Analysis of Deformation and Erosion during CME Evolution
Magnetised coronal mass ejections (CMEs) are quite substantially deformed during their journey form the Sun to the Earth. Moreover, the interaction of their internal magnetic field with the magnetic field of the ambient solar wind can cause deflection and erosion of their mass and magnetic flux. We...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-07-01
|
| Series: | Geosciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3263/11/8/314 |
| _version_ | 1797523690251878400 |
|---|---|
| author | Skralan Hosteaux Emmanuel Chané Stefaan Poedts |
| author_facet | Skralan Hosteaux Emmanuel Chané Stefaan Poedts |
| author_sort | Skralan Hosteaux |
| collection | DOAJ |
| description | Magnetised coronal mass ejections (CMEs) are quite substantially deformed during their journey form the Sun to the Earth. Moreover, the interaction of their internal magnetic field with the magnetic field of the ambient solar wind can cause deflection and erosion of their mass and magnetic flux. We here analyse axisymmetric (2.5D) MHD simulations of normal and inverse CME, i.e., with the opposite or same polarity as the background solar wind, and attempt to quantify the erosion and the different forces that operate on the CMEs during their evolution. By analysing the forces, it was found that an increase of the background wind density results in a stronger plasma pressure gradient in the sheath that decelerates the magnetic cloud more. This in turn leads to an increase of the magnetic pressure gradient between the centre of the magnetic cloud and the separatrix, causing a further deceleration. Regardless of polarity, the current sheet that forms in our model between the rear of the CME and the closed field lines of the helmet streamer, results in magnetic field lines being stripped from the magnetic cloud. It is also found that slow normal CMEs experience the same amount of erosion, regardless of the background wind density. Moreover, as the initial velocity increases, so does the influence of the wind density on the erosion. We found that increasing the CME speed leads to a higher overall erosion due to stronger magnetic reconnection. For inverse CMEs, field lines are not stripped away but added to the magnetic cloud, leading to about twice as much magnetic flux at 1 AU than normal CMEs with the same initial flux. |
| first_indexed | 2024-03-10T08:46:37Z |
| format | Article |
| id | doaj.art-2fa12548ff3a43fd9625e63d451bc413 |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-10T08:46:37Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj.art-2fa12548ff3a43fd9625e63d451bc4132023-11-22T07:47:39ZengMDPI AGGeosciences2076-32632021-07-0111831410.3390/geosciences11080314Analysis of Deformation and Erosion during CME EvolutionSkralan Hosteaux0Emmanuel Chané1Stefaan Poedts2Department of Mathematics, Centre for mathematical Plasma Astrophysics (CmPA), KU Leuven, Celestijnenlaan 200B, 3001 Leuven, BelgiumDepartment of Mathematics, Centre for mathematical Plasma Astrophysics (CmPA), KU Leuven, Celestijnenlaan 200B, 3001 Leuven, BelgiumDepartment of Mathematics, Centre for mathematical Plasma Astrophysics (CmPA), KU Leuven, Celestijnenlaan 200B, 3001 Leuven, BelgiumMagnetised coronal mass ejections (CMEs) are quite substantially deformed during their journey form the Sun to the Earth. Moreover, the interaction of their internal magnetic field with the magnetic field of the ambient solar wind can cause deflection and erosion of their mass and magnetic flux. We here analyse axisymmetric (2.5D) MHD simulations of normal and inverse CME, i.e., with the opposite or same polarity as the background solar wind, and attempt to quantify the erosion and the different forces that operate on the CMEs during their evolution. By analysing the forces, it was found that an increase of the background wind density results in a stronger plasma pressure gradient in the sheath that decelerates the magnetic cloud more. This in turn leads to an increase of the magnetic pressure gradient between the centre of the magnetic cloud and the separatrix, causing a further deceleration. Regardless of polarity, the current sheet that forms in our model between the rear of the CME and the closed field lines of the helmet streamer, results in magnetic field lines being stripped from the magnetic cloud. It is also found that slow normal CMEs experience the same amount of erosion, regardless of the background wind density. Moreover, as the initial velocity increases, so does the influence of the wind density on the erosion. We found that increasing the CME speed leads to a higher overall erosion due to stronger magnetic reconnection. For inverse CMEs, field lines are not stripped away but added to the magnetic cloud, leading to about twice as much magnetic flux at 1 AU than normal CMEs with the same initial flux.https://www.mdpi.com/2076-3263/11/8/314magnetohydrodynamics (MHD)magnetic reconnectionSuncoronal mass ejections (CMEs) |
| spellingShingle | Skralan Hosteaux Emmanuel Chané Stefaan Poedts Analysis of Deformation and Erosion during CME Evolution Geosciences magnetohydrodynamics (MHD) magnetic reconnection Sun coronal mass ejections (CMEs) |
| title | Analysis of Deformation and Erosion during CME Evolution |
| title_full | Analysis of Deformation and Erosion during CME Evolution |
| title_fullStr | Analysis of Deformation and Erosion during CME Evolution |
| title_full_unstemmed | Analysis of Deformation and Erosion during CME Evolution |
| title_short | Analysis of Deformation and Erosion during CME Evolution |
| title_sort | analysis of deformation and erosion during cme evolution |
| topic | magnetohydrodynamics (MHD) magnetic reconnection Sun coronal mass ejections (CMEs) |
| url | https://www.mdpi.com/2076-3263/11/8/314 |
| work_keys_str_mv | AT skralanhosteaux analysisofdeformationanderosionduringcmeevolution AT emmanuelchane analysisofdeformationanderosionduringcmeevolution AT stefaanpoedts analysisofdeformationanderosionduringcmeevolution |