Interacting CMEs and their associated flare and SEP activities

TL;DR

This study analyzes 25 interacting coronal mass ejections (CMEs) and their associated flare and solar energetic particle activities, revealing that primary CMEs are faster, more energetic, and linked to stronger flares and higher SEP intensities than pre-CMEs.

Contribution

It provides detailed analysis of interacting CMEs, their timing, energetics, and associated solar activities, highlighting differences between primary and pre-CMEs and their impact on space weather.

Findings

Primary CMEs are faster and more energetic than pre-CMEs.

Associated flares of primary CMEs are stronger (X and M class).

SEP intensity correlates with X-ray flare flux for western events.

Abstract

We have analyzed a set of 25 interacting events which are associated with the DH type II bursts. These events are selected from the Coronal Mass Ejections observed during the period 1997-2010 in SOHO/LASCO and DH type IIs in Wind/WAVES. Their pre and primary CMEs from nearby active regions are identified using LASCO and EIT images and their height-time diagrams. Their interacting time and height are obtained, and their associated activities, such as, flares and solar energetic particles (>10pfu) are also investigated. Results from the analysis are: primary CMEs are much faster than the pre-CMEs, their X-ray flares are also stronger (X and M class) compared to the flares (C and M class) of pre-CMEs. Most of the events occurred during the period 2000-2006. From the observed width and speed of pre and primary CMEs, the pre-CMEs are found to be less energetic than the primary CMEs. While the primary CMEs are tracked up to the end of LASCO field of view, most of the pre-CMEs are tracked up to < 26Rs. The SEP intensity is found to be related with the integrated flux of the X-ray flares associated with the primary CMEs for nine events originating from the western region.