关键词: 涡旋锋面, 风应力频率, 亚中尺度能量, 亚中尺度锋生

Abstract:

Frontal submesoscale processes can effectively cascade geostrophic energy forward to small-scale dissipation, playing a crucial role in the energy dissipation of mesoscale eddies. Surface buoyancy loss induced by wind forcing is one of the key mechanisms driving frontal submesoscale processes. However, the impacts and mechanisms of wind stress forcing at different frequencies on frontal submesoscale processes and their energy remain unclear. In this study, we investigate the effects of different wind stress frequencies on the submesoscale energy in eddies and their potential mechanisms using high-resolution idealized numerical experiments of an anticyclonic eddy. The results show that frontal submesoscale energy is modulated by wind-induced mixing under both high- and low-frequency wind stress forcing. A possible mechanism is that wind stress rapidly adjusts upper-ocean vertical mixing, which alters the vertical secondary circulation and affects submesoscale horizontal flow convergence, thereby modulating the frontal submesoscale frontogenesis process and ultimately leading to changes in submesoscale kinetic energy. Further trend analysis reveals that rapid variations of high-frequency wind stress are more conducive to extracting energy from the horizontal shear of the background flow for the growth of submesoscale kinetic energy. In contrast, low-frequency wind stress accumulates frontal intensity through stronger frontogenesis, more efficiently converting frontal available potential energy into kinetic energy. These findings contribute to a deeper dynamical understanding of oceanic mesoscale eddy variability and multi-scale energy budget processes.

Key words: eddy front, wind frequency, submesoscale energy, submesoscale frontogenesis