EDDY TRANSFER PROCESSES IN THE ATMOSPHERIC BOUNDARY-LAYER

In this work the influence of stratification (evaluated through the gradient Richardson number) on the eddy transfer of momentum and heat (K(m) and K(h)) has been studied. A wide range of Richardson numbers (Ri) has been covered with data recorded in summer at Valladolid (Spain) from a 100 m high tower situated on a flat and homogeneous terrain. The results show how the eddy transfers are inhibited for high stabilities (Ri >0.1), and the importance of the wind shear at night. Different mixing mechanisms have been studied (convection and shear). The ratio of eddy transfer coefficients shows no constant value and a sharp dependence on Richardson number. Finally the effect of surface thermal inversions on the turbulent transfer is analysed.