Oceanic Mesoscale Eddy Depletion Catalyzed by Internal Waves

Roy Barkan , Kaushik Srinivasan , Luwei Yang , James C. Mcwilliams , Jonathan Gula (1, 2) , Clément Vic

1 IUF - Institut universitaire de France
2 LOPS - Laboratoire d'Océanographie Physique et Spatiale

The processes leading to the depletion of oceanic mesoscale kinetic energy (KE) and the energization of near-inertial internal waves are investigated using a suite of realistically forced regional ocean simulations. By carefully modifying the forcing fields we show that solutions where internal waves are forced have ∼25% less mesoscale KE compared with solutions where they are not. We apply a coarse-graining method to quantify the KE fluxes across time scales and demonstrate that the decrease in mesoscale KE is associated with an internal wave-induced reduction of the inverse energy cascade and an enhancement of the forward energy cascade from sub-to super-inertial frequencies. The integrated KE forward transfer rate in the upper ocean is equivalent to half and a quarter of the regionally averaged near-inertial wind work in winter and summer, respectively, with the strongest fluxes localized at surface submesoscale fronts and filaments.

Mots clés: oceanic energy transfers; mesoscale eddies; submesoscale fronts; internal waves

Domaines: Planète et Univers [physics]; Sciences de la Terre

Roy Barkan, Kaushik Srinivasan, Luwei Yang, James C. Mcwilliams, Jonathan Gula, et al.. Oceanic Mesoscale Eddy Depletion Catalyzed by Internal Waves. Geophysical Research Letters, 2021, 48, ⟨10.1029/2021GL094376⟩. ⟨insu-03683256⟩