Speaker
Description
During their propagation from the Sun, through the solar corona and into the inner heliosphere, the coronal mass ejections (CMEs) encounter variable solar wind. Some of the recent studies of the in situ observations of CMEs, by the rather closely positioned spacecraft, showed very different CME signatures. Such different in situ CME signatures may be due to the distorted CME shape which results from its interaction with the variable ambient solar wind.
In this study we present how the CME-solar wind interaction influences two rather different CMEs, modelled by the 3D MHD model EUHFORIA and the cone CME model. The selected halo CMEs were first detected in the SOHO/LASCO C2 field of view at 16:24 UT on 07 December 2020, and at 15:48 UT on 28 November 2021. Both CMEs arrived at Earth although their main propagation direction was somewhat southward from the Sun-Earth line (Valentino & Magdalenic, 2024). Here we demonstrate how the data-driven modelling can help us to understand often very complex in situ signatures of CME. Namely, the interaction of the CME and the variable solar wind can induce strong distortions of the CME and the CME-driven shock. This structured CMEs will then show very different in situ CME signatures at spacecraft separated even as close as 4 degrees. We also found that the CME arrival time can vary by several hours depending on which part of the distorted CME impacted the spacecraft. Consequently, the forecasted CME arrival at the spacecraft or at Earth can significantly vary if the CMEs propagation direction changes even by a few degrees.
| Do you plan to attend in-person or online? | In-person |
|---|
