3.6
Eddy covariance measurements of turbulence in and above a roughness sublayer
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner
Co-spectral analyses of eddy covariance measurements of sensible heat fluxes and momentum flux with sonic anemometers on an 85 m tower in Oklahoma City during JU2003 and on a 60 m tower near Leon, Kansas, during CASES 99 are presented. In particular, the variations in the frequency and wavelength at which the peaks of the spectra occur are identified and related to the height above ground, the stability of the near surface layer, and the roughness elements over the fetches stratified by wind direction. The profiles of the parameters quantifying the co-spectra are given and compared among themselves and with similar analyses described in the literature. For sites and wind directions characterized by large roughness elements of buildings and trees resulting in a deep roughness sub-layer, the height dependence of these parameters is examined in greater detail.