A Conceptual Model for Extratropical Atmosphere-ocean Interaction

Equipped with the current understanding for atmosphere-ocean interaction, we build a simple system of coupled equations to portray the relationships among major atmospheric and oceanic modes, including the NAO, AMO, AMOC and ENSO. Another emphasis is placed on the air-sea heat fluxes as a function of time scale and how this provides insight into the coupling between ocean and atmosphere. Cross-correlation and spectral analysis are employed to characterize important aspects of these interactions. It is found that, a) the AMOC can be readily understood as a harmonic oscillator driven by the NAO; b) the two-way interaction between NAO and AMO, and also the influence of ENSO on both NAO and AMO are essential for reproducing important correlation features; and c) the consideration of heat fluxes provides additional explanatory power to our model. Our approach not only helps to clarify our understanding for the nature of the atmosphere-ocean interaction problem but also raises new and intriguing questions for future research.