A renewed interest in the dynamic and thermal structure of the atmospheric boundary layer (ABL) has recently revived, due to the contribution that this layer can provide to the improvement of skill of weather prediction and climate simulation in the most advanced general circulation models. The attention is particularly focused on non-stationary and non-homogeneous turbulent structures of this transition layer, for which many parametrization schemes, based on local- and non-local-closure assumptions, have been proposed. However, also stationary, non-homogeneous, continuous-turbulence conditions can give rise to some complication 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 theory and shows the results of a local-scaling analysis obtained by observation data of wind and temperature profiles in the ABL in the northern Po Valley
Study of Local Scaling in the Stable Atmospheric Boundary Layer for the Evaluation of Turbulence parameters
LONGHETTO, Arnaldo;BONINO, Giuseppe;CASSARDO, Claudio;RICHIARDONE, Renzo
1994-01-01
Abstract
A renewed interest in the dynamic and thermal structure of the atmospheric boundary layer (ABL) has recently revived, due to the contribution that this layer can provide to the improvement of skill of weather prediction and climate simulation in the most advanced general circulation models. The attention is particularly focused on non-stationary and non-homogeneous turbulent structures of this transition layer, for which many parametrization schemes, based on local- and non-local-closure assumptions, have been proposed. However, also stationary, non-homogeneous, continuous-turbulence conditions can give rise to some complication 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 theory and shows the results of a local-scaling analysis obtained by observation data of wind and temperature profiles in the ABL in the northern Po Valley
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