Simulated changes in ocean physics and carbon cycle for LGM experiments with shifting positions of the Southern Hemisphere westerly winds using the MITgcm, links to model results in NetCDF format, supplement to: Völker, Christoph; Köhler, Peter (2013): Responses of ocean circulation and carbon cycle to changes in the position of the Southern Hemisphere westerlies at Last Glacial Maximum. Paleoceanography, 28(4), 726-739

• Main Authors: Völker, Christoph, Köhler, Peter
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2016
• Subjects: File name; Comment; File size; Uniform resource locator/link to file; Antarctic; Southern Ocean; Antarc*; Antarctica; ice core; Sea ice
• Online Access: https://dx.doi.org/10.1594/pangaea.859463; https://doi.pangaea.de/10.1594/PANGAEA.859463

We explore the impact of a latitudinal shift in the westerly wind belt over the Southern Ocean on the Atlantic meridional overturning circulation (AMOC) and on the carbon cycle for Last Glacial Maximum background conditions using a state-of-the-art ocean general circulation model. We find that a southward (northward) shift in the westerly winds leads to an intensification (weakening) of no more than 10% of the AMOC. This response of the ocean physics to shifting winds agrees with other studies starting from preindustrial background climate, but the responsible processes are different. In our setup changes in AMOC seemed to be more pulled by upwelling in the south than pushed by downwelling in the north, opposite to what previous studies with different background climate are suggesting. The net effects of the changes in ocean circulation lead to a rise in atmospheric pCO2 of less than 10 atm for both northward and southward shift in the winds. For northward shifted winds the zone of upwelling of carbon- and nutrient-rich waters in the Southern Ocean is expanded, leading to more CO2 outgassing to the atmosphere but also to an enhanced biological pump in the subpolar region. For southward shifted winds the upwelling region contracts around Antarctica, leading to less nutrient export northward and thus a weakening of the biological pump. These model results do not support the idea that shifts in the westerly wind belt play a dominant role in coupling atmospheric CO2 rise and Antarctic temperature during deglaciation suggested by the ice core data. : Model runs were started from rest and integrated forward in time for 5000 years. The data archived here consist of annual mean values of the last 100 years (in case of sea ice: mean March or September sea ice distributions of the last 100 years) of the simulations.