Atmospheric and Climate Sciences > Vol.5 No.3, July 2015

José Augusto P. Veiga^1*, Mônica R. Queiroz²

¹Department of Meteorology, Institute of Technology, Amazonas State University, Manaus, Brazil.
²UNINORTE Laureate International Universities, Manaus, Brazil.

The effect of the surface gravity waves over sea surface roughness length (z₀) is investigated from several idealized numerical experiments with the Wave-Watch-III (WW3) model. The WW3 model is combined with a simplified model to estimate z₀, C_D, u_* and U₁₀ as function of the sea state. The impacts related to the presence of the ocean waves over z₀ are obtained from conditions of growing (young waves) and mature seas (old waves). The wave spectrum is obtained from WW3 model for each idealized simulation under uniform wind conditions. Uniform wind experiments range from 15 to 45 m/s. The simplified algorithm determines z₀, C_D, u_* and U₁₀ for cases of young waves, old waves and by the Charnock method. The results show that when the ocean is characterized by young waves, both z₀ and C_D (drag coefficient) increase while U₁₀ is reduced. In Charnock case, the values of z₀, C_D and U₁₀ have no dependence with the presence of gravity waves. Experiments using winds higher than 30 m/s result in young waves’ C_D values higher than the C_D value for old waves. Even for young waves C_D values are high for cases of strong winds. The results also show that in experiments using winds higher than 30 m/s the dependence between C_D and wave age becomes stronger, which is in accordance with other studies.

Surface Gravity Waves, Wind Sea, Ocean Waves, Young Waves, Old Waves

Veiga, J. and Queiroz, M. (2015) Impact of the Waves on the Sea Surface Roughness under Uniform Wind Conditions: Idealized Cases for Uniform Winds (Part I). Atmospheric and Climate Sciences, 5, 317-325. doi: 10.4236/acs.2015.53024.