DOI QR코드

DOI QR Code

MAGNETIC HELICITY CHANGES OF SOLAR ACTIVE REGIONS BY PHOTOSPHERIC HORIZONTAL MOTIONS

  • MOON Y.-J. (Big Bear Solar Observatory, NJIT, Korea Astronomy Observatory) ;
  • CHAE JONGCHUL (Big Bear Solar Observatory, NJIT, Department of Astronomy and Space Science, Chungnam National University) ;
  • PARK Y. D. (Korea Astronomy Observatory)
  • 발행 : 2003.06.01

초록

In this paper, we review recent studies on the magnetic helicity changes of solar active regions by photospheric horizontal motions. Recently, Chae(200l) developed a methodology to determine the magnetic helicity change rate via photospheric horizontal motions. We have applied this methodology to four cases: (1) NOAA AR 8100 which has a series of homologous X-ray flares, (2) three active regions which have four eruptive major X-ray flares, (3) NOAA AR 9236 which has three eruptive X-class flares, and (4) NOAA AR 8668 in which a large filament was under formation. As a result, we have found several interesting results. First, the rate of magnetic helicity injection strongly depends on an active region and its evolution. Its mean rate ranges from 4 to $17 {\times} 10^{40}\;Mx^2\;h^{-1}$. Especially when the homologous flares occurred and when the filament was formed, significant rates of magnetic helicity were continuously deposited in the corona via photospheric shear flows. Second, there is a strong positive correlation between the magnetic helicity accumulated during the flaring time interval of the homologous flares in AR 8100 and the GOES X-ray flux integrated over the flaring time. This indicates that the occurrence of a series of homologous flares is physically related to the accumulation of magnetic helicity in the corona by photospheric shearing motions. Third, impulsive helicity variations took place near the flaring times of some strong flares. These impulsive variations whose time scales are less than one hour are attributed to localized velocity kernels around the polarity inversion line. Fourth, considering the filament eruption associated with an X1.8 flare started about 10 minutes before the impulsive variation of the helicity change rate, we suggest that the impulsive helicity variation is not a cause of the eruptive solar flare but its result. Finally, we discuss the physical implications on these results and our future plans.

키워드

참고문헌

  1. Anwar, B., Acton, B. W., Hudson, H. S., Makita, M., McClymont, A. N., & Tsuneta, S. 1993, Rapid Sunspot Motion during a Major Flare, Sol. Phys., 147, 287 https://doi.org/10.1007/BF00690719
  2. Berger, M. A., & Field, G. B. 1984, The topological properties of magnetic helicity, J. Fluid Mech., 147, 133 https://doi.org/10.1017/S0022112084002019
  3. Burlaga, L. F. 1988, J. Geophys. Res., 93, 7217 https://doi.org/10.1029/JA093iA07p07217
  4. Canfield, R. C., & Pevtsov, A. A. 1999, Helicity and reconnection in the solar corona: observations, in Magnetic Helicity in Space and Laboratory Plasmas, ed. M. R. Brown, R. C. Canfield, & A. A. Pevtsov (Geophys. Monogr. 1ll; Washington, DC: AGU), 197
  5. Chae, J. 2000, The magnetic helicity sign of filament chirality, ApJ, 540, L115 https://doi.org/10.1086/312880
  6. Chae, J. 2001, Observational Determination of the Rate of Magnetic Helicity Transport through the Solar Surface via the Horizontal Motion of Field Line Footpoints, ApJ, 560, L95 https://doi.org/10.1086/324173
  7. Chae, J., Wang, H., Qiu, J., Goode, P. R., Strous, L., & Yun, H. S. 2001, The Formation of a Prominence in Active Region NOAA 8668. I. SOHO/MDI Observations of Magnetic Field Evolution, ApJ, 560, 476 (Paper IV) https://doi.org/10.1086/322491
  8. Chae, J., Moon, Y.-J., Rust, D. M., Wang, H, & Goode, P. R. 2003, Magnetic helicity pumping by twisted flux tube expansion, JKAS, 36, 33
  9. Choe, G. S. & Cheng, C. Z. 2000, A Model of Solar Flares and Their Homologous Behavior, ApJ, 541, 449 https://doi.org/10.1086/309415
  10. Choe, G. S. & Lee, L. C. 1992, Formation of solar prominences by photospheric shearing motions, Sol. Phys., 138, 291 https://doi.org/10.1007/BF00151917
  11. Demoulin, P., Mandrini, C. H., van Driel-Gesztelyi, L., Thompson, B. J., Plunkett, S., Kovari, Zs., Aulanier, G., & Young, A. 2002a, What is the source of the magnetic helicity shed by CMEs? The long-term helicity budget of AR 7978, A&A, 382, 650 https://doi.org/10.1051/0004-6361:20011634
  12. Demoulin, P., Mandrini, C. H., van Dnel-Gesztelyi, L., Lopez Fuentes, M. C., & Aulamer, G. 2002b, The Magnetic Helicity Injected by Shearing Motions, Sol. Phys., 207, 87 https://doi.org/10.1023/A:1015531804337
  13. DeVore, C. R. 2000, Magnetic helicity generation by Solar Differential Rotation, ApJ, 539, 944 https://doi.org/10.1086/309274
  14. Harvey, K. L. & Harvey, J. W. 1976, A study of the magnetic and velocity fields in an active region, Sol. Phys., 233, 246
  15. Herdiwijaya, D., Makita, M., & Anwar, B. 1997, The Proper Motion of Individual Sunspots, PASJ, 49, 235 https://doi.org/10.1093/pasj/49.2.235
  16. Kusano, K., T. Maeshiro, T. Yokoyama, & Sakurai, T. 2002, Measurement of magnetic helicity injection and free energy loading into the solar corona, ApJ, 577, 501 https://doi.org/10.1086/342171
  17. Moon, Y.-.L, Choe, G. S., Yun, H. S., & Park, Y. D. 2001, Flaring time interval distribution and spatial correlation of solar major flares, J. Geophys. Res., 106, A12, 29951 https://doi.org/10.1029/2000JA000224
  18. Moon, Y.-J., Chae, J., Choe, G. S., Wang, H., Park, Y. D., Yun, H. S., Yurchyshyn, V. B., & Good, P. R. 2002a, Flare Activity and Magnetic Helicity Injection by Photospheric Horizontal Motions, ApJ, 574, 1066 (Paper I) https://doi.org/10.1086/340975
  19. Moon, Y.-J., Chae, J., Wang, H., Choe, G. S., & Park, Y. D. 2002b, Impulsive Variations of Magnetic Helicity Change Rate associated with Eruptive Flares, ApJ, 580, 528 (Paper II) https://doi.org/10.1086/343130
  20. Moon, Y.-J., Chae, J., Wang, H., & Park, Y. D. 2003, Magnetic Helicity Change Rate Associated With Three X-class Eruptive Flares, Advances in Space Research, in press (Paper III)
  21. Nindos, A. & Zhang, H. 2002, Photospheric Motions and Coronal Mass Ejection Productivity ApJ, 573, L133 https://doi.org/10.1086/341937
  22. November, L. J., & Simon, G. W. 1988, Precise propermotion measurement ofsolar granulation, ApJ, 333, 427 https://doi.org/10.1086/166758
  23. Parker, E. N. 1974, The Dynamical Properties of Twisted Ropes of Magnetic Field and the Vigor of New Active Regions on the Sun, ApJ, 191, 245 https://doi.org/10.1086/152961
  24. Pevtsov, A. A., Canfield, R. C., & Metcalf, T. R. 1995, Latitudinal variation of helicity of photospheric magnetic fields, ApJ, 440, L109 https://doi.org/10.1086/187773
  25. Pevtsov, A. A., & Canfield, R. C. 1999, Helicity of the photospheric magnetic field, in Magnetic Helicity in Space and Laboratory Plasmas, ed. M. R. Brown, R. C. Canfield, & A. A. Pevtsov (Washington, DC: AGU Geophys. Monogr. 111, 103
  26. Rust, D. M. 1999, Magnetic helicity in solar filaments and coronal mass ejections, in Magnetic Helicity in Space and Laboratory Plasmas, ed. M. R. Brown, R. C. Canfield, & A. A. Pevtsov (Geophys. Monogr. 111; Washington, DC: AGU), 221
  27. Scherrer, P. H., Bogart, R. S., Bush, R. I., Hoeksema, J. T., Kosovichev, A. G., Schou, J., Rosenberg, W., Springer, L., Tarbel, T. D., Title, A., Wolfson, C. J., Zayer, I, MDI Engineering Team, 1995, The Solar Oscillation Investigation - Michelson Doppler Imager, Sol. Phys., 162, 129 https://doi.org/10.1007/BF00733429
  28. Wang, H., Ewell, M. W., Jr., Zirin, H., & Ai, G. 1994, Vector magnetic fie1d changes associated with X class flares, ApJ, 424, 436 https://doi.org/10.1086/173901
  29. Wang, H., Spirock, T. J., Qiu, J., Ji, H., Yurchyshyn, V. B., Moon, Y.-J., Denker, C., & Goode, P. R. 2002, Rapid Changes of Magnetic Fields Associated with Six X-class Flares, ApJ, 576, 497 https://doi.org/10.1086/341735
  30. Wheatland, M. S. 2000, Do Solar Flares Exhibit an Interval-size Relationship?, Sol. Phys., 191, 381 https://doi.org/10.1023/A:1005240712931

피인용 문헌

  1. EFFECTS OF THE NON-RADIAL MAGNETIC FIELD ON MEASURING MAGNETIC HELICITY TRANSPORT ACROSS THE SOLAR PHOTOSPHERE vol.804, pp.2, 2015, https://doi.org/10.1088/0004-637X/804/2/102
  2. What is the spatial distribution of magnetic helicity injected in a solar active region? vol.452, pp.2, 2006, https://doi.org/10.1051/0004-6361:20054643
  3. A STATISTICAL STUDY OF THE RELATIONSHIP BETWEEN THE TRANSPORT RATE OF MAGNETIC HELICITY AND SOLAR FLARES vol.704, pp.2, 2009, https://doi.org/10.1088/0004-637X/704/2/1622
  4. Survey of Magnetic Helicity Injection in Regions Producing X‐Class Flares vol.671, pp.1, 2007, https://doi.org/10.1086/522682
  5. Correlation between the Sharp Variation of the Transport Rate of Magnetic Helicity and Solar Eruptive Events vol.682, pp.2, 2008, https://doi.org/10.1086/591027
  6. Radial velocities of the photospheric matter in a solar flare with matter ejection vol.26, pp.1, 2010, https://doi.org/10.3103/S0884591310010034