Submesoscale pathways to turbulence in the surface boundary layer: Energetics, effects on tracers, and air-sea coupling

– Jacob Wenegrat, University of Maryland –

Résumé :

Our understanding of the pathways between submesoscale processes and turbulent mixing is rapidly evolving. In this talk I will review recent work connecting the dynamics of submesoscale fronts to turbulent mixing in the surface boundary layer through vertical geostrophic shear production and frontogenesis. These mechanisms both lead to enhanced turbulence that does not follow canonical boundary layer scalings, yet estimates suggest they may be of global significance. The implications of this for horizontal and vertical tracer fluxes will be explored using large-eddy simulations and observations of dye dispersion across the Gulf Stream north wall. Finally, I will conclude with a brief discussion of gaps in our understanding of these processes related to air-sea coupling, and new modeling advances that offer promise of new insights into the two-way interaction between submesoscale processes and boundary layer turbulence.