On Momentum Flux and Velocity Spectra Over Waves,
Abstract
Data from a research tower in Lake Ontario are used to study the validity of Monin-Obukhov 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 cospectra 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 Here, Monin-Obukhov similarity theory, and the classical logarithmic boundary layers are no longer valid.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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1999
- Accession Number
- ADA365355
Entities
People
- Kimmo K. Kahma
- Mark A. Donelan
- William M. Drennan
Organizations
- Rosenstiel School of Marine, Atmospheric, and Earth Science