Influence of background flow on evolution of saronic gulf sea breeze

Results from an experimental campaign at the coastline of the Saronic Gulf during the summer of 1992 are presented. The frontal intensity and the rotation of the wind hodograph at the shoreline during sea-breeze case:; are examined under different background flow conditions. The frontal intensity classification is based on the vertical velocities induced, as measured by a high resolution acoustic sounder. Three representative cases are presented. Conclusions are based on the analysis of all observed sea-breeze flows. Background off-shore or shore-parallel flows are more probable to create a strong or weak front, respectively. The development of frontal characteristics under background on-shore flow is attributed to off shore land features. The wind hodograph rotation is shown to be associated to the initial direction of the sea breeze, which is determined by the background flow direction. When the background flow possesses a westerly component the hodograph shows anticlockwise rotation, while an easterly background component causes the wind vector rotation to be clockwise.