1 high resolution unstructured grid for wave forecasting at coastal areas 14th ems annual meeting...
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HIGH RESOLUTION UNSTRUCTURED GRID FOR WAVE FORECASTING AT COASTAL AREAS
14th EMS Annual Meeting & 10th European Conference on Applied Climatology. October 2014 | Prague, Czech Rep.
Ángel Martínez Ferrer, [email protected] Justo Conde Criado, [email protected] Ernesto Barrera Rodríguez, [email protected]
SPANISH METEOROLOGICAL AGENCY. MARINE PROGRAM. MADRID
26/01/2008 AEMET, Agencia Estatal de Meteorología
High resolution unstructured grid for wave forecasting at coastal areas
SUMMARY
- State-of-the-art of wave models.
- Nesting scheme – from Ocean to Strait.
- Fractional steps.
- Network of forecasting modules.
- SWAN in the Strait.
- Unstructured grid for coastal areas.
- Buoy observations vs model forecasts.
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High resolution unstructured grid for wave forecasting at coastal areas
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Regional WW3 3-1.5’ and SWAN in the strait
High resolution unstructured grid for wave forecasting at coastal areas
Atlantic nesting: 24-12-6' --- regional
Regional nesting South + East: 3-1.5'---SWAN strait
area of study
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High resolution unstructured grid for wave forecasting at coastal areas
Flow unstabilities if Courant-Friedrichs-Levi condition is not met: Δt>Δx/c. Spatial propagation time step should be:
Δtp< Δx/cg =123766* Δx(º)*cos(latmax)*fmin
Iberia---- Δx=1’, latmax=37º, fmin=0.041Hz -> Δtp=80 s
… too much computing time!
Fractional steps philosophy:
WW3 alternates calculations among spatial and spectral propagations and source terms, so
Δtp ≤ 100 s
with higher time steps...
WHAT'S THE HIGHEST TIME STEP WITHOUT UNSTABILITY?
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High resolution unstructured grid for wave forecasting at coastal areas
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High resolution unstructured grid for wave forecasting at coastal areas
IT IS NECESSARY TO COMBINE DIFFERENT MEDIA
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High resolution unstructured grid for wave forecasting at coastal areas
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High resolution unstructured grid for wave forecasting at coastal areas
OBJECT OF STUDY- PASS BETWEEN ATLANTIC AND MEDITERRANEANSWAN AT x=3/8'
WINDS FROM HARMONIE AT 2.5 km (or less...)
Gibraltar strait: dense maritime trafic (W-E, and also N-S) with adverse meteorological conditions
Algeciras buoy
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High resolution unstructured grid for wave forecasting at coastal areas
EASTERLY EPISODE
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High resolution unstructured grid for wave forecasting at coastal areas
UNSTRUCTURED GRID AT THE STRAIT FOR COASTAL AREAS
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High resolution unstructured grid for wave forecasting at coastal areas
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High resolution unstructured grid for wave forecasting at coastal areas
COMPARISON WITH IN-SITU BUOY: