Resistive MHD reconstruction of two-dimensional coherent structures in space
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 spacecraft as it passes through a coherent structure in space. At least two components of directly measured electric fields (the spacecraf...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2010-11-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/28/2113/2010/angeo-28-2113-2010.pdf |
| _version_ | 1811306909863510016 |
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| author | W.-L. Teh B. U. Ö. Sonnerup J. Birn R. E. Denton |
| author_facet | W.-L. Teh B. U. Ö. Sonnerup J. Birn R. E. Denton |
| author_sort | W.-L. Teh |
| collection | DOAJ |
| description | 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 spacecraft 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 convenience, the resistivity tensor <I><B>η</B></I> is assumed
diagonal in the reconstruction coordinates, which allows its values to be
estimated from Ohm's law, <I><B>E</B></I>+<I><B>v</B></I>×<I><B>B</B></I>=<I><B>η</B></I>·<I><B>j</B></I>. In the present paper,
all three components of the electric field are used. We benchmark our
numerical code by use of an exact, axi-symmetric solution of the resistive
MHD equations and then apply it to synthetic data from a 3-D, resistive, MHD
numerical simulation of reconnection in the geomagnetic tail, in a phase of
the event where time dependence and deviations from 2-D are both weak. The
resistivity used in the simulation is time-independent and localized around
the reconnection site in an ellipsoidal region. For the magnetic field,
plasma density, and pressure, we find very good agreement between the
reconstruction results and the simulation, but the electric field and plasma
velocity are not predicted with the same high accuracy. |
| first_indexed | 2024-04-13T08:54:05Z |
| format | Article |
| id | doaj.art-19434440100a432da87c17a295a52925 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-13T08:54:05Z |
| publishDate | 2010-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-19434440100a432da87c17a295a529252022-12-22T02:53:20ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762010-11-01282113212510.5194/angeo-28-2113-2010Resistive MHD reconstruction of two-dimensional coherent structures in spaceW.-L. Teh0B. U. Ö. Sonnerup1J. Birn2R. E. Denton3Laboratory for Atmospheric and Space Physics, Boulder, CO, USADartmouth College, Hanover, NH, USALos Alamos National Laboratory, Los Alamos, NM, USADartmouth College, Hanover, NH, USAWe 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 spacecraft 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 convenience, the resistivity tensor <I><B>η</B></I> is assumed diagonal in the reconstruction coordinates, which allows its values to be estimated from Ohm's law, <I><B>E</B></I>+<I><B>v</B></I>×<I><B>B</B></I>=<I><B>η</B></I>·<I><B>j</B></I>. In the present paper, all three components of the electric field are used. We benchmark our numerical code by use of an exact, axi-symmetric solution of the resistive MHD equations and then apply it to synthetic data from a 3-D, resistive, MHD numerical simulation of reconnection in the geomagnetic tail, in a phase of the event where time dependence and deviations from 2-D are both weak. The resistivity used in the simulation is time-independent and localized around the reconnection site in an ellipsoidal region. For the magnetic field, plasma density, and pressure, we find very good agreement between the reconstruction results and the simulation, but the electric field and plasma velocity are not predicted with the same high accuracy.https://www.ann-geophys.net/28/2113/2010/angeo-28-2113-2010.pdf |
| spellingShingle | W.-L. Teh B. U. Ö. Sonnerup J. Birn R. E. Denton Resistive MHD reconstruction of two-dimensional coherent structures in space Annales Geophysicae |
| title | Resistive MHD reconstruction of two-dimensional coherent structures in space |
| title_full | Resistive MHD reconstruction of two-dimensional coherent structures in space |
| title_fullStr | Resistive MHD reconstruction of two-dimensional coherent structures in space |
| title_full_unstemmed | Resistive MHD reconstruction of two-dimensional coherent structures in space |
| title_short | Resistive MHD reconstruction of two-dimensional coherent structures in space |
| title_sort | resistive mhd reconstruction of two dimensional coherent structures in space |
| url | https://www.ann-geophys.net/28/2113/2010/angeo-28-2113-2010.pdf |
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