Fingering convection in geophysics and Astrophysics
Pascale Garaud
University of California at Santa Cruz
Double-diffusive instabilities can occur in fluids where both heat and
chemical composition control the buoyancy of the fluid. If these two
components diffuse at different rates, an instability can occur even
if the density is stably stratified. The fluid is then rapidly mixed by
small scale convective motions. Interestingly, secondary instabilities of
the turbulent convection can then occur, which excites very large-scale
motions, such as internal gravity waves or lateral intrusions. Another
spectacular outcome of the double-diffusion if the formation of persistent
large-scale "staircases" in the density, temperature and chemical
composition profiles.
Here, we present the first self-consistent theory for the development
of large-scale double-diffusive instabilities, compare them against
high-resolution and large-domain numerical simulations, and finally,
discuss their impact in the oceanographic context and in astrophysics.
Date: | Tuesday, 23 March 2010 |
Time: | 16:00 |
Where: | McGill University |
| Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103) |
Contact: | Robert Rutledge |
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