162582 20251017144620.0 doi 10.1016/j.apm.2025.116367 sideral 145117 ART-2025-145117 eng Llorente, Víctor J. Universidad de Zaragoza (orcid)0000-0003-3570-0202 Conserved quantities in the ocean surface boundary layer: A fresh perspective on a classical problem 2025 Access copy available to the general public Unrestricted Noether's (1918) (first) Theorem reveals three conservation laws from physical symmetries in the wind-induced ocean's surface boundary layer, as described by the Classical Ekman's (1905) Theory. The Lagrangian function used for the Ekman model is comprised of two terms. A term that accounts for vertical mixing, parametrized by a constant eddy viscosity coefficient, and a second term for the rotation of the current field due to Coriolis force. The derived conservation laws, which involve relationships between the helicity, enstrophy, and kinetic energy within the surface boundary layer, allow recovering and explaining well-known and new features of the Classical Ekman's (1905) Theory. Enstrophy, which is a property of the entire water column, can be readily obtained from the surface deflection angle at the surface alone. Conservation laws provide a theoretical explanation for the Bjerknes experiment, according to which the phase angle grows linearly with depth. Remarkably, a unique symmetry-preserving constant eddy viscosity coefficient can be determined from observations, provided that observations are described by Ekman's Theory. This outcome suggests that the determined value converges more closely to the true physical value compared to crude estimates by statistical fitting. info:eu-repo/semantics/openAccess by-nc https://creativecommons.org/licenses/by-nc/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Padilla, Enrique M. Díez-Minguito, Manuel Valle-Levinson, Arnoldo 2005 595 Universidad de Zaragoza Dpto. Matemática Aplicada Área Matemática Aplicada 150 (2025), 116367 [14 pp.] Appl. math. model. Applied mathematical modelling 0307-904X 2081772 http://zaguan.unizar.es/record/162582/files/texto_completo.pdf Versión publicada 1706770 http://zaguan.unizar.es/record/162582/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:162582 articulos driver 2025-10-17-14:21:15 ARTICLE