What controls the warming of the Antarctic Bottom Water supply to the Atlantic Ocean

During the last three decades, the Antarctic Bottom Water (AABW) that fills the bulk of the ocean abyss has exhibited a striking warming and contraction in volume over much of the world ocean, particularly in the Atlantic basin. While the causes of these changes are unknown, available evidence suggests that, in the Atlantic Ocean, the warming and contraction of AABW may be caused by changes in the strength and configuration of winds over the Weddell Sea, where much AABW is produced. AABW is the densest of the world's water masses, and is particularly important to global climate because of its role in drawing down heat and carbon into the depths of the ocean.

This project will test and quantify this hypothesis by (i) determining how the flow and properties of the AABW entering the Atlantic Ocean from the Weddell Sea respond to wind forcing, and (ii) assessing the dynamical processes connecting wind forcing perturbations to changes in AABW. The project will generate a thorough understanding of the ways in which changes in Antarctic winds may shape the heat content of the deepest layers of the global ocean abyss.