Features and Properties of Coronal Mass Ejection/Flare Current Sheets

Abstract

Solar eruptions occur when magnetic energy is suddenly converted into heat and kinetic energy by magnetic reconnection in a current sheet (CS). It is often assumed that CSs are too thin to be observable because the electric resistivity ηe in CSs is taken to be very small. In this work, we show the implications for the CS thickness d estimated from observations of three eruptions by the UVCS and the LASCO experiments on SOHO. We infer the effective ηe causing the rapid reconnection, which predicts much faster reconnection in a thick CS than that caused by the classical and anomalous resistivities. We find that in these events CSs are observable and have extremely large values of d and ηe, implying that large-scale turbulence is operating within CSs. We also discuss the properties of the so-called hyperresistivity caused by the tearing mode and the relation to our results.