Abstract
Distributions and characteristics of water mass and chlorofluorocarbons (CFCs) in the North Pacific are investigated by using a General Circulation Model (GCM). The anthropogenic CO2 uptake by the ocean is estimated with velocity fields derived from the GCM experiments. The sensitivity of the uptake to different diffusion parameterizations and different surface forcing used in the GCM is investigated by conducting the three GCM experiments; the diffusive processes are parameterized by horizontal and vertical eddy diffusion which is used in many previous models (RUN1), parameterized by isopycnal diffusion (RUN2), and isopycnal diffusion and perpetual winter forcing for surface temperature and salinity (RUN3). Realistic features for water masses and CFCs can be simulated by the isopycnal diffusion models. The horizontal and vertical diffusion model fails to simulate the salinity minimum and realistic penetration of CFCs into the ocean. The depth of the salinity minimum layer is better simulated under the winter forcing. The results suggest that both isopycnal parameterization and winter forcing are crucial for the model water masses and CFCs simulations. The oceanic uptake of anthropogenic CO2 in RUN3 is about 19.8 GtC in 1990, which is larger by about 10% than that in RUN1 with horizontal and vertical diffusive parameterization. RUN3 well simulates the realistic water mass structure of the intermediate layer considered as a candidate of oceanic sink for anthropogenic CO2. The results suggest that the previous models with horizontal and vertical diffusive parameterization may give the oceanic uptake of anthropogenic CO2 underestimated.
Similar content being viewed by others
References
Bryan, K. (1969): A numerical method for the study of the circulation of the world ocean. J. Comput. Phys., 4, 347–376.
Cox, M. D. (1984): A primitive equation, 3-dimensional model of the ocean. GFDL Ocean Group Technical Report, No. 1.
Cox, M. D. (1987): Isopycnal diffusion in a z-coordinate ocean model. Ocean Modeling, 74, 1–5.
Craig, A. P., J. L. Bullister, D. E. Harrison, R. M. Chervin and A. J. Semtner, Jr. (1998): A comparison of temperature, salinity, and chlorofluorocarbon observations with results from a 1° resolution three-dimensional global ocean model. J. Geophys. Res., 103, 1009–1119.
England, M. H. (1993): Representing the global-scale water masses in ocean general circulation models. J. Phys. Oceanogr., 23, 1,523–1,552.
England, M. H. (1995): Using chlorofluorocarbon to assess ocean climate models. Geophys. Res. Lett., 22, 3051–3054.
England, M. H. and A. C. Hirst (1997): Chlorofluorocarbon uptake in a world ocean model 2. Sensitivity to surface thermohaline forcing and subsurface mixing paramterizations. J. Geophys. Res., 102, 15,709–15,731.
England, M. H., V. Garçon and J.-F. Minster (1994): Chlorofluorocarbon uptake in a world ocean model, 1. Sensitivity to the surface gas forcing. J. Geophys. Res., 99, 25,215–25,233.
Friedli, H., H. Lotscher, H. Oeschger, U. Siegenthaler and B. Stauffer (1986): Ice core record of 13-C/12-C ratio of atmospheric CO2 in the past two centuries. Nature, 324, 237–238.
Gent, P. R. and J. C. McWilliams (1990): Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr., 20, 150–155.
Gent, P. R., J. Willebrand, T. J. McDougall and J. C. McWilliams (1995): Parameterizing eddy-induced tracer transports in ocean circulation models. J. Phys. Oceanogr., 25, 463–474.
Hellerman, S. and M. Rosenstein (1983): Normal monthly wind stress over the world ocean with error estimates. J. Phys. Oceanogr., 13, 1093–1104.
Hirst, A. C. and W. Cai (1994): Sensitivity of a world ocean GCM to changes in subsurface mixing parameterization. J. Phys. Oceanogr., 24, 1256–1277.
IPCC (Intergovernmental Panel on Climate Change) (1990): Climate Change. The IPCC Scientific Assessment, ed. by J. T. Houghton, G. J. Jenkins and J. J. Epshraus, Cambridge University Press, New York, 365 pp.
IPCC (Intergovernmental Panel on Climate Change) (1992): The Supplementary Report to the IPCC Scientific Assessment, ed. by J. T. Houghton, B. A. Callander and S. K. Varney, Cambridge University Press, New York, 200 pp.
IPCC (Intergovernmental Panel on Climate Change) (1994): Climate Change 1994: Radiative Forcing of Climate Change and an Evaluation of the IPCC IS92 Emissions Scenarios, ed. by J. T. Houghton, L. G. Meira Filho, J. Bruce, Hoesung Lee, B. A. Callander, E. Haites, N. Harris and K. Maskell, Cambridge University Press, New York, 339 pp.
IPCC (Intergovernmental Panel on Climate Change) (1995): Climate Change 1995: The Science of Climate Change, ed. by J. T. Houghton, L. G. Meira Filho, B. A. Callander, N. Harris, A. Kattenberg and K. Maskell, Cambridge University Press, New York, 572 pp.
Ishida, A., K. Nakata, S. Aoki, H. Kutsukake, M. Kishi and M. Kubota (1995): Numerical experiment of anthropogenic CO2 in the North Pacific. J. Adv. Mar. Sci. Tech. Soc., 1, 49–62.
Keeling, C. D. and T. P. Whorf (1991): Atmospheric CO2—Modern record, Mauna Loa. p. 12–15. In Trends '91: A Compendium of Data on Global Change, ORNL/CDIAC-46, ed. by T. A. Boden, R. J. Sepanski and F. W. Stoss, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A.
Krauss, W. and C. W. Böning (1987): Lagrangian properties of eddy fields in the northern North Atlantic as deduced from satellite-tracked buoys. J. Mar. Res., 45, 259–291.
Levitus, S., R. Burgett and T. Boyer (1994): World Ocean Atlas 1994, Vol. 3, Salinity, and Vol. 4, Temperature, NOAA Atlas NESDIS 3 and 4, U.S. Dep. of Comm., Washington, D.C.
Maier-Reimer, E. (1993): The biological pump in the greenhouse. Global and Planetary Change, 8, 13–15.
Neftel, A., E. Moor, H. Oeschger and B. Stauffer (1985): Evidence from polar ice cores for the increase in atmospheric CO2 in the past two centuries. Nature, 315, 45–47.
Pacanowski, R. C. (1995): The GFDL modular ocean model 2 user's guide and reference manual, Ver. 1,0, The GFDL Ocean Technical Report No. 3, GFDL, Princeton, N.J., U.S.A.
Qiu, B. (1995): Why is the spreading of the North Pacific Intermediate Water confined on density surfaces around σϑ = 26.8? J. Phys. Oceanogr., 25, 168–180.
Redi, M. H. (1982): Oceanic isopycnal mixing by coordinate rotation. J. Phys. Oceanogr., 12, 1154–1158.
Robitaille, D. Y. and A. J. Weaver (1995): Validation of subgrid-scale mixing schemes using CFCs in a global ocean model. Geophys. Res. Lett., 22, 2917–2920.
Sarmiento, J. L., J. C. Orr and U. Siegenthaler (1992): A perturbation simulation of CO2 uptake in an ocean general circulation model. J. Geophys. Res., 97, 3621–3645.
Siegenthaler, U. and F. Joos (1992): Use of a simple model for studying oceanic tracer distributions and the global carbon cycle. Tellus, 44B, 186–207.
Siegenthaler, U. and J. L. Sarmiento (1993): Atmospheric carbon dioxide and the ocean. Nature, 365, 119–125.
Tsunogai, S., T. Ono and S. Watanabe (1993): Increase in total carbonate in the western North Pacific water and a hypothesis on missing sink of anthropogenic carbon. J. Oceanogr., 49, 305–315.
Warner, M. J. and R. F. Weiss (1985): Solubility of chlorofluorocarbons 11 and 12 in water and seawater. Deep-Sea Res., 32A, 1485–1497.
Warner, M. J., J. L. Bullister, D. P. Wisegarver, R. H. Gammon and R. F. Weiss (1996): Basin-wide distributions of chlorofluorocarbons CFC-11 and CFC-12 in the North Pacific: 1985–1989. J. Geophys. Res., 101, 20,525–20,542.
Watanabe, Y. W., K. Harada and K. Ishikawa (1994): Chlorofluorocarbons in the central North Pacific and southward spreading time of North Pacific intermediate water. J. Geophys. Res., 99, 25,195–25,213.
Watanabe, Y. W., Y. Takahashi, T. Kitao and K. Harada (1996): Total amount of oceanic excess CO2 taken from the North Pacific subpolar region. J. Oceanogr., 52, 301–312.
Watanabe, Y. W., A. Ishida, M. Tamaki and M. Fukasawa (1997): Water column Inventories of chlorofluorocarbons and production rate of intermediate water in the North Pacific. Deep-Sea Res., 44, 1091–1104.
Yamanaka, G., Y. Kitamura and M. Endo (1998a): Formation of North Pacific Intermediate Water in Meteorological Research Institute ocean general circulation model 1. Subgrid-scale mixing and marginal sea fresh water. J. Geophys. Res., 103, 30,885–30,903.
Yamanaka, G., Y. Kitamura and M. Endo (1998b): Formation of North Pacific Intermediate Water in Meteorological Research Institute ocean general circulation model 2. Transient tracer experiments. J. Geophys. Res., 103, 30,905–30,921.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ishida, A., Nakata, K., Aoki, S. et al. Sensitivity of CFCs and Anthropogenic CO2 Uptake in a North Pacific GCM to Mixing Parameterization and Surface Forcing. Journal of Oceanography 57, 433–450 (2001). https://doi.org/10.1023/A:1021221200895
Issue Date:
DOI: https://doi.org/10.1023/A:1021221200895