Multidecadal preconditioning of the Maud Rise polynya region

• Published in: Ocean Science
• Main Authors: van Westen, René M., Dijkstra, Henk A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2020
• Subjects: article; Verlagsveröffentlichung; Maud Rise; Southern Ocean; Weddell
• Online Access: https://doi.org/10.5194/os-16-1443-2020; https://noa.gwlb.de/receive/cop_mods_00054733; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054384/os-16-1443-2020.pdf; https://os.copernicus.org/articles/16/1443/2020/os-16-1443-2020.pdf

In this paper, we consider Maud Rise polynya formation in a long (250-year) high-resolution (ocean 0.1∘, atmosphere 0.5∘ horizontal model resolution) of the Community Earth System Model. We find a dominant multidecadal timescale in the occurrence of these Maud Rise polynyas. Analysis of the results leads us to the interpretation that a preferred timescale can be induced by the variability of the Weddell Gyre, previously identified as the Southern Ocean Mode. The large-scale pattern of heat content variability associated with the Southern Ocean Mode modifies the stratification in the Maud Rise region and leads to a preferred timescale in convection through preconditioning of the subsurface density and consequently to polynya formation.