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Supplementary data:
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the LOVECLIM earth system models of intermediate complexity.
Model set up
Freshwater perturbation simulations have been conducted with the UVic ESCM and
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The freshwater perturbation experiment with the University of Victoria Earth System
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Climate Model (UVic ESCM v2.9) (Weaver et al. 2001) was performed under
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constant Last Glacial Maximum boundary conditions. The UVic ESCM consists of an
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ocean general circulation model (Modular Ocean Model, Version 2) with a resolution
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of 3.6º longitude and 1.8º latitude, coupled to a vertically integrated two dimensional
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energy-moisture balance model of the atmosphere including a parameterization of
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geostrophic wind stress anomalies, a dynamic-thermodynamic sea ice model, a land
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surface scheme, a dynamic global vegetation model, a marine carbon cycle model
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(Schmittner et al. 2008) and a sediment model. The model is initialized under constant
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Last Glacial Maximum (LGM, 21 ka B.P.) boundary conditions, which include orbital
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parameters, Northern Hemispheric ice extent and thickness (Peltier, 2002), an
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atmospheric CO2 content of 191 ppmv and Atmospheric 14 C of 393‰ (Reimer et
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al., 2009). To simulate a shutdown of the Atlantic Meridional Overturning Circulation,
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0.2Sv (1Sv =106m3/s) of freshwater is added into the North Atlantic region (55ºW-
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10ºW, 50ºN-65ºN) for 1000 years. While atmospheric CO2 is prognostic, atmospheric
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14 C is set constant at 393‰.
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To simulate a shutdown of the AMOC in LOVECLIM, a freshwater perturbation is
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conducted under constant pre-industrial climate boundary conditions similar to the
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ones described for the UVic model above. The atmospheric 14 C is kept constant at
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0 ‰. A highly idealized and constant freshwater perturbation of 0.5 Sv is applied to
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the North Atlantic (50ºN-70ºN, 70ºW-15ºE) for 2000 model years. As a consequence,
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the AMOC is reduced to values of about 4 Sv. LOVECLIM is based on the ECBilt-
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CLIO Earth system model of intermediate complexity extended by vegetation and
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marine carbon cycle components (Goosse et al., 2010). The sea ice-ocean component
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(CLIO) of LOVECLIM consists of a primitive equation level model with a horizontal
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resolution of 3◦ × 3◦ and 20 levels in the vertical with thicknesses ranging from 10 m
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to ∼700 m. CLIO uses a free surface and is coupled to a thermodynamic-dynamic sea
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ice model. Mixing along isopycnals, the effect of mesoscale eddies on transports and
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mixing as well as down-sloping currents at the bottom of continental shelves are
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parameterized (Goosse et al., 2010).
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The atmosphere component (ECBilt) is a spectral T21 model with 3 vertical levels
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and a horizontal resolution of about 5.625◦× 5.625◦. Diabatic heating due to radiative
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fluxes, the release of latent heat and the exchange of sensible heat with the surface are
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parameterized. The ocean, atmosphere and sea ice component of the ECBilt-CLIO
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model are coupled by exchange of momentum, heat and freshwater fluxes. More
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details on the LOVECLIM model can be found in Goosse et al., 2010.
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Figure S1:
Figure S1: Conventional radiocarbon ages of benthic and planktonic foraminifera in
core GS07-150-17/1GC-A.
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Figure S2:
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Figure S2: Timeseries of atmospheric (black line) and benthic (red triangles) Δ14C
over the last deglaciation (Reimer et al., 2013).
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Table S1:
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Table S2:
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Supplementary references:
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Goosse, H., V. Brovkin, T. Fichefet, R. Haarsma, P. Huybrechts, J. Jongma, A.
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Mouchet, F. Selten, P.-Y. Barriat, J.-M. Campin, E. Deleersnijder, E. Driesschaert, H.
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Goelzer, I. Janssens, M.-F. Loutre, M. A. M. Maqueda, T. Opsteegh, P.-P. Mathieu,
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G. Munhoven, E. J. Petters- son, H. Renssen, D. M. Roche, M. Schaeffer, B.
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Tartinville, A. Timmermann, and S. L. Weber . 2010. Description of the Earth system
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model of intermediate complexity LOVECLIM version 1.2, Geoscientific Model
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Development, 3, 603–633.
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Peltier, W. R. 2002. Global glacial isostatic adjustment: palaeogeodetic and
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space-geodetic tests of the ICE-4G (VM2) model. Journal of Quaternary
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Science, 17, 491–510.
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Reimer, P, Baillie, M, Bard, E, Bayliss, A, Beck, J, Blackwell, P, Ramsey, C,
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Buck, C, Burr, G, Edwards, R, Friedrich, M, Grootes, P, Guilderson, T, Hajdas,
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I, Heaton, T, Hogg, A, Hughen, K, Kaiser, K, Kromer, B, McCormac, F,
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Manning, S, Reimer, R, Richards, D, Southon, J, Talamo, S, Turney, C, van der
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Plicht, J, & Weyhenmeyer, C. 2009. Intcal09 and Marine09 radiocarbon age
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calibration curves, 0-50,000 years Cal BP. Radiocarbon, 51(4).
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Reimer, Paula, Bard, Edouard, Bayliss, Alex, Beck, J, Blackwell, Paul,
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Ramsey, Christopher Bronk, Buck, Caitlin, Cheng, Hai, Edwards, R Lawrence,
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Friedrich, Michael, Grootes, Pieter, Guilderson, Thomas, Haflidason, Haflidi,
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Hajdas, Irka, Hatt ́e, Christine, Heaton, Timothy, Hoffmann, Dirk, Hogg, Alan,
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Hughen, Konrad, Kaiser, K, Kromer, Bernd, Manning, Sturt, Niu, Mu, Reimer,
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Ron, Richards, David, Scott, E, Southon, John, Staff, Richard, Turney,
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Christian, & van der Plicht, Johannes. 2013. Intcal13 and Marine13
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radiocarbon age calibration curves 0–50,000 years Cal BP. Radiocarbon, 55(4).
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Schmittner, A., A. Oschlies, H. D. Matthews, and E. D. Galbraith .2008.
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Future changes in climate, ocean circulation, ecosystems, and biogeochemical
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cycling simulated for a business-as-usual CO2 emission scenario until year
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4000 AD, Global Biogeochem. Cycles, 22, GB1013.
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Weaver, AJ, Matthews, HD, Meissner, KJ, Saenko, O., Schmittner, A., Wang,
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HX, Yoshimori, M., Eby, M., Wiebe, EC, Bitz, CM, Duffy, PB, Ewen, TL,
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Fanning, AF, Holland, MM, & MacFadyen, A. 2001. The Uvic earth system
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climate model: Model description, climatology, and applications to past,
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present and future climates. Atmosphere-Ocean, 39(4), 361–428.
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