A gravity current is a primarily horizontal flow in a gravitational field that is  driven by a density difference. Gravity currents occur across all scales in  environmental fluid dynamics (e.g. sandstorms, sea breeze, avalanches, lava flows, estuaries, deep ocean, atmosphere).

Most work to date focuses on a perfectly mixed fluid intruding into another well  mixed fluid. We look at the influence of stratification in both the intruding and intruded fluids.

The videos show different laboratory and numerical simulations for intrusive gravity currents.

Relevant papers

D Bolster, M Dentz and T Le Borgne
Hyper Mixing in Shear Flow Sites
Water Resources Research, Water Resour. Res., 47, W09602, doi:10.1029/2011WR010737

D Bolster, I Neuweiler, M Dentz, J Carrera
The Impact of Buoyancy on Front Spreading in Heterogeneous Porous Media in Two-Phase Immiscible Flow
Water Resources Research, 47, W02508, doi:10.1029/2010WR009399, 2011

Benjamin Maurer, Diogo Bolster and Paul F Linden
Intrusive gravity currents between two stably stratified fluids
Journal of Fluid Mechanics, doi:10.1017/S0022112009993752, Volume 647, P 53-69

Bolster D., Hang A., Linden P.F. (2008)
"The Front Speed of an Intrusive Gravity Current into a Continuously Stratified Me-
dium", Journal of Fluid Mechanics - Vol 594, 369 - 377

Bolster D., Tartakovsky D.M., Dentz, M. (2007)
"Analytical Models of Contaminant Transport in Coastal Aquifers"
Advances in Water Resources, Vol 30(9) P.1962-1972