Intense Flare-CME Event of the Year 2015: Propagation and Interaction Effects between Sun and Earth's Orbit

TL;DR

This study analyzes the propagation and interaction of a powerful CME from the Sun in 2015, revealing its acceleration, expansion, and interaction effects with preceding solar wind structures using multi-wavelength observations.

Contribution

It provides detailed insights into the CME's evolution, speed, and interaction with prior CMEs, highlighting the role of internal magnetic energy in overcoming solar wind drag.

Findings

CME accelerated rapidly up to 6 R_sun

CME maintained speeds ≥800 km/s to 1 AU

Interaction increased turbulence levels

Abstract

In this paper, We report the interplanetary effects of a fast coronal mass ejection (CME) associated with the intense X2.7 flare that occurred on 05 May 2015. The near-Sun signatures of the CME at low-coronal heights $<$2 {R$_{\odot}$} are obtained from the EUV images at 171 {\AA} and metric radio observations. The intensity and duration of the CME-driven radio bursts in the near-Sun and interplanetary medium indicate this CME event to be an energetic one. The interplanetary scintillation data, along with the low-frequency radio spectrum, played a crucial role in understanding the radial evolution of the speed and expansion of the CME in the inner heliosphere as well as its interaction with a preceding slow CME. The estimation of the speed of the CME at several points along the Sun to 1 AU shows shows that i) the CME went through a rapid acceleration as well as expansion up to a height of $\approx$6 {R$_{\odot}$}, and ii) the CME continued to propagate at speed $\geq$800 kms$^{-1}$ between the Sun and 1 AU. These results show that the CME likely overcame the drag exerted by the ambient/background solar-wind with the support of its internal magnetic energy. When the CME interacted with a slow preceding CME, the turbulence level associated with the CME-driven disturbance increased significantly.