Turbulence and Heating in the Flank and Wake Regions of a Coronal Mass Ejection

As a coronal mass ejection (CME) passes, the flank and wake regions are typically strongly disturbed. Various instruments, including the Large Angle and Spectroscopic Coronagraph (LASCO), the Atmospheric Imaging Assembly (AIA), and the Coronal Multi-channel Polarimeter (CoMP), observed a CME close to the east limb on 26 October 2013. A hot (approximate to 10 MK) rising blob was detected on the east limb, with an initial ejection flow speed of approximate to 330 kms(-1). The magnetic structures on both sides and in the wake of the CME were strongly distorted, showing initiation of turbulent motions with Doppler-shift oscillations enhanced from approximate to +/- 3 kms(-1) to approximate to +/- 15 kms(-1) and effective thermal velocities from approximate to 30 kms(-1) to approximate to 60 kms(-1), according to the CoMP observations at the Fe XIII line. The CoMP Doppler-shift maps suggest that the turbulence behaved differently at various heights; it showed clear wave-like torsional oscillations at lower altitudes, which are interpreted as the antiphase oscillation of an alternating red/blue Doppler shift across the strands at the flank. The turbulence seems to appear differently in the channels of different temperatures. Its turnover time was approximate to 1000 seconds for the Fe 171 A channel, while it was approximate to 500 seconds for the Fe 193 A channel. Mainly horizontal swaying rotations were observed in the Fe 171 A channel, while more vertical vortices were seen in the Fe 193 A channel. The differential-emission-measure profiles in the flank and wake regions have two components that evolve differently: the cool component decreased over time, evidently indicating a drop-out of cool materials due to ejection, while the hot component increased dramatically, probably because of the heating process, which is suspected to be a result of magnetic reconnection and turbulence dissipation. These results suggest a new turbulence-heating scenario of the solar corona and solar wind.