EGU23-103, updated on 22 Feb 2023
https://doi.org/10.5194/egusphere-egu23-103
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Energetic Constraints on Baroclinic Eddy Heat Transport in a Rotating Annulus

Cheng Qian, Peter Read, and David Marshall
Cheng Qian et al.
  • University of Oxford, Atmospheric Oceanic and Planetary Physics, Oxford, United Kingdom of Great Britain – England, Scotland, Wales (cheng.qian@physics.ox.ac.uk)

We measure baroclinic eddy heat transport in a differentially heated rotating annulus laboratory experiment to test mesoscale ocean eddy parameterization frameworks. The differentially heated rotating annulus comprises a fluid placed between two upright coaxial cylinders which are maintained at different temperatures, usually with a cooled inner cylinder and a heated outer.  The annular tank is placed on a rotating table which provides conditions for baroclinic eddies to develop and equilibrate in different flow regimes, depending upon the imposed conditions. As the rotation speed is increased, the equilibrated flow changes from a steady or periodically varying low wavenumber pattern to a more complex, time-varying flow dominated by higher wavenumbers. With a topographic beta effect produced by conically sloping upper boundary, more complex flow regimes are observed combining zonal jets and eddies forming one or more parallel storm tracks. With this possibility to explore varied flow regimes, our experimental approach combines laboratory calorimetry and visualization measurements along with numerical simulations to derive the eddy heat transport properties. In the following, we focus on the visualisation measurement to test related assumptions and parametric dependencies for eddy transport. We first test the assumptions of a down-gradient temperature flux-gradient relationship, determining coefficients of the eddy transport tensor, and exploring scaling relations for the eddy coefficients. A clear statistical scaling is found between eddy heat fluxes and physical variables such as eddy energy, the beta effect, and the temperature contrast.

How to cite: Qian, C., Read, P., and Marshall, D.: Energetic Constraints on Baroclinic Eddy Heat Transport in a Rotating Annulus, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-103, https://doi.org/10.5194/egusphere-egu23-103, 2023.