CONTaCTS

Project funded by the Make Our Planet Great Again program (2019-2024). Principal investigators: W.K. Dewar (Florida State University) and MEOM scientists. Collaborations in LOPS (Brest) and LMD (Paris).

Consistent OceaN Turbulence for ClimaTe Simulators

The Earth’s climate evolution and sensitivity to human influences strongly depend on the dynamics of the ocean, which absorbs most of the excess heat and greenhouse gases, redistributes them around the globe, and may eventually flux them back into the atmosphere. Numerical climate simulators now partially resolve the oceanic mesoscale turbulence (scales of ~100km, the strongest ocean variability process involved in climate dynamics) and provide more consistent solutions than their laminar predecessors.

The dynamical sources and spontaneous cascade of mesoscale turbulence towards larger scales are rather well known and simulated today. In contrast, the cascade of mesoscale toward finer, sub- mesoscale turbulence (scales of ~10km) represents a significant sink of kinetic energy, which is still crudely understood, quantified, and simulated. More importantly, the misrepresentation in ocean models of this small-scale energy sink adversely affects the ocean’s full energy spectrum, hence yields substantial inconsistencies in ocean-atmosphere models used for climate projections.

The CONTaCTS projects aims to study and parameterize this missing effect where it is critical: within the surface and bottom boundary layers of the ocean, where it interacts with the atmosphere and topography. We propose to develop such parameterizations for O(10km) resolution models, based on the analysis of existing O(1km) resolution North Atlantic simulations (eNATL60, see a relative vorticity snapshot in the figure below).

The CONTaCTS project team gathers experts in Geophysical Fluid Dynamics, submeso-/meso-scale turbulence, and high-resolution ocean modeling. The project will contribute to improve ocean models (in particular NEMO), future climate simulators, interpret and exploit future observations at very high resolution (SWOT satellite altimeter to be launched in late 2022), with foreseen benefits for operational oceanography.

  • Ajayi, A., Le Sommer, J., Chassignet, E. P., Molines, J.-M., Xu, X., Albert, A., and Dewar, W.K.: Diagnosing cross-scale kinetic energy exchanges from two submesoscale permitting ocean models. Journal of Advances in Modeling Earth Systems, 13 (2021): e2019MS001923. https://doi.org/10.1029/2019MS001923.
  • Dewar, W.K., and B. Deremble. Ocean energy, fluxes and an Anti-Anti-Turbulence Conjecture. Ocean and Coastal Research (2021). https://doi.org/10.1590/2675-2824070.21042wkd.
  • Jamet, Q., Deremble, B., Wienders, N., Uchida, T., and Dewar, W.K. On Wind-driven Energetics of Subtropical Gyres. Journal of Advances in Modeling Earth Systems (2021). https://doi.org/10.1029/2020MS002329.
  • Jamet, Q., Ajayi, A., Le Sommer, J., Penduff, T., Hogg, A., & Dewar, W.K. On Energy Cascades in General Flows: A Lagrangian Application. Journal of Advances in Modeling Earth Systems (2020). https://doi.org/10.1029/2020MS002090.
  • Jamet, Q., Dewar, W. K., Wienders, N., Deremble, B., Close, S., & Penduff, T. Locally and remotely forced subtropical AMOC variability: A matter of time scales. Journal of Climate, 33(12), 5155–5172 (2020). https://doi.org/10.1175/JCLI-D-19-0844.1.
  • Uchida, T., Q. Jamet, A. Poje, and W.K. Dewar: An ensemble-based eddy and spectral analysis, with application to the Gulf Stream. Journal of Advances in Modeling Earth Systems (2021). https://doi.org/10.1029/2021MS002692.
  • Uchida, T., B. Deremble, W. Dewar & T. Penduff. Diagnosing the Eliassen-Palm flux from a quasigeostrophic double gyre ensemble (2021). https://doi.org/10.5281/zenodo.5496375.
  • Uchida, T., B. Deremble and T. Penduff. The seasonal variability of the ocean energy cycle from a quasigeostrophic double gyre ensemble. Fluids (2021). https://doi.org/10.3390/fluids6060206.
  • Zhou, H, H Liu, S Tan, W Yang, Y Li, X Liu, F Yu, X Li and WK Dewar, The observed North Equatorial Counter Current in the far western Pacific Ocean during the 2014-2016 El Niño. Journal of Physical Oceanography (2021). https://doi.org/10.1175/JPO-D-20-0293.1.
  • Uchida, T., Q. Jamet, W. Dewar, J. Le Sommer, T. Penduff, & D. Balwada. Diagnosing the thickness weighted averaged eddy-mean flow interaction from an eddying North Atlantic ensemble. Part I: The Eliassen-Palm flux. J. Adv. Mod. Earth Sys. (2022). https://doi.org/10.1029/2021MS002866.
  • Zhou, H, WK Dewar, W Yang, H Liu, X Chen, R Li, C Liu and G Gopalakrishnan. Observations and modelling of symmetric instability in the ocean interior in the Northwestern Equatorial Pacific. Comm. Earth Env. (2022). https://doi.org/10.1038/s43247-022-00362-4.
  • Jamet, Q, S Leroux, WK Dewar, T Penduff, J Le Sommer, J-M Molines and J Gula, Non-local Eddy- Mean Kinetic Energy Transfers in Submesoscale-Permitting Ensemble Simulations. Journal of Advances in Modeling Earth Systems (2022). https://doi.org/10.1029/2022MS003057.
  • Hogg, A, T Penduff, S Close, WK Dewar, N Constantinou, J Martinez-Moreno, Circumpolar variations in the chaotic nature of Southern ocean eddy dynamics, Journal of Geophysical Research: Oceans (2022). https://doi.org/10.1029/2022JC018440.
  • Uchida, T, et al and WK Dewar, Cloud-based framework for inter-comparing submesoscale permitting realistic ocean models, Geophysical Model Development (2022). https://doi.org/10.5194/gmd-15-5829-2022.
  • Chen, X, WK Dewar, E Chassignet, M Bourassa, S Morey and G Gopalakrishnan, On the feedback between air-sea turbulent momentum flux and oceanic submesoscale processes. Journal of Geophysical Research-Oceans (2022). https://doi.org/10.1029/2022JC018767.
  • Uchida, T, D Balwada, Q Jamet, WK Dewar B Deremble, T Penduff and J Le Sommer, Cautionary tales from the mesoscale eddy transport tensor. Ocean Modelling (2023). https://doi.org/10.31223/X5C063.
  • Uchida, T, Q Jamet, A Poje, N Wienders, WK Dewar and B Deremble, Wavelet-based wavenumber spectral estimate of eddy kinetic energy: Idealized quasi-geostrophic flow. Journal of Advances in Modeling Earth Systems (2023). https://doi.org/10.31223/X5C063.
  • Kravtsov, S, I Mastilovic, A Hogg, WK Dewar and J Blundell, A Moist Quasi-Geostrophic Coupled Model: MQ-GCM2.0. Geoscientific Model Development (2022). https://doi.org/10.5194/gmd-15-7449-2022.
  • Uchida, T., B. Deremble & S. Popinet. Deterministic model of the eddy dynamics for a midlatitude ocean model. J. Phys. Ocean. (2022). https://doi.org/10.1175/JPO-D-21-0217.1.

Contact : Thierry Penduff

eNATL60