The Model (5)
Horizontal Advection
Two of the thermodynamical variables T, S, and density are advected
(user selectable), with the third calculated from the equation of state.
If HYCOM is run in MICOM mode, advection is performed as in
MICOM 2.8, with T and S advected in layer 1 (the mixed layer) and S
only advected in the isopycnic layers.