5th NOAA Testbeds and Proving Grounds Workshop, April 16-18, 2014

André van der Westhuysen, Joannes Westerink, Juan Gonzalez, Jane Smith,

Jamie Rhome, Jesse Feyen, Cristina Forbes, Julio Morell, Aurelio Mercado,

Jay Veeramony, Hugh Cobb, Carlos Anselmi, Ernesto Morales

IOOS Coastal and Ocean Modeling Testbedfor Puerto Rico and the Virgin Islands

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1. Objective

2. Activities

3. Modeling requirements

4. Model selection

5. Storm case selection

6. First results: Tidal modeling, Wave impacts

7. Conclusions

Content

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To extend the present wave/surge operational forecasting capability from mild-sloped coastal areas such as the US East and Gulf of Mexico coasts to steep-sloped

areas such as Caribbean and Pacific islands. Facilitate the transition to NOAA’s National Hurricane Center and local WFOs.

www.nhc.noaa.gov/climo

Objective

www.caricoos.org

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Activities

Phase 1: Model, test case and metric selection• Define desired operational model

requirements.• Identify candidate models to meet these.• Selection and formatting of test cases.• Define metrics for model evaluation.

Phase 2: Comparison over regional field cases• Model evaluations over complex regional

field cases, featuring hurricane meteorological forcing, high-resolution topo/bathy, roughness values from benthic maps and rainfall run-off inputs.

• Performance compared: accuracy vs. cost.

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Rincon, PR

Activities (2)

Phase 3: Model comparison over reef transects• Detailed cross-reef simulations with coupled

spectral wave and hydrodynamic models.

• Results compared with observations and phase-resolving wave models.

Phase 4: Recommendations and dissemination• Compile recommendations on

advantages/disadvantages of various modeling approaches for operations.

• Facilitate the transition to operations at the National Hurricane Center and WFOs.

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Modeling requirements • Guidance requirements set by National Hurricane Program• Guidance needed to determine which evacuation zones to order • Operational requirements:

a) Has to flow through AWIPS in order to be usableb) Time (and timeliness) is critical – order of minutesc) Numerical stability is essentiald) Advisories every 6 h, but more frequent special advisories issued if storms change quickly

• Physics requirements (from COMT1 and otherwise):a) Apply probabilistic approaches before landfall – deterministic only after landfallb) Evacuation zones are typically “chunky” – high-fidelity output lost in operational applicationc) SLOSH: Use a larger model domain, improve parametric wind model and addition of waves

(critical over reefs)d) Unknown impact of resolution and physics over reefse) Importance of submerged reefs in tidesf) Importance of bed friction/percolation

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Model selection

• UND: ADCIRC+SWAN, FUNWAVE• NHC: SLOSH+SWAN• NCEP: ADCIRC+WW3, NWPS• UPR: ADCIRC+SWAN• NRL: Delft3D+SWAN, TRITON

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Marilyn 1995Hugo 1989

George 1998

Lenny 1999

Isaac 2012

Storm selection for regional cases

Sandy 2012 (out of area)

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Cross-reef cases (Rincon, PR)

(1) Datawell Waverider (33 m, 2D wave spectrum)(1) Nortek AWAC (18 m, 2D wave spectrum)(2) Ocean Sensor Systems Pressure Sensor (6.54 m, 3.33 m)(1) Teledyne Sentinel ADCP (10 m channel)

DWR

AWACADCP

Press. Sens.

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Tidal modeling: ADCIRC+SWANM

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Amplitude Phase

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Tidal amplitudes and phasesM

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Amplitude Phase

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M2 Tidal Amplitude Validation

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M2 Tidal Phase Validation

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Wave impacts: SLOSH+SWAN

Surge only Surge + Waves

NWS/NHC/SSUHurricane George (1998), landfall

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Conclusions

1. Testbed to evaluate wave/surge operational modeling in steep-sloped regions such as the Caribbean and Pacific islands.

2. Features regional-scale and nearshore-scale field cases. To conclude with recommendations for operational environment.

3. Broad participation from academic and operational communities, with wide range of surge and wave models.

4. First results: Accurate ADCIRC tidal results through Puerto Rico, U.S. Virgin Islands and the Lesser Antilles (not available before).

5. Very localized difference of about -0.02 m with the observed M2 tidal amplitude on shelf between PR and the USVI (interface between (Atlantic Ocean and Caribbean Sea). M2 phases agree well with observed phases, except along PR south coast (but observations questionable).

6. Wave inclusion in SLOSH yields significant water level increase at landfall.

More information: testbed.sura.org

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