New Radiocarbon Constraints on the Upwelling of Abyssal Water to the Ocean’s Surface

摘要: The output from seven different ocean model simulations is compared on the basis of Δ14C difference between North Pacific deep water and Antarctic surface water. This set models produces a range Pacific-Antarctic differences -173‰ -108‰, all but smallest which are substantially larger than actual pre-bomb difference, -80 to -110‰. Predicted values highly correlated with quantity mid-depth flows out south. A circulation in most bottom back basin at differences, whereas inflow upwells through thermocline largest least realistic differences. According models, upwelled abyssal becomes entrained into wind-driven convergence toward equator. When it reaches spreads north south, producing minimum along detailed analysis both post-bomb data indicates that oldest tropical actually found south equator associated upwelling off Peru, not Toggweiler et al. (1991) trace low-Δ14C signal Peru raised around Antarctica pushed northward by circumpolar winds. even small amount (~3x106 m3·s -1) leaves characteristic distribution observed. One left general conclusion there very little top-to-bottom thermohaline world ocean. Virtually ocean’s occurs where mainly wind-forced. implications this for carbon cycle discussed.