Satistical Study of the Interplanetary Coronal Mass Ejections from 1996 to 2014

TL;DR

This study compiles and analyzes interplanetary coronal mass ejections (ICMEs) from 1996 to 2014, revealing correlations with the solar cycle, differences between magnetic clouds and non-cloud ICMEs, and properties of sheath regions.

Contribution

It provides a comprehensive statistical analysis of ICMEs over nearly two solar cycles, including new insights into their properties and their relation to solar activity and shocks.

Findings

ICMEs correlate with solar cycle variations.

Magnetic clouds are stronger than non-cloud ICMEs.

ICMEs with shocks are significantly more intense.

Abstract

In this work, we establish an ICME list from 1996 to 2014 based on the in-situ observations from the WIND and ACE satellites. Based on this ICME list, we extend the statistical analysis of the ICMEs to the solar maximum phase of solar cycle 24th. The analysis of the annual variations of the properties of ICMEs show that the number of ICMEs, the number of shocks, the percentage of ICMEs drove shocks, the magnetic field and plasma properties of ICMEs are well correlated with the solar cycle variation. The number of MCs do not show any correlation with sunspot number. But, the percentage of the MCs in ICMEs show good anti-correlation with the sunspot number. By comparison the parameters of MCs with None-MC ICMEs, we found that the MCs are stronger than the None-MC ICMEs . In addition, we compare the parameters of ICMEs with and without shocks. It is found that the ICMEs with shocks are much stronger than the ICME without shocks. Meanwhile, we discuss the distribution of the magnetic field and solar wind plasmas parameters of the sheath regions of ICMEs at first time. We find that the magnetic field and solar wind velocity in the sheath region are higher than them in the ejecta of ICMEs from statistical point of view.