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
Antoine Hochet
CORRESPONDING AUTHOR
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
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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
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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
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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.
Andrew Yool, Julien Palmiéri, Colin G. Jones, Lee de Mora, Till Kuhlbrodt, Ekatarina E. Popova, A. J. George Nurser, Joel Hirschi, Adam T. Blaker, Andrew C. Coward, Edward W. Blockley, and Alistair A. Sellar
Geosci. Model Dev., 14, 3437–3472, https://doi.org/10.5194/gmd-14-3437-2021, https://doi.org/10.5194/gmd-14-3437-2021, 2021
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The ocean plays a key role in modulating the Earth’s climate. Understanding this role is critical when using models to project future climate change. Consequently, it is necessary to evaluate their realism against the ocean's observed state. Here we validate UKESM1, a new Earth system model, focusing on the realism of its ocean physics and circulation, as well as its biological cycles and productivity. While we identify biases, generally the model performs well over a wide range of properties.
Rémi Tailleux
Ocean Sci., 17, 203–219, https://doi.org/10.5194/os-17-203-2021, https://doi.org/10.5194/os-17-203-2021, 2021
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Because the density of seawater depends on both temperature (T) and salinity (S), it is possible for seawater samples of the same density to have widely different T and S characteristics ranging from hot and salt (spicy) to fresh and cold (minty). For several decades, oceanographers have been debating how to best construct a variable for quantifying the
spicinessof seawater. This work discusses the relative merits and drawbacks of existing approaches and proposes a new way forward.
Lee de Mora, Alistair A. Sellar, Andrew Yool, Julien Palmieri, Robin S. Smith, Till Kuhlbrodt, Robert J. Parker, Jeremy Walton, Jeremy C. Blackford, and Colin G. Jones
Geosci. Commun., 3, 263–278, https://doi.org/10.5194/gc-3-263-2020, https://doi.org/10.5194/gc-3-263-2020, 2020
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We use time series data from the first United Kingdom Earth System Model (UKESM1) to create six procedurally generated musical pieces for piano. Each of the six pieces help to explain either a scientific principle or a practical aspect of Earth system modelling. We describe the methods that were used to create these pieces, discuss the limitations of this pilot study and list several approaches to extend and expand upon this work.
Malcolm J. Roberts, Alex Baker, Ed W. Blockley, Daley Calvert, Andrew Coward, Helene T. Hewitt, Laura C. Jackson, Till Kuhlbrodt, Pierre Mathiot, Christopher D. Roberts, Reinhard Schiemann, Jon Seddon, Benoît Vannière, and Pier Luigi Vidale
Geosci. Model Dev., 12, 4999–5028, https://doi.org/10.5194/gmd-12-4999-2019, https://doi.org/10.5194/gmd-12-4999-2019, 2019
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We investigate the role that horizontal grid spacing plays in global coupled climate model simulations, together with examining the efficacy of a new design of simulation experiments that is being used by the community for multi-model comparison. We found that finer grid spacing in both atmosphere and ocean–sea ice models leads to a general reduction in bias compared to observations, and that once eddies in the ocean are resolved, several key climate processes are greatly improved.
Lee de Mora, Andrew Yool, Julien Palmieri, Alistair Sellar, Till Kuhlbrodt, Ekaterina Popova, Colin Jones, and J. Icarus Allen
Geosci. Model Dev., 11, 4215–4240, https://doi.org/10.5194/gmd-11-4215-2018, https://doi.org/10.5194/gmd-11-4215-2018, 2018
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Climate change is expected to have a significant impact on the Earth's weather, ice caps, land surface, and ocean. Computer models of the Earth system are the only tools available to make predictions about how the climate may change in the future. However, in order to trust the model predictions, we must first demonstrate that the models have a realistic description of the past. The BGC-val toolkit was built to rapidly and simply evaluate the behaviour of models of the Earth's oceans.
David Storkey, Adam T. Blaker, Pierre Mathiot, Alex Megann, Yevgeny Aksenov, Edward W. Blockley, Daley Calvert, Tim Graham, Helene T. Hewitt, Patrick Hyder, Till Kuhlbrodt, Jamie G. L. Rae, and Bablu Sinha
Geosci. Model Dev., 11, 3187–3213, https://doi.org/10.5194/gmd-11-3187-2018, https://doi.org/10.5194/gmd-11-3187-2018, 2018
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We document the latest version of the shared UK global configuration of the
NEMO ocean model. This configuration will be used as part of the climate
models for the UK contribution to the IPCC 6th Assessment Report.
30-year integrations forced with atmospheric forcing show that the new
configurations have an improved simulation in the Southern Ocean with the
near-surface temperatures and salinities and the sea ice all matching the
observations more closely.
Davi Mignac, David Ferreira, and Keith Haines
Ocean Sci., 14, 53–68, https://doi.org/10.5194/os-14-53-2018, https://doi.org/10.5194/os-14-53-2018, 2018
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Four ocean reanalyses and two free-running models are compared to study the meridional transports in the South Atlantic. We analyse the underlying causes of the product differences in an attempt to understand the potential impact (and limitations) of the data assimilation (DA) in improving the simulated ocean states. The DA schemes can consistently constrain the basin interior transports, but not the overturning circulation dominated by the narrow South Atlantic western boundary currents.
G. Forget, D. Ferreira, and X. Liang
Ocean Sci., 11, 839–853, https://doi.org/10.5194/os-11-839-2015, https://doi.org/10.5194/os-11-839-2015, 2015
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Results from the ECCO v4 ocean state estimate identify the constraint of fitting Argo profiles as an effective observational basis for inverse estimation of regional turbulent transport rates. The estimated parameters' geography is physically plausible and exhibits close connections with the observed upper-ocean stratification. They yield a clear reduction in the model drift away from observations over multi-century-long simulations, including for independent biochemistry variables.
Related subject area
Approach: Analytic Theory | Depth range: All Depths | Geographical range: All Geographic Regions | Phenomena: Turbulence and Mixing
Understanding mixing efficiency in the oceans: do the nonlinearities of the equation of state for seawater matter?
R. Tailleux
Ocean Sci., 5, 271–283, https://doi.org/10.5194/os-5-271-2009, https://doi.org/10.5194/os-5-271-2009, 2009
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