Open AccessEvaluation of a Roughness Length Model and Sea Surface Properties with Data from the Baltic Sea
Author(s) -
Björn Carlsson,
Y. Papadimitrakis,
Anna Rutgersson
Publication year - 2010
Publication title -
journal of physical oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 143
eISSN - 1520-0485
pISSN - 0022-3670
DOI - 10.1175/2010jpo4340.1
Subject(s) - swell , sea state , roughness length , surface finish , surface roughness , wind wave , significant wave height , baltic sea , atmosphere (unit) , geology , momentum (technical analysis) , atmospheric sciences , meteorology , wind speed , mechanics , materials science , oceanography , physics , wind profile power law , thermodynamics , finance , economics , composite material
The exchange of momentum between the oceans and atmosphere is important for many atmospheric and oceanic processes and is mainly governed by the roughness of sea surface. The roughness can be expressed by a roughness length z0.Aroughness lengthmodel, based on the concept that z0 is determined by stochastic wave breaking, is presented. The model performance is evaluated using measurements from the Östergarnsholm site, in the Baltic Sea, and pertinent information from other recent investigations. The wave field and the roughness length variations are investigated during various sea state conditions dominated by wind-driven waves. It is found that several parameters, describing the characteristics of the wave field, are dependent on the amount of energy that long waves have relative to the energy of short, wind-driven waves of the sea spectrum (called the swell ratio). The impact of swell ratio on z0 can explain the discrepancies found in various results among relevant investigations. The roughness length model can well reproduce the observed roughness length. © 2010 American Meteorological Society