Articles | Volume 22, issue 7
Ann. Geophys., 22, 2291–2300, 2004
https://doi.org/10.5194/angeo-22-2291-2004

Special issue: Spatio-temporal analysis and multipoint measurements in space...

Ann. Geophys., 22, 2291–2300, 2004
https://doi.org/10.5194/angeo-22-2291-2004

  14 Jul 2004

14 Jul 2004

Electric field scales at quasi-perpendicular shocks

S. N. Walker1, H. St. C. K. Alleyne1, M. A. Balikhin1, M. André2, and T. S. Horbury3 S. N. Walker et al.
  • 1Department of Automatic Control and Systems Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
  • 2Swedish Institute of Space Physics, Uppsala Division, Box 537, SE-751 21 Uppsala, Sweden
  • 3Blackett Laboratory, ICSTM, Prince Consort Road, London. UK

Abstract. This paper investigates the short scale structures that are observed in the electric field during crossings of the quasi-perpendicular bow shock using data from the Cluster satellites. These structures exhibit large amplitudes, as high as 70 m Vm-1 and so make a significant contribution to the overall change in potential at the shock front. It is shown that the scale size of these short-lived electric field structures is of the order of a few cpe. The relationships between the scale size and the upstream Mach number and θBn are studied. It is found that the scale size of these structures decreases with increasing plasma β and as θBn→90°. The amplitude of the spikes remains fairly constant with increasing Ma and appears to increase as θBn→90°.