Unraveling the Weddell Gyre: exploring its dynamics and influence on Southern Ocean ventilation ...

• Main Author: Styles, Andrew
• Format: Thesis
• Language: English
• Published: University of Oxford 2023
• Subjects: Physical oceanography; Physics; Antarctic; Southern Ocean; The Antarctic; Weddell; Antarc*
• Online Access: https://dx.doi.org/10.5287/ora-0zd97vrzg; https://ora.ox.ac.uk/objects/uuid:a9319b69-b07d-4f9f-adf2-5fe88176d770

The Southern Ocean is an area of great importance when considering anthropogenic climate change but also an area of great uncertainty. Between climate projections, the Southern Ocean is where one finds the most disagreement in both heat and carbon uptake. The Weddell Gyre is the largest coherent circulation south of the Antarctic Circumpolar Current (ACC) and mediates the transport of water to and from the Antarctic shelf. Here we use a diverse range of methods to study the dynamics of the Weddell Gyre and its role in Southern Ocean ventilation. An idealized model of the Weddell Gyre and the ACC is used to investigate the gyre’s sensitivity to mesoscale eddies. The gyre is particularly strong at eddy-permitting resolutions (45 Sv with a noisy bathymetry) and weakest at eddy-parameterized resolutions (12 Sv). Simulations with partially resolved eddies have the largest horizontal density gradients. The steep isopycnals intensify the gyre's thermal wind transport and fuel tall columns of eddy kinetic energy ...