557
will contribute to testing the hypotheses regarding the interaction of plume
structure with photo-chemistry, productivity rates and bio-accumulation.
3.
Coastal ocean modeling
Developments in observing systems are matched by progress in recent
years in the capabilities of coastal ocean models, due in part to increases in
computer technologies but more significantly through improved methods in
computational fluid dynamics, attention to the physical veracity of
subgridscale parameterizations, the application of advanced data assimilation
methods, and widespread experimentation in the formulation of ecosystem
and biogeochemical models.
3.1
The Regional Ocean Modeling System – ROMS
The model we have adopted for the LEO, CBLAST, LATTE and other
similar high to medium resolution coastal modeling applications is the
Regional Ocean Modeling System (ROMS) (http://marine.rutgers.edu/po/
index.php?model=roms). ROMS is a versatile, free-surface, hydrostatic
primitive equation ocean circulation model developed by collaborators at
several institutions, but led by specialists at Rutgers and UCLA. The model
is being used for applications from the basin to coastal and estuarine scales
(e.g. Haidvogel et al. 2000, Marchesiello et al. 2003, Lutjeharms et al. 2003,
Peliz et al. 2003, Dinniman et al. 2003, MacCready and Geyer 2001).
ROMS is formulated in a vertical terrain-following ‘s-coordinate’ similar
to classic sigma-coordinate models, but with generalizations that allow
selective weighting of the vertical distribution of points toward the free
surface or seafloor, or both. The terrain-following coordinate is attractive for
coastal applications because provides an accurate representation of the
vortex stretching term that dominates coastal-trapped wave dynamics and
the bathymetric steering of coastal currents. The optional weighted
stretching of the vertical coordinate allows for enhanced resolution in the
upper ocean mixed layer and turbulent bottom boundary layer. The
horizontal discretization is by an orthogonal curvilinear Arakawa C-grid.
Shchepetkin and McWilliams (1998, 2003, 2004) describe in detail the
algorithms that comprise the ROMS computational kernel, and these have
been summarized recently by Haidvogel (2004). They include careful
formulation of the time-stepping algorithm to allow both exact conservation
and constancy preservation for tracers, while achieving enhanced stability
and accuracy in coastal applications where the free surface displacement is a
significant fraction of the total water depth. A redefinition of the barotropic
mode reduces the mode splitting error associated with solving the verticallyintegrated momentum equation on a much smaller time-step than the tracer
FORECAST AND MODELS FOR COASTAL OBSERVATORIES
will contribute to testing the hypotheses regarding the interaction of plume
structure with photo-chemistry, productivity rates and bio-accumulation.
3.
Coastal ocean modeling
Developments in observing systems are matched by progress in recent
years in the capabilities of coastal ocean models, due in part to increases in
computer technologies but more significantly through improved methods in
computational fluid dynamics, attention to the physical veracity of
subgridscale parameterizations, the application of advanced data assimilation
methods, and widespread experimentation in the formulation of ecosystem
and biogeochemical models.
3.1
The Regional Ocean Modeling System – ROMS
The model we have adopted for the LEO, CBLAST, LATTE and other
similar high to medium resolution coastal modeling applications is the
Regional Ocean Modeling System (ROMS) (http://marine.rutgers.edu/po/
index.php?model=roms). ROMS is a versatile, free-surface, hydrostatic
primitive equation ocean circulation model developed by collaborators at
several institutions, but led by specialists at Rutgers and UCLA. The model
is being used for applications from the basin to coastal and estuarine scales
(e.g. Haidvogel et al. 2000, Marchesiello et al. 2003, Lutjeharms et al. 2003,
Peliz et al. 2003, Dinniman et al. 2003, MacCready and Geyer 2001).
ROMS is formulated in a vertical terrain-following ‘s-coordinate’ similar
to classic sigma-coordinate models, but with generalizations that allow
selective weighting of the vertical distribution of points toward the free
surface or seafloor, or both. The terrain-following coordinate is attractive for
coastal applications because provides an accurate representation of the
vortex stretching term that dominates coastal-trapped wave dynamics and
the bathymetric steering of coastal currents. The optional weighted
stretching of the vertical coordinate allows for enhanced resolution in the
upper ocean mixed layer and turbulent bottom boundary layer. The
horizontal discretization is by an orthogonal curvilinear Arakawa C-grid.
Shchepetkin and McWilliams (1998, 2003, 2004) describe in detail the
algorithms that comprise the ROMS computational kernel, and these have
been summarized recently by Haidvogel (2004). They include careful
formulation of the time-stepping algorithm to allow both exact conservation
and constancy preservation for tracers, while achieving enhanced stability
and accuracy in coastal applications where the free surface displacement is a
significant fraction of the total water depth. A redefinition of the barotropic
mode reduces the mode splitting error associated with solving the verticallyintegrated momentum equation on a much smaller time-step than the tracer
FORECAST AND MODELS FOR COASTAL OBSERVATORIES