HR: 1330h
AN: G22A-0304    [PDF]
TI: Density anomalies in the mantle and gravitational core-mantle interaction
AU: * Kuang, W
EM: Weijia.Kuang-1@nasa.gov
AF: Space Geodesy Branch, NASA Goddard Space Flight Center, Greenbelt Rd, Greenbelt, MD 20771 United States
AU: Liu, L
EM: lanbo.liu@uconn.edu
AF: Department of Geology and Geophysics, University of Connecticut, 354 Mansfield Rd., Unit 2045, Storrs, CT 06269 United States
AB: Seismic studies suggest that the bulk of the mantle is heterogeneous, with the density varies in depth as well as in horizontal directions (latitude and longitude). This density variation produces a three-dimensional gravity field throughout the Earth. On the other hand, the core density also varies in both time and space, due to convective core flow. Consequently, the fluid outer core and the solid mantle interact gravitationally due to the mass anomalies in both regions. This gravitational core-mantle interaction could play a significant role in exchange of angular momentum between the core and the mantle, and thus the change in Earth's rotation on time scales of decades and longer. Aiming at estimating the significance of the gravitational core-mantle interaction on Earth's rotation variation, we introduce in our MoSST core dynamics model a heterogeneous mantle, with a density distribution derived from seismic results. In this model, the core convection is driven by the buoyancy forces. And the density variation is determined dynamically with the convection. Numerical simulation is carried out with different parameter values, intending to extrapolate numerical results for geophysical implications.
DE: 1213 Earth's interior--dynamics (8115, 8120)
DE: 1507 Core processes (8115)
DE: 1510 Dynamo theories
DE: 3210 Modeling
DE: 3230 Numerical solutions
SC: Geodesy [G]
MN: 2003 Fall Meeting