On flare-CME characteristics from Sun to Earth combining remote-sensing image data with in-situ measurements supported by modeling

摘要

We analyze the well observed flare-CME event from October 1, 2011(SOL2011-10-01T09:18) covering the complete chain of action - from Sun to Earth- for a better understanding of the dynamic evolution of the CME and itsembedded magnetic field. We study the solar surface and atmosphere associatedwith the flare-CME from SDO and ground-based instruments, and also track theCME signature off-limb from combined EUV and white-light data with STEREO. Byapplying 3D reconstruction techniques (GCS, total mass) to stereoscopicSTEREO-SoHO coronagraph data, we track the temporal and spatial evolution ofthe CME in interplanetary space and derive its geometry and 3D-mass. We combinethe GCS and Lundquist model results to derive the axial flux and helicity ofthe MC from in-situ measurements (Wind). This is compared to nonlinearforce-free (NLFF) model results as well as to the reconnected magnetic fluxderived from the flare ribbons (flare reconnection flux) and the magnetic fluxencompassed by the associated dimming (dimming flux). We find that magneticreconnection processes were already ongoing before the start of the impulsiveflare phase, adding magnetic flux to the flux rope before its final eruption.The dimming flux increases by more than 25% after the end of the flare,indicating that magnetic flux is still added to the flux rope after eruption.Hence, the derived flare reconnection flux is most probably a lower limit forestimating the magnetic flux within the flux rope. We find that the magnetichelicity and axial magnetic flux are reduced in interplanetary space by ~50%and 75%, respectively, possibly indicating to an erosion process. A massincrease of 10% for the CME is observed over the distance range from ~4-20 Rs.The temporal evolution of the CME associated core dimming regions supports thescenario that fast outflows might supply additional mass to the rear part ofthe CME.