STUDY OF LOCAL-SCALING IN THE STABLE ATMOSPHERIC BOUNDARY-LAYER FOR THE EVALUATION OF TURBULENCE PARAMETERS

A renewed interest in the dynamic and thermal structure of the atmosph eric boundary layer (ABL) has recently revived, due to the contributio n that this layer can provide to the improvement of skill of weather p rediction and climate simulation in the most advanced general circulat ion models. The attention is particularly focused on non-stationary an d non-homogeneous turbulent structures of this transition layer, for w hich many parametrization schemes, based on local- and non-local-closu re assumptions, have been proposed. However, also stationary, non-homo geneous, continuous-turbulence conditions can give rise to some compli cation in the ABL parametrization when air stability becomes stronger and stronger. In this situation, the governing scales of the classical non-local Monin-Obukhov similarity theory are no more representative, and new local scales must be derived from local forcings of the flux. This paper summarizes a few relevant points of the local-similarity t heory and shows the results of a local-scaling analysis obtained by ob servation data of wind and temperature profiles in the ABL in the nort hern Po Valley