Kinetic energy spectra of the horisontal wind vector were estimated from time series measured along the Risø 123 m meteorological tower throughout ten years. Also measurements from other localities (Station Nord, Greenland, and Karlstrup, Zealand) were uaed. Spectra and methods are presented and discussed. Emphasis is laid on the gain in information which is achieved when the components of the wind vector are considered rather than just the wind speed. Spectral equations in the frequency domain are derived from the equations of motion. B is shown how a ratio including the Coriolia parameter, the quadrature spectrum of the components, the energy spectrum, and the frequency can be used to determine the explicit effect of the rotating of the earth on the kinetic energy spectrum. The wind structure in thsSoundary layer, as measured at the Risø site, audits relation to the diurnal cycle and horisontal inhomogenslttss of surface temperature are Investigated. The date reveal an exceptionally large turning of the wind with the height above the ground. It is shown that this feature can be given a phenomsnologlcal description by making an analogy to the thermal wind effect.
|Place of Publication||Roskilde, Denmark|
|Publisher||Risø National Laboratory|
|Number of pages||103|
|Publication status||Published - 1975|
|Series||Denmark. Forskningscenter Risoe. Risoe-R|
- Risø report 285