Biogeochemical fields were initialized using databased climatologies; for instance, DIC was from the Global Ocean Data Analysis Project (GLODAP; Key et al. 2004) and nutrients were from the World Ocean Atlas (WOA; Garcia et al. 2006). Subsequently, the fully coupled model was integrated for a period of 1000yr to allowthedeepoceantoapproachequilibrium;thetracer fields resulting from this spinup procedure were used to initialize a 1000-yr steady-state climate simulation (Lindsay et al. 2012, manuscript submitted to J. Climate), in which atmospheric CO2 was held constant at preindustrial levels (pCO2atm 5 284.7ppm). In this paper, we examine two ‘‘twentieth century’’ simulations branched off this steady-state run after 150 years of integration