Hybrid Reconstruction to Derive 3D Height-Time Evolution for Coronal Mass Ejections

TL;DR

This paper introduces a hybrid 3D reconstruction method combining forward and inverse modeling to accurately determine the height-time evolution of CMEs from multiple observations, improving understanding of their asymmetric expansion.

Contribution

A novel hybrid reconstruction approach that integrates forward flux rope modeling with inverse density fitting to derive true 3D CME evolution from coronagraph data.

Findings

Successfully applied to the 31 Dec 2007 CME data

Revealed asymmetric expansion rates of the CME

Produced detailed 3D height-time plots for CME components

Abstract

We present a hybrid combination of forward and inverse reconstruction methods using multiple observations of a coronal mass ejection (CME) to derive the 3D 'true' Height-Time plots for individual CME components. We apply this hybrid method to the components of the 31 Dec 2007 CME. This CME, observed clearly in both the STEREO A and STEREO B COR2 white light coronagraphs, evolves asymmetrically across the 15 solar radius field of view with in a span of three hours. The method has two reconstruction steps. We fit a boundary envelope for the potential 3D CME shape using a flux rope-type model oriented to best match the observations. Using this forward model as a constraining envelope, we then run an inverse reconstruction solving for the simplest underlying 3D electron density distribution that can, when rendered, reproduce the observed coronagraph data frames. We produce plots for each segment to establish the 3D or "true" Height-Time plots for each center of mass as well as for the bulk CME motion, and use these plots along with our derived density profiles to estimate the CME asymmetric expansion rate.