Abstract
Mean spectra of vertical wind velocity, temperature, and humidity and co-spectra of vertical turbulent heat and moisture fluxes are reported, normalized in terms of the similarity theory of Monin-Obukhov. The measurements were made in April 1967 at light-house ‘Alte Weser’ at a height of 30 m above the German Bight. Ten spectra measured under conditions of moderate instability (z/L ≃ −0.08) have been used for the evaluation of a mean spectral curve. The humidity fluctuations have been determined from simultaneous turbulence measurements of temperature and radiorefractive-index, which were obtained by a microwave refractometer.
Similar to the BOMEX measurements discussed by Phelps and Pond (1971) our results also show a dissimilarity between the fluctuations of temperature and humidity. Accordingly, in the range of lower and higher natural frequencies, significant differences were present between the co-spectra of the vertical heat and moisture fluxes, although the mean peak frequencies of both the fluxes nearly correspond to that of the mean vertical wind-velocity spectrum (f m≃ 0.35).
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Kruspe, G. Measurements of fluctuations of vertical wind velocity, temperature and radio-refractive index above the sea. Boundary-Layer Meteorol 6, 257–267 (1974). https://doi.org/10.1007/BF00232488
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DOI: https://doi.org/10.1007/BF00232488