An Assessment of realistic winds for the Balearic Islands wave forecast

Trabajo presentado en EOF2010, I Encuentro de la Oceanografía Física Española, celebrada del 13 al 15 de octubre de 2010 en Barcelona (España), y organizada por el Centro Mediterráneo de Investigaciones Marinas y Medioambientales del CSIC (ICM-CSIC) y el Laboratorio de Ingeniería Marítima de la Universitat Politécnica de Catalunya (LIM-UPC)We have implemented a Third Generation wave model in the Balearic Islands, western Mediterranean, an ideal scenario to study the propagation and forecasting of coastal waves and its relation to local wind conditions, and interactions with swell of different characteristics. The wave hindcast in the coastal region around Mallorca and Cabrera Islands was assessed. The attention was centred in November 2008, when an important event with strong SW winds generated large swell waves (with significant fetch). The model results are validated at three different coastal wave buoys locations around the islands. Additionally, the wave model sensitivity to different wind fields was assessed. The wind data sets were divided into two groups according to their spatial resolution. The first group consists of atmospheric models with relatively coarse resolutions: HIRLAM, WRF and ECMWF with 16, 30 and 25 km, respectively. The second includes atmospheric winds with higher resolution: HIRLAM (5 km) and WRF (6 and 1.5 km). Results obtained show that high resolution wind forcing is more adequate for wave studies in coastal areas, because the local variability of the wind is specifically included giving rise to model significant wave height (Hs) in agreement with observations in coastal waters. However, at Cabrera the nearest location from the coast (9 km), the mean absolute error for Hs increased when the wave model was forced with the WRF (1.5 km) winds; on the case of strong SW winds episodes, the Hs was overestimatedPeer Reviewe