March 8, 2013, 12:00 pm - 1:00 pm

March 8, 12:00 pm - 1:00 pm

The Characteristic Processes of Momentum Transports and Energy Dissipation In Buneman Turbulence

Haihong Che, NASA/GSFC (NPP)

To understand the nature of anomalous resistivity in magnetic reconnection, we study the momentum transports and energy dissipation associated with Buneman instability in a thin current layer. Using 3D particle-in-cell simulations, the generalized Ohm's law is investigated. It is shown that the energy dissipation and momentum transports during Buneman instability involve two coupled dynamic processes: I) The turbulence friction (drag) dissipates both the streaming energy of electron beams and the associated magnetic energy. The decrease of magnetic field maintains an inductive electric field that re-accelerates electrons. The net loss of streaming energy is converted into electron heat; II) The local mean convective momentum and the anomalous thermal momentum transports sustain the localized Buneman-driven electric field. The local momentum transports are the micro-macro link in the anomalous heating process. Compared with collisional heating, except for a time lag between the kinetic momentum transfer and the increase of temperature, the turbulence drag resembles the collisional resistivity.