Dynamical linkages between distinct oceanic regimes around Antarctica
Adele Morrison
Authors: Adele Morrison (ANU), Christina Schmidt (UNSW), Hannah Dawson (UTAS)
Abstract: Warm ocean water reaching Antarctica is driving ice loss, underscoring the need to understand what controls ocean temperature on the continental shelf. The Antarctic margins feature distinct oceanic regimes with regional differences in the slope current, air-sea fluxes, and heat delivery to ice shelves. While previous studies have deepened our understanding, they have largely focused on dynamics within localised continental shelf regions.
Our findings reveal strong dynamical linkages between different regimes, indicating that isolated regional approaches may overlook key processes. Coastal and slope currents connect neighbouring sectors, resulting in strong and widespread connectivity around the continent with rapid downstream propagation.
We highlight two specific examples of dynamical connectivity:
- Weakened formation at dense water hotspots strengthens the coastal current and causes cooling on the continental shelf that can persist for 4000 km downstream.
- Enhanced meltwater input in warm shelf regions triggers coastal-trapped waves that propagate freshening signals up to 3000 km within 2–3 months, suppressing downstream dense water formation.
These results highlight the importance of zonal connectivity in shaping dynamics around the Antarctic margins and improving projections of future ice loss.
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