A role of magnetic pumping mechanisms in the formation of a sunspot «royal zone»
Heading:
| 1Krivodubskij, VN 1Astronomical Observatory of the Taras Shevchenko National University of Kyiv, Kyiv, Ukraine |
| Kosm. nauka tehnol. 2005, 11 ;(3-4):112-119 |
| https://doi.org/10.15407/knit2005.03.112 |
| Publication Language: Russian |
Abstract: Two «magnetic antibuoyancy- mechanisms: i) lurbulenl diamagnetlsm and ii) magnetic pumping produced by radial inhomugeneily of plasma density (∆p -effect) are attracted to compensate the flux losses caused by the magnelic buoyancy in the generation region in the solar convection zone (SCZ). The Sun's roiation which endows the ∆p -effect with new properties is laken into accounl. It is shown dial al high and polar latitudes anlibuoyancy effects block Ihe magnetic fields in the deep layers of the SCZ. At the same time, in Ihe deep layers localed a! middle to low latitudes Ihe rotational grad rho effcel causes Ihe upward magnelic pumping which logcther with buoyancy facilitates ihe removal of strong magnetic fields (300–400 mT( lo solar surface where they then arise in ihe «royal zone* as sunspots.
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References:
1. Benevolenskaya E. E., Pudovkin M. I. Modeling of the 22-year solar activity cycle within the framework of the dynamo theory with allowance for the primary field. Astron. Zhurn., 61 (4), 783—788 (1984) [in Russian].
2. Vainshtein S. I. Magnetic fields in space, 240 p. (Nauka, Moscow, 1983) [in Russian].
3. Vainshtein S. I., Zeldovich Ia. B., Ruzmaikin A. A. The turbulent dynamo in astrophysics, 352 p. (Nauka, Moscow, 1980) [in Russian].
4. Gnevyshev M. N., Ohl A. I. On the 22-year cycle of solar activity. Astron. Zhurn., 25 (1), 18—20 (1948) [in Russian].
5. Dudorov A. E. The Dependence of the Magnetic Field Strength on the Density of the Interstellar HI Clouds. Astron. Tsirkulyar, No. 1446, 1—3 (1986) [in Russian].
6. Dudorov A. E., Krivodubskij V. N., Ruzmaikina T. V., Ruzmaikin A. A. The large-scale internal solar magnetic field. Astron. Zhurn., 66 (4), 809— 821 (1989) [in Russian].
7. Zeldovich Ya. B. The magnetic field in the two-dimensional motion of a conducting turbulent fluid. ZhETF, 31, 154—156 (1956) [in Russian].
8. Kichatinov L. L. The magnetohydrodynamics of mean fields in an inhomogeneous turbulent medium. Magnitnaia Gidrodinamika, No. 3, 67—73 (1982) [in Russian].
9. Kichatinov L. L., Krivodubs'kii V. N. Effect of solar rotation on turbulent transfer of the large-scale magnetic field in the convective zone. Kinematika Fiz. Nebesn. Tel, 7 (6), 30—39 (1991) [in Russian].
10. Kichatinov L. L., Pipin V. V. Buoyancy of the mean magnetic field in a turbulent medium. Pis'ma v Astronomicheskii Zhurnal, 19 (6), 557—563 (1993) [in Russian].
11. Krause F., Radler K.-H. Mean- Field Magnetohydrodynamics and Dynamo Theory, 320 p. (Mir, Moscow, 1984) [in Russian].
12. Krivodubskij V. N. Magnetic field transfer in the turbulent solar envelope. Astron. Zhurnal, 61 (2), 354—365 (1984) [in Russian].
13. Krivodubskij V. N. The transfer of the large-scale solar magnetic field due to the inhomogeneity of matter in the convective zone. Pis'ma v Astronomicheskii Zhurnal, 13 (9), 803—810 (1987) [in Russian].
14. Krivodubskij V. N. Turbulent transfer of the large-scale magnetic field in the rotating convective zone of the sun. Astron. Zhurnal, 69 (4), 842— 849 (1992) [in Russian].
15. Parker E. N. Cosmical magnetic fields. Vols.1-2: Vol.1, 608 p.; Vol. 2, 480 p. (Mir, Moscow, 1982) [in Russian].
16. Pudovkin M. I., Benevolenskaia E. E. The quasisteady primordial magnetic field of the sun, and the intensity variations of the solar cycle. Pis'ma v Astronomicheskii Zhurnal, 8 (8), 506—509 (1982) [in Russian].
17. Antia H. M., Chitre S. M., Thompson M. J. On variations of the latitudinal structure of the solar convection zone. Astron. and Astrophys., 399, 329—336 (2003).
https://doi.org/10.1051/0004-6361:20021760
https://doi.org/10.1051/0004-6361:20021760
18. Basu S., Antia H. M. Changes in solar dynamics from 1995 to 2002. Astrophys. J., 585, 553—565 (2003).
https://doi.org/10.1086/346020
https://doi.org/10.1086/346020
19. Boyer D. W., Levy E. H. Oscillating dynamo magnetic field in the presence of the external nondynamo field. The influence of a solar primordial field. Astrophys. J., 277 (2), 848—861 (1984).
https://doi.org/10.1086/161755
https://doi.org/10.1086/161755
20. Braun D. L., Fan Y. Helioseismic measurements of the subsurface meridional flow. Astrophys. J., 508, L105—L108 (1998).
https://doi.org/10.1086/311727
https://doi.org/10.1086/311727
21. Drobyshevskij E. M. Magnetic field transfer by two-dimensional convection and solar «semi-dynamo». Astrophys. Space Sci., 46, 41—49 (1977).
https://doi.org/10.1007/BF00643752
https://doi.org/10.1007/BF00643752
22. Duvall T. L., Dziembowski W. A., Goode P. R., et al. Internal rotation of the sun. Nature, 310, 22—25 (1984).
https://doi.org/10.1038/310022a0
https://doi.org/10.1038/310022a0
23. Dziembowski W. A., Goode P. R. The toroidal magnetic field in the Sun. Astrophys. J., 347 (2), 540—550 (1989).
https://doi.org/10.1086/168144
https://doi.org/10.1086/168144
24. Dziembowski W. A., Goode P. R., Kosovichev A. G., Schou J. Signatures of the rise of cycle 23. Astrophys. J., 537, 1026—1038 (2000).
https://doi.org/10.1086/309056
25. Giles P. M., Duval T. L., Scherrer P. H., Bogart R. S. A subphotospheric flow of material from the Sun’s equator to its poles. Nature, 390, 52—54 (1997).
https://doi.org/10.1038/36294
https://doi.org/10.1086/309056
25. Giles P. M., Duval T. L., Scherrer P. H., Bogart R. S. A subphotospheric flow of material from the Sun’s equator to its poles. Nature, 390, 52—54 (1997).
https://doi.org/10.1038/36294
26. Hathaway D. H., Gilman P. A., Toomre J. Convection instability when the temperature gradient and rotation vector are obloque to gravity. 1. Fluids without diffusion. Geophys. Astrophys. Fluid Dyn., 13 (4), 289—301 (1979).
https://doi.org/10.1080/03091927908243778
https://doi.org/10.1080/03091927908243778
27. Hathaway D. H., Gilman P., Harvey J. W., et al. GONG observations of solar surface flows. Science, 272, 1306—1309 (1996).
https://doi.org/10.1126/science.272.5266.1306
https://doi.org/10.1126/science.272.5266.1306
28. Howe R., Christensen-Dalsgaard J., Hill F., et al. Dynamic variations at the base of the solar convection zone. Science, 287, 2456—2460 (2000).
https://doi.org/10.1126/science.287.5462.2456
https://doi.org/10.1126/science.287.5462.2456
29. Kitchatinov L. L. Turbulent transport of magnetic fields in a highly conducting rotating fluid and the solar cycle. Astron. and Astrophys., 243 (2), 483—491 (1991).
30. Kitchatinov L. L., Rudiger G. Magnetic field advection in inhomogeneous turbulence. Astron. and Astrophys., 260, 494—498 (1992).
31. Kryvodubskyj V. N., Rudiger G., Kichatinov L. L. Non-linear diamagnetic transfer and magnetic buoyancy of large-scale magnetic field in the convective zone of the Sun. Bulletin of Kyiv University. Astronomy, No. 33, 55—58 (1994).
32. Leighton R. B. A magneto-kinetic model of the solar cycle. Astrophys. J., 156, 1—26 (1969).
https://doi.org/10.1086/149943
https://doi.org/10.1086/149943
33. Nandy D., Choudhuri A. R. Solar dynamo models with realistic internal rotation. Science, 296, 1671 —1674 (2002).
https://doi.org/10.1126/science.1070955
https://doi.org/10.1126/science.1070955
34. Parker E. N. The formation of sunspots from the solar toroidal field. Astrophys. J., 121, 491—507 (1955).
https://doi.org/10.1086/146010
https://doi.org/10.1086/146010
35. Ruzmaikina T. V. The role of magnetic field in star formation. In: Magnetic Fields in Astrophysics, 267—291 (London, 1983).
36. Schüssler M. Stellar dynamo theory. In: Stenflo J. O. (Ed.) Solar and Stellar Magnetic Fields: Origins and Coronal Effects: Symp. IAU 102, Zurich, 1982, 213—236 (Reidel, Dordrecht, 1983).
https://doi.org/10.1007/978-94-009-7181-3_22
https://doi.org/10.1007/978-94-009-7181-3_22
37. Stix M. The Sun, 200 p. (Verlag, Berlin, 1989).