July 13, 2012, 12:00 pm - 1:00 pm

July 13, 12:00 pm - 1:00 pm

The Importance of Anomalous Momentum Transport in Fast Magnetic Reconnection

Dr. Haihong Che, Naval Research Laboratory/George Mason University

Magnetic reconnection has been thought as an important mechanism for fast releasing of magnetic energy observed in space explosive events (Solar flare, substorms…). This talk will briefly introduce the major progresses made in the past two decades on understanding of the physical processes in the diffusion region of fast non-turbulent magnetic reconnection. Observations have associated turbulence with reconnections, the role of turbulence in magnetic reconnection has been a long-time puzzle in both theory and observation. For the first time the recent particle-in-cell simulation conclusively demonstrates that the anomalous momentum transport generated by electron velocity shear instabilities (or filamentary instabilities) abruptly accelerate magnetic reconnection process (Che et al., 2011, Nature). This result does not support the generally invoked anomalous resistivity for breaking of magnetic field lines. This talk will also discuss the fundamental difference and connection between the kinetic anomalous momentum transport and the MHD anomalous viscosity which has been dubbed as hypper-resistivity in MHD turbulent reconnection.