Rising from the deep South Atlantic to the upper Southern Ocean

About a decade ago, I never considered the existence of neither eddies nor meanders in the ocean, which now excite me a lot. So, it cheered me up when Prof. Helen Phillips (UTas) and Prof. Nathan Bindoff (AAPP) suggested for me to move my research topic from the deep limb of the Atlantic Meridional Overturning Circulation, where the DWBC is located, to another branch of the Meridional Overturning Circulation which the ACC is part of.

During my PhD, I learned how to diagnose the impact of a meander south of Australia on air-sea interaction and water subduction. In this work, we show that the crests of ACC meanders lose heat to the atmosphere and have relatively deep mixed layer than the troughs. We also show that the coupling of the vertical velocities at the base of the mixed layer with the lateral induction of fluid in ACC meanders lead to localized subduction of Antarctic Intermediate Water (AAIW) at the exit of Polar Front meanders' crests (Vilela-Silva et al., 2024). The AAIW subduction is one relevant piece of the climate puzzle.

The diagnostics above are relevant for discussions about the locations of carbon removal from the atmosphere to the ocean at subduction regions. In parallel to the subduction analysis in a standing meander, we also explored the subduction in an eddying Southern Ocean. The current review papers indicate that the eddy-induced subduction in the Southern Ocean has been estimated using eddy diffusivity coefficients to parameterize the effect of eddies in coarse-resolution observational products. In our work, we compute the eddy-induced subduction following the definition \textit{per se} in a high-resolution ocean-sea ice model without any parameterization or spatial filter. The preliminary results indicate that the fine-scale signal of mode and intermediate water subduction is mainly driven by steep changes in the seafloor bathymetry (Vilela-Silva et al., in preparation to JPO).

Finally, the PhD also offered me the training from Prof. Phillips, Dr. Benoit Legresy (CSIRO), and Dr. Kurt Polzin (WHOI) to observe the Southern Ocean in Dec/2022 with submesoscale observations at the Macquarie Meander region under SWOT voyage. Additionally, receiving the ``Best Student Inquisitor'' award at the COSIMA VI workshop showed me the importance of asking appropriate questions for each topic.