Solar wind magnetohydrodynamic turbulence energy transfer rate ordered by magnetic field topology

The magnetic field fluctuations that mediate a magnetohydrodynamic turbulent cascade have distinct magnetic topologies and associated energy transfer rates. Magnetic field topology is classified by the magnetic field gradient tensor constructed from solar wind observations by the four spacecraft tetrahedron on a scale of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mo>∼</a:mo><a:mn>40</a:mn></a:math> proton gyroradii. Energy transfer rates are estimated instantaneously from the third-order term. We find on average 25% and up to 60% larger forward energy transfer rates in hyperbolic topology compared to flux ropes/plasmoids. Hyperbolic topology, consistent with reconnection, preferentially contributes to the forward energy cascade in magnetohydrodynamic turbulence in the solar wind. This forward cascade is a candidate mechanism for heating the solar wind.