Using Sea Level to Determine the Strength, Structure and Variability of the Cape Horn Current

• Published in: Geophysical Research Letters
• Main Authors: Zheng, Qi, Bingham, Rory, Andrews, Oliver
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: altimetry; Cape Horn Current; sea level; volume transport; Antarctic; Cape Horn; The Antarctic; Antarc*
• Online Access: https://hdl.handle.net/1983/391998c1-9985-47bc-92b5-1481f20bb291; https://research-information.bris.ac.uk/en/publications/391998c1-9985-47bc-92b5-1481f20bb291; https://doi.org/10.1029/2023GL105033; http://www.scopus.com/inward/record.url?scp=85175718866&partnerID=8YFLogxK

The Cape Horn Current (CHC) is one of the components of the Antarctic Circumpolar Current system that enables it to fulfill its crucial role as a conduit between ocean basins. Despite this, to-date there have been very few measurements of CHC strength and none continuous in time or space. Here, we use a combination of ocean models, one free-running and one data-assimilating, and satellite altimetry (1993–2021) to estimate the time-dependent strength of the CHC at 10 transects along its length. We find the time-mean CHC transport increases from 0.4 ± 0.5 Sv near 49°S to 5.3 ± 2.2 Sv at Cape Horn, with peak-to-peak interannual fluctuations of 0.8–3.4 Sv. Although, theoretically, increased run-off from a wasting Patagonian Ice-field would strengthen its flow, the CHC appears quite stable over the last 29 years, with little evidence of a coherent, long-term increase or decrease in the strength of the current.