Haidvogel, D. B., H. Arango, W. P. Budgell, B. D. Cornuelle, E. Curchitser,
E. Di Lorenzo, K. Fennel, W. R. Geyer, A. J. Hermann, L. Lanerolle,
J. Levin, J. C. McWilliams, A. J. Miller, A. M. Moore, T. M. Powell,
A. F. Shchepetkin, C. R. Sherwood, R. P. Signell, J. C. Warner,
and J. Wilkin, 2008:
Ocean forecasting in terrain-following coordinates:
Formulation and skill assessment of the Regional
Ocean Modeling System.
Journal of Computational Physics, 227, 3595-3624.
Systematic improvements in algorithmic design of regional ocean circulation models have led to significant enhancement
in simulation ability across a wide range of space/time scales and marine system types. As an example, we briefly
review the Regional Ocean Modeling System, a member of a general class of three-dimensional, free-surface, terrain-following
numerical models. Noteworthy characteristics of the ROMS computational kernel include: consistent temporal
averaging of the barotropic mode to guarantee both exact conservation and constancy preservation properties for tracers;
redefined barotropic pressure-gradient terms to account for local variations in the density field; vertical interpolation
performed using conservative parabolic splines; and higher-order, quasi-monotone advection algorithms. Examples of
quantitative skill assessment are shown for a tidally driven estuary, an ice-covered high-latitude sea, a wind- and buoyancy-forced
continental shelf, and a mid-latitude ocean basin. The combination of moderate-order spatial approximations,
enhanced conservation properties, and quasi-monotone advection produces both more robust and accurate, and less diffusive,
solutions than those produced in earlier terrain-following ocean models. Together with advanced methods of data
assimilation and novel observing system technologies, these capabilities constitute the necessary ingredients for multi-purpose
regional ocean prediction systems.