Features of scatterometer wind observations in the Adriatic Sea

The Mediterranean Sea is a basin where the wind circulation at sub-synoptic scales may be strongly influenced by the coastal orography and by the presence of many islands. As a consequence, meteorological phenomena at spatial scales of up to a few kilometres are very common. They are important for the whole dynamic of the atmosphere but their simulation by atmospheric models is difficult. In the Adriatic Sea, for instance, the channelling effects due to the presence of the Apennines and Balkan Mountains chains occurs under the influence of both north-easterly and south-easterly winds. In this context, satellite wind observations from microwave scatterometers are of primary importance. With a spatial resolution of c. 25 km by 25 km, they provide a thorough description of many meso-scale phenomena, such as frontal systems and orographic winds, as well as of the structure of the regional wind systems (Guymer and Zecchetto, 1993; Zecchetto and Cappa, 2001; Zecchetto et al., 2002). This chapter aims to illustrate the potentialities offered by scatterometer wind observations in the characterization of wind fields in the Adriatic Sea, and to discuss their possible use as forcing fields in storm surge hindcasting. The second describes the main characteristics of the scatterometer wind observations, their present and future availability, and their temporal sampling of basins like the Adriatic Sea. In the third, two case studies are presented, one of bora and one of scirocco, the two most important winds in the Adriatic Sea. How these wind types are described by the scatterometer is compared with how they are described by the analysis wind fields. The fourth discusses the possible advantages in considering the scatterometer winds as meteorological forcing for storm surge hindcasting, while the last section is devoted to conclusions and recommendations for future work.