Incorporating nearshore processes into ROMS

John Warner, USGS

• USGS Participation – 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?

Outline

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

Community Sediment Community Sediment Transport Modeling ProgramTransport 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, ...)

Some of our recent contributions to ROMS1) 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. 81-113.

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:10.1029/2004JC002691.

along channel

Comparisons between model and observed

salinity

Time series at site N3 (river km 22).

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 transportWarner, 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

Sediment transport componentsSuspended sediment transport

when b > ce

Erosion formulation

Deposition formulation

SinksSourcesx

CK

x

CK

xx

CU

t

CVH

ii

i /32,1

z

CwSink s

ce

cebESource

10

Bed Model

gDs

sfsf

*

2/3* 047.08 sf

3gDq sbl

non-dimensional shear stress

non-dimensional sediment flux

bed load transport rate, kg m-1s-1

Bed load transport: Meyer-Peter Muller

Waves – Currents – SedimentInteraction

Process studies: point mass releasesS

uspe

nded

Dep

osit

ed

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

(1) Rho point sourcesexisting 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

#define ANA_PSOURCE (or from NetCDF file)

Flux of water imposed in the vertical at rho points.

step2d.F: zeta = zeta + Qbar *dt / (dx dy)

omega.F: = Qsrc

step3d_t.F: FC = Qsrc * t

X X

diffusers, river mass, GW, precip

rivers

1) #define craig_banner

2) #define tke_wavediss

(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 .

wc *su ~ 100; = surface stress

-- How get Zos ?

#define charnok

#define zo_hsig

~ 0.25 w = wave energy dissipationw

sk

t

z

k

3*sw

sk

t ucz

k

nnsft

m p

μswn

sftm p

μk

s

t zzLkcn

uczzLkmcz

ψ0

12/1103*0

10 )(

nnsft

m p

μn

sftm p

μk

s

t zzLkcn

zzLkmcz

ψ0

12/1100

10 )(

guaZos /2* a = 1400

ss aHZo a = 0.5; Hs = significant wave height

(3) Sediment bedload formulationBedload transport due to combined waves + currents

Soulsby, R.L., and Damgaard, J.S. 2005. Bedload transport in coastal waters. Coastal Engineering, 52, p. 673-689.

5.031 dsgq xbx

5.031 dsgq yby

Bedload flux (m3/s/m of width)

current dir

_|_ to current dir

(4) Wetting and Drying

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

Formulation in other models:

Why is it a problem? (reminder: D = h + )

- non-negative grid cell thickness (log layer)

- D ~= 0! Conservancy properties of model divides by D.

- Wave number calculations [sqrt (gh)]

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.

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.

Wetting and DryingSuisun Bay, Northern San Francisco Bay, CA

ToGolden Gate

ToSacramento

(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).

Radiation Stress Method-Mellor, G. L. 2003 The three-dimensional current and surface wave equations. Journal of Physical Oceanography 33, 1978-1989.- Mellor, G. L. 2004 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

Test case w/ radiation stress method

Hs = 2.0 mT = 10 s

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.

Generalized Lagrangian Mean Method

• Model Coupling Toolkit -Mathematics and Computer Science Division Argonne National Laboratoryhttp://www-unix.mcs.anl.gov/mct/R. Jacob, J. Larson, E. Ong, “M×N Communication and Parallel Interpolation in CCSM Using the Model Coupling Toolkit”, (Preprint) ANL/MCSP1225-0205, Mathematics and Computer Science Division, Argonne National Laboratory, Feb 2005. 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-P1208-1204, Mathematics and Computer Science Division, Argonne National Laboratory, Dec 2004. Submitted to International Journal for High Performance Computing Applications.

(6) Model coupling

• Earth System Modeling Framework http://www.esmf.ucar.edu/

"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 LaboratoryNASA 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 UniversityMassachusetts Institute of Technology UCLA Center for Ocean-Land-Atmosphere Studies Programme for Integrated Earth System Modeling (PRISM) Common Component Architecture (CCA)

Model connectivity programs

Atm. Model (M nodes)

Call MCT World

Define GlobalSegMapDefine AttrVectDefine Router

Call MCT World

Define GlobalSegMapsDefine AttrVectsDefine RoutersDefine AccumulatorsRead Matrix elements

Call MCT World

Define GlobalSegMapDefine AttrVectDefine Router

Coupler (N nodes) Ocean Model (P nodes)

Initialization

Read Atmosphere Data

Read Ocean Data

MCT_Send(AtrVect, Router) MCT_Recv(AAtrVect, ARouter)MCT_Recv(OAtrVect, ORouter)

InterpolateMCT_Send(AtrVect, Router)

MCT_Recv(AtrVect, Router)

MCT_Recv(AtrVect, Router)

Data Transfers using the MCT

MCT_Send(AAtrVect, ARouter)Synchronization point

MCT_Send(OAtrVect, ORouter)

Current Inter - Model Coupling

Perlin, OSU

Schaffer/Arango

USGS

u, v, h Dwave,HwaveLwave,

Pwave_top,Pwave_bot,Ub_swan

Wave_dissip

Interconnection of many modeling components

- Allow many different and new models to communicate using a common data transfer strucutre.

Newmodel

master.FROMS- init- run- finalize

COAMPS- init- run- finalize

WRF- init- run- finalize

NEW- init- run- finalize

SWAN- init- run- finalize

- MCT is really the network architecture that allows inter-model communications and contains

Coupler

Inlet Test

ubar = 0.5 m/s depth (m)

2

16

Hs = 2.0 mT = 10 s

1200 m

1200 m

4 cases:1) SWAN uncoupled2) ROMS uncoupled without rad stress terms3) ROMS uncoupled with rad stress terms and SWAN forcing (from 1)4) ROMS + SWAN coupled

Inlet test results

effect of currents on waves(swan uncoupled vs coupled)

SWAN Hs

wave generated currents(roms uncoupled vs. coupled)

ROMS zeta + u/v

Summary

• Inocorporated processes for1) 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