Correlation between Foam-Bubble Size and Drag Coefficient in Hurricane Conditions

Abstract

Recently proposed model of foam impact on the air sea drag coefficient Cd has been employed for the estimation of the efficient foam-bubble radius Rb variation with wind speed U10 in hurricane conditions. The model relates Cd (U10) with the efficient roughness length Zeff (U10) represented as a sum of aerodynamic roughness lengths of the foam free and foam covered sea surfaces Zw (U10 ), and Zf (U10) weighted with the foam coverage coefficient. This relation is treated for known phenomenological distributions Cd (U10), Zw (U10) at strong wind speeds as an inverse problem for the efficient roughness parameter of foam-covered sea surface Zf (U10).