SEASONAL SYNOPTIC COMPOSITE MEANS OF THE SURFACE VECTOR WIND SPEED ASSOCIATED WITH HIGH SEA WAVES IN THE EASTERN MEDITERRANEAN.

EXTENDED ABSTRACT Meteorological parameters and patterns have a significant influence on sea wave characteristics. Moreover, sea waves are highly affected by sea level pressure, wind speed and wind direction. Sea waves are of great interest due to the impacts they have on sailing and on the development of erosion processes at coastal environments. Thus, the analysis of sea wave characteristics is of importance in socio-economic and environmental sectors. Goal of this research is to analyze how wind waves of the Eastern Mediterranean (Aegean and Ionian Seas) relate to synoptic composite means of surface vector wind. For this work, the data used were provided by the Poseidon Marine Monitoring Network of the Hellenic Centre of Marine Research. Deep water located buoys in the Greek Seas, with a recording interval of 3 hours (a recording period of 17 minutes) and a sampling frequency of 1Hz; provide datasets of sea surface elevation for the period 2006-2011. To analyze the data, the authors used MatLab and its toolbox WAFO, in order to obtain wave characteristics such as height and period. Afterwards, daily means of these wave parameters were estimated and the upper 10% were selected from a total of 6921 measurements. The Aegean and the Ionian Sea were described by 4202 and 2719 measurements respectively. NCEP-NCAR seasonal composite means of the vector wind were estimated for the dates with the upper 10% of daily means of wave height and period, for each one of the two examined Seas. The analysis showed that high values of wave height and period do not always occur under the similar weather patterns. During winter and spring, one can observe similar composite vector wind patterns for both examined Seas. Additionally, in the Aegean Sea during the summer season, the north Etesian winds influence wave height and period accordingly, while northwest winds dominate over Ionian Sea. Different composite patterns appear in autumn when north winds appear in Aegean against west winds in Ionian Sea. The authors will include in future work the impact of climate change using different SRES scenarios, on wave parameters as well as weather characteristics.