Determining Mean Electron Temperature Variation Along Magnetic Field Lines in the Earth's Plasma-sheet Using Multipoint Measurements From Cluster
Abstract
Multi-point electron temperature measurements from the Cluster constellation of spacecraft orbiting in tetrahedral formation provide a framework for calculating the local electron temperature dependence on plasma sheet location. Separate parallel and perpendicular temperature components may vary strongly along two or even three dominant directions. Nevertheless, six representative plasma sheet crossings using varying Cluster tetrahedron scale sizes indicate the mean temperature variation in a given direction is dominated by the component along a single direction of maximal temperature change. The temperature variation perpendicular to this dominant direction is relatively small. Because plasma transport occurs preferentially along the direction of the magnetic field, it is reasonable to infer the temperature should be constant along B-field lines. However, the observed magnetic field, and Tsyganenko-modeled field for our crossings have significant component along the dominant direction, and so exhibit large temperature variation along B. Temperature variations may persist regardless of plasma mixing in the plasma sheet. Implications for plasma sheet models, Alfven waves, and field-line resonances will be presented based on plasma, energetic particle and magnetic field line detailed analysis.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMSM43A1737P
- Keywords:
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- 7833 SPACE PLASMA PHYSICS / Mathematical and numerical techniques;
- 7859 SPACE PLASMA PHYSICS / Transport processes;
- 7894 SPACE PLASMA PHYSICS / Instruments and techniques