1. Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results
- Author
-
J.-A. Sauvaud, 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, Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut for Rymdfysik, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Institute for the Study of Earth, Oceans, and Space [Durham] (EOS), University of New Hampshire (UNH), Max-Planck-Institut für Extraterrestrische Physik (MPE), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Imperial College London, Max-Planck-Institut für Aeronomie (MPI Aeronomie), Max-Planck-Gesellschaft, Space Program, Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, University of California [Berkeley], University of California-University of California, Consiglio Nazionale delle Ricerche (CNR), and Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Field line ,Population ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,7. Clean energy ,01 natural sciences ,Ion ,Physics::Plasma Physics ,Electric field ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,lcsh:Science ,education ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Physics ,education.field_of_study ,lcsh:QC801-809 ,Plasma sheet ,Geology ,Astronomy and Astrophysics ,Plasma acceleration ,lcsh:QC1-999 ,Magnetic field ,lcsh:Geophysics. Cosmic physics ,13. Climate action ,Space and Planetary Science ,Physics::Space Physics ,Magnetopause ,lcsh:Q ,Atomic physics ,lcsh:Physics - Abstract
This paper presents the first observations with Cluster of a very dense population of thermal ionospheric ions (H+, He+, O+) 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-3) 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.Key words. Ionosphere (planetary ionosphere; plasma convection) Magnetospheric physics (magnetopause, cusp and boundary layers)
- Published
- 2001
- Full Text
- View/download PDF