The response of the Southern Ocean to freshwater hosing in an equilibrated 1º NEMO configuration with realistic ventilation

Under a warming climate ice sheets are releasing freshwater to the ocean and affecting the global ocean circulation. One important region where freshwater is released and impacts the global ocean is the Antarctic continental shelf, where Antarctic Bottom Water (AABW) is formed. The response of AABW formation and circulation to increased glacial melt is uncertain, because global ocean models struggle to capture AABW formation, sinking and spreading across the abyss. Here, we present an equilibrated 1º degree global ocean-ice configuration with AABW formation on the shelves and realistic abyssal ventilation. This configuration also includes dye and age tracers that track ventilation pathways and timescales. Using this model, we perform an idealized ‘antwater’ hosing experiment, releasing exactly 0.1 Sv of freshwater uniformly around the Antarctic coast for a century (without offset from surface salinity restoring). The response of Southern Ocean circulation and ventilation is analysed and discussed in the context of previous model studies.