SURA Super-Regional Testbed on Coastal Inundation – Extra-tropical Storm Harry V. Wang, Yi-cheng Teng, Yanqiu Meng and Derek Loftis Virginia Institute of Marine Science The College of William & Mary Joseph Zhang Oregon Health and Science University NSF Land and Water Margin Research Center SURA super-regional testbed meeting on coastal inundation

Outline 1. SELFE set up 2.Analysis of surge and tides results for V2.0 Case studied: 2005 and 2007 storms 3D results without wind wave Preliminary results with wind wave 3. What is WWM? (Dr. Yinglong Joseph Zhang)

Results Analyses Plan for the Inundation Testbed v2.0 Tides: Datum adjustment = 0 m (NAVD88 approx = MSL using reference in Boston and Plymouth, baroclinic / sterric effects in open BC forcing) Forcing: July – August 2010 elevation time series provided by UMassD (predicted by the Gulf of Maine FVCOM tidal model with inclusion of five major tidal constituents-M2, N2, S2, K1 and O1). Runs: 2D Mannings n = D run, 11 vertical layers, quadratic bottom friction using: Where zab = height of the lowest grid cell above the bottom and zo is a function of depth: Note, inside Scituate, H < 40 m, and therefore zo should =0.003 m. Analysis: model elevation time series at Scituate NOAA gauge – location/data provided by UMassD Skill: IMEDS – time series comparisons for elevation Model – Model Comparisons from skill assessment - extra-tropical domain

Set Up for 2D and 3D mode SELFE model Model domains: Situate a domain Tidal boundary conditions: M2, K1, O1, S2, N2, provided by FVCOM Time step = 180 s, total run time = 45 days For 2D, Manning n=0.025 was used. For 3D, Vertical 11 S-layers were used; The wind forcing 9x9 km WRF wind at 10 m height. The model and data comparison was conducted for May 2010

**SELFE-WWM used 21 frequencies and 24 angles to simulate wind waves

WWM II (Wind Wave Model) The Wind Wave Model is one of the first 3rd generation spectral wave models, which solves the Eulerian form of the Wave Action Equation on unstructured meshes. The Model was developed in cooperation between the National Cheng Kung University, Taiwan (Dr. Hsu) and the Technical University of Darmstadt, Germany (Drs. Roland and Zanke). The Motivation was the inflexibility of freely available spectral wave models to discretize complicated domains. The numerical schemes of the WWMII (Roland, 2009) will be available in WWIII V4.0 The WWMII was successfully coupled to SELFE to account for the effect of waves on circulation

Physics in the WWMII The WWM II incorporates: SWAN Model deep and shallow water physics WAM Model (ECMWF Version) Fabrice Ardhuin’s of deep water physics (see JCOMM Project ( services.org/Wave-Forecast-Verification- Project.html) services.org/Wave-Forecast-Verification- Project.html

Numerical schemes in the WWM II Operator Splitting Methods (OSM) e.g. WWIII or WWM –1 st Step – Spectral part –2 nd Step – Geographical space –3 rd Step – Integration of the source terms

Numerical schemes in the WWM II Numerical methods for the sub-problems –Geographical space Galerkin schemes (non-monotone, conservative, implicit) Residual distribution schemes (monotone, conservative, higher order, explicit/implicit – parallelization of implicit scheme underway) –Source term integration Semi-implicit (WAM) or (SWAN) Dynamical (WWIII) Runge-Kutta –Spectral space Ultimate Quickest (explicit, 3 rd order in space and time) Crank-Nicholson (implicit, 2 nd order in space and time) Runge-Kutta WENO (explicit, 5 th order in space, 3 rd order in time) WWM fully coupled to SELFE –Callable as a routine –Use same sub-grid – efficiency Radiation stress formulations –Longuet-Higgins and Stewart (2D) –Xia (2004), Mellor (2003), Ardhuin (in progress) Benchmarks –L31, L51, analytical, hurricane Isabel (2003)….

ONR testbed: L31 x (m) Set up (m) Time (hours)

ONR testbed: L51

Nicholson test STC model (Nicholson et al. 1997)