Magnetic structure and propagation of wwo interacting CMEs from the sun to saturn

作     者：Palmerio, Erika Nieves-Chinchilla, Teresa Kilpua, Emilia K.J. Barnes, David Zhukov, Andrei N. Jian, Lan K. Witasse, Olivier Provan, Gabrielle Tao, Chihiro Lamy, Laurent Bradley, Thomas J. Leila Mays, M. Möstl, Christian Roussos, Elias Futaana, Yoshifumi Masters, Adam Sánchez-Cano, Beatriz 

作者机构：Space Sciences Laboratory University of California–Berkeley BerkeleyCA United States CPAESS University Corporation for Atmospheric Research BoulderCO United States Heliophysics Science Division NASA Goddard Space Flight Center GreenbeltMD United States Department of Physics University of Helsinki Helsinki Finland STFC RAL Space Rutherford Appleton Laboratory Harwell Campus Oxfordshire United Kingdom Solar–Terrestrial Centre of Excellence—SIDC Royal Observatory of Belgium Brussels Belgium Skobeltsyn Institute of Nuclear Physics Moscow State University Moscow Russia ESTEC European Space Agency Noordwijk Netherlands School of Physics and Astronomy University of Leicester Leicester United Kingdom  Koganei Japan LESIA Observatoire de Paris PSL CNRS UPMC Université Paris Diderot Meudon France LAM Pythéas Aix Marseille Université CNRS CNES Marseille France Space Research Institute Austrian Academy of Sciences Graz Austria Institute of Geodesy Graz University of Technology Graz Austria Max Planck Institute for Solar System Research Göttingen Germany Swedish Institute of Space Physics Kiruna Sweden The Blackett Laboratory Imperial College London London United Kingdom 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2021年

核心收录：

主　　题：Magnetic structure 

摘      要：One of the grand challenges in heliophysics is the characterisation of coronal mass ejection (CME) magnetic structure and evolution from eruption at the Sun through heliospheric propagation. At present, the main difficulties are related to the lack of direct measurements of the coronal magnetic fields and the lack of 3D in-situ measurements of the CME body in interplanetary space. Nevertheless, the evolution of a CME magnetic structure can be followed using a combination of multi-point remote-sensing observations and multi-spacecraft in-situ measurements as well as modelling. Accordingly, we present in this work the analysis of two CMEs that erupted from the Sun on 28 April 2012. We follow their eruption and early evolution using remote-sensing data, finding indications of CME–CME interaction, and then analyse their interplanetary counterpart(s) using in-situ measurements at Venus, Earth, and Saturn. We observe a seemingly single flux rope at all locations, but find possible signatures of interaction at Earth, where high-cadence plasma data are available. Reconstructions of the in-situ flux ropes provide almost identical results at Venus and Earth but show greater discrepancies at Saturn, suggesting that the CME was highly distorted and/or that further interaction with nearby solar wind structures took place before 10 AU. This work highlights the difficulties in connecting structures from the Sun to the outer heliosphere and demonstrates the importance of multi-spacecraft studies to achieve a deeper understanding of the magnetic configuration of CMEs. © 2021, CC BY.