Supplementary data: Model set up
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Model set up Freshwater perturbation simulations have been conducted with the UVic ESCM and the LOVECLIM earth system models of intermediate complexity. The freshwater perturbation experiment with the University of Victoria Earth System Climate Model (UVic ESCM v2.9) (Weaver et al. 2001) was performed under constant Last Glacial Maximum boundary conditions. The UVic ESCM consists of an ocean general circulation model (Modular Ocean Model, Version 2) with a resolution of 3.6º longitude and 1.8º latitude, coupled to a vertically integrated two dimensional energy-moisture balance model of the atmosphere including a parameterization of geostrophic wind stress anomalies, a dynamic-thermodynamic sea ice model, a land surface scheme, a dynamic global vegetation model, a marine carbon cycle model (Schmittner et al. 2008) and a sediment model. The model is initialized under constant Last Glacial Maximum (LGM, 21 ka B.P.) boundary conditions, which include orbital parameters, Northern Hemispheric ice extent and thickness (Peltier, 2002), an atmospheric CO2 content of 191 ppmv and Atmospheric 14 C of 393‰ (Reimer et al., 2009). To simulate a shutdown of the Atlantic Meridional Overturning Circulation, 0.2Sv (1Sv =106m3/s) of freshwater is added into the North Atlantic region (55ºW-10ºW, 50ºN-65ºN) for 1000 years. While atmospheric CO2 is prognostic, atmospheric 14 C is set constant at 393‰. To simulate a shutdown of the AMOC in LOVECLIM, a freshwater perturbation is conducted under constant pre-industrial climate boundary conditions similar to the ones described for the UVic model above. The atmospheric 14 C is kept constant at 0 ‰. A highly idealized and constant freshwater perturbation of 0.5 Sv is applied to the North Atlantic (50ºN-70ºN, 70ºW-15ºE) for 2000 model years. As a consequence, the AMOC is reduced to values of about 4 Sv. LOVECLIM is based on the ECBilt-CLIO Earth system model of intermediate complexity extended by vegetation and marine carbon cycle components (Goosse et al., 2010). The sea ice-ocean component (CLIO) of LOVECLIM consists of a primitive equation level model with a horizontal resolution of 3◦ × 3◦ and 20 levels in the vertical with thicknesses ranging from 10 m to ∼700 m. CLIO uses a free surface and is coupled to a thermodynamic-dynamic sea ice model. Mixing along isopycnals, the effect of mesoscale eddies on transports and mixing as well as down-sloping currents at the bottom of continental shelves are parameterized (Goosse et al., 2010). The atmosphere component (ECBilt) is a spectral T21 model with 3 vertical levels and a horizontal resolution of about 5.625◦× 5.625◦. Diabatic heating due to radiative fluxes, the release of latent heat and the exchange of sensible heat with the surface are parameterized. The ocean, atmosphere and sea ice component of the ECBilt-CLIO model are coupled by exchange of momentum, heat and freshwater fluxes. More details on the LOVECLIM model can be found in Goosse et al., 2010. Figure S1: 
Figure S1: Conventional radiocarbon ages of benthic and planktonic foraminifera in core GS07-150-17/1GC-A. Figure S2: 
Figure S2: Timeseries of atmospheric (black line) and benthic (red triangles) Δ14C over the last deglaciation (Reimer et al., 2013). Directory: 3489 3489 -> Summary of 2007 atlantic tropical cyclone activity and verification of author’s seasonal and monthly forecasts 3489 -> Please type or print very clearly Download 478.84 Kb. Share with your friends:
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