The system of model equations (4.1)-(4.7) is completed by a set of boundary conditions. The kinematic boundary conditions define the ocean domain and describe its volume budget. The sea floor is defined by specifying a surface with no normal flow. The sea surface is defined by means of an equation of motion of the sea surface height.
The dynamic boundary conditions prescribe the flux of various quantities such as momentum, heat, and passive tracers through the ocean boundaries. The sea floor employs insulation conditions for heat, salt, and passive tracers; i.e., no-normal tracer flux through the sea floor. Geothermal heating can be set through the model's tracer source field. At the ocean surface, boundary conditions are supplied for heat, passive tracers, and momentum. If fresh water flux is not considered in the volume budget, an additional virtual salinity flux is needed.