Large plasma velocities along the magnetic field line in the auroral zone

Jones, G. O. L., Williams, P. J. S., Winser, K. J., Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172 and Suvanto, K. (1988) Large plasma velocities along the magnetic field line in the auroral zone. Nature, 336 (6196). pp. 231-232. ISSN 0028-0836 doi: 10.1038/336231a0

Abstract/Summary

In the auroral zone, ionospheric plasma often moves horizontally at more than 1 km s−1, driven by magnetospheric electric fields, but it has usually been assumed that vertical velocities are much smaller. On occasions, however, plasma has been seen to move upwards along the magnetic field line at several hundred m s−1. These upward velocities are associated with electric fields strong enough to heat the ion population and drive it into a non-thermal state1,2. Here we report observations of substantial upwards acceleration of plasma, to velocities as high as 500 m s−1. An initial upthrust was provided by a combined upwelling of the neutral atmosphere and ionosphere but the continued acceleration at greater heights is explained by a combination of enhanced plasma pressure and the 'hydrodynamic mirror force'3. This acceleration marks an important stage in the transport of plasma from the ionosphere into the magnetosphere.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38889
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Nature Publishing Group
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