Multispacecraft observations of interplanetary shocks: Nonplanarity and energetic particles

Numerical simulations of the evolution of interplanetary shocks exhibit growth of distortions of the shock front and nonuniformity of energetic particles from place to place near the shock surface. In this work we use multispacecraft (ACE, Wind, IMP 8, Geotail, Interball-Tail, SOHO, and Genesis) observations near Earth to search for such effects. On scales of 10(5) to 10(6) km, most of the 26 shocks studied were inconsistent with planar structures or with spherical structures with a radius of 1 AU. The average local radius of curvature was similar to 3x10(6) km. There were also differences in the intensities and time profiles of energetic particle fluxes seen at both ACE and Wind.