Ds. Intriligator et al., STREAM INTERFACES AND ENERGETIC IONS .2. ULYSSES TEST OF PIONEER RESULTS, Geophysical research letters, 22(10), 1995, pp. 1173-1176
Ulysses measurements of energetic and solar wind particles taken near
5 AU between 20 and 30 degrees south latitude during a well-developed
recurring corotating interaction region (CIR) show that the CIR's coro
tating energetic ion population (CEIP) associated with the trailing re
verse shock starts within the CIR at the stream interface. This is con
sistent with an earlier result obtained by Pioneers 10 and 11 in the e
cliptic plane between 4 and 6 AU. The Ulysses/Pioneer finding ns notew
orthy since the stream interface is not magnetically connected to the
reverse shock, but lies 12-17 corotation hours from it. Thus, the find
ing seems to be inconsistent with the basic model that generates CEIP
particles at the reverse shock and propagates them along field lines.
Eliminating the inconsistency probably entails an extension of the sta
ndard model such as cross-field diffusion or a non-shock energization
process operating near the stream interface closer to the sun.