An experimental study of the turbulence statistics in a lagoon

Simultaneous measurements of three-dimensional velocity components and free -surface elevations were carried out in the lagoon of Fogliano, to investigate the statistical characteristics of turbulence produced in the flow by the action of wind over the free surface. Measurements were made in typical spring–summer environmental conditions, characterized by a gentle sea-breeze wind. Two measurement points were chosen far from the only tidal channel of the lagoon to evidence the role of the wind in generating turbulence. The analysis of velocity data has proved: (1) the presence of a significant oscillatory motion due to wind waves, which affects the entire water column and interferes with the lagoon bottom; (2) an evident degree of anisotropy between larger horizontal and vertical turbulent scales; (3) the existence of a scaling range where the relative scaling exponents, calculated using the Extended Self Similarity, have a scale-independent behaviour.