Cluster observations of complex 3D magnetic structures at the magnetopause

On June 30, 2001, around 0530 UT, Cluster was moving along the magnetopause with spacecraft on both sides of the discontinuity. The configuration was `quasi-ideal' with magnetic field and plasma flow almost aligned in the magnetosheath and nearly anti-parallel to the magnetospheric field. Cluster observed several perturbations with leading and trailing edges corresponding respectively to tangential and rotational discontinuities. They present a complex 3D topology, consistent with the inter-linking of flux tubes resulting from reconnections occurring at different sites.