Effects of the September 2014 coronal mass ejection chain in the inner Solar System and the response of the Martian ionosphere

¹ Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, Italy
² School of Physics and Astronomy, University of Leicester, Leicester, UK
³ Department of Geophysics, Graduate School of Science, Kyoto University, Kyoto, Japan

^★ Corresponding author; alessandro.ippolito@ingv.it

Received: 26 November 2024
Accepted: 9 February 2025

Abstract

Context. During September 2014, intense solar activity led to a number of coronal mass ejections (CMEs) propagating in the heliosphere. The strong perturbation in the interplanetary magnetic field and the remarkable enhancements in the energetic particle fluxes accelerated by the shock waves associated with the CMEs affected the environments of the inner planets of the Solar System.

Aims. Taking advantage of a relatively favorable position in terms of angular distance among Mercury, Earth, and Mars, our purpose is to observe the evolution and impact of strong solar events, providing an overview of the impact of the same solar phenomena on different planetary environments, with special interest in the response of Mars’ ionosphere as this may have implications for future exploration of the red planet.

Methods. We used observations from a fleet of spacecraft distributed in the inner Solar System, such as STEREO B, MESSENGER, Mars Express, and SOHO, to perform a characterization of the interaction with the planets, investigating some of the main effects of the CMEs on the different planetary environments. Besides, we applied a numerical simulation to reconstruct the magnetic connection from Mercury, Earth, and Mars to the solar corona on the dates on which the CME events occurred.

Results. We find that the CMEs events analyzed here induced remarkable effects that affected all the environments of the inner planets of the Solar System. Enhancements in the solar energetic particle fluxes were observed at Mercury, Earth, and Mars, with different characteristics. In addition, a solar radio burst was observed both at Earth and Mars, together with strong disturbances in the geomagnetic field, and diffuse echoes and radio black outs in the Martian ionosphere.

Conclusions. The proposed multi-spacecraft and multiparameter analysis, along with the numerical simulations for reconstructing the magnetic footpoints of the Parker spiral on the Sun’s surface, offer a detailed cause-and-effect framework for studying space weather events in the Solar System.