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HAL - OMP | |
| HAL : hal-00712416, version 1 |
| DOI : 10.1029/2012GL052366 |
| Fiche détaillée |  Récupérer au format |
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| Geophysical Research Letters 39 (2012) L15101 |
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| Equatorially confined warm trapped ions at around 100 eV near the plasmapause |
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| M. Yamauchi 1I. Dandouras 2 |
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| (2012) |
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| Near the equatorial plasmapause at around 4-5 Earth radius (RE) geocentric distance, pancake distributed tens of eV ions are sometimes found, as previously reported by Olsen et al. (1987). Cluster CIS data during perigee traversals in 2001-2002 (nearly 200 traversals) revealed new features of these equatorially-trapped warm ions. (1) The characteristic energy of He+ is often higher than that of H+. (2) Some events show non-thermal ring distribution for He+ rather than superthermal pancake distribution. H+ can also have the ring distribution in such events. (3) While majority of the events are dispersion-free, some events show energy-time dispersion, indicating drifts from different local times. (4) The time scale of the development is about an hour, which is much shorter than the drifting time of these ions around the Earth. Cluster statistics also confirmed some results from the previous studies: (5) These ions are confined within a few degrees of latitudinal range near the equator, and have nearly 90{degree sign} pitch angles. (6) At a geocentric distance of about 4-4.5 RE where Cluster traversed the equator during its perigee, the probability of observing clear events is about 40-45% in the noon and dusk sectors and about 20-25% in the night-to-dawn sector. (7) They are dominated by H+ with variable content of He+. The He+/H+ ratio is much less than 5% for the majority of the cases. |
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| 1 : | Swedish Institute of Space Physics (IRF) |
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Swedish Institute of Space Physics |
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| 2 : | Institut de recherche en astrophysique et planétologie (IRAP) |
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CNRS : UMR5277 – Université Paul Sabatier [UPS] - Toulouse III – Observatoire Midi-Pyrénées |
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| 3 : | Institut Pierre-Simon-Laplace (IPSL) |
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CNRS : FR636 – Institut de recherche pour le développement [IRD] – CEA – CNES – INSU – Université Pierre et Marie Curie [UPMC] - Paris VI – Université de Versailles Saint-Quentin-en-Yvelines – Ecole normale supérieure de Paris - ENS Paris |
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| 4 : | Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) |
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CNRS : UMR8190 – Université Pierre et Marie Curie [UPMC] - Paris VI – Université de Versailles Saint-Quentin-en-Yvelines – INSU |
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| 5 : | Université Versailles Saint-Quentin en Yvelines (UVSQ) |
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Université de Versailles Saint-Quentin-en-Yvelines |
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| heppi |
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| Domaine | : | Physique/Physique/Physique Atmosphérique et Océanique Physique/Physique/Physique des plasmas |
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| Inner magnetosphere – Plasmapause – Ring distribution – Warm Ion – Wave-particle interaction |
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| hal-00712416, version 1 | |
| http://hal.archives-ouvertes.fr/hal-00712416 | |
| oai:hal.archives-ouvertes.fr:hal-00712416 | |
| Contributeur : Catherine Cardon | |
| Soumis le : Mercredi 27 Juin 2012, 09:17:58 | |
| Dernière modification le : Dimanche 28 Octobre 2012, 17:41:32 | |
