Articles | Volume 15, issue 1
https://doi.org/10.5194/os-15-21-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-15-21-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Isoneutral control of effective diapycnal mixing in numerical ocean models with neutral rotated diffusion tensors
Department of Meteorology, University of Reading, Reading, UK
Rémi Tailleux
Department of Meteorology, University of Reading, Reading, UK
David Ferreira
Department of Meteorology, University of Reading, Reading, UK
Till Kuhlbrodt
Department of Meteorology, University of Reading, Reading, UK
National Center for Atmospheric Science, Reading, UK
Related authors
No articles found.
Robin S. Smith, Tarkan A. Bilge, Thomas J. Bracegirdle, Paul R. Holland, Till Kuhlbrodt, Charlotte Lang, Spencer Liddicoat, Tom Mitcham, Jane Mulcahy, Kaitlin A. Naughten, Andrew Orr, Julien Palmieri, Antony J. Payne, Steven Rumbold, Marc Stringer, Ranjini Swaminathan, Sarah Taylor, Jeremy Walton, and Colin Jones
Earth Syst. Dynam., 17, 475–493, https://doi.org/10.5194/esd-17-475-2026, https://doi.org/10.5194/esd-17-475-2026, 2026
Short summary
Short summary
There is a dangerous amount of uncertainty in our predictions of climate change in polar regions because some of feedbacks that might lead to changes that are too rapid for us to adapt to, or that cannot be reversed. We have run a set of simulations with a state-of-the-art Earth System Model that helps improve our understanding of how climate in these regions might change. Some of the aspects we investigate are reversible but many are not, especially those affecting ice sheets and sea level.
Lily Greig and David Ferreira
Ocean Sci., 22, 1261–1278, https://doi.org/10.5194/os-22-1261-2026, https://doi.org/10.5194/os-22-1261-2026, 2026
Short summary
Short summary
Submesoscale eddies in the ocean (0.1–10 km) are often missing from global climate models, yet they impact nutrient transport, sea ice coverage, and ocean overturning. Using submesoscale-resolving simulations, we show that these eddies near the sea ice edge impact air-sea heat fluxes, ice cover, and ocean heat storage in summer, and mixed layer depth in winter. These findings highlight the need to better represent submesoscale eddies in sea ice – covered regions of global climate models.
John W. Rostron, Alejandro Bodas-Salcedo, David M. H. Sexton, Colin G. Jones, Edward W. Blockley, Till Kuhlbrodt, Jane P. Mulcahy, Tamzin E. Palmer, Saloua Peatier, Mark A. Ringer, Steven T. Rumbold, Benjamin M. Sanderson, Yongming Tang, and Martin R. Willet
EGUsphere, https://doi.org/10.5194/egusphere-2026-1676, https://doi.org/10.5194/egusphere-2026-1676, 2026
Short summary
Short summary
The Met Office’s latest weather and climate model warms very strongly in response to increases in carbon dioxide. We created a modified version of the model with a more moderate warming response by adjusting key model parameters, using both automated methods and expert judgement. The new model matches historical temperatures more closely and is better suited for studies of long‑term climate, but has reduced overall accuracy when simulating the baseline climate.
Remi Tailleux
EGUsphere, https://doi.org/10.5194/egusphere-2025-4595, https://doi.org/10.5194/egusphere-2025-4595, 2025
Preprint archived
Short summary
Short summary
The Lorenz reference state, key to ocean energetics in available potential energy (APE) theory, is traditionally viewed as a global fluid property implying distant interactions. This paper reframes it as a local environmental constraint controlling deviations from equilibrium, measurable via the study of buoyancy oscillations and akin to gravity's local tug. This paradigmatic shift resolves causality paradoxes, bolstering APE's role in theories of ocean circulation, energetics, and mixing.
Holly C. Ayres, David Ferreira, Wonsun Park, Joakim Kjellsson, and Malin Ödalen
Weather Clim. Dynam., 5, 805–820, https://doi.org/10.5194/wcd-5-805-2024, https://doi.org/10.5194/wcd-5-805-2024, 2024
Short summary
Short summary
The Weddell Sea Polynya (WSP) is a large, closed-off opening in winter sea ice that has opened only a couple of times since we started using satellites to observe sea ice. The aim of this study is to determine the impact of the WSP on the atmosphere. We use three numerical models of the atmosphere, and for each, we use two levels of detail. We find that the WSP causes warming but only locally, alongside an increase in precipitation, and shows some dependence on the large-scale background winds.
Jane P. Mulcahy, Colin G. Jones, Steven T. Rumbold, Till Kuhlbrodt, Andrea J. Dittus, Edward W. Blockley, Andrew Yool, Jeremy Walton, Catherine Hardacre, Timothy Andrews, Alejandro Bodas-Salcedo, Marc Stringer, Lee de Mora, Phil Harris, Richard Hill, Doug Kelley, Eddy Robertson, and Yongming Tang
Geosci. Model Dev., 16, 1569–1600, https://doi.org/10.5194/gmd-16-1569-2023, https://doi.org/10.5194/gmd-16-1569-2023, 2023
Short summary
Short summary
Recent global climate models simulate historical global mean surface temperatures which are too cold, possibly to due to excessive aerosol cooling. This raises questions about the models' ability to simulate important climate processes and reduces confidence in future climate predictions. We present a new version of the UK Earth System Model, which has an improved aerosols simulation and a historical temperature record. Interestingly, the long-term response to CO2 remains largely unchanged.
Cited articles
de Boyer Montégut, C., Madec, G., Fischer, A. S., Lazar, A., and Iudicone,
D.: Mixed layer depth over the global ocean: An examination of profile data
and a profile-based climatology, J. Geophys. Res.-Oceans,
109, https://doi.org/10.1029/2004JC002378, 2004. a
Gnanadesikan, A., Pradal, M.-A., and Abernathey, R.: Isopycnal mixing by
mesoscale eddies significantly impacts oceanic anthropogenic carbon uptake,
Geophys. Res. Lett., 42, 4249–4255, 2015. a
Hill, C., Ferreira, D., Campin, J.-M., Marshall, J., Abernathey, R., and
Barrier, N.: Controlling spurious diapycnal mixing in eddy-resolving
height-coordinate ocean models–Insights from virtual deliberate tracer
release experiments, Ocean Model., 45, 14–26, 2012. a
Huber, M., Tailleux, R., Ferreira, D., Kuhlbrodt, T., and Gregory, J.: A
traceable physical calibration of the vertical advection-diffusion equation
for modeling ocean heat uptake, Geophys. Res. Lett., 42, 2333–2341,
https://doi.org/10.1002/2015gl063383, 2015. a
Iselin, C. O.: The influence of vertical and lateral turbulence on the
characteristics of the waters at mid-depths, EOS T. Am. Geophys. Un., 20, 414–417, 1939. a
Jackett, D. R. and McDougall, T. J.: A neutral density variable for the world's
oceans, J. Phys. Oceanogr., 27, 237–263,
https://doi.org/10.1175/1520-0485(1997)027<0237:andvft>2.0.co;2, 279, 1997. a, b, c, d
Klocker, A. and McDougall, T. J.: Influence of the Nonlinear Equation of State
on Global Estimates of Dianeutral Advection and Diffusion, J.
Phys. Oceanogr., 40, 1690–1709, https://doi.org/10.1175/2010jpo4303.1,
2010. a
Klocker, A., McDougall, T. J., and Jackett, D. R.: A new method for forming approximately neutral surfaces,
Ocean Sci., 5, 155–172, https://doi.org/10.5194/os-5-155-2009, 2009. a, b
Kuhlbrodt, T. and Gregory, J.: Ocean heat uptake and its consequences for the
magnitude of sea level rise and climate change, Geophys. Res. Lett.,
39, https://doi.org/10.1029/2012GL052952, 2012. a
Ledwell, J. R., Watson, A. J., and Law, C. S.: Mixing of a tracer in the
pycnocline, J. Geophys. Res.-Oceans, 103, 21499–21529,
1998. a
Lumpkin, R. and Speer, K.: Global ocean meridional overturning, J.
Phys. Oceanogr., 37, 2550–2562, 2007. a
McDougall, T. J.: thermobaricity, cabbeling, and water-mass conversion, J. Geophys. Res.-Oceans, 92, 5448–5464,
https://doi.org/10.1029/JC092iC05p05448, 134, 1987. a
McDougall, T. J. and Jackett, D. R.: On the helical nature of neutral
trajectories in the ocean, Prog. Oceanogr., 20, 153–183,
https://doi.org/10.1016/0079-6611(88)90001-8, 26, 1988a. a
McDougall, T. J. and Jackett, D. R.: On the helical nature of neutral
trajectories in the ocean, Prog. Oceanogr., 20, 153–183,
1988b. a
McDougall, T. J., Groeskamp, S., and Griffies, S. M.: On geometrical aspects of
interior ocean mixing, J. Phys. Oceanogr., 44, 2164–2175,
2014. a
Megann, A.: Estimating the numerical diapycnal mixing in an eddy-permitting
ocean model, Ocean Model., 121, 19–33,
https://doi.org/10.1016/j.ocemod.2017.11.001,
2018. a, b
Montgomery, R.: The present evidence on the importance of lateral mixing
processes in the ocean, B. Am. Meteorol. Soc., 21,
87–94, 1940. a
Munk, W. and Wunsch, C.: Abyssal recipes II: energetics of tidal and wind
mixing, Deep-Sea Res. Pt. I, 45,
1977–2010, https://doi.org/10.1016/s0967-0637(98)00070-3, 1998. a
Munk, W. H.: Abyssal recipes, in: Deep Sea Research and Oceanographic
Abstracts, 13, 707–730, Elsevier, 1966. a
Nurser, A. J. G., Marsh, R., and Williams, R. G.: Diagnosing water mass
formation from air-sea fluxes and surface mixing, J. Phys.
Oceanogr., 29, 1468–1487,
https://doi.org/10.1175/1520-0485(1999)029<1468:dwmffa>2.0.co;2, 1999. a
Polzin, K. L., Toole, J. M., Ledwell, J. R., and Schmitt, R. W.: Spatial
variability of turbulent mixing in the abyssal ocean, Science, 276, 93–96,
https://doi.org/10.1126/science.276.5309.93, 1997. a
Pradal, M.-A. and Gnanadesikan, A.: How does the Redi parameter for mesoscale
mixing impact global climate in an Earth system model?, J. Adv. Model. Earth Sy., 6, 586–601, 2014. a
Saenz, J. A., Tailleux, R., Butler, E. D., Hughes, G. O., and Oliver, K. I. C.:
Estimating Lorenz's Reference State in an Ocean with a Nonlinear Equation of
State for Seawater, J. Phys. Oceanogr., 45, 1242–1257,
https://doi.org/10.1175/jpo-d-14-0105.1, 2015. a, b, c
Solomon, H.: On the representation of isentropic mixing in ocean circulation
models, J. Phys. Oceanogr., 1, 233–234, 1971. a
Speer, K. G.: A note on average cross-isopycnal mixing in the North Atlantic
ocean, Deep-Sea Res. Pt. I, 44,
1981–1990, https://doi.org/10.1016/s0967-0637(97)00054-x, 1997. a, b
Tailleux, R.: Neutrality Versus Materiality: A Thermodynamic Theory of Neutral
Surfaces, Fluids, 1, 32, https://doi.org/10.3390/fluids1040032, 2016.
a, b
Urakawa, L., Saenz, J., and Hogg, A.: Available potential energy gain from
mixing due to the nonlinearity of the equation of state in a global ocean
model, Geophys. Res. Lett., 40, 2224–2228, 2013. a
Walin, G.: On the relation between sea-surface heat flow and thermal
circulation in the ocean, Tellus, 34, 187–195, 180, 1982. a