•Vertical
Coordinates
–Hybrid
coordinates
•Nearsurface:
z-coordinates
•Shallow water: sigma
(terrain-following) coordinates
•Coordinates are
isopycnic in the bulk of the ocean interior
–Isopycnic coordinates
(MICOM mode)
•Hybrid Vertical
Coordinate Scheme (part 1)
–In the open ocean, the coordinates are isopycnic except year the surface where minimum coordinate separation is enforced. The
minimum separation differs for each layer,
giving the user great flexibility to set the vertical coordinate structure in the z-coordinate
domain.
–A cushion function described in Bleck and Benjamin (1993) provides a smooth transition between the isopycnic and z-coordinate
domains.
–To activate the sigma
coordinate domain, the user specifies the number of sigma coordinates n and the coordinate separation d.
Vertical coordinates become terrain-following
where bottom depth is less than n*d. In extremely
shallow water, the coordinates revert to level coordinates.