Electric field scales at quasi-perpendicular shocks

S. N. Walker (1) , H. St. C. K. Alleyne (1) , M. A. Balikhin (1) , M. André (2) , T. S. Horbury (3)

1 Department of Automatic Control and Systems Engineering
2 IRF - Swedish Institute of Space Physics [Uppsala / Kiruna]
3 Blackett Laboratory

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 c/?_pe. The relationships between the scale size and the upstream Mach number and ?_Bn are studied. It is found that the scale size of these structures decreases with increasing plasma ? and as ?_Bn?90°. The amplitude of the spikes remains fairly constant with increasing M_a and appears to increase as ?_Bn?90°.

Domaines: Océan, Atmosphère; Sciences de la Terre

S. N. Walker, H. St. C. K. Alleyne, M. A. Balikhin, M. André, T. S. Horbury. Electric field scales at quasi-perpendicular shocks. Annales Geophysicae, 2004, 22 (7), pp.2291-2300. ⟨hal-00317475⟩