HR: 17:00h
AN: SH34A-05    [Abstracts]
TI: On shock strength and electric fields in the inner heliosphere
AU: * Bale, S D
EM: bale@ssl.berkeley.edu
AF: University of California, Berkeley, Space Sciences Laboratory University of California, Berkeley, CA 94720-7450 United States
AB: I explore the scaling of shock strength, cross-shock and convection electric field with heliospheric radius in the inner heliosphere. In the low $\beta_e$ inner heliosphere, the primary contribution to the cross-shock field may be due to Hall currents, which are shown to scale non-monotonically with Mach number and exhibit a local minimum near the Alfv\`en speed peak at several solar radii. This allows that the shock and cross-shock component of the convection fields are nearly equal $|\vec{E}_{shock}| \approx (\vec{v} \times \vec{B})_x$, which is a condition for high efficiency of the shock-surfing mechanism of ion acceleration. Shock-surfing is thought to be a injection mechanism to diffusive acceleration and, indeed, observations show that energetic ion events are often accelerated at near this same heliospheric radius.
DE: 7851 Shock waves
DE: 2114 Energetic particles, heliospheric (7514)
DE: 2139 Interplanetary shocks
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting