Measure the Propagation of a halo CME and Its Driven Shock with the Observations from a Single Perspective at Earth

TL;DR

This study combines multiple observational methods to accurately reconstruct the 3D propagation of a halo CME and its shock from a single perspective at Earth, enhancing understanding of CME dynamics.

Contribution

The paper introduces a novel GCS-PR method that integrates polarization ratio analysis with GCS modeling to derive 3D CME parameters from a single viewpoint.

Findings

Good consistency among different reconstruction methods.

First application of PR method to LASCO/C2 polarimetric features.

Successful 3D characterization of CME and shock propagation.

Abstract

We present a detailed study of an earth-directed coronal mass ejection (Full halo CME) event happened on 2011 February 15 making use of white light observations by three coronagraphs and radio observations by Wind/WAVES. We applied three different methods to reconstruct the propagation direction and traveling distance of the CME and its driven shock. We measured the kinematics of the CME leading edge from white light images observed by STEREO A and B, tracked the CME-driven shock using the frequency drift observed by Wind/WAVES together with an interplanetary density model, and obtained the equivalent scattering centers of the CME by Polarization Ratio(PR) method. For the first time, we applied PR method to different features distinguished from LASCO/C2 polarimetric observations and calculated their projections onto white light images observed by STEREO A and B. By combining the graduated cylindrical shell (GCS) forward modeling with the PR method, we proposed a new GCS-PR method to derive 3D parameters of a CME observed from a single perspective at Earth. Comparisons between different methods show a good degree of consistence in the derived 3D results.