Interactions between the Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation

Recent many studies indicated that the decadal changes over the Atlantic Ocean may contribute to the climate changes over the Indian and the Pacific Oceans. Previous studies also show that the ENSO events may impact on the Atlantic and the Indian Ocean. This leaves a question: could the Atlantic and Pacific decadal variabilities interact with each other? We tried to discuss this problem through coupled model simulations. We restore the SST patterns represent the AMO and PDO respectively to the earth system model. For each experiment, we conduct ensemble runs with 12 ensemble members to investigate the roles of both external forcing (outside the basin) and internal variability (inside the basin). Results show that the AMO (+) may trigger the PDO (-) pattern, while there is also strong internal variability (with in the Pacific basin) which may trigger and amplify the PDO event. On the other hand, the impact of the PDO on the AMO is not statistically significant. In the coupled model, the AMO event is more attributed to the variability of the deep ocean circulation, rather than the remote forcing from the Pacfic.