We can calculate the total freshwater mass and heat fluxes into the ice/ocean component from a spin up run with fixed SST. Given a climatology of ocean mixed layer depths, we can calculate the implied ocean heat convergence at the base of the mixed layer. This will incorporate the actual ocean heat transports, but also a residual component related to any errors in the surface heat or mass fluxes. This ocean heat convergence can be input into a thermodynamic mixed layer to give a Q-flux model. Depending on whether ice advection is turned on (see above), the horizontal transport of the sea ice is or is not incorporated into the ocean heat convergence. A full sea ice thermodynamic calculation is performed for this model. Generally this model takes 20 to 30 years to come into thermal equilibrium with any change in forcing, but this can be changed by specifying the maximum mixed layer depth (smaller implies a faster equilibration).
There is an option to allow diffusion into the deep ocean by replacing OCNML with ODEEP in the run deck. This requires a 10 year spin up of the Q-flux model in order to properly set the deeper layers (12 layers, down to 5000m).