1. 1 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, amartinezf@aemet.es Justo Conde Criado, jcondec@aemet.es Ernesto Barrera Rodríguez, jbarrera@aemet.esamartinezf@aemet.esjcondec@aemet.es SPANISH METEOROLOGICAL AGENCY. MARINE PROGRAM. MADRID

2. 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.

3. 3 www.aemet.es 3 High resolution unstructured grid for wave forecasting at coastal areas

4. 4 www.aemet.es 4 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

5. 5 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?

6. 6 High resolution unstructured grid for wave forecasting at coastal areas

7. 7 IT IS NECESSARY TO COMBINE DIFFERENT MEDIA

8. 8 High resolution unstructured grid for wave forecasting at coastal areas

9. 9 OBJECT OF STUDY- PASS BETWEEN ATLANTIC AND MEDITERRANEAN SWAN 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

10. 10 High resolution unstructured grid for wave forecasting at coastal areas EASTERLY EPISODE

11. 11 High resolution unstructured grid for wave forecasting at coastal areas UNSTRUCTURED GRID AT THE STRAIT FOR COASTAL AREAS

12. 12 High resolution unstructured grid for wave forecasting at coastal areas

13. 13 High resolution unstructured grid for wave forecasting at coastal areas COMPARISON WITH IN-SITU BUOY: