HR: 1340h
AN: GP33C-1442    [Abstracts]
TI: Tidal Magnetic Models: A New Field Modelling Approach
AU: * Hawe, J B
EM: j.b.hawe@liv.ac.uk
AF: University of Liverpool, Department of Earth and Ocean Sciences, 4 Brownlow Street, Liverpool, L69 3GP, United Kingdom
AU: Holme, R
EM: r.t.holme@liv.ac.uk
AF: University of Liverpool, Department of Earth and Ocean Sciences, 4 Brownlow Street, Liverpool, L69 3GP, United Kingdom
AB: For many years it has been recognised that the passive flow of the circulating oceans through the Earth's magnetic field generates a secondary field through the process of motional induction. However, while this phenomena is known to exist, little work has been carried out to characterise these secondary fields. Global flows such as tides have received some attention, but have not been the subject of an intensive magnetic field modelling process. Here we present a new, multi-mode spherical harmonic field model derived to represent the induced magnetic field associated with global tides. By integrating data from all three of the major orbiting satellites, CHAMP, SAC-C and Oersted, in both scalar and vector forms, we are able to derive a tidal model that in preliminary testing has been found to be consistent with early work by others. We are also able to extend the latitude range of the model from mid latitudes into the previously problematic, high latitude region. This model also has the potential to be expanded to include any number of previously unstudied tidal modes, thus giving the opportunity to greatly increase our understanding of global tidal behaviour on a whole range of timescales.
DE: 1541 Satellite magnetics: main field, crustal field, external field
DE: 1599 General or miscellaneous
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting