Annales Geophysicae
Annales Geophysicae
Annales Geophysicae
Articles | Volume 34, issue 1
Articles | Volume 34, issue 1
Ann. Geophys., 34, 85–89, 2016
https://doi.org/10.5194/angeo-34-85-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Ann. Geophys., 34, 85–89, 2016
https://doi.org/10.5194/angeo-34-85-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 34, issue 1

ANGEO Communicates 21 Jan 2016

ANGEO Communicates | 21 Jan 2016

Ion Bernstein waves in the magnetic reconnection region

Y. Narita1,2, R. Nakamura1, W. Baumjohann1, K.-H. Glassmeier2,3, U. Motschmann4,5, and H. Comişel4,6 Y. Narita et al.
Show author details
  • 1Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, 8042 Graz, Austria
  • 2Institut für Geophysik und extraterrestrische Physik, Technische Universität Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig, Germany
  • 3Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
  • 4Institut für Theoretische Physik, Technische Universität Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig, Germany
  • 5Deutsches Zentrum für Luft- und Raumfahrt, Institut für Planetenforschung, Rutherfordstr. 2, 12489 Berlin, Germany
  • 6Institute for Space Sciences, Atomiştilor 409, P.O. Box MG-23, Bucharest-Măgurele, 077125, Romania
Received: 02 Dec 2015 – Accepted: 12 Jan 2016 – Published: 21 Jan 2016

Abstract. Four-dimensional energy spectra and a diagram for dispersion relations are determined for the first time in a magnetic reconnection region in the magnetotail using data from four-spacecraft measurements by the Cluster mission on a spatial scale of 200 km, about 0.1 ion inertial lengths. The energy spectra are anisotropic with an extension in the perpendicular direction and axially asymmetric with respect to the mean magnetic field. The dispersion diagram in the plasma rest frame is in reasonably good agreement with the ion Bernstein waves at the second and higher harmonics of the proton gyrofrequency. Perpendicular-propagating ion Bernstein waves likely exist in an outflow region of magnetic reconnection, which may contribute to bifurcation of the current sheet in the outflow region.

How to cite. Narita, Y., Nakamura, R., Baumjohann, W., Glassmeier, K.-H., Motschmann, U., and Comişel, H.: Ion Bernstein waves in the magnetic reconnection region, Ann. Geophys., 34, 85–89, https://doi.org/10.5194/angeo-34-85-2016, 2016.
Download
Short summary
Four-spacecraft Cluster observations of turbulent fluctuations in the magnetic reconnection region in the geomagnetic tail show for the first time an indication of ion Bernstein waves, electromagnetic waves that propagate nearly perpendicular to the mean magnetic field and are in resonance with ions. Bernstein waves may influence current sheet dynamics in the reconnection outflow such as a bifurcation of the current sheet.
Read more