An investigation of boundary layer dynamics of Sardinia island under sea breeze conditions
Melas, D. Lavagnini, A. and Sempreviva A.-M.
[abstract] A numerical mesoscale model is utilized to study the wind field and the boundary layer structure in the island of Sardinia during typical summer conditions. The numerical model is three-dimensional and employs a higher-order turbulence closure scheme. The model simulations were performed for summer conditions characterized by weak synoptic forcing from the northwest and clear skies. These conditions favor the development of thermal circulations, the most significant being the sea breeze systems. The nighttime wind patterns are generally dominated by topography which leads to the development of strong drainage flow. On the other hand, as it is revealed in the simulated wind field, at midday the wind has an onshore component at virtually every coastline. The well-organized sea breezes systems interact to produce convergence zones. Another interesting feature is the development of a cyclonic eddy pattern during late afternoon hours. The model predictions are compared to observations taken at a network of near-surface wind stations and rawinsonde profiles from the Cagliari airport. Available observations agreed fairly well with model predictions.