Results 131 to 140 of about 416 (175)
Some of the next articles are maybe not open access.
Contemporary Physics, 1997
Three-dimensional numerical simulations of convection and magnetic field generation in the Earth's core now span several hundred thousand years; the magnetic field created during most of this time has an intensity, structure and time dependence similar to the present geomagnetic field. Five models are described here.
Gary A. Glatzmaier, Paul H. Roberts
openaire +1 more source
Three-dimensional numerical simulations of convection and magnetic field generation in the Earth's core now span several hundred thousand years; the magnetic field created during most of this time has an intensity, structure and time dependence similar to the present geomagnetic field. Five models are described here.
Gary A. Glatzmaier, Paul H. Roberts
openaire +1 more source
Computational aspects of geodynamo simulations
Computing in Science & Engineering, 2000For almost 50 years, researchers have attempted to understand the geodynamo, a mechanism that maintains the Earth's geomagnetic field. The authors discuss their results using the Glatzmaier-Roberts model to create numerical simulations of the geodynamo (G.A. Glatzmaier and P.H. Roberts, 1995).
Gary A. Glatzmaier, Thomas C. Clune
openaire +1 more source
1999
The main part of the geomagnetic field is generated by self-induction in the Earth’s molten core. The geodynamo mechanism is not yet fully understood as an M.H.D. problem even though we have many constraints coming from observations, as well as from geophysical and geo-chemical theories. This Earth’s science problem combines many of the difficulties we
D. Jault, P. Cardin, H. C. Nataf
openaire +1 more source
The main part of the geomagnetic field is generated by self-induction in the Earth’s molten core. The geodynamo mechanism is not yet fully understood as an M.H.D. problem even though we have many constraints coming from observations, as well as from geophysical and geo-chemical theories. This Earth’s science problem combines many of the difficulties we
D. Jault, P. Cardin, H. C. Nataf
openaire +1 more source
Earth's Core and the Geodynamo
Science, 2000Earth's magnetic field is generated by fluid motion in the liquid iron core. Details of how this occurs are now emerging from numerical simulations that achieve a self-sustaining magnetic field. Early results predict a dominant dipole field outside the core, and some models even reproduce magnetic reversals.
openaire +2 more sources
On the theory of the geodynamo
Physics of the Earth and Planetary Interiors, 1996Abstract I trace the development of geodynamo theory leading from Larmor's original hypothesis (Larmor, 1919, Rep. Br. Assoc. Adv. Sci., A, 159–160) to the present. I consider a number of kinematic results, from Cowling's proof (Cowling, 1934, Mon. Not. R. Astron.
openaire +1 more source
Geophysical & Astrophysical Fluid Dynamics, 1987
Abstract This paper describes a re-investigation of the geomagnetic dynamo model proposed by Braginsky (1978). This axisymmetric nonlinear model was dominated by Lorentz and Coriolis forces, and was maintained by a specified thermal wind and by a specifiedα-effect.
S. I. Braginsky, Paul H. Roberts
openaire +1 more source
Abstract This paper describes a re-investigation of the geomagnetic dynamo model proposed by Braginsky (1978). This axisymmetric nonlinear model was dominated by Lorentz and Coriolis forces, and was maintained by a specified thermal wind and by a specifiedα-effect.
S. I. Braginsky, Paul H. Roberts
openaire +1 more source
An iterative scheme for a geodynamo system
International Journal of Computer Mathematics, 2006In this paper we propose an iterative scheme for a nonlinear spherical geodynamo model and carry out convergence analysis of this scheme. Our model is a coupled system of fluid velocity u , total kinematic pressure P and magnetic field B . They are governed by the Navier–Stokes equations and the dynamo equations. Using the mathematical induction method
openaire +1 more source
Energetic scaling of the geodynamo
Geomagnetism and Aeronomy, 2013The typical scales, velocities, and magnetic fields in the liquid core of the Earth are determined by using the analysis results of the magnitude of energy that is available for the geodynamo, physical regularities, and observational data. In this work, it is justified that the geomagnetic field is mainly generated in a regime where the magnetic ...
openaire +1 more source
Dynamics of the core, geodynamo
Reviews of Geophysics, 1995“The mechanism for generating the geomagnetic field remains one of the central unsolved problems in geoscience.” So states the report on the National Geomagnetic Initiative (NGI) prepared by the U.S. Geodynamics Committee, et al [1993], with advice from the NGI Workshop held in Washington D.C. in March 1992.
openaire +1 more source
The geodynamo’s unique longevity
Physics Today, 2013New insights into how Earth’s magnetic field has been sustained for billions of years closely link the planet’s core and mantle in the dynamo process.
openaire +1 more source