Analysis of a global Moreton wave observed on October 28, 2003

TL;DR

This study analyzes a prominent global Moreton wave from October 28, 2003, revealing its propagation characteristics, relation to EIT waves, and association with CME activity, providing insights into wave initiation and evolution.

Contribution

It presents detailed observations of a global Moreton wave with dual centers, linking it to CME expansion and correlating it with EIT wavefronts, which advances understanding of wave-CME interactions.

Findings

Mean wave velocity 900-1100 km/s

Wave initiated by CME expanding flanks

EIT and Moreton waves are different signatures of the same process

Abstract

We study the well pronounced Moreton wave that occurred in as- sociation with the X17.2 are/CME event of October 28, 2003. This Moreton wave is striking for its global propagation and two separate wave centers, which implies that two waves were launched simultane- ously. The mean velocity of the Moreton wave, tracked within different sectors of propagation direction, lies in the range of v ~ 900-1100 km/s with two sectors showing wave deceleration. The perturbation profile analysis of the wave indicates amplitude growth followed by amplitude weakening and broadening of the perturbation profile, which is con- sistent with a disturbance first driven and then evolving into a freely propagating wave. The EIT wavefront is found to lie on the same kinematical curve as the Moreton wavefronts indicating that both are different signatures of the same physical process. Bipolar coronal dim- mings are observed on the same opposite East-West edges of the active region as the Moreton wave ignition centers. The radio type II source, which is co-spatially located with the first wave front, indicates that the wave was launched from an extended source region (& 60 Mm). These findings suggest that the Moreton wave is initiated by the CME expanding flanks.