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Dartmouth Scholarship

Series

2010

Magnetic field

Articles 1 - 2 of 2

Full-Text Articles in Physics

Resistive Mhd Reconstruction Of Two-Dimensional Coherent Structures In Space, W L. Teh, B U. Sonnerup, J Birn, R E. Denton Nov 2010

Resistive Mhd Reconstruction Of Two-Dimensional Coherent Structures In Space, W L. Teh, B U. Sonnerup, J Birn, R E. Denton

Dartmouth Scholarship

We present a reconstruction technique to solve the steady resistive MHD equations in two dimensions with initial inputs of field and plasma data from a single space- craft as it passes through a coherent structure in space. At least two components of directly measured electric fields (the spacecraft spin-plane components) are required for the reconstruction, to produce two-dimensional (2-D) field and plasma maps of the cross section of the structure. For con- venience, the resistivity tensor η is assumed diagonal in the reconstruction coordinates, which allows its values to be es- timated from Ohm’s law, E+v×B=η·j. In the present paper, …


On Arc-Polarized Structures In The Solar Wind, B U. Sonnerup, S E. Haaland, G Paschmann Jun 2010

On Arc-Polarized Structures In The Solar Wind, B U. Sonnerup, S E. Haaland, G Paschmann

Dartmouth Scholarship

A theoretical model is proposed to account for some of the behavior of arc-polarized magnetic structures seen in the solar wind. To this end, an exact analytical solu- tion is developed that describes infinite plane wave trains of arbitrary amplitude in a plasma governed by ideal Hall MHD. The main focus is on intermediate-mode wave trains, which display double-branched magnetic hodogram signatures sim- ilar to those seen in the solar wind. The theoretically derived hodograms have field rotation in the ion-polarized sense at a slightly depressed field magnitude on one branch and an electron-polarized rotation at a slightly enhanced field …