Abstract
We compare large-scale filtergrams of a hitherto neglected class 1B flare with previously published vector magnetograms and maps of photospheric longitudinal electric current density (Hagyard et al., 1985). The vector magnetic fields were mapped simultaneously with the eruption of this flare. We find a coincidence, to within the ±2″ registration accuracy of the data, between the flare kernels and the locations of maximum shear and of peak values in the longitudinal electric current density. The kernels brighten in a way which implies that the preflare heating and the main release of flare energy are spatially coincident within the limits of resolution (≈2″). A pronounced magnetic shear exists in the vertical direction at the location of the strongest flare kernels. We provide evidence that the electric currents could be maintained by the energy stored in the sheared transverse magnetic field and that the amount of energy released is proportional to the amount stored. These circumstances are consistent with theories in which flares are triggered by plasma instabilities due to surplus electric currents.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Alfvén, H. and Carlqvist, P.: 1967, Solar Phys. 1, 220.
Ding, Y. J., Hong, Q. F., Hagyard, M. J., and Deloach, A. G: 1985, in Hagyard, M. J. (ed.), Measurements of Solar Vector Magnetic Fields, NASA CP 2374, p. 379.
Hagyard, M. J., Low, B. C., and Tandberg-Hanssen, E.: 1981, Solar Phys. 73, 257.
Hagyard, M. J., Moore, R. L., and Emslie, A. G.: 1984a, Adv. Space Res. 4, No. 7, 71.
Hagyard, M. J., Smith, J. B., Jr., Teuber, D., and West, E. A.: 1984b, Solar Phys. 91, 115.
Hagyard, M. J., West, E. A., and Smith, J. B., Jr.: 1985, in C. de Jager and Chen Biao (eds.), Proceedings of Kunming Workshop on Solar Physics and Interplanetary Travelling Phenomena, Vol. I, Science Press, Beijing, China, p. 179.
Hong, Q. F., Ding, Y. J., and Luan, D.: 1982, Acta Astron. Sinica 23, 327.
Krall, K. R., Smith, J. B., Jr., Hagyard, M. J., West, E. A., and Cummings, N. P.: 1982, Solar Phys. 79, 59.
Lin Yuanzhang, Wang Zhengzhi, Wu Fei, Ding Youji, and Hong Qinfang: 1985, in C. de Jager and Chen Biao (eds.), Proceedings of Kunming Workshop on Solar Physics and Interplanetary Travelling Phenomena, Vol. I, Science Press, Beijing, China, p. 259.
Machado, M. E., Somov, B. V., Rovira, M. G., and de Jager, C.: 1983, Solar Phys. 85, 157.
Moreton, G. E. and Severny, A. B.: 1968, Solar Phys. 3, 282.
Priest, E. R., Gaizauskas, V., Hagyard, M. J., Schmahl, E. J., and Webb, D. F.: 1986, in M. R. Kundu and B. Woodgate (eds.), Energetic Phenomena on the Sun, NASA CP 2439, p. 1.
Solar Geophysical Data: 1980, Nos. 249 and 430, Part I; Nos. 434 and 435, Part II.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yuanzhang, L., Gaizauskas, V. Coincidence between Hα flare kernels and peaks of observed longitudinal electric current densities. Sol Phys 109, 81–90 (1987). https://doi.org/10.1007/BF00167400
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00167400