Decoupling of the Surface and Bottom‐Intensified Antarctic Slope Current in Regions of Dense Shelf Water Export

• Published in: Geophysical Research Letters
• Main Authors: Wilma G. C. Huneke, Adele K. Morrison, Andrew McC. Hogg
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Antarctic slope current; dense shelf water; Antarctica; plume transport; Geophysics. Cosmic physics; QC801-809; Antarctic; The Antarctic; Antarc*; Sea ice
• Online Access: https://doi.org/10.1029/2023GL104834; https://doaj.org/article/3c1ea88f630147f8bc7c778601e300dd

Abstract The Antarctic Slope Current is guided by the topographic gradient of the Antarctic continental slope and creates a dynamical barrier between the continental shelf and the open ocean. The current's vertical structure varies around the continent affecting cross‐slope water mass exchange with consequences for Antarctic mass loss, ventilation of the deep ocean, and carbon uptake. The Antarctic Slope Current is surface‐intensified in many regions but bottom‐intensified in regions of dense overflows. This study investigates the role of dense overflows in modifying the dynamics of the bottom‐intensified flow using a 0.1° global ocean‐sea ice model. The occurrence of bottom‐intensification is tightly linked with dense overflows and bottom speeds correlate with dense overflows on interannual time scales. A lack of vertical connectivity between the bottom and surface flow, however, suggests that the along‐slope bottom water flows are coincidentally co‐located with the Antarctic Slope Current, rather than dynamically a part of the current.