Evolution of a sea-breeze day through the analysis of the momentum, temperature and turbulence budgets

The temporal and spatial evolution of a quasi-ideal sea breeze (SB) over the island of Mallorca in the Western Mediterranean is analyzed, making use of the budgets provided by a numerical model. Momentum, temperature and turbulence kinetic energy budgets are inspected, comparing the relative weight of each term and identifying which processes are more important in the different stages of the breeze cycle, to provide a comprehensive description of its evolution.

The general description of the SB for the whole island is given, and the focus using the budgets is put on the South-Eastern basin. The temperature gradient between land and sea created by the morning solar radiation is transmitted upwards by the turbulence. The acceleration inland resulting from the density gradient is dragged at the lower layers by turbulence whereas compensatory motions are generated above. The evolution of the process is described through five phases, from the generation of the initial conditions to its final decay.

This quasi-ideal case has been used to check the goodness of two simple analytical models of the SB, that perform relatively well as they use the turbulence as a surrogate of the missing advection terms in the layers above 200 m. These models are formulated here in a more consistent manner in the turbulence parametrization than the original propositions.