Dr. Raffaele Marino (CNRS, France) will deliver a talk on the topic, "Enhanced turbulence and local dissipation generated by extreme vertical drafts in stratified flows" in IAP Colloquium on 22nd September 2022.
He will talk about the his team's work on Stratified geophysical flows that can develop extreme events in the form strong vertical drafts and temperature bursts, resulting from the interplay of gravity waves and turbulent motions, through a mechanism producing the amplification of the fields in a range of the governing parameters of geophysical interest (Feraco et al., EPL 2018, 2021). Performing direct numerical simulations of the Boussinesq equations with Froude numbers observable in geophysical scenarios, they show how these structures - which appear intermittently in space and time - do generate patches of turbulence and enhance kinetic and potential energy dissipation (Marino et al., PRF 2022). They were able to show as well that due to the emergence of extreme vertical velocity drafts in stratified geophysical fluids, roughly 10% of the domain flow can account for up to 50% of the global volume dissipation. their results suggest that vertical drafts are essential for stratified flows to be as efficient as homogeneous isotropic turbulent flows in dissipating energy.