Hydromagnetic Waves and Progress in the University of Maryland Three Meter Experiment DI31A-2393 1378965 http://www.youtube.com/watch?v=K-xSCgW912o The University of Maryland Three Meter experiment is currently operational in novel MHD parameter regimes, with and without an imposed external magnetic field. We are pursuing several different courses of exploration, continuing the search for supercritical dynamo action by in the hydrodynamical parameter space and researching the effect of strong applied magnetic field on known hydrodynamic states. As of this writing we have reached magnetic Reynolds number $Rm= ΔØmega r_i (r_o-r_i)/eta$ up to 300 in several different hydrodynamic states. With applied field, we may reach Elsasser number $Lambda = sigma B_0^2 / rhoØmega$ significantly exceeding unity, though at lower Rm. For Rossby number $Ro = ΔØmega/Ømega=-1.7 $, and Ekman number $E=nu/(2Ømega R^2)~10^{-7}$, a range where we have previously observed inertial modes excited by steady differential rotation, the addition of an externally applied magnetic field with Elsasser number up to $Lambda = 0.25$ at the center of the experiment (larger near the outer sphere equator) leads to several changes in the observed waves, including the emergence of a new, slowly rotating $m=1$ wave with a frequency between $0.1Ømega-0.2Ømega$ and the opposite equatorial symmetry from all observed inertial modes. This wave may be a magnetocoriolis wave, and we will report on these observations as well as any further progress we have made in the search for spherical Couette dynamos.
Daniel S Zimmerman1, Santiago A Triana1, Daniel P Lathrop2, 1 1. IREAP, University of Maryland, College Park, MD, USA; 2. Physics, University of Maryland, College Park, MD, USA