Multidecadal Preconditioning of the Maud Rise Polynya Region

• Main Authors: Westen, René M., Dijkstra, Henk A.
• Format: Text
• Language: English
• Published: 2020
• Subjects: Maud Rise; Southern Ocean; Weddell
• Online Access: https://doi.org/10.5194/os-2020-25; https://os.copernicus.org/preprints/os-2020-25/

In this paper, we consider Maud Rise polynya formation in a long (250 years) high-resolution (ocean 0.1°, atmosphere 0.5° horizontal model resolution) of the Community Earth System Model. We find a dominant multidecadal time scale in the occurrence of these Maud Rise polynyas. Analysis of the results leads us to the interpretation that a preferred time scale 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 time scale in convection through preconditioning of the subsurface density, and consequently to polynya formation.