An Intense Flare–CME Event in 2015: Propagation and Interaction Effects Between the Sun and Earth’s Orbit

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.