Implementation and validation of a new operational wave forecasting system of the Mediterranean Monitoring and Forecasting Centre in the framework of the Copernicus Marine Environment Monitoring Service

Abstract

Abstract. Within the framework of the Copernicus Marine Environment Monitoring Service (CMEMS), an operational wave forecasting system for the Mediterranean Sea has been implemented by the Hellenic Centre for Marine Research (HCMR) and evaluated through a series of preoperational tests and subsequently for 1 full year of simulations (2014). The system is based on the WAM model and it has been developed as a nested sequence of two computational grids to ensure that occasional remote swell propagating from the North Atlantic correctly enters the Mediterranean Sea through the Strait of Gibraltar. The Mediterranean model has a grid spacing of 1∕24∘. It is driven with 6-hourly analysis and 5-day forecast 10 m ECMWF winds. It accounts for shoaling and refraction due to bathymetry and surface currents, which are provided in offline mode by CMEMS. Extensive statistics on the system performance have been calculated by comparing model results with in situ and satellite observations. Overall, the significant wave height is accurately simulated by the model while less accurate but reasonably good results are obtained for the mean wave period. In both cases, the model performs optimally at offshore wave buoy locations and well-exposed Mediterranean subregions. Within enclosed basins and near the coast, unresolved topography by the wind and wave models and fetch limitations cause the wave model performance to deteriorate. Model performance is better in winter when the wave conditions are well defined. On the whole, the new forecast system provides reliable forecasts. Future improvements include data assimilation and higher-resolution wind forcing.

An Operational Wave System within the Monitoring Program of a Mediterranean Beach

“…The results presented in Section 3 show that the operational wave system performs better in deep waters and intermediate waters than in the nearshore. This outcome is in agreement with Ravdas et al [10] who found relatively low correlations at coastal locations. Whereas correlation coefficients for wind speed and significant wave height are 0.91 and 0.93 in deep waters at the Lion buoy site, they drop to 0.62 and 0.85 when computed data are compared with measurements in the nearshore at Poetto beach.…”

“…Under the same lead-time range, the relative error passes from 17 to 28% at La Revellata buoy and from 28 to 35% at Poetto beach. This deterioration of the wave forecast accuracy with the lead-time is likely to be related to larger uncertainties in the wind forcing fields [10,37]. Despite the accuracy loss, the relative error remains under moderate values, confirming the reliability of the prediction for the time window covered by the simulation.…”

“…In this study, special attention is devoted to the identification of the model limitations in reproducing coastal wave conditions generated over limited Mediterranean fetches (on the order of hundreds of km) and under the local influence of varying sea breezes. Wave modelling under these environmental conditions has been recognized as particularly challenging by the literature [10,11], thus requiring further research.…”

From Observation to Information and Users: The Copernicus Marine Service Perspective

“…At the regional level, the impact of assimilating satellite observations on the Med-Wave system has been evaluated considering the Med-Waves-V4 system, assimilating along-track significant wave height observations from Jason-2 and Saral satellites at 3-hourly intervals, vs. the Med-Waves-V3.2 system without data assimilation (Ravdas et al, 2018). Data assimilation improves results along satellite tracks, as well as at the great majority of the wave buoy locations.…”

Impact of the October 2018 Storm Vaia on Coastal Boulders in the Northern Adriatic Sea

“…In addition, the computation of the bottom stress of the ocean models (respectively, ROMS and ADCIRC) was updated in order to consider the spatial distribution of the sediment grain size at the bottom of the Adriatic Sea, extracted from the Adriatic Seabed database [40], and the wave effects. To reproduce the storm as accurately as possible, the basic module was set up to run for three days between 27 October and 30 October 2018, with initial conditions and boundary forcing provided by (1) the 6 hourly ERA-Interim reanalysis fields [41], (2) the daily analysis MEDSEA-Ocean fields [42], and (3) the hourly MEDSEA-Wave fields [43]. The nearshore module, forced by the results of the basic module, was set up to run between midday on 28 and 30 October 2018.…”