Quondum posted an interesting comment on Dr. Curry's Blog. It is interesting to me because it is very similar to the moisture model I have been playing with.
Since the oceans absorb most of their energy near the equator, the absorbed energy is roughly twice the "true" surface absorbed energy used in radiant models. Shown above as ~345 Wm-2 and the majority of the internal energy of the oceans migrates to the poles. For the oceans, a different set of "averages" apply than would apply to the atmosphere. There is effectively two greenhouse effects, an atmospheric "greenhouse" and an ocean "greenhouse" with two different "average" source and sink values, gotcha!
Quondum would run into this same situation with his/her Helmholtz free energy model. Since the oceans constantly shift from fresh to saline dominate modes, there will be roughly 9Wm-2 of "slop" in the reference isothermal layer common to both the atmospheric and ocean systems. This is not an insurmountable obstacle, but would require very close attention to the "bookkeeping" when determining the dissipation energy.
To add to the complexity, the poles are not uniform sinks for either the oceans or the atmosphere. The Southern pole is a much better ocean sink and the Northern pole a much better atmospheric sink. Since the southern pole is a better sink for the majority of the heat capacity of the total system (the oceans), it would more likely limit the "sensitivity" of both atmospheric and oceans to any uniform common forcing.