A significant influence of changes in the westerly winds over the Southern Ocean was proposed as a mechanism to explain a large portion of the glacialatmospheric pCO2 drawdown [Toggweiler et al., 2006]. However, additional modelling studies do not confirm the size and even thesign of the impact of southern hemispheric winds on the glacial pCO2 as suggested by Toggweiler [Menviel et al., 2008; Tschumi et al., 2008].We here add to this discussion and explore the potential contribution of changes in the latitudinal position of the winds on Southern Ocean physics and the carbon cycle by using a state-of-the-art ocean general circulation model(MITgcm) in a spatial resolution increasing in the Southern Ocean (2° lon; 2°lat NH; 2°cos(alpha) SH). Under glacial boundary conditions (GLAMAP SST and SSS) (a) the direct effect of a northwards shift in the westerlies wind belt and (b) via its influence on sea ice coverage on ocean physics and the carbon cycle is investigated. For the latter the dynamic thermodynamic sea ice module of theMITgcm is used.We discuss how the change in carbon cycling is related to the upwelling strength and pattern in the Southern Ocean.References:Menviel, L.; Timmermann, A.; Mouchet, A. & Timm, O. Climate and marine carbon cycle response to changes in the strength of the southern hemispheric westerlies. Paleoceanography, 2008, 23, PA4201; doi: 10.1029/2008PA001604.Toggweiler, J. R.; l. Russell, J. & Carson, S. R. Midlatitude westerlies,atmospheric CO2, and climate change during the ice ages. Paleoceanography, 2006, 21, PA2005; doi: 10.1029/2005PA001154.Tschumi, T.; Joos, F. & Parekh, P. How important are Southern Hemisphere wind changes for low glacial carbon dioxide? A model study. Paleoceanography, 2008, 23, PA4208, doi: 10.1029/2008PA001592.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 3: Lessons from the Past > WP 3.1: Past Polar Climate and inter-hemispheric Coupling
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 4: Synthesis: The Earth System from a Polar Perspective
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 4: Synthesis: The Earth System from a Polar Perspective > WP 4.2: The Earth System on Long Time Scales