Evaluation and application of the ROMS 1-way embedding procedure to the central california upwelling system
Institute of Geophysics and Planetary Physics, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1567, United States; Institut de Recherche pour le Développement, 213 rue Lafayette, Paris, France; Institut d'Informatique et Mathématiques Appliquées de Grenoble, Laboratoire de Modélisation et Calcul, BP 53, 38041 Grenoble Cedex 9, France; Department of Oceanography, University of Cape Town, Rondebosch 7701, South Africa; Unité Mixte de Recherche LEGOS, Centre IRD de Bretagne, BP 70, 29280 Plouzané, France
What most clearly distinguishes near-shore and off-shore currents is their dominant spatial scale, O (1-30) km near-shore and O (30-1000) km off-shore. In practice, these phenomena 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 regional-scale circulation at an affordable computational cost, a 1-way grid embedding capability has been integrated into the Regional Oceanic Modeling System (ROMS). It takes advantage of the AGRIF (Adaptive Grid Refinement in Fortran) Fortran 90 package based on the use of pointers. After a first evaluation in a baroclinic vortex test case, the embedding procedure has been applied to a domain that covers the central upwelling region off California, around Monterey Bay, embedded in a domain that spans the continental U.S. Pacific Coast. Long-term simulations (10 years) have been conducted to obtain mean-seasonal statistical equilibria. The final solution shows few discontinuities at the parent-child domain boundary and a valid representation of the local upwelling structure, at a CPU costs only lightly greater than for the inner region alone. The solution is assessed by comparison with solutions for the whole US Pacific Coast at both low and high resolutions and to solutions for only the inner region at high resolution with mean-seasonal boundary conditions. © 2005 Elsevier Ltd. All rights reserved.
Algorithms; Approximation theory; Boundary conditions; Kinetic energy; Mathematical models; Numerical methods; Ocean currents; Polynomials; Statistical methods; Coastal upwelling; Eddy kinetic energy; Mesoscale eddies; Ocean models; Oceanography; boundary condition; kinetic energy; mesoscale eddy; upwelling; California Shelf; Pacific Ocean