ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-27-913-2009 Remote sensing of local structure of the quasi-perpendicular Earth's bow shock by using field-aligned beams Miao B. 1 Kucharek H. 1 Möbius E. 1 Mouikis C. 1 Matsui H. 1 Liu Y. C.-M. 1 Lucek E. A. 2 Dept. of Physics and Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH, USA Space and Atmospheric Physics, Imperial College, London, SW7 2BZ, UK 02 03 2009 27 3 913 921 Copyright: © 2009 B. Miao et al. 2009 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/27/913/2009/angeo-27-913-2009.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/27/913/2009/angeo-27-913-2009.pdf

Field-aligned ion beams (FABs) originate at the quasi-perpendicular Earth's bow shock and constitute an important ion population in the foreshock region. The bulk velocity of these FABs depends significantly on the shock normal angle, which is the angle between shock normal and upstream interplanetary magnetic field (IMF). This dependency may therefore be taken as an indicator of the local structure of the shock. Applying the direct reflection model to Cluster measurements, we have developed a method that uses proton FABs in the foreshock region for remote sensing of the local shock structure. The comparison of the model results with the multi-spacecraft observations of FAB events shows very good agreement in terms of wave amplitude and frequency of surface waves at the shock front.

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