Work

Balanced to Unbalanced Motions at a Submesoscale Front and Energy Transfer From Eddy Splitting

Year: 2026

Type: article

Abstract: Submesoscale dynamics play a crucial role in energy redistribution in the upper ocean but remain challenging to observe due to their small spatial and temporal scales. We use ship‐based observations of an oceanic submesoscale front sampled at high resolution while repeatedly traversed to observe deformation and splitting of an embedded cyclonic eddy. The velocity field from a shipboard acoustic Doppler current profiler was analyzed with spectral Helmholtz techniques and structure functions to examine the partitioning of kinetic energy into rotational and divergent components and energy transfer between mesoscales and submesoscales. During the eddy splitting, intensified mesoscale strain enhances the divergent component of kinetic energy in the mixed layer, where Rossby numbers are . This coincides with a transient forward energy cascade from mesoscales to submesoscales. The wave‐vortex decomposition reveals enhanced wave‐like energy during and after splitting, with subsurface maxima indicative of near‐inertial wave activity and downward energy propagation.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl119756

Authors: Cristina Martí‐Solana, Simón Ruiz, T. M. Shaun Johnston, Amala Mahadevan, Ananda Pascual

Institutions: Mediterranean Institute for Advanced Studies, Scripps Institution of Oceanography, Woods Hole Oceanographic Institution

Language: English

Topic: Oceanographic and Atmospheric Processes

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,190

Funder: Office of Naval Research