TY - JOUR T1 - Estimates of anthropogenic carbon uptake from four three-dimensional global ocean models JF - Global Biogeochemical Cycles Y1 - 2001 A1 - Orr, J. C. A1 - Maier-Reimer, E. A1 - Mikolajewicz, U. A1 - Monfray, P. A1 - Sarmiento, J. L. A1 - Toggweiler, J. R. A1 - Taylor, N. K. A1 - Palmer, J. A1 - Gruber, N. A1 - Sabine, C. L. A1 - Le Quere, C. A1 - Key, R. M. A1 - Boutin, J. AB - We have compared simulations of anthropogenic CO2 in the four three-dimensional ocean models that participated in the first phase of the Ocean Carbon-Cycle Model Intercomparison Project (OCMIP), as a means to identify their major differences. Simulated global uptake agrees to within +/- 19%, giving a range of 1.85 +/-0.35 Pg C yr(-1) for the 1980-1989 average, Regionally, the Southern Ocean dominates the present-day air-sea flux of anthropogenic CO2 in all models, with one third to one half of the global uptake occurring south of 30 degreesS. The highest simulated total uptake in the Southern Ocean was 70% larger than the lowest. Comparison with recent data-based estimates of anthropogenic CO2 suggest that most of the models substantially overestimate storage in the Southern Ocean; elsewhere they generally underestimate storage by less than 20%. Globally, the OCMIP models appear to bracket the real ocean's present uptake, based on comparison of regional data-based estimates of anthropogenic CO2 and bomb C-14. Column inventories of bomb C-14 have become more similar to those for anthropogenic CO2 with the time that has elapsed between the Geochemical Ocean Sections Study (1970s) and World Ocean Circulation Experiment (1990s) global sampling campaigns. Our ability to evaluate simulated anthropogenic CO2 would improve if systematic errors associated with the data-based estimates could be provided regionally. VL - 15 IS - 1 N1 - 417rwTimes Cited:187Cited References Count:64 JO - Estimates of anthropogenic carbon uptake from four three-dimensional global ocean models ER - TY - JOUR T1 - How much deep water is formed in the Southern Ocean? JF - Journal of Geophysical Research-Oceans Y1 - 1998 A1 - Broecker, W. S. A1 - Peacock, S. L. A1 - Walker, S. A1 - Weiss, R. A1 - Fahrbach, E. A1 - Schroeder, M. A1 - Mikolajewicz, U. A1 - Heinze, C. A1 - Key, R. A1 - Peng, T. H. A1 - Rubin, S. AB - Three tracers are used to place constraints on the production rate of ventilated deep water in the Southern Ocean. The distribution of the water mass tracer PO4* ("phosphate star") in the deep sea suggests that the amount of ventilated deep water produced in the Southern Ocean is equal to or greater than the outflow of North Atlantic Deep Water from the Atlantic. Radiocarbon distributions yield an export flux of water from the North Atlantic which has averaged about 15 Sv over the last several hundred years. CFC inventories are used as a direct indicator of the current production rate of ventilated deep water in the Southern Ocean. Although coverage is as yet sparse, it appears that the CFC inventory is not inconsistent with the deep water production rate required by the distributions of PO4* and radiocarbon. It has been widely accepted that the major part of the deep water production in the Southern Ocean takes place in the Weddell Sea. However, our estimate of the Southern Ocean ventilated deep water flux is in conflict with previous estimates of the flux of ventilated deep water from the Weddell Sea, which lie in the range 1-5 Sv. Possible reasons for this difference are discussed. VL - 103 IS - C8 N1 - Zz547Times Cited:115Cited References Count:44 JO - How much deep water is formed in the Southern Ocean? ER -