Toward a better understanding of the effects of mesoscale air-sea interactions on the Antartic Circumpolar Current dynamics using coupled ocean-atmosphere models

Strong westerly winds blowing in the Southern Ocean enhance a unique oceanic dynamic composed of the world's strongest ocean current, the Antarctic Circumpolar Current (ACC), and a vertical circulation, the Overturning Circulation. Although these currents play a central role in shaping our climate, and despite numerous international observational and modeling programs, the processes controlling their strength and variability remain poorly understood, especially those related to fine-scale oceanic processes and their interactions with the atmosphere. To fill this gap, this study aims to understand both the direct and indirect effects of air-sea interactions on the dynamics of the ACC, including the large-scale, mesoscale (10-100 km), and eddy mean flow interactions (the inverse and direct energy cascade). We focus on two main air-sea interactions: the current feedback (CFB), which corresponds to the influence of surface ocean currents on the overlying atmosphere, and the thermal feedback (TFB), which is essentially the influence of ocean surface temperature and its gradients on heat and momentum fluxes. To achieve our goals, we developed a first set of coupled ocean (CROCO) - atmosphere (WRF) simulations of an idealized atmospheric storm track coupled to an idealized ACC with a spatial resolution up to 4 km for the ocean and 10 km for the atmosphere for a period of 75 years. We will present our first results, focusing in particular on the mean oceanic and atmospheric dynamics and the exchange of kinetic and potential energy between the ocean and the atmosphere.