Seasonal to Interannual Cross‐Scale Energy Transfer Variability: Observational Insight From the Santa Barbara Channel

Abstract Kinetic energy (KE) transfer between spatial scales contributes to the ocean's energy budget by linking scales of KE supply and KE dissipation. Numerical simulations have indicated that for scales smaller than the baroclinic deformation radius, cross‐scale KE transfer has complex spatial and temporal variability, modulated by mixed layer properties, fronts, and eddies. Here, over a decade of upper‐ocean surface velocity data, collected from high‐frequency radar within the Santa Barbara Channel, are used to estimate cross‐scale KE transfer. The transfer of KE across 7 km has strong seasonal and interannual variations linked to energy exchange with the atmosphere. This study observationally confirms (a) the importance of the surface divergence field in determining the direction of the KE transfer and (b) the equi‐partitioning of KE transfer between divergent and straining motions. The temporal variability in KE transfer suggests that surface forcing influences the long‐term redistribution of energy between scales.