Abstract
The properties of power-spectra and cross-spectra of horizontal turbulence in high winds are mainly described. The data of wind were obtained from the observations made with the use of cup anemometers which were mounted at five elevations of 26, 67, 107, 173 and 253 meters on the Tokyo-Tower. The maximum of mean wind speed in the data was 33.2 m/s at the elevation of 253 meters. Tentative conclusions are as follows :
(1) It seemed that the power-spectral curves were rather broader than Davenport's formula at the peak of curves, and belonged to “over land trajectory type” designated by Panofsky and McCormick.
(2) The spatial structure of turbulence was examined from the coherence between velocities at each pair of neighbouring stations. The structure showed that the spatial correlation of velocities became zero, when the ratio of vertical separation to the wave length was 0.2.
(3) Phase spectra between velocities at each pair of the stations showed an interesting pattern:The fluctuation of the winds became out of phase at the frequency where the turbulence energy had a maximum value (the frequency, was about 0.02c/s).
(4) The rate of dissipation of turbulence energy and nondimensional constant C2 in the spectral equation were obtained from both the profile of wind velocity and the onedimensional energy spectrum.
