Spatial and temporal characterisation of the western boundary current system of the Weddell Gyre

Abstract

This doctoral thesis investigates the physical mechanisms behind the variability of the Western Boundary Current System (WBCS) of the Weddell Gyre, a key component of the Southern Ocean circulation that regulates abyssal ventilation and global climate. Situated along the Antarctic Peninsula, the WBCS comprises multiple frontal jets, including the Antarctic Coastal Current (CC), the Antarctic Slope Front (ASF), and the Weddell Front (WF), which govern the exchange of heat, salt, and dense waters between the continental shelf and the open ocean. Despite its central role in water mass transformation and Antarctic Bottom Water (AABW) export, knowledge of its structure and dynamics has remained limited due to scarce observations and model uncertainties. Using an integrated approach that combines ocean reanalysis products, satellite observations, and ship-based hydrographic and velocity data, this thesis provides a comprehensive characterization of the WBCS at seasonal to interannual scales.