On the Magnetic Flux Budget in Low‐Corona Magnetic Reconnection and Interplanetary Coronal Mass Ejections

We present the first quantitative comparison between the total magnetic re- connection flux in the low-corona in the wake of coronal mass ejections (CMEs) and the magnetic flux in magnetic clouds (MCs) that reach 1 AU 2 - 3 days after CME onset. The total reconnection flux is measured from flare ribbons, and the MC flux is computed using in-situ observations at 1 AU, all ranging from 1020−22 Mx. It is found that for the studied 9 events in which the association between flares, CMEs, and MCs is identified, the MC flux is correlated with the total re- connection fluxr. Further, the poloidal (azimuthal) MC fluxp is comparable with reconnection fluxr, and the toroidal (axial) MC fluxt is a fraction of r. Events associated with filament eruption do not exhibit a differentt,p −r relation from events not accompanied by erupting filaments. The revealed rela- tions between these independently measured physical quantities suggest that, for the studied samples, the magnetic flux and twist of interplanetary magnetic flux ropes, reflected by MCs, are highly relevant to low-corona magnetic reconnection during the eruption. We discuss the implication on the formation mechanism of twisted magnetic flux ropes, namely, whether the helical structure of the mag- netic flux rope is largely pre-existing or formed in-situ by low-corona magnetic reconnection. We also measure magnetic flux encompassed in coronal dimming regions (d) and discuss its relation with reconnection flux inferred from flare ribbons and MC flux.