1. Incorporating nearshore processes into ROMS
John Warner, USGS

2. Outline USGS Participation Overview of some contributions to the model
Role of USGS
Overview of some contributions to the model
(mostly driven by our needs in regional apps)
Turbulence closures (GLS)
Sediment transport
MPDATA
Recent advancements
Q_PSOURCE - wetting/drying
surface tke flux - wave/current interactions
bedload - model coupling
Summary /where are we going?

3. Role of Coastal & Marine Geology
We provide scientific information to
Describe and understand the earth
Minimize losses from natural disasters
Manage resources
Enhance / protect quality of life
Need numerical models for:
Study basic science processes
Regional projects (Mass Bay, South Carolina, Adriatic, …)
Prediction (shoreline change, coastal evolution, aggregate resources, restoration, natural disasters)
N. Myrtle Beach-March 1993

4. Community Sediment Transport Modeling Program Chris Sherwood, Rich Signell, John Warner, Brad Butman
Promote/test/select/develop/adopt/improve/maintain community models
Advance instrumentation and data analysis techniques for making measurements to test and improve sediment-transport models.
Advance software analysis and visualization tools that support model applications.
Apply sediment transport models to benefit regional studies
(South Carolina, North Carolina, Mass Bay, Adriatic, Hudson River, ...)

5. Some of our recent contributions to ROMS
1) Turbulence closures (GLS)
Warner, J.C., Sherwood, C.R., Arango, H.G., and Signell, R.P. (2005)
“Performance of four turbulence closure models implemented using a
generic length scale method.” Ocean Modelling 8, p
Warner, J. C., W. R. Geyer, and J. A. Lerczak (2005), Numerical modeling
of an estuary: A comprehensive skill assessment, J. Geophys. Res., 110,
C05001, doi: /2004JC
along channel
Comparisons between model and observed
salinity
Time series at site N3 (river km 22).

6. recent contribs (cont'd)
2) Surface tke flux due to wave breaking
3) Isobaric drifters (constant z or constant depth)
4) Monotonic advection scheme (MPDATA)
5) Suspended sediment and bed load transport
Warner, J.C., Sherwood, C.R., Signell, R.P., Butman, B., Arango, H.G., Shchepetkin, A., nad Blaas, M. (in prep.) Community Sediment Transport Model User’s Guide, Version 1.0, USGS Open File Report No. XXXX.
6) Bed framework + transport of multiple sediment classes
7) Wave/current bottom boundary layer interactions

7. Sediment transport components
Suspended sediment transport
Bed Model
Erosion formulation
when tb > tce
Deposition formulation
Bed load transport: Meyer-Peter Muller
non-dimensional shear stress
non-dimensional sediment flux
bed load transport rate, kg m-1s-1

8. Waves – Currents – Sediment Interaction

9. Test Cases Open channel flow W Wind r 3) Mixed layer deepening LDm
3) Mixed layer deepening
2) Closed basin,
wind-driven circulation
4) Tidal flow around
a headland
5) Estuarine circulation

10. Process studies: point mass releases
Suspended
Deposited

11. Incorporating a few nearshore processes
1) Rho point sources (#define Q_PSOURCE)
2) Surface tke fluxes (zo_hsig, tke_wavediss
charnok, craig_banner)
3) Sediment bedload transport
4) Wetting and drying
5) Wave/current interactions
6) Model coupling

12. diffusers, river mass, GW, precip
(1) Rho point sources
existing formulation:
#define UV_PSOURCE, TS_PSOURCE
#define ANA_PSOURCE (or from NetCDF file)
Flux of water imposed at horizontal u or v points.
step2d.F: ubar = Qbar / (dy H); vbar = Qbar / (dx H)
step3d_uv.F: u = Qsrc / (dy Hz); v = Qsrc / (dx Hz);
step3d_t.F: FX = Hz u on * Tsrc
additional method:
#define Q_PSOURCE, TS_PSOURCE
Flux of water imposed in the vertical at rho points.
step2d.F: zeta = zeta + Qbar *dt / (dx dy)
omega.F: W = Qsrc
step3d_t.F: FC = Qsrc * t
rivers X X
diffusers, river mass, GW, precip

13. a = 0.5; Hs = significant wave height
(2) Surface tke fluxes
Two formulations to account for surface injection of tke due to breaking waves.
For GLS each formulation requires boundary conditions for k and y.
~ 100;
= surface stress
1) #define craig_banner
2) #define tke_wavediss
a ~ 0.25
= wave energy dissipation
-- How get Zos ?
#define charnok
#define zo_hsig
a = 1400
a = 0.5; Hs = significant wave height

14. (3) Sediment bedload formulation
Bedload transport due to combined waves + currents
Soulsby, R.L., and Damgaard, J.S Bedload transport in coastal waters.
Coastal Engineering, 52, p
Bedload flux (m3/s/m of width)
current dir
_|_ to current dir

15. Formulation in other models:
(4) Wetting and Drying
Why is it a problem? (reminder: D = h + h > 0)
- non-negative grid cell thickness (log layer)
- D ~= 0! Conservancy properties of model divides by D.
- Wave number calculations [sqrt (gh)]
Formulation in other models:
Typical implementation is flux blocking at velocity points.
DELFT 3D, RMA2 - velocity set = 0 when D < Dcrit; 'rewet' for D > 2*Dcrit.
possibility of strong gradients -> oscillations
GETM - factor multiplier in momentum eqts.,
shallow water balance (g dh/dx ~ Cd u |V|/D)
does not guarantee D >0 (needs other criteria).
Trim3D - implicit formulation, flux blocking on next dt.
POM WAD - set u/v = 0 when D|vel pt < Dcrit

16. ROMS: wetting and drying
Our approach (maybe consistent with EFDC (?))
Special form of "cell face blocking"
Divide problem into 2 processes:
Wetting : let it happen!
Drying : if D|rho pt < Dcrit
only allow flux inward.

17. ROMS: wetting and drying
Methodology:
1) initial rho_mask establishes permanent land locations
(rmask = 0 --> will never be "wet")
2) initial free surface draped over all elevations
3) in step2d, after zeta_new calc
if D|rho pt < Dcrit then rmask_wet = 0.
calc umask_wet, vmask_wet,
ubar_new = uber_new * umask * umask_wet (same for v)
4) in step3d_uv, use same wet mask to block u and v.

18. Wetting and Drying Suisun Bay, Northern San Francisco Bay, CATo
Sacramento To
Golden Gate

19. (5) Wave current interactions
- Wind generated waves.
- Waves shoal and refract.
- Waves propagating into the coastal zone can generate significant nearshore currents.
- Waves nonlinearly interact with these currents and currents generated from other processes (such as tides).

20. Radiation Stress Method
-Mellor, G. L The three-dimensional current and surface wave equations. Journal of Physical Oceanography 33,
- Mellor, G. L Some consequences of the three-dimensional currents and surface wave equations. Preprint.
start w/ momentum eqs.
coordinate transformation
avg over 'wave period'
resulting 2D eqtns.
resulting 3D eqtns.
needs:
Hwave, Lwave, Dwave

21. Test case w/ radiation stress method
Hs = 2.0 m
T = 10 s

22. but is it correct ?? Recent Habilitation by Fabrice Ardhuin
- attempts to reconcile 3 approaches of:
Mellor radiation stress method
McWilliams et al vortek force method
Generalized Lagrangian Mean method
- suggests that Mellor left out a few terms that are of same order as leading terms
- suggests an inconsistency in the vortex force formulations surface boundary condition
- suggests that GLM provides a more consistent framework that covers entire water column.

23. Generalized Lagrangian Mean Method

24. Model connectivity programs
(6) Model coupling
Model connectivity programs
Model Coupling Toolkit -
Mathematics and Computer Science Division Argonne National Laboratory
R. Jacob, J. Larson, E. Ong, “M×N Communication and Parallel Interpolation in CCSM Using the Model Coupling Toolkit”, (Preprint) ANL/MCSP , Mathematics and Computer Science Division, Argonne National Laboratory, Feb Submitted to International Journal for High Performance Computing Applications.
J. Larson, R. Jacob, E. Ong, “The Model Coupling Toolkit: A New Fortran90 Toolkit for Building Multiphysics Parallel Coupled Models”, (Preprint) ANL/MCS-P , Mathematics and Computer Science Division, Argonne National Laboratory, Dec Submitted to International Journal for High Performance Computing Applications.
Earth System Modeling Framework
"The ESMF defines an architecture for composing multi-component applications and includes data structures and utilities for developing model components.  "
Partners: NOAA Geophysical Fluid Dynamics Laboratory NOAA National Centers for Environmental Prediction
NSF National Center for Atmospheric Research NASA Goddard Global Modeling and Assimilation Office
NASA Goddard Institute for Space Studies NASA Jet Propulsion Laboratory NASA Goddard Land Information Systems project DOD Naval Research Laboratory
DOD Air Force Weather Agency DOD Army Engineer Research and Development Center DOE Los Alamos National Laboratory DOE Argonne National Laboratory
University of Michigan Princeton University Massachusetts Institute of Technology UCLA
Center for Ocean-Land-Atmosphere Studies Programme for Integrated Earth System Modeling (PRISM)
Common Component Architecture (CCA)

25. Data Transfers using the MCT
Atm. Model (M nodes)
Coupler (N nodes)
Ocean Model (P nodes)
Call MCT World
Define GlobalSegMap
Define AttrVect
Define Router
Call MCT World
Define GlobalSegMaps
Define AttrVects
Define Routers
Define Accumulators
Read Matrix elements
Call MCT World
Define GlobalSegMap
Define AttrVect
Define Router
Initialization
Read Atmosphere Data
Read Ocean Data
MCT_Send(AtrVect, Router)
MCT_Recv(AAtrVect, ARouter)
MCT_Recv(OAtrVect, ORouter)
Interpolate
MCT_Send(AtrVect, Router)
MCT_Recv(AtrVect, Router)
MCT_Send(AAtrVect, ARouter)
Synchronization point
MCT_Send(OAtrVect, ORouter)
MCT_Recv(AtrVect, Router)

26. Modifications required
ROMS
- #define waves_ocean
- waves_ocean.h
- waves_coupler.F
- I/O
SWAN
- become a library
- swancplr.ftn
- insert MCT coupling calls

27. Current Inter - Model Coupling
Dwave,
Hwave
Lwave,
Pwave_top,
Pwave_bot,
Ub_swan
Wave_dissip
u, v, h
Schaffer/
Arango
USGS
Perlin, OSU

28. Interconnection of many modeling components
master.F
ROMS
- init
- run
- finalize
WRF
- init
- run
- finalize
COAMPS
- init
- run
- finalize
SWAN
- init
- run
- finalize
NEW
- init
- run
- finalize
Coupler
New
model
- Allow many different and new models to communicate using a common data transfer strucutre.
- MCT is really the network architecture that allows inter-model communications and contains

29. Inlet Test depth (m) 4 cases: 1) SWAN uncoupled2
ubar = 0.5 m/s
depth (m)
Hs = 2.0 m
T = 10 s 16
1200 m
4 cases:
1) SWAN uncoupled
2) ROMS uncoupled without rad stress terms
3) ROMS uncoupled with rad stress terms
and SWAN forcing (from 1)
4) ROMS + SWAN coupled

30. Inlet test results ROMS zeta + u/v SWAN Hs effect of currents on waves
(swan uncoupled vs coupled)
wave generated currents
(roms uncoupled vs. coupled)

31. Summary Inocorporated processes for Future directions:
1) Rho point sources (#define Q_PSOURCE)
2) Surface tke fluxes ( zo_hsig, tke_wavediss
charnok, craig_banner)
3) Sediment bedload transport
4) Wetting and drying
5) Wave/current interactions
6) Model coupling
Future directions:
- turn on morphology - provide documentation
- model coupling - wave / current interaction