Recently, the interactions between the Pacific, the Atlantic, and the Indian Oceans have been attracting more attention, mainly because of their distinct impacts on the global climate variabilities, and the complicated underlying mechanisms. Therefore, I propose an “inter-basin interaction” session to be held at the 100th AMS meeting, to better demonstrate the recent progresses of this topic.
It is well known that the El Niño Southern Oscillation (ENSO), the dominant mode of global interannual variability, can significantly impact on the physical processes over the Indian Ocean and the Atlantic. The Atlantic and Indian Ocean interannual variability may feedback to the Pacific in turn: The El Niño-induced Indian Ocean warming usually influences the northwestern Pacific in the summer of the second year, known as the Indian Ocean-capacitor effect. The Atlantic Niño may trigger an east Pacific La Niña event, while the north tropical Atlantic warming usually drive a central Pacific La Niña, together augmenting the ENSO diversity. On decadal time scales, the positive phase of the Atlantic Multidecadal Oscillation (AMO) can heat the Indian Ocean and drive the Pacific into a negative Pacific Decadal Oscillation (PDO) mode, etc.
These inter-basin teleconnections exert distinct impacts on the global climate system. The Atlantic decadal variability may impact on the global energy balance and thus the “global warming hiatus” through its interactions with the Pacific. The Atlantic-Pacific interaction also has the potential to impact on the polar climate, triggering changes in the sea ice and land ice, and further the global sea level and the deep ocean circulation. The physical processes behind these teleconnections also have broad implications for the seasonal to multi-year predictability of the global climate system, as well as the projection of future climate.
Nevertheless, the mechanisms behind these teleconnections are very complicated. Interactions between different ocean basins are usually attributed to the resonance of multiple mechanisms and pathways. For example, the ENSO events may impact on the Indian Ocean and the Atlantic through the adjustment of the Walker circulation, and the stationary Rossby wave dynamics. On the other hand, the Atlantic warming may feedback to the Pacific through the wind-evaporation-SST (WES) effect and the Bjerknes feedback. More importantly, recent studies suggest that two-way interaction between any two oceans could be more vigorous than previously thought, that the three basins as a whole are a tightly interconnected system. These findings further complicate the physical mechanisms and pathways behind the interactions of the three ocean basins, which desire further discussion and investigation.
Above all, because of its significant climate impacts and complicated mechanisms, I propose a session focusing on “the interactions between the three ocean basins and their implication for the global climate variability”. It will cover topics including the establishment of teleconnection pathways, the impacts of inter-basin teleconnections on regional and global climate, the mechanisms of different teleconnection pathways, and implications of these inter-basin interactions for climate predictability and projection.