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SUMMARY:The problematic of energy transfer mechanisms and dissipation in s
 tratified turbulence has still many open questions
DTSTART:20101112T140000
DTSTAMP:20260428T090112Z
UID:f98919d1ccb29010a9316c3c663fabde56ee07328e6dd0258c2a440b
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr. Eletta Negretti\, Laboratoire d'hydrodynamique de l'Ecole 
 Polytechnique\, France\nHerein one important issue is to know if turbulent
  energy transfer from large vortices\, typically with a "pancake" shape\, 
 may occur directly to the small dissipative scales via small scale instabi
 lities\, as for example the gravitational and the shear instability. In or
 der to adress this question\, the linear stability of an isolated pancake 
 vortex in a stably stratified fluid is investigated. The base state is ass
 umed to be in cyclostrophic and hydrostatic balance. We show that the vort
 ex becomes unstable when the aspect ratio is below a critical value which 
 scales with the Froude number\, and that the dominant instability is gravi
 tational. The numerical results agree well with the gravitational instabil
 ity theory. We generalize the results to any vertical distribution of the 
 angular velocity and almost any profile of the vortex.
LOCATION:MEB10
STATUS:CONFIRMED
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