Joint Seminar: Transition and turbulence in stratified flows: examples from high-resolution simulations

The environment, despite and in some cases because of stratification, exhibits spatio-temporal variability over a wide range of spatial and temporal scales. We will discuss two examples motivated by oceanic flows where high-resolution large eddy simulations (LES) have been used to understand transition and turbulence in stratified flows. The first example is that of a stratified jet (the Equatorial undercurrents) that is nominally stable but observations show cyclic patches of turbulence. Numerical simulations are used to show that the system is marginally unstable and that the instabilities leading to turbulence have a systematic relation to wind and buoyancy forcing. The second example concerns topographically generated internal gravity waves. LES is used to show the emergence of nonlinear behavior and ultimately turbulence during wave generation at steep slopes as well as wave propagation through variable stratification.

Datum

29.10.2014

Uhrzeit

13:30 Uhr

Ort

Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg

ReferentIn

Sutanu Sarkar, UC San Diego

Chair

Juan Pedro Mellado

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