Submesoscale Eddy Parameterization

Omega includes an optional submesoscale mixed layer instability (MLI) parameterization through the SubmesoEddies class. When enabled, the model computes an eddy-induced transport velocity on edges and adds it to the normal transport velocity used by thickness and tracer advection to represent the transport due to the unresolved submesoscale eddies.

The current implementation follows the Fox-Kemper et al. (2011) (FK11) closure described in the Submesoscale Eddy Parameterization design document.

Configuration

Configure the parameterization in the Submeso section of the YAML input:

Submeso:
  Enable: false
  Tau: 172800.0
  Ce: 0.08
  LfMin: 1.0e3
  DsMax: 100.0e3

Enable: turns the parameterization on/off.
Tau: MLI timescale parameter (s), used to prevent division by zero at the equator.
Ce: nondimensional efficiency coefficient.
LfMin: minimum frontal width limiter (m).
DsMax: maximum grid-length limiter used in the closure (m).

Diagnostics

When enabled, the following fields are available in the Submeso field group:

GradBuoyEdgeInterface (s^-2): buoyancy gradient on edge interfaces.
EddyVelocity (m/s): eddy-induced transport velocity.