0000000000377210

AUTHOR

Juan Alejandro Valdivia

showing 3 related works from this author

A coupled-map model for the magnetotail current sheet

1999

A magnetic field model of the magnetotail current sheet in the form of a coupled-map lattice (CML) is presented. It is a continuously driven and based on the MHD diffusion equation. Solar wind vBs data (solar wind speed multiplied by the southward component of IMF) are used for driving the model, and it is shown to exhibit perturbations (avalanches) with power-law scalings in their distributions of duration and size. Such distributions may indicate self-organized critical (SOC) behavior. Furthermore, it is shown that the power spectra of the model outputs are of bicolor power-law form with different slopes for high and low frequencies. The model parameters determine the frequency of the bre…

PhysicsDiffusion equationSpectral densityGeophysicsPower lawSpectral lineComputational physicsMagnetic fieldCurrent sheetSolar windGeophysicsPhysics::Space PhysicsGeneral Earth and Planetary SciencesMagnetohydrodynamicsGeophysical Research Letters
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Nonlinear energy dissipation in a cellular automaton magnetotail field model

1999

A magnetic field model of the magnetotail current sheet based on cellular automaton (CA) is presented. The present isotropic model is a continuously driven, two-dimensional running CA. The model has a physical interpretation in terms of magnetohydrodynamic (MHD) equations, and features self-organized critical (SOC) behavior with power-law scalings both in durations and sizes of instabilities (avalanches). The model has nonlinear energy dissipation, and shows avalanches with and without an external trigger. Thus the model reproduces some of the statistical features recently observed in the magnetotail.

PhysicsField (physics)MechanicsDissipationCellular automatonMagnetic fieldNonlinear systemCurrent sheetGeophysicsClassical mechanicsPhysics::Space PhysicsGeneral Earth and Planetary SciencesMagnetohydrodynamic driveMagnetohydrodynamicsGeophysical Research Letters
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A coupled map as a model of the dynamics of the magnetotail current sheet

2001

Abstract A magnetic field model of the magnetotail current sheet in the form of a coupled-map lattice (CML) is presented. It is continuously driven (“running”) and based on the MHD diffusion equation. Solar wind vBS data (solar wind speed multiplied by the southward component of IMF) are used for driving the model, and it is shown to exhibit perturbations (avalanches) with power-law scalings in their distributions of duration and size. Such distributions may indicate self-organized critical (SOC) behavior. Furthermore, it is shown that the power spectra of the model outputs are of bicolor power-law form with different slopes for high and low frequencies. Although the “running” model gives p…

PhysicsAtmospheric ScienceDiffusion equationMechanicsPower lawSelf-organized criticalityMagnetic fieldSolar windCurrent sheetGeophysicsClassical mechanicsSpace and Planetary ScienceElectrical resistivity and conductivityPhysics::Space PhysicsMagnetohydrodynamicsJournal of Atmospheric and Solar-Terrestrial Physics
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