Disentangling Fine-Scale Wind and Current Contributions to Wave Height and Wave Steepness Gradients in the Gulf Stream Region
Year: 2025
Type: preprint
Abstract: The combined effects of fine‐scale wind—arising from air–sea coupling and intrinsic atmospheric dynamics—and current on sea states remain poorly understood, largely due to the scarcity of wave‐model analyses forced with high‐resolution coupled winds. We analyzed two coupled ocean–wave-atmosphere simulations in the Gulf Stream region: one included all interaction loops, the other without current effects on waves. Eddy composite analyses of significant wave height ($H_s$), combined with theory, show that currents dominate $H_s$ gradients through the current‐induced Doppler shift, overshadowing fine‐scale wind effects for wind‐dependent and wind‐independent wave systems. We extend the analysis to the mean square slope ($mss$), a higher‐order moment of the wave spectrum, sensitive to wind. When current effects on waves are included, $mss$ gradients in the composite eddy are stronger; however, the gradient‐intensity difference between simulations is smaller than for $H_s$. These results have implications for wave representation in climate models and enhancing wind retrieval from space.
Institutions: Laboratoire d’Études en Géophysique et Océanographie Spatiales, Centre National de la Recherche Scientifique, Université Toulouse III - Paul Sabatier, Institut de Recherche pour le Développement, Université de Toulouse, École Polytechnique, Laboratoire de Météorologie Dynamique, Florida State University, Service Hydrographique et Océanographique de la Marine
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
OpenAlex ID: W4413532013