Magnetic flux of colinear bipolar spot pairs

Abstract

It has been widely conjectured that solar flares are energized by the magnetic energy stored in complex active regions. Paradoxically, however, in attempting to show that magnetic changes cause or characterize flares, solar magnetic observations have produced equivocal results.In previous attempts at resolving the paradox, it has been contended that magnetic measurements are simply imprecise or that magnetic theories of flares are incorrect. We present an alternative explanation: the present use of magnetograms to examine active region structure through numerical integration of miscellaneous field lines (under various force-free assumptions) provides qualitative information only and does not utilize the quantitative information available. Therefore, we propose a new approach to the analysis of rnagnetograms which is illustrated with a highly symmetrized example that permits integration in closed form. The proposed approach exploits the cellular structure of the flux of field lines present in a complex active region. The various topological connectivities distinguish parent and daughter flux cells. A function F is developed expressing the flux partitioned into the daughter cell of interconnected field lines in a potential field. This F is a function of the location, strength, and relative motions of the photospheric sources. Then dF/dt is used as an EMF in the direct calculation of the stored magnetic energy available for flare production. In carrying out this program the flux partitioning surface (separatrix) is calculated along with its line of self-intersection (separator). The separator is the location of the principal energy release site.

Laboratory Experiments on Reconnection in Current Sheets

“…18) (Machado et al, 1983), is quite relevant here. We believe this is the first time the 3-D separator-separatrix structure, originally proposed by Sweet (1958), has been explicitly considered other than in several papers by our colleagues and ourselves (Bratenahl and Baum, 1976b;Baum et al, 1978aBaum et al, , 1979Bratenahl, 1980, 1982).…”

“…The fibers, however, define the footpoints of field lines making up topologically distinct tubular flux cells. As these are shuffled about by the powerful convective motion below, EMF f s are generated (Baum, et al, 1978(Baum, et al, , 1979Bratenahl andd Baura, 1982) which drive the lively solar activity above, as Ionson (1985) mentioned yesterday. On this basis, we expect reconnection in pinch current sheets to be by far the dominant dynamic dissipation mode in the solar atmosphere.…”

Three-dimensional magnetic reconnection and its application to solar flares

“…Yeh 1976; Baum et al. 1979; Lau & Finn 1990). This led to a definition of various topological objects, such as separators, which connect pairs of null points of opposite sign.…”

“…Studies of kinematic reconnection at null points were soon extended from two dimensions to three dimensions (e.g. Yeh 1976;Baum et al 1979;Lau & Finn 1990). This led to a definition of various topological objects, such as separators, which connect pairs of null points of opposite sign.…”