Oey, L-Y., and P. Chen, 1992: A nested-grid ocean model: with application
to the simulation of meanders and eddies in the Norwegian Coastal Current.
Journal of Geophysical Research, 97(C12), 20,063-20,086.
Abstract: Oceanic flow phenomena vary in such large ranges of time
and spatial scales that even with the fastest and largest computer to-date,
one cannot, at reasonable costs, compute large-scale circulation and at
the same time resolve mesoscale features like fronts and/or eddies; yet
these features are dynamically important, and their inclusion may determine
how well we can model the mean flow, including the deep-ocean circulation.
A two-way interactive, nested-grid, primitive-equation model is developed
here for coastal ocean applications. Notable features of the model are
(1) nesting can be specified on any subregion of a coarse-grid, large domain,
and there can be more than one nest if required; (2) the nested region
can be "hot-started" from earlier calculation results of the
coarse-grid region, that is, the code automatically (by a change of an
input flag) generates topography, wind forcing, climatology, currents,
density and other prognostic variables in the nest and steps forward in
time; (3) a time-splitting integration, with small timesteps in the nest
and large timesteps in the coarse-grid domain, is used; and (4) nested
variables are driven by coarse-grid solutions around the nest's boundaries,
where a flow relaxation scheme may be used, and at the same time drive
the coarse-grid evolution through its averaged action in the overlapped
region. To demonstrate its robustness, the model is applied in a February/March
1988 real-time simulation of meanders and eddies in the Norwegian Coastal
Current, initialized from a 585 days' quasi-equilibrium calculation. The
simulation includes meteorological forcings, inflows/outflows across the
open boundaries (inflow of the North Atlantic warm water in particular),
tides, coastal and Baltic discharges, and wintertime hydrography for depths
> 500 m. From March 20 to 31, the development of a meander between the
Froya and the Halten Banks is simulated. The timing and location of the
meander agree well with observed hydrography.