Articles | Volume 22, issue 7
https://doi.org/10.5194/angeo-22-2291-2004
https://doi.org/10.5194/angeo-22-2291-2004
14 Jul 2004
 | 14 Jul 2004

Electric field scales at quasi-perpendicular shocks

S. N. Walker, H. St. C. K. Alleyne, M. A. Balikhin, M. André, and T. S. Horbury

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°.