During the austral summer 1993-94 turbulence data have been taken in a coastal region of Antarctica over a gently sloping surface. The objective of this study is to determine how the turbulent structure of the stable boundary layer is perturbed by slope and waves. Spectral analysis of wind velocity components evidences the production of energy, prevalently in the mid frequency subrange, by local orographic forcing. The power contribute of waves is highly variable as single or multiple waves of different amplitudes are observed. A criterion, based on the shear stress correlation coefficient, to distinguish turbulent flows from the ones affected also by waves activity is suggested. This procedure should give an estimate of the relative entity of wavy and turbulent contributes to velocity standard deviations.
Turbulence characteristics of a stable boundary layer over sloping terrain
Cava D;
1997
Abstract
During the austral summer 1993-94 turbulence data have been taken in a coastal region of Antarctica over a gently sloping surface. The objective of this study is to determine how the turbulent structure of the stable boundary layer is perturbed by slope and waves. Spectral analysis of wind velocity components evidences the production of energy, prevalently in the mid frequency subrange, by local orographic forcing. The power contribute of waves is highly variable as single or multiple waves of different amplitudes are observed. A criterion, based on the shear stress correlation coefficient, to distinguish turbulent flows from the ones affected also by waves activity is suggested. This procedure should give an estimate of the relative entity of wavy and turbulent contributes to velocity standard deviations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
