A data assimilation scheme to improve the wave predictions in the Black Sea

The objective of the work is to evaluate a data assimilation scheme for improving the reliability of the wave predictions in the Black Sea. A wave modeling system, SWAN based, has been implemented in the Black Sea and it was extensively tested against both in situ and remotely sensed measurements. Subsequently, this system was focused on various coastal environments in a multi-level nested scheme. In order to assimilate the satellite data, for the wave generation level that covers the entire basin of the Black Sea, an Optimal Interpolation (OI) technique has been implemented. SWAN model simulations have been performed covering a 10-year time interval (1999-2008). For this period, Hs measurements from the following satellites were available: ERS-2, Poseidon, JASON-1, JASON-2, GEOSAT Follow-On (GFO), ENVISAT, TOPEX. The assimilation technique was performed for a time window of 24h considering the first 5 satellites for assimilation and the last two (ENVISAT and TOPEX) for validations. The results show that the assimilation scheme implemented induces a visible improvement of all the statistical parameters evaluated, increasing in this way the reliability of the wave predictions. The work is still ongoing being focused on the prediction of the major storms and as a further step all the satellites will be considered for assimilation, while validations are going to be performed against various in situ measurements.