The Bransfield current system

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Sangrà, Pablo, Gordo, Carmen, Hernández-Arencibia, Mónica, Marrero-Díaz, Ángeles, Rodríguez-Santana, Ángel, Stegner, Alexander, Martínez-Marrero, Antonio, Pelegrí, Josep Lluís, Pichon, Thierry
• Format: Article in Journal/Newspaper
• Language: English
• Published: Pergamon Press 2011
• Subjects: Bransfield Strait; Bransfield Current; Circumpolar DeepWater; Anticylonic eddies; Gravity current; Antarctic; Antarctic Peninsula; Central Basin; Madariaga; South Shetland Islands; The Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10261/73651; https://doi.org/10.1016/j.dsr.2011.01.011

13 pages, 15 figures, 2 tables We use hydrographic data collected during two interdisciplinary cruises, CIEMAR and BREDDIES, to describe the mesoscale variability observed in the Central Basin of the Bransfield Strait (Antarctica). The main mesoscale feature is the Bransfield Front and the related Bransfield Current, which flows northeastward along the South Shetland Island Slope. A laboratory model suggests that this current behaves as a gravity current driven by the local rotation rate and the density differences between the Transitional Zonal Water with Bellingshausen influence (TBW) and the Transitional Zonal Water with Weddell Sea influence (TWW). Below the Bransfield Front we observe a narrow (10. km wide) tongue of Circumpolar Deep Water all along the South Shetland Islands Slope. At the surface, the convergence of TBW and TWW leads to a shallow baroclinic front close to the Antarctic Peninsula (hereafter Peninsula Front). Between the Bransfield Front and the Peninsula Front we observe a system of TBW anticyclonic eddies, with diameters about 20. km that can reach 300. m deep. This eddy system could be originated by instabilities of the Bransfield Current. The Bransfield Current, the anticyclonic eddy system, the Peninsula Front and the tongue of Circumpolar Deep Water, are the dynamically connected components of the Bransfield Current System This work was supported by the Spanish government through project BREDDIES (REN2001-2650) and COUPLING (CTM2008-06343-CO2-01). The laboratory experiments were part of the TopIECC project founded by the French program LEFE-INSU. Part of this work was written while PS was visiting the group of Prof. James C. McWilliams at the Atmospheric and Oceanic Sciences department of the UCLA supported with a scholarship from the Spanish Government (Salvador de Madariaga, PR2010-0517) Peer Reviewed