HR: 09:00h
AN: GP31A-05 INVITED    [Abstracts]
TI: Satellite Induction Studies Based on Spatiotemporal Analysis of Low-Earth Orbit Magnetometer Data
AU: * Everett, M E
EM: everett@geo.tamu.edu
AF: Dept. of Geology and Geophysics, Texas A&M University, College Station, TX 77843, United States
AB: An overall perspective is given of geomagnetic induction based on spatiotemporal analysis of low-Earth orbit satellite magnetometer data. The goal of geomagnetic induction is to map 3-D electrical conductivity of Earth's mantle. This is a primary objective, for example, of the swarm multi-satellite mission. The eventual aim of satellite geomagnetic induction is to perform 3-D inversions of low-Earth orbiting satellite magnetometer data to map 3-D electrical conductivity distribution of the mantle and to compare with global seismic tomographic images. There are certain advantages to performing this work directly in the spatiotemporal domain, i.e. by performing track-by-track fits instead of estimating frequency-domain response functions. The main challenges arise from the fact that the geological signal from induced currents exhibits length-scale dependent heterogeneity and is small in magnitude. Furthermore, the external Sq and Dst source geometries are poorly represented by the F10.7 and Dst indices. A 1-D time-domain inversion of storm-time CHAMP data reveals a jump in mantle electrical conductivity deeper than transition zone depths, consistent with an earlier magsat analysis. Some future possibilities for satellite induction studies are outlined at the conclusion of the talk.
DE: 1515 Geomagnetic induction
DE: 1517 Magnetic anomalies: modeling and interpretation
DE: 1541 Satellite magnetics: main field, crustal field, external field
DE: 1545 Spatial variations: all harmonics and anomalies
DE: 1555 Time variations: diurnal to decadal
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting