Magnetic topology of actively evolving and passively convecting structures in the turbulent solar wind

Multipoint in-situ Cluster observations of the solar wind are analysed to identify the magnetic field line topology and current density of turbulent structures using magnetic field gradient tensor invariants. Identified structures are classified as actively evolving if their magnetic field varies significantly from the force-free configuration. We find that at least 35% of all structures are both actively evolving and carrying the strongest currents, actively dissipating, and heating the plasma. These structures are comprised of 1/5 3D plasmoids, 3/5 flux ropes, and 1/5 3D X-points consistent with magnetic reconnection. Actively evolving and passively advecting structures are both close to log-normally distributed. This provides direct evidence for the significant role of strong turbulence, evolving via magnetic shearing and reconnection, in mediating dissipation and solar wind heating.