The numerical model solves for
prognostic variables 
, 
, 
, 
, S, 
and l
as a function of
time, starting from a specified set of initial conditions, and
forced by the wind stress and buoyancy flux at the ocean surface
and prescribed transports at open lateral boundaries. These
prognostic variables are staggered not only in the horizontal but
also in the vertical direction. While q, l, w, 
,
are located
at 
levels, variables 
, 
, 
, S, and 
are staggered in the
vertical and therefore located between two corresponding 
levels
(see Figure 19).
Note that w, q, l, 
, S, 
, 
, 
are
located at the center of the grid, while 
, 
are staggered in
the horizontal as described earlier (see also Figure 19). While
shear stresses 
and 
are staggered in the horizontal in the
same way as 
and 
respectively, they are however located at
levels.
