Alternating Connectivity with Temporal Delays between the Pacific, Atlantic, and Indian Oceans

Sea surface temperature (SST) variability interacts dynamically across the Pacific, Atlantic, and Indian oceans, exerting pronounced influence on global climate. However, the mechanism of signal transmission among these basins remains unclear. Using complex network analysis of lead–lag SST connections, results indicate that dominant interannual influences shift sequentially across the Pacific, Atlantic, and Indian oceans. At short-term lags (≤6 months), the Pacific strongly affects the Indian Ocean. For medium-term lags (7 to 19 months), the Atlantic exerts greater influence on the Pacific. At long-term lags (≥20 months), pronounced SST connections emerge from both the Indian and Pacific oceans toward the Atlantic. Coupled Model Intercomparison Project Phase 6 models capture short-term Pacific impacts effectively, but only a limited subset reproduces medium- and long-term interbasin linkages. Furthermore, model projections consistently suggest intensification of these cross-basin interactions under future warming scenarios. Quantitative evaluation of lead–lag signal flow among oceans enhances understanding of interbasin interactions and large-scale climate variability.