eprintid: 1394572 rev_number: 42 eprint_status: archive userid: 608 dir: disk0/01/39/45/72 datestamp: 2013-05-29 20:16:08 lastmod: 2021-10-21 23:20:11 status_changed: 2013-05-29 20:16:08 type: article metadata_visibility: show item_issues_count: 0 creators_name: Török, T creators_name: Temmer, M creators_name: Valori, G creators_name: Veronig, AM creators_name: van Driel-Gesztelyi, L creators_name: Vršnak, B title: Initiation of coronal mass ejections by sunspot rotation ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F63 note: The final publication is available at link.springer.com abstract: We study a filament eruption, two-ribbon flare, and coronal mass ejection (CME) that occurred in NOAA Active Region 10898 on 6 July 2006. The filament was located South of a strong sunspot that dominated the region. In the evolution leading up to the eruption, and for some time after it, a counter-clockwise rotation of the sunspot of about 30 degrees was observed. We suggest that the rotation triggered the eruption by progressively expanding the magnetic field above the filament. To test this scenario, we study the effect of twisting the initially potential field overlying a pre-existing flux-rope, using three-dimensional zero-β MHD simulations. We first consider a relatively simple and symmetric system, and then study a more complex and asymmetric magnetic configuration, whose photospheric-flux distribution and coronal structure are guided by the observations and a potential field extrapolation. In both cases, we find that the twisting leads to the expansion of the overlying field. As a consequence of the progressively reduced magnetic tension, the flux-rope quasi-statically adapts to the changed environmental field, rising slowly. Once the tension is sufficiently reduced, a distinct second phase of evolution occurs where the flux-rope enters an unstable regime characterised by a strong acceleration. Our simulations thus suggest a new mechanism for the triggering of eruptions in the vicinity of rotating sunspots. date: 2013-09 official_url: http://dx.doi.org/10.1007/s11207-013-0269-9 vfaculties: VMPS oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_source: Scopus elements_id: 872236 doi: 10.1007/s11207-013-0269-9 lyricists_name: Valori, Gherardo lyricists_name: Van Driel-Gesztelyi, Lidia lyricists_id: GVALO42 lyricists_id: LVAND77 full_text_status: public publication: Solar Physics volume: 286 number: 2 pagerange: 453 -477 issn: 0038-0938 citation: Török, T; Temmer, M; Valori, G; Veronig, AM; van Driel-Gesztelyi, L; Vršnak, B; (2013) Initiation of coronal mass ejections by sunspot rotation. Solar Physics , 286 (2) 453 -477. 10.1007/s11207-013-0269-9 <https://doi.org/10.1007/s11207-013-0269-9>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1394572/1/Torok_etal_2013_SolarPhysics_286_453.pdf