To Couple or Not To Couple
description
Transcript of To Couple or Not To Couple
To Coupleor
Not To Couple
John Warner, USGS
• Overview of some recent advancements to ROMS– sediment transport components– wave/current interactions– model coupling
• Focus on Model Coupling– MCT, ROMS, SWAN
• How to develop a coupled ROMS-SWAN application (inlet test example)
• Summary /where are we going?
Outline
What is model coupling?
Model A running on M nodes.
78 processor cluster -WHOI shared
Model B running on N nodes.
Model C ………
………
(it also works here)
……
with communications between all models.
Why Couple models?
• Your model doesn't have all the physics !– For example, waves are needed from a different
source, such as another model or data• Provide dynamic feedback
– nonlinear interactions between forcing (i.e. wave-currents-morphology).
http://www.cofc.edu
Where / when is model coupling important ?
Surface winds Groundwater
Sea iceWaves
http://www.cofc.edu/CGOInquiry/tidalinlets.htm
Model Coupling ToolkitMathematics 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.
How are we coupling models?
MCT is an open-source package that provides MPI based communications between all nodes of a distributed memory
modeling component system. Download and compile as libraries that are linked to. (like netcdf)
Model A "M" processors
Model B "N" processors
Plan to change coupler to ESMF in the near future
Earth System Modeling Framework http://www.esmf.ucar.edu/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)
What do we need from SWAN, and what does SWAN want from ROMS?
u, v, , h
Dwave, Hwave, Lwave,Pwave_top, Pwave_bot,Ub_swan, Wave_dissip
Recent advancements to ROMS
Roller Model
3D momentum equations
0
' 'z z z z zz z
z
z xyz xx px
H u uH u vH u H u H p uf H v H g u w
t x y s x x s H s
H SH S S
x y s
0
' 'z z z z zz z
z
z xy z yy py
H v uH v vH v H v H p vf H u H g v w
t x y s y y s H s
H S H S S
x y s
0 0
10 z
p gH
s
0z z zH u H v H
t x y s
' 'z z z z
sourcez
H C uH C vH C H C Cc w C
t x y s s H s
(wave - current interaction adds new terms)
x:
y:
continuity:
scalar transport:
s:
Radiation stress terms2
2
2
2
2
2
x x x xxx CS CC CS CC SS CS R z
x y x yxy yx CS CC R z
y y y yyy CS CC CS CC SS CS R z
k k k k cS k E F F F F F F A R
k Lk
k k k k cS S kE F F A R
k Lk
k k k k cS k E F F F F F F A R
k Lk
4
1 tanh2
z
sR
1 coth2
1 coth2
SSpx CC SS CS SS
SSpy CC SS CS SS
kD kDF ES F F F s E EF kD
x x x
kD kDF ES F F F s E EF kD
y y y
sinh 1 cosh 1
sinh sinh
sinh 1 cosh 1
cosh cosh
SS CS
SC CC
kD s kD sF F
kD kD
kD s kD sF F
kD kD
2 /16sE gH wave energy:
2cosh 2 1 cosh 2 12;
sinh 2 sinh 2
yx R Rs s
kkD s kD sk D g A D g Au E v E
c kD L c kD L
Mellor, G. L. (2003). The three-dimensional current and surface wave equations. Journal of Physical Oceanography 33, 1978-1989.
where
verticalshape
functions:
roller function:
stokes velocities:
horizontal radiation stresses:
vertical radiation stresses:
Roller model based on:Svendsen, I. A. (1984). Wave heights and set-up in a surf zone, Coastal Engineering, 8, 303-329.Svendsen, I, Haas, K and Zhao, Q (2002). Quasi-3D Nearshore Circulation Model SHORECIRC, CACR Report 2002-01.
Mellor, G. L. (2005). Some consequences of the three-dimensional current and surface wave equations. Journal of Physical Oceanography 35, 2291-2298.
Depth-integrated equations
xyxxsx bx
Du uDu vDu SSpf Dv D
t x y x x y
xy yysy by
Dv vDu vDv S Spf Du D
t x y y x y
0
Du Dv
t x y
2
2 2
2
2 2
2
2 2
1
2
1
2
g gx x x x Rxx
g x y x y Rxy yx
g y y g y y Ryy
c ck k k k c AS E E
c c Lk k
c k k k k c AS S E
c Lk kc k k c k k c A
S E Ec c Lk k
2
12 sinh 2g
c kDc
k kD
; y yx x R Rs s
k E kk E k g A g Au v
ck D k c L ck D k c L
group speed:
x:
y:
continuity:
horizontaldepth-integrated radiation stresses:
where
stokes velocities:
Velocities are Lagrangian !! So we are recoding to make them all Eulerian.
SWAN (the wave model)
yx wc Nc N c N c N SN
t x y
cx, cy = propagation velocities (x- and y- directions) = relative frequency = wave direction
S = source/sink term for: - wind-wave generation - wave breaking - bottom dissipation - nonlinear wave-wave interactions
SWAN accounts for shoaling, diffraction, partial transmission, and reflection.
N = wave action density (energy density / relative frequency)
Booij, N., R.C. Ris and L.H. Holthuijsen, 1999, A third-generation wave model for coastal regions, Part I, Model description and validation, J.Geoph.Research, 104, C4, 7649-7666.Booij, N., R.C. Ris and L.H. Holthuijsen, 1999, A third-generation wave model for coastal regions, Part II, Model description and validation, J.Geoph.Research, 104, C4, 7649-7666.Booij, N., Haagsma, IJ.G., Holthuijsen, L.H., Kieftenburg, A.T.M.M., Ris, R.C., van der Westhuysen, A.J., and Zijlema, M. (2004). SWAN Cycle III version 40.41 User Manual, Delft University of Technology.
pretty good user’s manual !!!
Simple example of an uncoupled application
to demonstrate wave driven flows ….
Shoreface test case
test case setup
1) use SWAN to predict wave heights, wave dissip, wave direction,wave length, wave period2) results from SWAN were used as forcing to ROMS and Shorecirc.
Thanks to Kevin Haas at Ga Tech Savannah
( )0 ( ) xx
bx
Shg h
x x
2 2 xyd
SC v u v
x
How does the coupled modeling system work?
Model organization
master.F
mpi_init
initrun
finalize
initrun
finalize
{{
SWAN
ROMS
init_file (# procs/model)
init, run, and finalize
ROMS SWAN
init(grid decomp)
run(sync. point)
finalize
init_paraminit_parallelinit_scaclarsinit_couplingro
ms_
init
rom
s_ru
n
main3d .....
waves_coupling...
mpi_finalizeclose_io
rom
s_fi
nali
ze
MPI_INIT
SW
INIT
MP
IS
WM
AIN
SW
EX
ITM
PI
SWINITSWREAD (grid)
init_coupling
swanmain .....
ocean_coupling...
mpi_finalizeclose_io
Grid decomposition (during initialization)
ROMS SWAN
-Each tile is on a separate processor.
-Each tile registerswith MCT.
init_coupling
ROMS- init_coupling SWAN- init_coupling
1
1
22
3
3
processed by each ROMS tileprocessed by each SWAN tile
Synchronization (run phase)
ROMS- cocean_oupling SWAN- waves_coupling
MCT
MCT
processed by each ROMS tile processed by each SWAN tile
How to set up a Coupled ROMS / SWAN application
Use INLET_TEST as an example.This application is provided in ROMS 2.3
You need to compile and install MCT (only once).You need all the input files for a stand alone ROMS simulation.You need all the input files for a stand alone SWAN simulation.
We have some m files to make ROMS grids, SWAN grids from ROMS grids,SWAN wave forcing files, SWAN wind forcing files, etc.
Step 1: cppdefs.h
INLET_TESTis already set up to
have model coupling
NEARSHORE_MELLOR activates radiation stress terms in momentum equations.
WAVES_OCEAN activates coupling to the wave model.
Step 2: coupling input file
Set number of processors for each model.
coupling_inlet_test.in
Set synchronizationinterval.
File names.(SWAN = INPUT)
Step 3: ROMS input file
Make sure number of tiles
= number of processorsspecified in
coupling input file
ocean_inlet_test.in
Step 4: SWAN input file
Keep these 2 sets ofcommands for CURRENT and
WLEV. These activateinternal SWAN flags.
INPUT
MANY MORE commands further in this file. RTFSM.
Step 5: makefile
SWAN_COUPLEactivates compiler
directives forMCT libraries.
Needs MPI
Step 6: compile and run
make
mpirun –np M*N ./oceanM ROMS/External/coupling_inlet_test.in
Inlet Test
ubar = 0.5 m/s depth (m)
2
16
Hs = 2.0 mT = 10 s
1200 m
1200 m
Use the inlet test case as an example. This test case will be distributed with ROMS 2.3
Inlet test (preliminary look)
1) Two-way coupled simulation shows wave-current interaction: reduced magnitude of currents and increased wave height.2) Coupled simulation has lower velocity and less erosion offshore of inlet.3) Lateral BC effects of wave model.
SWAN ROMS
SWAN ROMS
Where are we heading with this?
New directory structure for ROMS 2.3
COAMPSWRF
Others …
(Natalie Perlin OSU, but not formalized into Rutgers version yet)
Summary
• Model enhancements include :– sediment transport components– wave/current interaction– model coupling
• Developed a coupled ocean-wave modeling system.• New directory structure to allow coupling to other models.• ROMS 2.3 release – in a few weeks after finalize
Lagrangian to Eulerian issue.