1 research outputs found
Long-term simulation of the boundary layer flow over the double-ridge site during the Perdigão 2017 field campaign
The Perdigão campaign 2017 was an international field
campaign to measure the flow and its diurnal variation in the atmospheric
boundary layer over complex terrain. A huge data set of meteorological
observations was collected over the double-hill site by means of
state-of-the-art meteorological measurement techniques. A focus of the
campaign was the interaction of the boundary layer flow with a single wind
turbine, which was located on the south-western (SW) ridge top. In this
study, a long-term nested large-eddy simulation (LES) of 49-day duration with a
maximum horizontal resolution of 200 m is used to describe both the general
meteorological situation over Spain and Portugal and the local small-scale
flow structures over the double hill during the intensive observation period
(IOP). The simulations show that frequently observed nocturnal low-level jets
(LLJs) from the NE have their origin over the slopes of the elevated plateau
between the Portuguese Serra da Estrela and the Spanish Sierra de Gata
mountain ranges N and NE of Perdigão and that the diurnal clockwise
turning of the wind direction over the double ridge is induced by slope and
valley winds under weak synoptic conditions. It is found that, in spite of the
long simulation time, modelled and observed wind structures on the ridge tops
agree well, while along-valley flow within the valley is underestimated by
the model.</p