On momentum flux and velocity spectra over waves
نویسندگان
چکیده
Data from a research tower in Lake Ontario are used to study the validity of MoninObukhov scaling in the marine atmospheric boundary layer under various wave conditions. It is found that over pure wind seas, the velocity spectra and cospectra follow established universal scaling laws. However in the presence of swells outrunning weak winds, velocity spectra and co-spectra no longer satisfy universal spectral shapes. Here, Monin-Obukhov similarity theory, and the classical logarithmic boundary layers are no longer valid. It is further shown that in the presence of such swells the momentum flux can be significantly modified over pure wind sea values. The implications of these findings for bulk flux estimations and on the inertial dissipation method for calculating fluxes are discussed.
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