Driving mechanisms of Atlantic Niño under different vertical ocean resolutions

The Atlantic Niño controls the boreal summer tropical Atlantic variability at interannual time scales, with pronounced climate impacts in adjacent and remote areas. Changes in the spatial configuration of the Atlantic Niño has been reported during the observational record, coinciding with a modification of the background state and associated teleconnections. The driving mechanisms of the Atlantic Niño have been also changed in recent decades.

The aim of the present study is to explore the role of the ocean background state in the Atlantic Niño diversity and associated air-sea mechanisms. For such purpose, we will use two twin 30-year high-resolution simulations performed in the H2020-EU NEXTGEMS project. Both simulations have the same horizontal resolution (10km) and only differ in the vertical stratification of the upper 20m: 2m layers for the THIN simulation and 10m layers for the THICK one.

To this aim, the Bjerknes feedback and ocean wave propagation are analyzed, and a complete heat budget analysis will be computed and compared in both simulations. Finally, the role of the background state in the modification of air-sea interactions and thus, in Atlantic Niño diversity will be also investigated.