HR: 1340h
AN: GP33A-0931 [Abstracts]
TI: Wave motions in rotating, spherical, hydromagnetic experiments
AU: * Kelley, D H
EM: dhk@umd.edu
AF: Institute for Research in Electronics and Applied Physics, Institute for Physical Science and
Technology, Department of Physics, and Department of Geology, University of Maryland, College Park, MD 20742,
United States
AU: Zimmerman, D S
EM: danzimmerman@gmail.com
AF: Institute for Research in Electronics and Applied Physics, Institute for Physical Science and
Technology, Department of Physics, and Department of Geology, University of Maryland, College Park, MD 20742,
United States
AU: Triana, S A
EM: repepo@gmail.com
AF: Institute for Research in Electronics and Applied Physics, Institute for Physical Science and
Technology, Department of Physics, and Department of Geology, University of Maryland, College Park, MD 20742,
United States
AU: Lathrop, D P
EM: lathrop@umd.edu
AF: Institute for Research in Electronics and Applied Physics, Institute for Physical Science and
Technology, Department of Physics, and Department of Geology, University of Maryland, College Park, MD 20742,
United States
AB:
The geodynamo problem---understanding how Earth's magnetic field
arises---has seen great progress in recent years, from
self-generation in many numerical simulations to the Bullard-von
Karman dynamo achieved in an experiment by Bourgoin et al.\
(New J Phys 8 12:329, 2006). First, motivated by
the geometry of the Earth, we have constructed a 60~cm
differentially rotating spherical shell for experiments with liquid
sodium, observing the presence of inertial modes at certain rotation
rate combinations (Kelley et al., to appear in
Geophys Astro Fluid 2007). The experimental inertial modes
match analytically-known inertial modes of the full sphere in their
wavenumbers, frequencies, and spatial structures. Second, motivated
by Dudley and James's observation (Philos Tr R Soc S-A
425 1869:407-429, 1989) of dynamo action in numerical
simulations, we have modified the above spherical system to allow
S1T1 forcing in a rotating, full sphere. Again wave motions
are present, and initial results are consistent with the dispersion
relation for full-sphere Rossby waves.
UR: http://complex.umd.edu
DE: 1507 Core processes (1213, 8115)
DE: 1515 Geomagnetic induction
DE: 1599 General or miscellaneous
DE: 4430 Complex systems
DE: 4490 Turbulence (3379, 4568, 7863)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting