Observation of Energy Conversion Near the X-line in Asymmetric Guide-field Reconnection

With high-resolution data of the recently launched Magnetospheric Multiscale mission, the present study reports an asymmetric guide-field reconnection at the dayside magnetopause, which has a density asymmetry N _MSP/N _MSH ∼ 15 on the two sides of the current sheet and a guide field B _g ∼ 1.4B _{L, MSH} in the out-of-plane direction, exhibiting all the two-fluid features including Alfvénic plasma jets and Hall field systems. Using the First Order Taylor Expansion method, we identify the X-line of this reconnection. Different from previous observations, the energy conversion dominantly occurs sunward of the X-line, while the local waves arise simultaneously. The qualitative analysis about the electron energization in this reconnection is proposed, suggesting that the guide field may play an important role in modifying the location where the energy conversion occurs together with the electric field near the X-line.