Electron Surfing Acceleration at Rippled Reconnection Fronts

Abstract The reconnection front (RF), one of the most efficient accelerators particles in terrestrial magnetosphere, is a sharp plasma boundary resulting from transient magnetic reconnection. It has been both theoretically predicted and observationally confirmed that electron-scale substructures can develop at RFs. How such structures modulate electron energization transport not fully explored. Based on high-resolution data MMS spacecraft particle tracing simulations, we investigate compare acceleration across two typical RFs with or without rippled structures. Both observations simulations reveal high-energy flux behind RF increases more dramatically if electrons encounter surface, as compared to smooth surface. main mechanism surfing acceleration, which are trapped by ripples, due large local field gradient, therefore undergo motion along motional electric field.