, due modulation intertropical convergence zone (ITCZ) position. Conversely, affects equally as a consequence anomalous subsidence over entire triggered warm anomalies Pacific. Such results suggest an improvement predictability will directly revert into better prediction changes longer timescales.