Conferencia
Abstract:
We study the long term evolution of a set of bipolar active regions (ARs) in which the main photospheric polarities are seen to rotate one around the other during several solar rotations. After showing that differential rotation cannot produce this large change in the tilt angle, we interpret this peculiar evolution as being the result of the emergence of magnetic flux tubes that are distorted with respect to the classical Ω-loop shape. A possible origin of this distortion is the nonlinear development of a kink-instability. Flux tubes deformed by this mechanism must have the same sign of twist and writhe. From the observed evolution of the tilt of the bipoles, we derive the sign of the writhe of the tube forming each AR; while we compute the sign of the twist from transverse field measurements. Comparing the handedness of the magnetic twist and writhe, we find that the presence of kink-unstable flux tubes is coherent with no more than 32% of the studied cases; so, a small fraction of these peculiar ARs can be explained by this process. Then, we discuss the role that other mechanisms may play inducing the inferred deformation, such as the Coriolis force ort external rotational motions of the plasma as the tube ascends in the convection zone.
Registro:
| Documento: | Conferencia |
| Título: | On the origin of peculiar active regions |
| Autor: | Mandrini, C.H.; López Fuentes, M.C.; Démoulin, P.; Van Driel-Gesztelyi, L.; Pevtsov, A.A.; Sawaya-Lacoste H. |
| Ciudad: | Santorini |
| Filiación: | Inst. de Astronomia y Fisica Espacio, CC.67, Suc.28, 1428 Buenos Aires, Argentina Observatoire de Paris, Meudon, DASOP, F-92195 Meudon Principal Cedex, France Centre for Plasma Astrophysics, K.U. Leuven, Celestijnenlaan 200B, 3001 Heverleen, Belgium Mullard Space Science Lab., Univ. College London, United Kingdom Natl. Solar Observ./Sacramento Peak, P.O. Box 62, Sunspot, NM 88349, United States |
| Palabras clave: | Active regions; Magnetic fields; Photosphere; Extraterrestrial atmospheres; Magnetic fields; Magnetic flux; Plasmas; Rotation; Sun; Active regions; Coriolis force; Photospheric polarities; Solar rotations; Astrophysics |
| Año: | 2002 |
| Número: | 505 |
| Página de inicio: | 121 |
| Página de fin: | 124 |
| Título revista: | Proceedings of the Magnetic Coupling of the solar Atmosphere Euroconference and IAU Colloquium 188 |
| Título revista abreviado: | Eur Space Agency Spec Publ ESA SP |
| ISSN: | 03796566 |
| CODEN: | ESPUD |
| Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n505_p121_Mandrini |
Referencias:
- Ambrož, P., (2001) Solar Phys., 199, p. 251
- Berger, M., (1984) Geophys. Astrophys. Fluid Dyn., 30, p. 79
- Green, L.M., López Fuentes, M.C., Mandrini, C.H., Démoulin, P., Van Driel-Gesztelyi, L., Culhane, J.L., (2002) Solar Phys., , in press
- Hale, G.E., Ellerman, F., Nicholson, S.B., Joy, A.H., (1919) ApJ, 49, p. 153
- Hale, G.E., Nicholson, S.B., (1925) ApJ, 62, p. 270
- Komm, R.W., Howard, R.F., Harvey, J.W., (1993) Solar Phys., 147, p. 207
- Linton, M.G., Fisher, G.H., Dahlburg, R.G., Fan, Y., (1999) ApJ, 522, p. 1190
- Longcope, D.W., Fisher, G.H., Pevtsov, A.A., (1998) ApJ, 507, p. 417
- López Fuentes, M., Démoulin, P., Mandrini, C.H., Van Driel-Gesztelyi, L., (2000) ApJ, 544, p. 540
- Pevtsov, A.A., Canfield, R.C., Metcalf, T.R., (1995) ApJ, 440, pp. L117
- Zwaan, C., (1985) Solar Phys., 100, p. 397A4 - National Obserwatory of Athens; Max-Planck Institute fur Aeronomie; European Commission; European Space Agency; International Space Agency
Citas:
---------- APA ----------
Mandrini, C.H., López Fuentes, M.C., Démoulin, P., Van Driel-Gesztelyi, L., Pevtsov, A.A. & Sawaya-Lacoste H. (2002) . On the origin of peculiar active regions. Proceedings of the Magnetic Coupling of the solar Atmosphere Euroconference and IAU Colloquium 188(505), 121-124.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n505_p121_Mandrini [ ]
---------- CHICAGO ----------
Mandrini, C.H., López Fuentes, M.C., Démoulin, P., Van Driel-Gesztelyi, L., Pevtsov, A.A., Sawaya-Lacoste H. "On the origin of peculiar active regions" . Proceedings of the Magnetic Coupling of the solar Atmosphere Euroconference and IAU Colloquium 188, no. 505 (2002) : 121-124.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n505_p121_Mandrini [ ]
---------- MLA ----------
Mandrini, C.H., López Fuentes, M.C., Démoulin, P., Van Driel-Gesztelyi, L., Pevtsov, A.A., Sawaya-Lacoste H. "On the origin of peculiar active regions" . Proceedings of the Magnetic Coupling of the solar Atmosphere Euroconference and IAU Colloquium 188, no. 505, 2002, pp. 121-124.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n505_p121_Mandrini [ ]
---------- VANCOUVER ----------
Mandrini, C.H., López Fuentes, M.C., Démoulin, P., Van Driel-Gesztelyi, L., Pevtsov, A.A., Sawaya-Lacoste H. On the origin of peculiar active regions. Eur Space Agency Spec Publ ESA SP. 2002(505):121-124.Available from: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n505_p121_Mandrini [ ]
