Oceanography The Official Magazine of
The Oceanography Society
Volume 31 Issue 02

View Issue TOC
Volume 31, No. 2
Pages 63 - 71

Chaotic Variability of Ocean Heat Content: Climate-Relevant Features and Observational Implications

Thierry Penduff Guillaume SérazinStéphanie LerouxSally CloseJean-Marc MolinesBernard BarnierLaurent BessièresLaurent TerrayGuillaume Maze
Article Abstract

Global ocean models that admit mesoscale turbulence spontaneously generate a substantial interannual-to-multidecadal chaotic intrinsic variability in the absence of atmospheric forcing variability at these timescales. This phenomenon is substantially weaker in non-turbulent ocean models but provides a marked stochastic flavor to the low-​frequency variability in eddying ocean models, which are being coupled to the atmosphere for next-generation climate projections. In order to disentangle the atmospherically forced and intrinsic ocean variabilities, the OCCIPUT (OceaniC Chaos – ImPacts, strUcture, predicTability) project performed a long (1960–2015), large ensemble (50 members) of global ocean/sea ice 1/4° simulations driven by the same atmospheric reanalysis, but with perturbed initial conditions. Subsequent ensemble statistics show that the ocean variability can be seen as a broadband “noise,” with characteristic scales reaching multiple decades and basin sizes, locally modulated by the atmospheric variability. In several mid-latitude regions, chaotic processes have more impact than atmospheric variability on both the low-frequency variability and the long-term trends of regional ocean heat content. Consequently, certain climate-relevant oceanic signals cannot be unambiguously attributed to atmospheric variability, raising new issues for the detection, attribution, and interpretation of oceanic heat variability and trends in the presence of mesoscale turbulence.


Penduff, T., G. Sérazin, S. Leroux, S. Close, J.-M. Molines, B. Barnier, L. Bessières, L. Terray, and G. Maze. 2018. Chaotic variability of ocean heat content: Climate-relevant features and observational implications. Oceanography 31(2):63–71, https://doi.org/10.5670/oceanog.2018.210.


Arbic, B.K., M. Müller, J.G. Richman, J.F. Shriver, A.J. Morten, R.B. Scott, G. Sérazin, and T. Penduff. 2014. Geostrophic turbulence in the frequency–​wavenumber domain: Eddy-driven low-frequency variability. Journal of Physical Oceanography 44:2,050–2,069, https://doi.org/​10.1175/JPO-D-13-054.1.

Arbic, B.K., R.B. Scott, G.R. Flierl, A.J. Morten, J.G. Richman, and J.F. Shriver. 2012. Nonlinear cascades of surface oceanic geostrophic kinetic energy in the frequency domain. Journal of Physical Oceanography 42:1,577–1,600, https://doi.org/​10.1175/JPO-D-11-0151.1.

Barnett, T.P., D.W. Pierce, and R. Schnur. 2001. Detection of anthropogenic climate change in the world’s oceans. Science 292:270–274, https://doi.org/​10.1126/science.1058304.

Barnier, B., T. Penduff, and C. Langlais. 2010. Eddying vs. laminar ocean circulation models and their applications. Chapter 10 in Operational Oceanography in the 21st Century. A. Schiller and G.B. Brassington, eds, Springer.

Bellomo, K., L.N. Murphy, M.A. Cane, A.C. Clement, and L.M. Polvani. 2017. Historical forcings as main drivers of Atlantic multidecadal variability in the CESM Large Ensemble. Climate Dynamics 50:3,687–3,698, https://doi.org/10.1007/s00382-017-3834-3.

Bessières, L., S. Leroux, J.-M. Brankart, J.-M. Molines, M.-P. Moine, P.-A. Bouttier, T. Penduff, L. Terray, B. Barnier, and G. Sérazin. 2017. Development of a probabilistic ocean modelling system based on NEMO 3.5: Application at eddying resolution. Geoscientific Model Development 10:1,091–1,106, https://doi.org/10.5194/gmd-10-1091-2017.

Charney, J.G. 1971. Geostrophic turbulence. Journal of Atmospheric Sciences 28:1,087–1,095, https://doi.org/10.1175/​1520-0469(1971)028​<1087:GT>​2.0.CO;2.

Chen, C., I. Kamenkovich, and P. Berloff. 2016. Eddy trains and striations in quasigeostrophic simulations and the ocean. Journal of Physical Oceanography 46:2,807–2,825, https://doi.org/​10.1175/JPO-D-16-0066.1.

Church, J.A., N.J. White, L.F. Konikow, C.M. Domingues, J.G. Cogley, E. Rignot, J.M. Gregory, M.R. van den Broeke, A.J. Monaghan, and I. Velicogna. 2011. Revisiting the Earth’s sea-level and energy budgets from 1961 to 2008. Geophysical Research Letters 38, L18601, https://doi.org/​10.1029/​2011GL048794.

Colin de Verdière, A., and T. Huck. 1999. Baroclinic instability: An oceanic wavemaker for interdecadal variability. Journal of Physical Oceanography 29:893–910, https://doi.org/​10.1175/​1520-0485​(1999)029​<0893:BIAOWF>​2.0.CO;2.

Ferrari, R., and C. Wunsch. 2009. Ocean circulation kinetic energy: Reservoirs, sources, and sinks. Annual Review of Fluid Mechanics 41:253–282, https://doi.org/10.1146/annurev.fluid.40.111406.102139.

Fjortoft, R. 1953. On the changes in the spectral distribution of kinetic energy for two-dimensional nondivergent flow. Tellus 5:225–230, https://doi.org/​10.3402/tellusa.v5i3.8647.

Gleckler, P.J., B.D. Santer, C.M. Domingues, D.W. Pierce, T.P. Barnett, J.A. Church, K.E. Taylor, K.M. AchutaRao, T.P. Boyer, M. Ishii, and P.M. Caldwell. 2012. Human-induced global ocean warming on multidecadal timescales. Nature Climate Change 2:524–529, https://doi.org/​10.1038/nclimate1553.

Good, S.A., M.J. Martin, and N.A. Rayner. 2013. EN4: Quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates. Journal of Geophysical Research 118:6,704–6,716, https://doi.org/​10.1002/​2013JC009067.

Grégorio, S., T. Penduff, G. Sérazin, J.-M. Molines, B. Barnier, and J. Hirschi. 2015. Intrinsic variability of the Atlantic Meridional Overturning Circulation at interannual-to-multidecadal timescales. Journal of Physical Oceanography 45(7):1,929–1,946, https://doi.org/10.1175/JPO-D-14-0163.1.

Gulev, S.K., M. Latif, N. Keenlyside, W. Park, and K.P. Koltermann. 2013. North Atlantic Ocean control on surface heat flux on multidecadal timescales. Nature 499:464–467, https://doi.org/10.1038/nature12268.

Griffies, S.M., A. Biastoch, C. Böning, F. Bryan, G. Danabasoglu, E.P. Chassignet, M.H. England, R. Gerdes, H. Haak, R.W. Hallberg, and others. 2009. Coordinated ocean-ice reference experiments (COREs). Ocean Modelling 26(1):1-46, https://doi.org/10.1016/j.ocemod.2008.08.007.

Holloway, G. 2004. From classical to statistical ocean dynamics. Surveys in Geophysics 25:203–219, https://doi.org/10.1007/s10712-004-1272-3.

Huck, T., O. Arzel, and F. Sévellec. 2015. Multidecadal variability of the overturning circulation in presence of eddy turbulence. Journal of Physical Oceanography 45(1):157–173, https://doi.org/​10.1175/JPO-D-14-0114.1.

IPCC. 2013. Climate Change, 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. T.F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex, and P.M. Midgley, eds, Cambridge University Press, Cambridge, UK, and New York, NY, USA, 1,535 pp., https://doi.org/10.1017/CBO9781107415324.

Kraichnan, R.H. 1967. Inertial ranges in two-dimensional turbulence. Physics of Fluids 10:1,417–1,423, https://doi.org/10.1063/1.1762301.

Leroux, S., T. Penduff, L. Bessières, J. Molines, J. Brankart, G. Sérazin, B. Barnier, and L. Terray. 2018. Intrinsic and atmospherically forced variability of the AMOC: Insights from a large-ensemble ocean hindcast. Journal of Climate 31:1,183–1,203, https://doi.org/10.1175/JCLI-D-17-0168.1.

Llovel, W., S. Guinehut, and A. Cazenave. 2010. Regional and interannual variability in sea level over 2002–2009 based on satellite altimetry, Argo float data and GRACE ocean mass. Ocean Dynamics 60:1,193–1,204, https://doi.org/10.1007/s10236-010-0324-0.

Menary, M.B., W. Park, K. Lohmann, M. Vellinga, M.D. Palmer, M. Latif, and J.H. Jungclaus. 2012. A multimodel comparison of centennial Atlantic meridional overturning circulation variability. Climate Dynamics 38:2,377–2,388, https://doi.org/​10.1007/s00382-011-1172-4.

Nerem, R.S., B.D. Beckley, J.T. Fasullo, B.D. Hamlington, D. Masters, and G.T. Mitchum. 2018. Climate-change-driven accelerated sea-level rise detected in the altimeter era. Proceedings of the National Academy of Sciences of the United States of America 115(9):2,022–2,025, https://doi.org/​10.1073/pnas.1717312115.

O’Kane, T.J., R.J. Matear, M.A. Chamberlain, J.S. Risbey, B.M. Sloyan, and I. Horenko. 2013. Decadal variability in an OGCM Southern Ocean: Intrinsic modes, forced modes and metastable states. Ocean Modelling 69:1–21, https://doi.org/​10.1016/j.ocemod.2013.04.009.

O’Rourke, A.K., B.K. Arbic, and S.M. Griffies. 2018. Frequency-domain analysis of atmospherically forced versus intrinsic ocean surface kinetic energy variability in GFDL’s CM2-O model hierarchy. Journal of Climate 31:1,789–1,810, https://doi.org/​10.1175/JCLI-D-17-0024.1.

Penduff, T., B. Barnier, L. Terray, L. Bessières, G. Sérazin, J.-M. Brankart, M.-P. Moine, J.-M. Molines, and P. Brasseur. 2014. Ensembles of eddying ocean simulations for climate. CLIVAR Exchanges No. 65 19(2):26–29.

Penduff, T., M. Juza, B. Barnier, J. Zika, W.K. Dewar, A.-M. Treguier, J.-M. Molines, and N. Audiffren. 2011. Sea-level expression of intrinsic and forced ocean variabilities at interannual time scales. Journal of Climate 24:5,652–5,670, https://doi.org/10.1175/JCLI-D-11-00077.1.

Purkey, S.G., and G.C. Johnson. 2010. Warming of global abyssal and deep Southern Ocean waters between the 1990s and 2000s: Contributions to global heat and sea level rise budgets. Journal of Climate 23:6,336–6,351, https://doi.org/​10.1175/​2010JCLI3682.1.

Rhein, M., S.R. Rintoul, S. Aoki, E. Campos, D. Chambers, R.A. Feely, S. Gulev, G.C. Johnson, S.A. Josey, A. Kostianoy, and others. 2013. Observations: Ocean. Chapter 3 in Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, T.F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex, and P.M. Midgley, eds, Cambridge University Press, Cambridge, UK, and New York, NY, USA.

Riser S.C., H.J. Freeland, D. Roemmich, S. Wijffels, A. Troisi, M. Belbéoch, D. Gilbert, J. Xu, S. Pouliquen, A. Thresher, and others. 2016. Fifteen years of ocean observations with the global Argo array. Nature Climate Change 6:145–153, https://doi.org/10.1038/nclimate2872.

Scott, R.B., and F. Wang. 2005. Direct evidence of an oceanic inverse kinetic energy cascade from satellite altimetry. Journal of Physical Oceanography 35:1,650–1,666, https://doi.org/​10.1175/JPO2771.1.

Sérazin, G. 2016. Empreinte de la variabilité intrinsèque océanique sur l’océan de surface: caractérisation et processus. PhD Thesis, Université de Toulouse.

Sérazin, G., A. Jaymond, S. Leroux, T. Penduff, L. Bessières, W. Llovel, B. Barnier, J.-M. Molines, and L. Terray. 2017. A global probabilistic study of the ocean heat content low-frequency variability: Atmospheric forcing versus oceanic chaos. Geophysical Research Letters 44:5,580–5,589, https://doi.org/10.1002/2017GL073026.

Sérazin, G., B. Meyssignac, T. Penduff, L. Terray, B. Barnier, and J.-M. Molines. 2016. Quantifying uncertainties on regional sea-level rise induced by multi-decadal oceanic intrinsic variability. Geophysical Research Letters 43:8,151–8,159, https://doi.org/10.1002/2016GL069273.

Sérazin, G., T. Penduff, B. Barnier, J.M. Molines, B.K. Arbic, M. Müller, and L. Terray. In press. Inverse cascades of kinetic energy as a source of low-​frequency intrinsic variability: A global OGCM study. Journal of Physical Oceanography, https://doi.org/​10.1175/​JPO-D-17-0136.1.

Sérazin, G., T. Penduff, S. Grégorio, B. Barnier, J.-M. Molines, and L. Terray. 2015. Intrinsic variability of sea-level from global 1/12° ocean simulations: Spatio-temporal scales. Journal of Climate 28:4,279–4,292, https://doi.org/​10.1175/JCLI-D-14-00554.1.

Sévellec, F., and A.V. Fedorov. 2013. The leading, interdecadal eigenmode of the Atlantic meridional overturning circulation in a realistic ocean model. Journal of Climate 26:2,160–2,183, https://doi.org/​10.1175/JCLI-D-11-00023.1.

Sgubin, G., S. Pierini, and H.A. Dijkstra. 2014. Intrinsic variability of the Antarctic Circumpolar Current system: Low-and high-frequency fluctuations of the Argentine Basin flow. Ocean Science 10:201–213, https://doi.org/10.5194/os-10-201-2014.

Taylor, K.E., R.J. Stouffer, and G.A. Meehl. 2012. An overview of CMIP5 and the experiment design. Bulletin of the American Meteorological Society 93:485–498, https://doi.org/10.1175/BAMS-D-11-00094.1.

Venaille, A., J. Le Sommer, J.-M. Molines, and B. Barnier. 2011. Stochastic variability of oceanic flows above topography anomalies. Geophysical Research Letters 38, L16611, https://doi.org/​10.1029/​2011GL048401.

Wolfe, C.L., P. Cessi, and B.D. Cornuelle. 2017. An intrinsic mode of interannual variability in the Indian Ocean. Journal of Physical Oceanography 47:701–719, https://doi.org/10.1175/JPO-D-16-0177.1.

Zivkovic, T., and K. Rypdal. 2013. ENSO dynamics: Low-dimensional-chaotic or stochastic? Journal of Geophysical Research 118:2,161–2,168, https://doi.org/​10.1002/jgrd.50190.