References

ANGEO

Annales Geophysicae

ANGEO

Ann. Geophys.

1432-0576

Copernicus Publications

Göttingen, Germany

10.5194/angeo-29-2253-2011

Proton/electron temperature ratio in the magnetotail

Artemyev

A. V.

¹ Baumjohann

² Petrukovich

A. A.

¹ Nakamura

² Dandouras

⁴ ³ Fazakerley

⁵

Space Research Institute, Russian Academy of Sciences, Moscow, Russia

Space Research Institute, Austrian Academy of Sciences, Graz, Austria

IRAP, University of Toulouse, UPS-OMP, Toulouse, France

CNRS, IRAP, 9 Ave. Colonel Roche, BP 44346, 31028 Toulouse cedex 4, France

Mullard Space Science Laboratory, London, UK

15 12 2011

29 12 2253 2257

2011

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We study the temperature ratio of protons and electrons based on statistics of Cluster observations in the Earth's magnetotail from 2001 to 2004. During these years, from June to November, the Cluster spacecraft visited the plasma sheet at the distance r~−19 RE. We use proton and electron moments collected in the central region of the plasma sheet (|Z|<5 RE). We find an average ratio of proton and electron temperatures ⟨Tp/Te ⟩ ≈ 3.5. The dependence of Tp on Te can be approximated by the power-law function: Tp ≈ 11Te0.62, where Tp and Te are measured in MK. A previous reported ratio ⟨Tp/Te ⟩ ~ 7 is limited to small electron temperatures <20 MK. The observations with the high electron temperature correspond to smaller values of the electron density and larger values of the proton and electron bulk velocities. A correlation between Te and curlometer current density is not found.

References 1

Artemyev, A. V., Petrukovich, A. A., Zelenyi, L. M., Nakamura, R., Malova, H. V., and Popov, V. Y.: Thin embedded current sheets: Cluster observations of ion kinetic structure and analytical models, Ann. Geophys., 27, 4075–4087, <a href="http://dx.doi.org/10.5194/angeo-27-4075-2009">https://doi.org/10.5194/angeo-27-4075-2009</a>, 2009.

Artemyev, A. V., Petrukovich, A. A., Nakamura, R., and Zelenyi, L. M.: Cluster statistics of thin current sheets in the Earth magnetotail: specifics of the dawn flank, proton temperature profiles and electrostatic effects., \jgr, 116, A09233, <a href="http://dx.doi.org/10.1029/2011JA016801">https://doi.org/10.1029/2011JA016801</a>, 2011a.

Artemyev, A. V., Zelenyi, L. M., Petrukovich, A. A., and Nakamura, R.: Hot electrons as tracers of large-scale structure of magnetotail current sheets, \grl, 38, L14102, <a href="http://dx.doi.org/10.1029/2011GL047979">https://doi.org/10.1029/2011GL047979</a>, 2011b.

Ashour-Abdalla, M., Berchem, J. P., Buechner, J., and Zelenyi, L. M.: Shaping of the magnetotail from the mantle – Global and local structuring, \jgr, 98, 5651–5676, <a href="http://dx.doi.org/10.1029/92JA01662">https://doi.org/10.1029/92JA01662</a>, 1993.

Ashour-Abdalla, M., Frank, L. A., Paterson, W. R., Peroomian, V., and Zelenyi, L. M.: Proton velocity distributions in the magnetotail: Theory and observations, \jgr, 101, 2587–2598, <a href="http://dx.doi.org/10.1029/95JA02539">https://doi.org/10.1029/95JA02539</a>, 1996.

Ashour-Abdalla, M., , et al.}: {Observations and simulations of non-local acceleration of electrons in magnetotail magnetic reconnection events, Nature Physics, 7, 360–365, <a href="http://dx.doi.org/10.1038/nphys1903">https://doi.org/10.1038/nphys1903</a>, 2011.

Balogh, A., Carr, C. M., Acuña, M. H., Dunlop, M. W., Beek, T. J., Brown, P., Fornacon, K.-H., Georgescu, E., Glassmeier, K.-H., Harris, J., Musmann, G., Oddy, T., and Schwingenschuh, K.: The Cluster Magnetic Field Investigation: overview of in-flight performance and initial results, Ann. Geophys., 19, 1207–1217, <a href="http://dx.doi.org/10.5194/angeo-19-1207-2001">https://doi.org/10.5194/angeo-19-1207-2001</a>, 2001.

Baumjohann, W., Paschmann, G., and Cattell, C. A.: Average plasma properties in the central plasma sheet, \jgr, 94, 6597–6606, <a href="http://dx.doi.org/10.1029/JA094iA06p06597">https://doi.org/10.1029/JA094iA06p06597</a>, 1989.

Dunlop, M. W., Southwood, D. J., Glassmeier, K.-H., and Neubauer, F. M.: Analysis of multipoint magnetometer data, Adv. Space Res., 8, 273–277, <a href="http://dx.doi.org/10.1016/0273-1177(88)90141-X">https://doi.org/10.1016/0273-1177(88)90141-X</a>, 1988.

Johnstone, A. D., , et al.}: {Peace: a Plasma Electron and Current Experiment, ßr, 79, 351–398, <a href="http://dx.doi.org/10.1023/A:1004938001388">https://doi.org/10.1023/A:1004938001388</a>, 1997.

Kaufmann, R. L., Paterson, W. R., and Frank, L. A.: Relationships between the ion flow speed, magnetic flux transport rate, and other plasma sheet parameters, J. Geophys. Res., 110, A09216, <a href="http://dx.doi.org/10.1029/2005JA011068">https://doi.org/10.1029/2005JA011068</a>, 2005.

Lavraud, B., Borovsky, J. E., , et al.}: {Tracing solar wind plasma entry into the magnetosphere using ion-to-electron temperature ratio, \grl, 36, L18109, <a href="http://dx.doi.org/10.1029/2009GL039442">https://doi.org/10.1029/2009GL039442</a>, 2009.

Lyons, L. R.: Electron energization in the geomagnetic tail current sheet, \jgr, 89, 5479–5487, <a href="http://dx.doi.org/10.1029/JA089iA07p05479">https://doi.org/10.1029/JA089iA07p05479</a>, 1984.

Lyons, L. R. and Speiser, T. W.: Evidence for current sheet acceleration in the geomagnetic tail, J. Geophys. Res., 87, 2276–2286, <a href="http://dx.doi.org/10.1029/JA087iA04p02276">https://doi.org/10.1029/JA087iA04p02276</a>, 1982.

Phan, T.-D., Paschmann, G., Baumjohann, W., Sckopke, N., and Luehr, H.: The magnetosheath region adjacent to the dayside magnetopause: AMPTE/IRM observations, \jgr, 99, 121–141, <a href="http://dx.doi.org/10.1029/93JA02444">https://doi.org/10.1029/93JA02444</a>, 1994.

Rème, H., Aoustin, C., Bosqued, J. M., Dandouras, I., Lavraud, B., Sauvaud, J. A., Barthe, A., Bouyssou, J., Camus, Th., Coeur-Joly, O., Cros, A., Cuvilo, J., Ducay, F., Garbarowitz, Y., Medale, J. L., Penou, E., Perrier, H., Romefort, D., Rouzaud, J., Vallat, C., Alcaydé, D., Jacquey, C., Mazelle, C., d'Uston, C., Möbius, E., Kistler, L. M., Crocker, K., Granoff, M., Mouikis, C., Popecki, M., Vosbury, M., Klecker, B., Hovestadt, D., Kucharek, H., Kuenneth, E., Paschmann, G., Scholer, M., Sckopke, N., Seidenschwang, E., Carlson, C. W., Curtis, D. W., Ingraham, C., Lin, R. P., McFadden, J. P., Parks, G. K., Phan, T., Formisano, V., Amata, E., Bavassano-Cattaneo, M. B., Baldetti, P., Bruno, R., Chionchio, G., Di Lellis, A., Marcucci, M. F., Pallocchia, G., Korth, A., Daly, P. W., Graeve, B., Rosenbauer, H., Vasyliunas, V., McCarthy, M., Wilber, M., Eliasson, L., Lundin, R., Olsen, S., Shelley, E. G., Fuselier, S., Ghielmetti, A. G., Lennartsson, W., Escoubet, C. P., Balsiger, H., Friedel, R., Cao, J.-B., Kovrazhkin, R. A., Papamastorakis, I., Pellat, R., Scudder, J., and Sonnerup, B.: First multispacecraft ion measurements in and near the Earth's magnetosphere with the identical Cluster ion spectrometry (CIS) experiment, Ann. Geophys., 19, 1303–1354, <a href="http://dx.doi.org/10.5194/angeo-19-1303-2001">https://doi.org/10.5194/angeo-19-1303-2001</a>, 2001.

Zelenyi, L. M., Zogin, D. V., and Büchner, J.: Quasiadiabatic dynamics of charged particles in the tail of the magnetosphere, Cosmic Research, 28, 369–380, 1990.