Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results
This paper presents the first observations with Cluster of a very dense population of thermal ionospheric ions (H<sup>+</sup>, He<sup>+</sup>, O<sup>+</sup>) locally "accelerated" perpendicularly to the local magnetic field in a region ad...
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Copernicus Publications
2001-09-01
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Series: | Annales Geophysicae |
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doaj-f400966b87f24081abf03369ffbbdcab2020-11-24T20:42:04ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762001-09-01191523153210.5194/angeo-19-1523-2001Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster resultsJ.-A. Sauvaud0R. Lundin1R. Lundin2H. Rème3J. P. McFadden4C. Carlson5G. K. Parks6E. Möbius7L. M. Kistler8B. Klecker9E. Amata10A. M. DiLellis11V. Formisano12J. M. Bosqued13I. Dandouras14P. Décréau15M. Dunlop16L. Eliasson17A. Korth18B. Lavraud19M. McCarthy20CESR, Toulouse, FranceInstitut for Rymdfysik, Kiruna, SwedenCESR, Toulouse, FranceCESR, Toulouse, FranceSpace Sciences Laboratory, University of California, Berkeley, USASpace Sciences Laboratory, University of California, Berkeley, USASpace Sciences Laboratory, University of California, Berkeley, USAEOS, University of New Hampshire, Durham, NH, USAEOS, University of New Hampshire, Durham, NH, USAMPI für extraterrestrische Physik, Garching, GermanyIFSI, Rome, ItalyIFSI, Rome, ItalyIFSI, Rome, ItalyCESR, Toulouse, FranceCESR, Toulouse, FranceLPCE, Orléans, FranceImperial College, London, UKInstitut for Rymdfysik, Kiruna, SwedenMPI für Aeronomie, Katlenburg-Lindau, GermanyCESR, Toulouse, FranceSpace Program, University of Washington, USAThis paper presents the first observations with Cluster of a very dense population of thermal ionospheric ions (H<sup>+</sup>, He<sup>+</sup>, O<sup>+</sup>) locally "accelerated" perpendicularly to the local magnetic field in a region adjacent to the magnetopause and on its magnetospheric side. The observation periods follow a long period of very weak magnetic activity. Recurrent motions of the magnetopause are, in the presented cases, unexpectedly associated with the appearance inside closed field lines of recurrent energy structures of ionospheric ions with energies in the 5 eV to ~1000 eV range. The heaviest ions were detected with the highest energies. Here, the ion behaviour is interpreted as resulting from local electric field enhancements/decreases which adiabatically enhance/lower the bulk energy of a local dense thermal ion population. This drift effect, which is directly linked to magnetopause motions caused by pressure changes, allows for the thermal ions to overcome the satellite potential and be detected by the suprathermal CIS Cluster experiment. When fast flowing, i.e. when detectable, the density (~ 1 cm<sup>-3</sup>) of these ions from a terrestrial origin is (in the cases presented here) largely higher than the local density of ions from magnetospheric/plasma sheet origin which poses again the question of the relative importance of solar and ionospheric sources for the magnetospheric plasma even during very quiet magnetic conditions.<br><br><b>Key words. </b>Ionosphere (planetary ionosphere; plasma convection) Magnetospheric physics (magnetopause, cusp and boundary layers)https://www.ann-geophys.net/19/1523/2001/angeo-19-1523-2001.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
J.-A. Sauvaud R. Lundin R. Lundin H. Rème J. P. McFadden C. Carlson G. K. Parks E. Möbius L. M. Kistler B. Klecker E. Amata A. M. DiLellis V. Formisano J. M. Bosqued I. Dandouras P. Décréau M. Dunlop L. Eliasson A. Korth B. Lavraud M. McCarthy |
spellingShingle |
J.-A. Sauvaud R. Lundin R. Lundin H. Rème J. P. McFadden C. Carlson G. K. Parks E. Möbius L. M. Kistler B. Klecker E. Amata A. M. DiLellis V. Formisano J. M. Bosqued I. Dandouras P. Décréau M. Dunlop L. Eliasson A. Korth B. Lavraud M. McCarthy Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results Annales Geophysicae |
author_facet |
J.-A. Sauvaud R. Lundin R. Lundin H. Rème J. P. McFadden C. Carlson G. K. Parks E. Möbius L. M. Kistler B. Klecker E. Amata A. M. DiLellis V. Formisano J. M. Bosqued I. Dandouras P. Décréau M. Dunlop L. Eliasson A. Korth B. Lavraud M. McCarthy |
author_sort |
J.-A. Sauvaud |
title |
Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results |
title_short |
Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results |
title_full |
Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results |
title_fullStr |
Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results |
title_full_unstemmed |
Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results |
title_sort |
intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first cluster results |
publisher |
Copernicus Publications |
series |
Annales Geophysicae |
issn |
0992-7689 1432-0576 |
publishDate |
2001-09-01 |
description |
This paper presents the
first observations with Cluster of a very dense population of thermal
ionospheric ions (H<sup>+</sup>, He<sup>+</sup>, O<sup>+</sup>) locally
"accelerated" perpendicularly to the local magnetic field in a region
adjacent to the magnetopause and on its magnetospheric side. The observation
periods follow a long period of very weak magnetic activity. Recurrent motions
of the magnetopause are, in the presented cases, unexpectedly associated with
the appearance inside closed field lines of recurrent energy structures of
ionospheric ions with energies in the 5 eV to ~1000 eV range. The
heaviest ions were detected with the highest energies. Here, the ion behaviour
is interpreted as resulting from local electric field enhancements/decreases
which adiabatically enhance/lower the bulk energy of a local dense thermal ion
population. This drift effect, which is directly linked to magnetopause motions
caused by pressure changes, allows for the thermal ions to overcome the
satellite potential and be detected by the suprathermal CIS Cluster experiment.
When fast flowing, i.e. when detectable, the density (~ 1 cm<sup>-3</sup>) of
these ions from a terrestrial origin is (in the cases presented here) largely
higher than the local density of ions from magnetospheric/plasma sheet origin
which poses again the question of the relative importance of solar and
ionospheric sources for the magnetospheric plasma even during very quiet
magnetic conditions.<br><br><b>Key words. </b>Ionosphere (planetary
ionosphere; plasma convection) Magnetospheric physics (magnetopause, cusp and
boundary layers) |
url |
https://www.ann-geophys.net/19/1523/2001/angeo-19-1523-2001.pdf |
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