Collisionless magnetic reconnection in an asymmetric current sheet

摘要: [1] The process of collisionless magnetic reconnection in an ion-scale current sheet containing strong gradients the density and field strength across layer is investigated using two-dimensional particle-in-cell simulations. Such a configuration contains normal polarization electric on high field/low (magnetospheric) side layer. In initial-value simulations for such asymmetric sheet, rate saturation level are found to be smaller by factors 2–3 compared with similar-scale symmetric sheet. These rates probably too small explain observations at dayside magnetopause. The addition external-driving increases substantially. This driven characterized nearly parallel inflow electrons along magnetosheath separatrices as attempt flow from low layer, outward Poynting flux magnetospheric associated out-of-plane field, ion outflow jet. region also exhibits patchy structure electron velocity distributions counterstreaming feature. moderate uniform guide component (shear angle ≳110°) has no appreciable effect but does produce drift X line direction diamagnetic fraction Alfven speed.