A dissection of the physics of seasonal cycle of oceanic upper layer stratification is necessary to improve climate predictions of biogeochemical cycles. We present a time series of vertical profiles of ε, the dissipation rate of turbulent kinetic energy, obtained from a microstructure profiler during the destratification period (summer-to-winter) at a mid-latitude 75m-deep coastal site. Significant correlation is obtained in the mixed layer depth (MLD) with a model combining effects of wind, wave, and buoyancy forcings, estimated from bulk parameters ~10 hours before observations, and used to identify the dominant forcings leading to MLD deepening. Intermittency at surface is correlated with seasonal storminess, and we observe a quadratic relation between kurtosis and skewness for ε statistics. By splitting the time series into layers, we observe the co-location of patches of higher ε with the shear maxima of the two first baroclinic modes, and significant correlations with surface wind stress in the transitional layer the past 24 hours, and at longer scale (4.25 days) in the baroclinic layer, suggesting that internal waves activity influences the setup of mixing intensity despite the lack of tidal forcing. The low-passed microstructure shear distribution seems to support this hypothesis despite possible signal contamination. In the highly stratified layers associated to salt-fingering (MLD’s basis and below), the buoyancy Reynolds number indicates a buoyancy regime control with low mixing value (0.2 x 10e-5 m²/s). More turbulent flows are identified in both surface and bottom layers (0.6 - 0.8 x 10e-5 m²/s), suggesting a seasonal erosion of the stratification by the boundary processes.