ROMS Embedded Gridding, Test and Application for the
Simulation of the Central Upwelling of the Pacific Coast of the
United States
Pierrick Penven
Institute of Geophysics and Planetary Physics
University of California at Los Angeles, USA
Laurent Debreu
Institut d'Informatique et Mathematiques Appliquees de Grenoble
Laboratoire de Modelisation et Calcul, Grenoble, France
Patrick Marchesiello
Institute of Geophysics and Planetary Physics
University of California at Los Angeles, USA
What most clearly distinguishes near-shore and off-shore currents is
their dominant spatial scale, O(1-10) km near-shore and O(100-1000) km
off-shore. In practice, therefore, they are usually both measured and
modeled with separate methods. In particular, it is infeasible for
any regular computational grid to be large enough to simultaneously
resolve well both types of currents.
In order to obtain local solutions at high resolution while
preserving the large-scale circulation at affordable
computational cost, a nesting capability has been integrated
into the Regional Ocean Modeling System. It takes
advantage of the AGRIF (Adaptive Grid Refinement in Fortran)
Fortran 90 package based on the use of pointers.
The nesting procedure has been applied to a domain that covers the
central upwelling region of the United States West Coast, around
Monterey Bay, embedded into a domain including the whole US Pacific
Coast. Long term simulations (10 years) have been conducted to
obtain yearly cyclic statistical equilibria. The final solution
shows no discontinuities at the parent-child domain boundary and a
valid representation of the upwelling structure, at a CPU cost only
slightly greater than for the inner region alone. The solution
is compared to a model of the whole US Pacific Coast
at high resolution.