Eddies in the ocean
Mesoscale eddies in the ocean, sometimes referred to as the oceanic equivalent of atmospheric storms, derive their energy from the large-scale flow mainly through baroclinic instability processes. These processes are parameterized in climate models with down-gradient parameterizations using eddy diffusivities. In geostrophic turbulence, eddies then tend to transfer their energy upscale in an inverse cascade. But ultimately, this energy has to be dissipated and it is largely unknown how and where.
Our scientists specifically assess one important pathway to dissipation, the spontaneous emission of gravity waves by the quasi-balanced flows, and analyze drifter and float data to estimate eddy production and Lagrangian mixing from observations, models and theory.
Specific research questions in Area L are:
- How is the balanced flow dissipated in the ocean, and how important is the route to dissipation via spontaneous wave generation?
- What are the limits and validities of the eddy diffusion model and how can we quantify and parameterize the effects of mesoscale eddies in an energy-consistent way?
Conti, G. and G. Badin (2019). Velocity statistics for point vortices in the local α-models of turbulence, Geophysical and Astrophysical Fluid Dynamics, doi:10.1080/03091929.2019.1572750
Mohamad, H., and M. Oliver (2019). A direct construction of a slow manifold for a semilinear wave equation of Klein–Gordon type. Journal of Differential Equations.
Badin, G., M. Oliver and S. Vasylkevych (2018). Geometric Lagrangian averaged Euler-Boussinesq and Primitive Equations, Journal of Physics A: Mathematical and Theoretical, 51, 455501, doi:10.1088/1751-8121/aae1cb
Dräger-Dietel, J., Jochumsen, K., Griesel, A., and Badin, G. (2018). Relative dispersion of surface drifters in the Benguela upwelling region. Journal of Physical Oceanography.
Franzke, C. L., Oliver, M., Rademacher, J. D., and Badin, G. (2018). Multi-scale methods for geophysical flows, Springer (in press).
Badin, G. and Barry, A., (2018) Collapse of generalized Euler and surface quasi-geostrophic point-vortices, Physical Review E, 98, 023110, doi.org/10.1103/PhysRevE.98.023110
Domeisen, D.I.V. , Badin, G. and Koszalka, I., (2018) How predictable are the Arctic and North Atlantic Oscillations? Exploring the variability and predictability of the Northern Hemisphere, Journal of Climate, 31, 997-1014, doi.org/10.1175/JCLI-D-17-0226.1
Conti, G., & Badin, G. (2017). Hyperbolic Covariant Coherent Structures in Two Dimensional Flows.Fluids 2017, 2(4), 50. doi: 10.3390/fluids2040050
Blender, R., & Badin, G. (2017).Construction of Hamiltonian and Nambu Forms for the Shallow Water Equations. Fluids 2017, 2 (2), doi:10.3390/fluids2020024.
Blender, R., & Badin, G. (2017). Viscous dissipation in 2D fluid dynamics as a symplectic process and its metriplectic representation. The European Physical Journal Plus, 132(3), 137.