Comprehensive Analysis of Coronal Mass Ejection Mass and Energy Properties Over a Full Solar Cycle

TL;DR

This study analyzes CME mass and energy over a full solar cycle using LASCO data, revealing two classes of CMEs, their dependence on height, and periodic variations, providing new insights into solar eruptive phenomena.

Contribution

It presents the first comprehensive analysis of CME mass and energy over a complete solar cycle, including new methods and findings on CME classifications and periodicities.

Findings

Identification of two CME classes: 'normal' and 'pseudo'

CME mass and energy stabilize above 10 solar radii

Detected a six-month periodicity in CME mass from 2003 onwards

Abstract

The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high quality images and regular cadence. This is the first time that such a dataset becomes available and constitutes a unique resource for the study of CMEs. In this paper, we present a comprehensive investigation of the solar cycle dependence on the CME mass and energy over a full solar cycle (1996-2009) including the first in-depth discussion of the mass and energy analysis methods and their associated errors. Our analysis provides several results worthy of further studies. It demonstrates the possible existence of two event classes; 'normal' CMEs reaching constant mass for $>10$ R$_{\sun}$ and 'pseudo' CMEs which disappear in the C3 FOV. It shows that the mass and energy properties of CME reach constant levels, and therefore should be measured, only above $\sim 10 R_\sun$. The mass density ($g/R_\sun^2$) of CMEs varies relatively little ($<$ order of magnitude) suggesting that the majority of the mass originates from a small range in coronal heights. We find a sudden reduction in the CME mass in mid-2003 which may be related to a change in the electron content of the large scale corona and we uncover the presence of a six-month periodicity in the ejected mass from 2003 onwards.