Predictability and Decadal Variability of the North Atlantic Ocean State Evaluated from a Realistic Ocean Model

Florian Sévellec Ocean and Earth Science, University of Southampton, Southampton, United Kingdom

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Alexey V. Fedorov Department of Geology and Geophysics, Yale University, New Haven, Connecticut

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Abstract

This study investigates the excitation of decadal variability and predictability of the ocean climate state in the North Atlantic. Specifically, initial linear optimal perturbations (LOPs) in temperature and salinity that vary with depth, longitude, and latitude are computed, and the maximum impact on the ocean of these perturbations is evaluated in a realistic ocean general circulation model. The computations of the LOPs involve a maximization procedure based on Lagrange multipliers in a nonautonomous context. To assess the impact of these perturbations four different measures of the North Atlantic Ocean state are used: meridional volume and heat transports (MVT and MHT) and spatially averaged sea surface temperature (SST) and ocean heat content (OHC). It is shown that these metrics are dramatically different with regard to predictability. Whereas OHC and SST can be efficiently modified only by basin-scale anomalies, MVT and MHT are also strongly affected by smaller-scale perturbations. This suggests that instantaneous or even annual-mean values of MVT and MHT are less predictable than SST and OHC. Only when averaged over several decades do the former two metrics have predictability comparable to the latter two, which highlights the need for long-term observations of the Atlantic meridional overturning circulation in order to accumulate climatically relevant data. This study also suggests that initial errors in ocean temperature of a few millikelvins, encompassing both the upper and deep ocean, can lead to ~0.1-K errors in the predictions of North Atlantic sea surface temperature on interannual time scales. This transient error growth peaks for SST and OHC after about 6 and 10 years, respectively, implying a potential predictability barrier.

Corresponding author address: Florian Sévellec, Ocean and Earth Science, University of Southampton, Waterfront campus, European Way, Southampton, SO14 3ZH, United Kingdom. E-mail: florian.sevellec@noc.soton.ac.uk

Abstract

This study investigates the excitation of decadal variability and predictability of the ocean climate state in the North Atlantic. Specifically, initial linear optimal perturbations (LOPs) in temperature and salinity that vary with depth, longitude, and latitude are computed, and the maximum impact on the ocean of these perturbations is evaluated in a realistic ocean general circulation model. The computations of the LOPs involve a maximization procedure based on Lagrange multipliers in a nonautonomous context. To assess the impact of these perturbations four different measures of the North Atlantic Ocean state are used: meridional volume and heat transports (MVT and MHT) and spatially averaged sea surface temperature (SST) and ocean heat content (OHC). It is shown that these metrics are dramatically different with regard to predictability. Whereas OHC and SST can be efficiently modified only by basin-scale anomalies, MVT and MHT are also strongly affected by smaller-scale perturbations. This suggests that instantaneous or even annual-mean values of MVT and MHT are less predictable than SST and OHC. Only when averaged over several decades do the former two metrics have predictability comparable to the latter two, which highlights the need for long-term observations of the Atlantic meridional overturning circulation in order to accumulate climatically relevant data. This study also suggests that initial errors in ocean temperature of a few millikelvins, encompassing both the upper and deep ocean, can lead to ~0.1-K errors in the predictions of North Atlantic sea surface temperature on interannual time scales. This transient error growth peaks for SST and OHC after about 6 and 10 years, respectively, implying a potential predictability barrier.

Corresponding author address: Florian Sévellec, Ocean and Earth Science, University of Southampton, Waterfront campus, European Way, Southampton, SO14 3ZH, United Kingdom. E-mail: florian.sevellec@noc.soton.ac.uk
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  • Arzel, O., T. Huck, and A. Colin de Verdière, 2006: The different nature of the interdecadal variability of the thermohaline circulation under mixed and flux boundary conditions. J. Phys. Oceanogr., 36, 1703–1718, doi:10.1175/JPO2938.1.

    • Search Google Scholar
    • Export Citation
  • Baehr, J., and R. Piontek, 2014: Ensemble initialization of the oceanic component of a coupled model through bred vectors at seasonal-to-interannual timescales. Geosci. Model Dev., 7, 453–461, doi:10.5194/gmd-7-453-2014.

    • Search Google Scholar
    • Export Citation
  • Blanke, B., and P. Delecluse, 1993: Variability of the tropical Atlantic Ocean simulated by a general circulation model with two different mixed-layer physics. J. Phys. Oceanogr., 23, 1363–1388, doi:10.1175/1520-0485(1993)023<1363:VOTTAO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Branstator, G., and H. Teng, 2014: Is AMOC more predictable than North Atlantic heat content? J. Climate, 27, 3537–3550, doi:10.1175/JCLI-D-13-00274.1.

    • Search Google Scholar
    • Export Citation
  • Colin de Verdière, A., 1988: Buoyancy driven planetary flow. J. Mar. Res., 46, 215–265, doi:10.1357/002224088785113667.

  • Collins, M., and B. Sinha, 2003: Predictability of decadal variations in the thermohaline circulation and climate. Geophys. Res. Lett., 30, 1306, doi:10.1029/2002GL016504.

    • Search Google Scholar
    • Export Citation
  • Collins, M., and Coauthors, 2006: Interannual to decadal climate predictability in the North Atlantic: A multimodel-ensemble study. J. Climate, 19, 1195–1203, doi:10.1175/JCLI3654.1.

    • Search Google Scholar
    • Export Citation
  • Delworth, T. L., and M. E. Mann, 2000: Observed and simulated multidecadal variability in the Northern Hemisphere. Climate Dyn., 16, 661–676, doi:10.1007/s003820000075.

    • Search Google Scholar
    • Export Citation
  • Dufresne, J.-L., and Coauthors, 2013: Climate change projections using the IPSL-CM5 Earth System Model: From CMIP3 to CMIP5. Climate Dyn., 40, 2123–2165, doi:10.1007/s00382-012-1636-1.

    • Search Google Scholar
    • Export Citation
  • Epstein, E. S., 1988: Long-range weather prediction: Limits of predictability and beyond. Wea. Forecasting, 3, 69–75, doi:10.1175/1520-0434(1988)003<0069:LRWPLO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Farrell, B. F., and P. J. Ioannou, 1996a: Generalized stability theory. Part I: Autonomous operators. J. Atmos. Sci., 53, 2025–2040, doi:10.1175/1520-0469(1996)053<2025:GSTPIA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Farrell, B. F., and P. J. Ioannou, 1996b: Generalized stability theory. Part II: Nonautonomous operators. J. Atmos. Sci., 53, 2041–2053, doi:10.1175/1520-0469(1996)053<2041:GSTPIN>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Farrell, B. F., and P. J. Ioannou, 2001: Accurate low-dimensional approximation of the linear dynamics of fluid flow. J. Atmos. Sci., 58, 2771–2789, doi:10.1175/1520-0469(2001)058<2771:ALDAOT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Frederiksen, J. S., 2000: Singular vectors, finite-time normal modes, and error growth during blocking. J. Atmos. Sci., 57, 312–333, doi:10.1175/1520-0469(2000)057<0312:SVFTNM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., and C. Wunsch, 2000: Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature, 408, 453–457, doi:10.1038/35044048.

    • Search Google Scholar
    • Export Citation
  • Gent, P. R., and J. C. McWilliams, 1990: Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr., 20, 150–155, doi:10.1175/1520-0485(1990)020<0150:IMIOCM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Ghil, M., 2002: Natural climate variability. Encyclopedia of Global Environmental Science, Vol. 1, T. E. Munn, M. MacCracken, and J. Perry, Eds., J. Wiley and Sons, 544–549.

  • Goldenberg, S. B., C. W. Landsea, A. M. Mestas-Nuñez, and W. M. Gray, 2001: The recent increase in Atlantic hurricane activity: Causes and implications. Nature, 293, 474–479, doi:10.1126/science.1060040.

    • Search Google Scholar
    • Export Citation
  • Griffies, S. M., and K. Bryan, 1997: A predictability study of simulated North Atlantic multidecadal variability. Climate Dyn., 13, 459–487, doi:10.1007/s003820050177.

    • Search Google Scholar
    • Export Citation
  • Hasselmann, K., 1976: Stochastic climate models: Part I. Theory. Tellus, 28A, 473–485, doi:10.1111/j.2153-3490.1976.tb00696.x.

  • Hawkins, E., and R. Sutton, 2009a: Decadal predictability of the Atlantic Ocean in a coupled GCM: Forecast skill and optimal perturbations using linear inverse modeling. J. Climate, 22, 3960–3978, doi:10.1175/2009JCLI2720.1.

    • Search Google Scholar
    • Export Citation
  • Hawkins, E., and R. Sutton, 2009b: The potential to narrow uncertainty in regional climate predictions. Bull. Amer. Meteor. Soc., 90, 1095–1107, doi:10.1175/2009BAMS2607.1.

    • Search Google Scholar
    • Export Citation
  • Hawkins, E., and R. Sutton, 2011: Estimating climatically relevant singular vectors for decadal predictions of the Atlantic Ocean. J. Climate, 24, 109–123, doi:10.1175/2010JCLI3579.1.

    • Search Google Scholar
    • Export Citation
  • Hirschi, J., J. Baehr, J. Marotzke, J. Stark, S. Cunningham, and J.-O. Beismann, 2003: A monitoring design for the Atlantic meridional overturning circulation. Geophys. Res. Lett., 30, 1413, doi:10.1029/2002GL016776.

    • Search Google Scholar
    • Export Citation
  • Huck, T., and G. K. Vallis, 2001: Linear stability analysis of three-dimensional thermally-driven ocean circulation: Application to interdecadal oscillations. Tellus, 53A, 526–545, doi:10.1111/j.1600-0870.2001.00526.x.

    • Search Google Scholar
    • Export Citation
  • IPCC, 2013: Climate Change 2013: The Physical Science Basis. Cambridge University Press, 1535 pp.

  • Kushnir, Y., 1994: Interdecadal variations in North Atlantic sea surface temperature and associated atmospheric conditions. J. Climate, 7, 141–157, doi:10.1175/1520-0442(1994)007<0141:IVINAS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Levitus, S., 1989: Interpentadal variability of temperature and salinity at intermediate depths of the North Atlantic Ocean, 1970–1974 versus 1955–1959. J. Geophys. Res., 94, 16 125–16 131, doi:10.1029/JC094iC11p16125.

    • Search Google Scholar
    • Export Citation
  • Li, Y., S. Peng, and D. Liu, 2014: Adaptive observation in the South China Sea using CNOP approach based on a 3-D ocean circulation model and its adjoint model. J. Geophys. Res. Oceans, 119, 8973–8986, doi:10.1002/2014JC010220.

    • Search Google Scholar
    • Export Citation
  • Lorenz, E. N., 1963: Deterministic nonperiodic flow. J. Atmos. Sci., 20, 130–141, doi:10.1175/1520-0469(1963)020<0130:DNF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Lorenz, E. N., 1965: A study of the predictability of a 28-variable atmospheric model. Tellus, 17, 321–333, doi:10.1111/j.2153-3490.1965.tb01424.x.

    • Search Google Scholar
    • Export Citation
  • Madec, G., and M. Imbard, 1996: A global ocean mesh to overcome the North Pole singularity. Climate Dyn., 12, 381–388, doi:10.1007/BF00211684.

    • Search Google Scholar
    • Export Citation
  • Madec, G., P. Delécluse, M. Imbard, and C. Lévy, 1998: OPA 8.1 ocean general circulation model reference manual. Institut Pierre-Simon Laplace Tech. Rep. 11, 91 pp.

  • Marti, O., and Coauthors, 2010: Key features of the IPSL ocean atmosphere model and its sensitivity to atmospheric resolution. Climate Dyn., 34, 1–26, doi:10.1007/s00382-009-0640-6.

    • Search Google Scholar
    • Export Citation
  • Martinez-Villalobos, C., and D. J. Vimont, 2016: The role of the mean state in meridional mode structure and growth. J. Climate, 29, 3907–3921, doi:10.1175/JCLI-D-15-0542.1.

    • Search Google Scholar
    • Export Citation
  • Mignot, J., and S. Bony, 2013: Presentation and analysis of the IPSL and CNRM climate models used in CMIP5. Climate Dyn., 40, 2089, doi:10.1007/s00382-013-1720-1.

    • Search Google Scholar
    • Export Citation
  • Msadek, R., K. W. Dixon, T. L. Delworth, and W. Hurlin, 2010: Assessing the predictability of the Atlantic meridional overturning circulation and associated fingerprints. Geophys. Res. Lett., 37, L19608, doi:10.1029/2010GL044517.

    • Search Google Scholar
    • Export Citation
  • Mu, M., and Z. Zhang, 2006: Conditional nonlinear optimal perturbations of a two-dimensional quasigeostrophic model. J. Atmos. Sci., 63, 1587–1604, doi:10.1175/JAS3703.1.

    • Search Google Scholar
    • Export Citation
  • Persechino, A., J. Mignot, D. Swingedouw, S. Labetoulle, and E. Guilyardi, 2013: Decadal predictability of the Atlantic meridional overturning circulation and climate in the IPSL-CM5A-LR model. Climate Dyn., 40, 2359–2380, doi:10.1007/s00382-012-1466-1.

    • Search Google Scholar
    • Export Citation
  • Phillips, N. A., 1963: Geostrophic motions. Rev. Geophys., 1, 123–176, doi:10.1029/RG001i002p00123.

  • Pohlmann, H., M. Botzet, M. Latif, A. Roesch, M. Wild, and P. Tschuck, 2004: Estimating the decadal predictability of coupled AOGCM. J. Climate, 17, 4463–4472, doi:10.1175/3209.1.

    • Search Google Scholar
    • Export Citation
  • Redi, M. H., 1982: Oceanic isopycnal mixing by coordinate rotation. J. Phys. Oceanogr., 12, 1154–1158, doi:10.1175/1520-0485(1982)012<1154:OIMBCR>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Salmon, R., 1998: Lectures on Geophysical Fluid Dynamics. Oxford University Press, 400 pp.

  • Sévellec, F., and A. V. Fedorov, 2013a: The leading, interdecadal eigenmode of the Atlantic meridional overturning circulation in a realistic ocean model. J. Climate, 26, 2160–2183, doi:10.1175/JCLI-D-11-00023.1.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., and A. V. Fedorov, 2013b: Model bias reduction and the limits of oceanic decadal predictability: Importance of the deep ocean. J. Climate, 26, 3688–3707, doi:10.1175/JCLI-D-12-00199.1.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., and A. V. Fedorov, 2015: Optimal excitation of AMOC decadal variability: Links to the subpolar ocean. Prog. Oceanogr., 132, 287–304, doi:10.1016/j.pocean.2014.02.006.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., and T. Huck, 2015: Theoretical investigation of the Atlantic multidecadal oscillation. J. Phys. Oceanogr., 45, 2189–2208, doi:10.1175/JPO-D-14-0094.1.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., and A. V. Fedorov, 2016: AMOC sensitivity to surface buoyancy fluxes: Stronger ocean meridional heat transport with a weaker volume transport? Climate Dyn., 47, 1497–1513, doi:10.1007/s00382-015-2915-4.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., M. Ben Jelloul, and T. Huck, 2007: Optimal surface salinity perturbations influencing the thermohaline circulation. J. Phys. Oceanogr., 37, 2789–2808, doi:10.1175/2007JPO3680.1.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., T. Huck, M. Ben Jelloul, N. Grima, J. Vialard, and A. Weaver, 2008: Optimal surface salinity perturbations of the meridional overturning and heat transport in a global ocean general circulation model. J. Phys. Oceanogr., 38, 2739–2754, doi:10.1175/2008JPO3875.1.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., T. Huck, M. Ben Jelloul, and J. Vialard, 2009: Nonnormal multidecadal response of the thermohaline circulation induced by optimal surface salinity perturbations. J. Phys. Oceanogr., 39, 852–872, doi:10.1175/2008JPO3998.1.

    • Search Google Scholar
    • Export Citation
  • Sévellec, F., T. Huck, and A. Colin de Verdière, 2010: From centennial to millennial oscillation of the thermohaline circulation. J. Mar. Res., 68, 723–742, doi:10.1357/002224011795977635.

    • Search Google Scholar
    • Export Citation
  • Strogatz, S. H., 1994: Nonlinear Dynamics and Chaos with Applications to Physics, Biology, Chemistry and Engineering. Perseus, 498 pp.

  • Sutton, R. W., and D. L. R. Hodson, 2005: Atlantic Ocean forcing of North American and European summer climate. Science, 309, 115–118, doi:10.1126/science.1109496.

    • Search Google Scholar
    • Export Citation
  • Talley, L. D., J. L. Reid, and P. E. Robbins, 2003: Data-based meridional overturning streamfunctions for the global ocean. J. Climate, 16, 3213–3226, doi:10.1175/1520-0442(2003)016<3213:DMOSFT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Taylor, K. E., R. J. Stouffer, and G. A. Meehl, 2012: An overview of CMIP5 and the experiment design. Bull. Amer. Meteor. Soc., 93, 485–498, doi:10.1175/BAMS-D-11-00094.1.

    • Search Google Scholar
    • Export Citation
  • Teng, H., G. Branstator, and G. H. Meehl, 2011: Predictability of the Atlantic overturning circulation and associated surface patterns in two CCSM3 climate change ensemble experiments. J. Climate, 24, 6054–6076, doi:10.1175/2011JCLI4207.1.

    • Search Google Scholar
    • Export Citation
  • Tziperman, E., 1997: Inherently unstable climate behaviour due to weak thermohaline ocean circulation. Nature, 386, 592–595, doi:10.1038/386592a0.

    • Search Google Scholar
    • Export Citation
  • Tziperman, E., and P. J. Ioannou, 2002: Transient growth and optimal excitation of thermohaline variability. J. Phys. Oceanogr., 32, 3427–3435, doi:10.1175/1520-0485(2002)032<3427:TGAOEO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Tziperman, E., L. Zanna, and C. Penland, 2008: Nonnormal thermohaline circulation dynamics in a coupled ocean–atmosphere GCM. J. Phys. Oceanogr., 38, 588–604, doi:10.1175/2007JPO3769.1.

    • Search Google Scholar
    • Export Citation
  • Vimont, D. J., 2010: Transient growth of thermodynamically coupled variations in the tropics under an equatorially symmetric mean state. J. Climate, 23, 5771–5789, doi:10.1175/2010JCLI3532.1.

    • Search Google Scholar
    • Export Citation
  • Weaver, A. T., J. Vialard, and D. L. T. Anderson, 2003: Three- and four-dimensional variational assimilation with a general circulation model of the tropical Pacific Ocean. Part I: Formulation, internal diagnostics and consistency checks. Mon. Wea. Rev., 131, 1360–1378, doi:10.1175/1520-0493(2003)131<1360:TAFVAW>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Yoden, S., and M. Nomura, 1993: Finite-time Lyapunov stability analysis and its application to atmospheric predictability. J. Atmos. Sci., 50, 1531–1543, doi:10.1175/1520-0469(1993)050<1531:FTLSAA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Zanna, L., 2012: Forecast skill and predictability of observed Atlantic sea surface temperatures. J. Climate, 25, 5047–5056, doi:10.1175/JCLI-D-11-00539.1.

    • Search Google Scholar
    • Export Citation
  • Zanna, L., and E. Tziperman, 2005: Nonnormal amplification of the thermohaline circulation. J. Phys. Oceanogr., 35, 1593–1605, doi:10.1175/JPO2777.1.

    • Search Google Scholar
    • Export Citation
  • Zanna, L., and E. Tziperman, 2008: Optimal surface excitation of the thermohaline circulation. J. Phys. Oceanogr., 38, 1820–1830, doi:10.1175/2008JPO3752.1.

    • Search Google Scholar
    • Export Citation
  • Zanna, L., P. Heimbach, A. M. Moore, and E. Tziperman, 2011: Optimal excitation of interannual Atlantic meridional overturning circulation variability. J. Climate, 24, 413–427, doi:10.1175/2010JCLI3610.1.

    • Search Google Scholar
    • Export Citation
  • Zu, Z., M. Mu, and H. A. Dijkstra, 2013: Optimal nonlinear excitation of decadal variability of the North Atlantic thermohaline circulation. Chin. J. Oceanol. Limnol., 31, 1368–1374, doi:10.1007/s00343-014-3051-4.

    • Search Google Scholar
    • Export Citation
  • Zu, Z., M. Mu, and H. A. Dijkstra, 2016: Optimal initial excitations of decadal modification of the Atlantic meridional overturning circulation under the prescribed heat and freshwater flux boundary conditions. J. Phys. Oceanogr., 46, 2029–2047, doi:10.1175/JPO-D-15-0100.1.

    • Search Google Scholar
    • Export Citation
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