Antarctic circumpolar current strength in the FOCI climate model: Parameterizing vs. explicitly simulating mesoscale eddies ...

• Main Authors: Martin, Torge, Kjellsson, Joakim, Deutloff, Jakob, Noack, Julia, Ödalen, Malin, Wahl, Sebastian, Zeller, Mathias
• Format: Conference Object
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Antarctic; Southern Ocean; The Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.57757/iugg23-3802; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5020743

<!--!introduction!--> The Antarctic Circumpolar Current (ACC) is shaped by westerly winds, a meridional density gradient, topography and mesoscale activity. Ekman-driven isopycnal sloping is counterbalanced by eddy mixing. Many global climate models deal with a Southern Ocean (SO) warm bias and bottom water formation issues. Eddy processes are often parameterized in absence of sufficient resolution. Increasingly frequent, ocean grids at 1/4˚–1/12˚ are applied allowing for some representation of the mesoscale and eddy parameterization is thus turned off. We use FOCI, a global climate model based on ECHAM and NEMO atmosphere and ocean models with the capability of two-way nesting in the ocean to discuss related effects. Grid refinement south of 28˚S from 1/2˚ to 1/10˚ enables a realistic representation of mesoscale dynamics in the latitude band of the ACC, whereas standard GM-parameterization is applied to the non-eddying model. In both model configurations the deep, dense water layer is eroding over the ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...