Daniel Lathrop
University of Maryland
Seminar Information
~ Meeting ID: 997 2053 2758
Laboratory turbulence experiments are a natural place for examining planetary fluid flows. Rotation, shear, zonal flows, and the associated torques/angular momentum fluxes are all easily instantiated in the lab. In addition, by using a conducting fluid one can study the conditions of planetary cores and magnetic field / fluid interactions. Using a series of experiments, of increasing size and increasing power input (now a three-meter diameter system), we have examined liquid sodium spherical Couette flows to better understand planetary cores. The engineering and safety planning challenges in building an experiment with 12.5 tons of metallic sodium rotating at 4 Hz were an interesting part of the project. We have uncovered precessional flows, inertial waves, turbulent bi-stability, many turbulent states, magnetic field gain by the Omega effect, all while being sub-dynamo. In addition, we are exploring how machine-learning tools can be used to do short-term prediction of the time evolution of our turbulent laboratory magnetic field variation. We have modified the experiment this year to increase the helicity in the system by putting baffles on the inner sphere as motivated by Finke and Tilgner’s computational dynamo studies, and are preparing new experiments for this Fall.
Daniel Lathrop received a B.A. in physics from the University of California at Berkeley in 1987, and a Ph.D. in physics from the University of Texas at Austin in 1991. He then served at Yale University as a postdoctoral fellow, research affiliate, and lecturer, and as Assistant Professor at Emory University. He joined the University of Maryland in 1997, the year he received a Presidential Early Career Award from the National Science Foundation. Daniel Lathrop is now Professor of Physics and Professor of Geology and a Fellow of the American Physical Society. His research in the Nonlinear Dynamics group at Maryland focuses on turbulent fluid flows, geomagnetism, and experiments on superfluid helium. Dr. Lathrop served as the Director of the Institute for Research in Electronics and Applied Physics from 2006 to 2012. He received the Stanley Corrsin Award in 2012 from the American Physical Society for this work in quantum fluids. He is a UMD Distinguished Scholar-Teacher.