1. 学术报告：磁重联区霍尔效应的动力学Alfven波解释--MMS卫星的观测验证 时间：2017.4.19日下午2：30 地点：教学行政楼1512室 报告人：戴磊研究员 单位：空间中心 摘要：Recent in-situ observations from MMS and THEMIS reveal that the electric field normal to the reconnection current layer, often called the Hall electric field (En), is mainly balanced by the ion pressure gradient. Here we present theoretical explanations indicating that this observation fact is a manifestation of Kinetic Alfven Waves (KAW) physics. The ion pressure gradient represents the finite gyroradius effect of KAW, leading to ion intrusion across the magnetic field lines. Electrons stream along the magnetic field lines to track ions, resulting in field-aligned currents and the associated pattern of the out-of-plane Hall magnetic field (Bm). The ratio En/Bm is on the order of the Alfven speed, as predicted by the KAW theory. The KAW physics further provides new perspectives on how ion intrusion may trigger electric fields suitable for reconnection to occur.

李勤秀 Posted at 2017-04-17 08:31 CST Last modified at 2017-04-17 08:33 CST Link to this poster Top