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Incorporating nearshore processes into ROMS

Incorporating nearshore processes into ROMS. John Warner, USGS. Outline. 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

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Incorporating nearshore processes into ROMS

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  1. Incorporating nearshore processes into ROMS John Warner, USGS

  2. Outline • 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?

  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 ProgramChris 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. 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. 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. Some of our recent contributions to ROMS 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 – SedimentInteraction

  9. Process studies: point mass releases Suspended Deposited

  10. 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

  11. (1) Rho point sources rivers X X 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 #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: W = Qsrc step3d_t.F: FC = Qsrc * t diffusers, river mass, GW, precip

  12. (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

  13. (3) Sediment bedload formulation Soulsby, R.L., and Damgaard, J.S. 2005. Bedload transport in coastal waters. Coastal Engineering, 52, p. 673-689. Bedload transport due to combined waves + currents Bedload flux (m3/s/m of width) current dir _|_ to current dir

  14. (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)] 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:

  15. 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.

  16. 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.

  17. Wetting and DryingSuisun Bay, Northern San Francisco Bay, CA To Sacramento To Golden Gate

  18. (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).

  19. 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

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

  21. 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.

  22. Generalized Lagrangian Mean Method

  23. (6) Model coupling Model connectivity programs • Model Coupling Toolkit - • Mathematics and Computer Science Division Argonne National Laboratory • http://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. • 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 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)

  24. Data Transfers using the MCT Atm. Model (M nodes) Coupler (N nodes) Ocean Model (P nodes) Call MCT World Define GlobalSegMaps Define AttrVects Define Routers Define Accumulators Read Matrix elements Call MCT World Define GlobalSegMap Define AttrVect Define Router 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)

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

  26. 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

  27. Inlet Test 1200 m 2 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

  28. 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)

  29. Summary • Inocorporated processes for 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

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