ALBERT

Description: In the framework of the Mediterranean Forecasting System project (MFS) sub-regional and regional numerical ocean forecasting systems performance are assessed by mean of model-model and model-data comparison. Three different operational systems have been considered in this study: the Adriatic REGional Model (AREG); the AdriaROMS and the Mediterranean Forecasting System general circulation model (MFS model). AREG and AdriaROMS are regional implementations (with some dedicated variations) of POM (Blumberg and Mellor, 1987) and ROMS (Shchepetkin and McWilliams, 2005) respectively, while MFS model is based on OPA (Madec et al., 1998) code. The assessment has been done by means of standard scores. The data used for operational systems assessment derive from in-situ and remote sensing measurements. In particular a set of CTDs covering the whole western Adriatic, collected in January 2006, one year of SST from space born sensors and six months of buoy data. This allowed to have a full three-dimensional picture of the operational forecasting systems quality during January 2006 and some preliminary considerations on the temporal fluctuation of scores estimated on surface (or near surface) quantities between summer 2005 and summer 2006. In general, the regional models are found to be colder and fresher than observations. They eventually outperform the large scale model in the shallowest locations, as expected. Results on amplitude and phase errors are also much better in locations shallower than 50 m, while degraded in deeper locations, where the models tend to have a higher homogeneity along the vertical column compared to observations. In a basin-wide overview, the two regional models show some dissimilarities in the local displacement of errors, something suggested by the full three-dimensional picture depicted using CTDs, but also confirmed by the comparison with SSTs. In locations where the regional models are mutually correlated, the aggregated mean-square-error has been found to be lower, which is a useful outcome of having several operational systems in the same region.