Back to Departmental Colloquium: Spring 2013
Departmental Colloquium
Date: Thursday, Mar 28, 2013
Time: 4:15PM
Location: JWB 335
Jean-Luc Thiffeault
University of Wisconsin-Madison
Title |
Biomixing: when organisms stir their environment |
Abstract |
As fish, micro-organisms, or other bodies move through a fluid, they stir their surroundings. This can be beneficial to some fish, since the plankton they eat depends on a well-stirred medium to feed on nutrients. Bacterial colonies also stir their environment, and this is even more crucial for them since at small scales there is no turbulence to help mixing. It has even been suggested that the total biomass in the ocean makes a significant contribution to large-scale vertical transport, but this is still a contentious issue. We propose a simple model of the stirring action of moving bodies through both inviscid and viscous fluids. An attempt will be made to explain existing data on the displacements of small particles, which exhibits probability densities with exponential tails. A large-deviation approach helps to explain some of the data, but mysteries remain. This is joint work with Steve Childress, George Lin, and Peter Mueller. |
Probability
Data Science and Machine Learning