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Strong correlation between the drag coefficient and the shape of the wind sea spectrum over a broad range of wind speeds
Author(s) -
Takagaki Naohisa,
Komori Satoru,
Suzuki Naoya,
Iwano Koji,
Kuramoto Takenori,
Shimada Satoshi,
Kurose Ryoichi,
Takahashi Keiko
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl053988
Subject(s) - roughness length , wind speed , drag coefficient , anemometer , wind profile power law , log wind profile , drag , wind gradient , wind wave , mechanics , physics , doppler effect , meteorology , surface roughness , momentum (technical analysis) , computational physics , atmospheric sciences , finance , astronomy , economics , thermodynamics , quantum mechanics
Momentum transfer across the wind‐driven breaking air‐water interface under strong wind conditions was experimentally investigated using a high‐speed wind‐wave tank together with field measurements at normal wind speeds. An eddy correlation method was utilized to measure roughness length and drag coefficient from wind velocity components measured by laser Doppler and phase Doppler anemometers. As a result, a new model for the roughness length and drag coefficient was proposed for predicting momentum transfer across the sea surface under both normal and strong wind conditions using the universal relationship between energy and significant frequency of wind waves normalized by the roughness length. The model shows that the roughness length and drag coefficient are uniquely determined at all wind speeds by energy and significant frequency of wind waves, and they can be given against U 10 only from the measurements of the wave parameters and one‐point mean air velocity in the logarithmic law region.