Results 1 to 10 of about 1,386 (209)
Simulating 2 Ga of geodynamo history
Geophysical Research Letters, 2016 The paleomagnetic record indicates the geodynamo has been active over much of Earth history with surprisingly little trend in paleointensity. Variability, however, is expected from models that predict a sharp increase in intensity following inner core ...
Peter E Driscoll
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Geophysical Research Letters, 2019 In a metal, as in Earth's core, the thermal and electrical conductivities are assumed to be correlated. In a planetary dynamo this implies a contradiction: that both electrical conductivity, which makes it easier to induce current and magnetic field, and
Peter E. Driscoll, Zhixue Du
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Advances in geodynamo modelling
Geophysical and Astrophysical Fluid Dynamics, 2019 ABSTRACTThis paper reviews the remarkable developments in numerical geodynamo simulations over the last few years. Simulations with Ekman numbers as low as E=10−8E=10−8 are now within reach and more and more details of the observed field are recovered by computer models.
Johannes Wicht, Sabrina Sanchez
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Late Cambrian geomagnetic instability after the onset of inner core nucleation [PDF]
Nature Communications, 2023 The Ediacaran Period marks a pivotal time in geodynamo evolution when the geomagnetic field is thought to approach the weak state where kinetic energy exceeds magnetic energy, as manifested by an extremely high frequency of polarity reversals, high ...
Yong-Xiang Li +7 more
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Magnetic Helicity and the Geodynamo [PDF]
Fluids, 2021 We present theoretical and computational results in magnetohydrodynamic turbulence that we feel are essential to understanding the geodynamo. These results are based on a mathematical model that focuses on magnetohydrodynamic (MHD) turbulence, but ...
John V. Shebalin
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Extraordinarily long duration of Eocene geomagnetic polarity reversals [PDF]
Communications Earth & EnvironmentOne of the most intriguing attributes of Earth’s magnetic field is that it reverses polarity. Previous palaeomagnetic records mainly from the last ~17 million years indicate that the reversal process typically occurs over ten thousand or fewer years ...
Yuhji Yamamoto +3 more
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Effect of time-dependent forcing on pole reversals in a conceptual dynamo model [PDF]
Scientific ReportsIn this paper, we present a new, statistical framework for understanding the dynamics of polarity reversals under time-dependent forcing. The methods are thought to be generally applicable to geodynamo models in any scenario involving a time-dependent ...
Mátyás Herein +2 more
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Terrestrial atmospheric ion implantation occurred in the nearside lunar regolith during the history of Earth’s dynamo [PDF]
Communications Earth & EnvironmentLight volatile elements in the lunar regolith are thought to be a mixture of the solar wind and Earth’s atmosphere, the latter sourced in the absence of geomagnetic field.
Shubhonkar Paramanick +3 more
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Direct and inverse cascades in the geodynamo [PDF]
Nonlinear Processes in Geophysics, 2008 The rapid rotation of planets causes cyclonic thermal turbulence in their cores which may generate the large-scale magnetic fields observed outside the planets. We investigate numerically a model based on the geodynamo equations in simplified geometry,
M. Reshetnyak, P. Hejda
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BASIC SYSTEMS FOR THE GEOMAGNETIC FIELD [PDF]
Vestnik KRAUNC: Fiziko-Matematičeskie Nauki, 2010 The system of own solenoidal fields of operator Laplace which can be used for decomposition of a geomagnetic field in a kernel of the Earth is described.
Vodinchar G.M., Kruteva L.K.
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